Note: Descriptions are shown in the official language in which they were submitted.
CONTACT TIP, GAS DIFFUSER, AND NOZZLE FOR WELDING TORCH
CROSS REFERENCE TO RELATED APPLICATIONS
100011 This application claims priority to U.S. Patent Application No.
15/622,912, filed June 14,
2017, and entitled "Contact Tip, Gas Diffuser, and Nozzle for Welding Torch."
BACKGROUND
[00021 The present disclosure relates generally to M1G welding systems and,
more particularly,
to gas nozzles, gas diffusers, contact tips and liner assemblies for use in
welding torches of MIG
welding systems.
100031 MIG welding is a process that has increasingly become ubiquitous in
various industries
and applications. Manual MIG welding processes (i.e., welding in which a
person holds and
manipulates a MIG welding torch during the process) have been a staple of the
welding industry for
some time. Additionally, as welding has increased in general, automated MIG
welding processes
have also becoming increasingly popular. In either style of MIG welding,
certain components of the
MIG welding torch tend to wear over time, and need replacement. These
components are
commonly referred to as "consumables". Consumable replacement is an
undesirable activity, as it
takes time away from the actual welding process. In industry, this translates
into reduced
productivity and increased costs.
10004] Therefore, it may be advantageous to provide a consumable design that
maximizes the
performance of these wear parts and simplifies their replacement. The present
subject matter
provides an improved design for gas nozzles, gas diffusers, contact tips, and
liner assemblies for use
in welding torches of MIG welding systems.
SUMMARY
[0005] Certain embodiments commensurate in scope with the originally claimed
subject matter
are summarized below. These embodiments are not intended to limit the scope of
the claimed
subject matter, but rather these embodiments are intended only to provide a
brief summary of
possible forms of the subject matter. Indeed, the subject matter may encompass
a variety of forms
that may be similar to or different from the embodiments set forth below.
CA 3066773 2021-07-09
- 2 -
[0006] In certain embodiments, a welding contact tip includes a first axial
end portion having a
welding wire outlet of an internal bore of the welding contact tip. The
welding contact tip also
includes a threaded middle portion adjacent the first axial end portion. The
threaded middle portion
includes external threads. The welding contact tip further includes a second
axial end portion
adjacent the threaded middle portion. The first axial end portion includes a
tapered outer surface
adjacent the threaded middle portion.
[0007] In certain embodiments, a system includes a welding contact tip that
includes a first axial
end portion having a welding wire outlet of an internal bore of the welding
contact tip, a threaded
middle portion adjacent the first axial end portion, and a second axial end
portion adjacent the
threaded middle portion. The threaded middle portion includes external
threads. The system also
includes a gas diffuser having internal threads configured to mate with the
external threads of the
threaded middle portion of the welding contact tip. The welding contact tip
and gas diffuser are
configured such that, upon fully seating the welding contact tip into the gas
diffuser, the second
axial end portion of the welding contact tip (including an axial end face of
the second axial end
portion) does not contact any internal surface of the gas diffuser.
[0008] In certain embodiments, a welding torch assembly includes a gas
diffuser having an outer
circumferential groove having an outer surface with first and second walls
that extend radially
outward from first and second opposite axial sides of the outer surface. The
welding torch assembly
also includes a nozzle having an inner circumferential rib with a tapered
inner surface. The welding
torch assembly further includes a compressible member disposed within the
outer circumferential
groove of the gas diffuser and the inner circumferential rib of the nozzle.
[0008A] In certain embodiments, a system includes a welding contact tip having
a first axial end
portion having a welding wire outlet of an internal bore of the welding
contact tip, a threaded middle
portion adjacent the first axial end portion, and a second axial end portion
adjacent the threaded
middle portion. The threaded middle portion has external threads and the
second axial end portion
extends the remaining length of the welding contact tip adjacent the threaded
middle portion to an
axial end face; and a gas diffuser having internal threads configured to mate
with the external threads
of the threaded middle portion of the welding contact tip. The gas diffuser
does not contact the
second axial end portion and the gas diffuser does not contact the axial end
face of the of the welding
contact tip when the welding contact tip is fully threaded into the gas
diffuser, such that an exterior of
the second axial end portion and the axial end face are exposed to shielding
gas within the gas
diffuser. The gas diffuser includes a plurality of gas ports, the entireties
of the plurality of gas ports
Date Recue/Date Received 2022-10-13
- 2a -
being positioned further than the axial end face of the second axial end
portion toward the first axial
end portion, in the axial direction, when the welding contact tip is fully
threaded into the gas diffuser.
[0008B] In certain embodiments, a system includes includes a welding contact
tip having a first
axial end portion having a welding wire outlet of an internal bore of the
welding contact tip, a
threaded middle portion adjacent the first axial end portion, and a second
axial end portion adjacent
the threaded middle portion. The threaded middle portion has external threads.
The second axial end
portion includes a first portion adjacent the threaded middle portion and a
second portion adjacent the
first portion. An outer diameter of the second portion is larger than an outer
diameter of the first
portion. An inner diameter of the second portion is larger than both an inner
diameter of the first
portion and an inner diameter of the internal bore of the welding contact tip,
and a gas diffuser
having internal threads configured to mate with the external threads of the
threaded middle portion of
the welding contact tip. The gas diffuser is spaced from the second axial end
portion of the welding
contact tip when the welding contact tip is fully threaded into the gas
diffuser. A total axial length of
the contact tip is in a range of 2.540 cm to 4.128 cm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other features, aspects, and advantages of the present
disclosure will become
better understood when the following detailed description is read with
reference to the
accompanying drawings in which like characters represent like parts throughout
the drawings,
wherein:
[0010] FIG. 1 is an embodiment of a metal inert gas (MIG) welding system
with a power source
and a wire feeder, in accordance with an embodiment;
[0011] FIG. 2 is a side view of an embodiment of a welding torch of the MIG
welding system of
FIG. 1, in accordance with an embodiment;
Date Regue/Date Received 2022-10-13
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
3
[0012] FIG. 3 is a cross-sectional perspective view of a portion of the
welding torch of FIG. 2, in
accordance with an embodiment;
[0013] FIG. 4 is a cross-sectional side view of the portion of the welding
torch of FIG. 3, in
accordance with an embodiment;
[0014] FIG. 5 is a cross-sectional side view of a contact tip of FIG. 3, in
accordance with an
embodiment;
[0015] FIG. 6 is a cross-sectional perspective view of a portion of the
welding torch of FIG. 2, in
accordance with an embodiment;
[0016] FIGS. 7A through 71 are various views of a contact tip of FIG. 6, in
accordance with an
embodiment;
[0017] FIGS. 8A through 8E are various views of a gas diffuser of FIG. 6,
in accordance with an
embodiment;
[0018] FIGS. 9A through 9D are various view of a liner stop, of a welding
torch liner assembly,
of FIG. 6, in accordance with an embodiment;
[0019] FIG. 10 is a perspective view of a rear connector of a welding torch
coupled to a liner
receiver of a welding torch liner assembly, in accordance with an embodiment;
[0020] FIG. 11 is a cross-sectional perspective view of the rear connector
of the welding torch
and the liner receiver of the welding torch liner assembly of FIG. 10, in
accordance with an
embodiment;
[0021] FIG. 12 is a cross-sectional side view of the rear connector of the
welding torch and the
liner receiver of the welding torch liner assembly of FIGS. 10 and 11, in
accordance with an
embodiment;
[0022] FIG. 13 is a perspective view of a rear connector of a welding torch
configured to be
coupled to a liner receiver of a welding torch liner assembly, in accordance
with an embodiment;
[0023] FIG. 14 is a perspective view of the rear connector of the welding
torch coupled to the
liner receiver of the welding torch liner assembly of FIG. 13, in accordance
with an embodiment;
[0024] FIG. 15 is a cross-sectional perspective view of the rear connector
of the welding torch
and the liner receiver of the welding torch liner assembly of FIGS. 13 and 14,
in accordance with an
embodiment;
[0025] FIG. 16 is a cross-sectional side view of the rear connector of the
welding torch and the
liner receiver of the welding torch liner assembly of FIGS. 13-15, in
accordance with an
embodiment;
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
4
[0026] FIG. 17 is a perspective view of a rear connector of a welding torch
coupled to a liner
receiver of a welding torch liner assembly, in accordance with an embodiment;
[0027] FIG. 18 is a cross-sectional perspective view of the rear connector
of the welding torch
and the liner receiver of the welding torch liner assembly of FIG. 17, in
accordance with an
embodiment;
[0028] FIG. 19 is a cross-sectional side view of the rear connector of the
welding torch and the
liner receiver of the welding torch liner assembly of FIGS. 17 and 18, in
accordance with an
embodiment;
[0029] FIG. 20 is a perspective view of a collet of the liner receiver of
FIGS. 17-19, in
accordance with an embodiment; and
[0030] FIGS. 21A through 211 are various views of another exemplary contact
tip similar to the
contact tip of FIGS. 7A through 7I, in accordance with an embodiment.
DETAILED DESCRIPTION
[0031] One or more embodiments of the present disclosure will be described
below, in an effort
to provide a concise description of these embodiments, all features of an
actual implementation may
not be described in the specification. It should be appreciated that in the
development of any such
actual implementation, as in any engineering or design project, numerous
implementation-specific
decisions are made to achieve the developers' specific goals, such as
compliance with system-
related and business-related constraints, which may vary from one
implementation to another.
Moreover, it should be appreciated that such a development effort might be
complex and time
consuming, but would nevertheless be a routine undertaking of design,
fabrication, and manufacture
for those of ordinary skill having the benefit of this disclosure.
[0032] In conventional MIG welding systems, gas nozzles are axially pushed
onto a gas diffuser,
and the gas nozzle is held in place by a frictional fit between the two parts.
More specifically, the
gas diffuser often consists of a relatively flexible member (such as a rubber
or steel ring) mounted
about a circumference of the gas diffuser that, in its relaxed state, has a
slightly larger outer diameter
than an internal bore of the gas nozzle. In many conventional systems, the
internal bore of the gas
nozzle that engages with the gas diffuser is substantially constant in
diameter along its length.
[0033] As the gas nozzle is pushed onto the gas diffuser, the flexible
member radially
compresses, allowing the gas nozzle to be installed over the flexible member
and fully onto the gas
diffuser. In general, the flexible member remains in a compressed state as
long as the gas nozzle is
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
installed on the gas diffuser. In the compressed state, the flexible member
continuously applies a
radial force to the internal bore of the gas nozzle. In general, this radial
force provides enough axial
friction to prevent the gas nozzle from sliding off of the gas diffuser during
use. The friction force,
however, is low enough that the gas nozzle may be removed from the gas
diffuser without requiring
the use of tools (e.g., by a user with his hands).
[0034] Relying on axial friction alone to retain the gas nozzle to the gas
diffuser can be
problematic. Over time, the friction force inevitably lessens, and the gas
nozzle may fall off of the
gas diffuser. In addition, the flexible member must be stiff enough during its
life cycle to provide
adequate radial force to retain the gas nozzle, but not so stiff as to make
gas nozzle
installation/removal difficult. Furthermore, the flexible member must also not
be so stiff as to wear
away at the internal bore of the gas nozzle during the repeated
installations/removals encountered
during normal use.
[0035] Embodiments of the present disclosure incorporate a flexible member
on the gas diffuser
that radially compresses as the gas nozzle is installed. However, the
embodiments of the present
disclosure include an internal bore of the gas nozzle that is not of a
constant diameter along its
engagement length with the gas diffuser. Rather, the embodiments of the
present disclosure include
an internal bore of the gas nozzle that allows the flexible member to apply an
axial retention force in
addition to a frictional force.
[0036] In addition, conventional MIG welding systems often include a
contact tip having an
external threaded portion which mates with internal threads at a front axial
end of a gas diffuser. In
such designs, the external threading is typically located at, or adjacent to,
a rear axial end of the
contact tip. Certain designs also feature a tapered seat area directly on the
rear axial end of the
contact tip to which the threaded area adjoins. In these configurations, when
the contact tip is fully
installed into the gas diffuser, only the rear face of the contact tip is
exposed to welding gas. It
should be noted that, as described herein, a "front axial end" (or "distal
end" or "distal axial end")
refers to an axial end of a component that is nearer to an axial end of the
welding torch at which a
welding arc is generated and, conversely, a "rear axial end" (or "proximal
end" or "proximal axial
end") refers to an axial end of a component that is farther away from an axial
end of the welding
torch at which a welding arc is generated.
[0037] Embodiments of the present disclosure, contrary to conventional
systems, include external
threads near the axial center (i.e., near the middle of the length) of the
contact tip. As such, a
substantial portion of the rear axial end of the contact tip remains
unthreaded. This area may be
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
6
referred to as a "cooling tail". In such embodiments, the gas diffuser is
configured such that when
the contact tip is fully installed, the entire unthreaded rear axial portion
(i.e., the cooling tail) of the
contact tip protrudes into the welding gas stream. As such, the external
surfaces of the unthreaded
rear axial portion (including the real axial end face) of the contact tip are
fully exposed to the
welding gas. Placing this rear axial portion of the contact tip into the
welding gas stream helps to
cool the contact tip during use, thereby leading to better performance and
longer life cycles of the
cooling tip. Embodiments of the present disclosure also include reduced amount
of contact tip
surface area exposed to the welding arc during use. By limiting this exposed
surface area, less
radiant heat is absorbed into the contact tip, thereby also leading to better
performance and longer
life cycles of the cooling tip. Another benefit of the relatively long cooling
tail feature of the contact
tip is that it provides a centering lead that helps to axially align the
contact tip with the gas diffuser
as the contact tip is being installed. As the contact tip is urged into the
gas diffuser, the cooling tail
of thc contact tip limits the axial angle (i.e., the "approach angle") between
the contact tip and the
gas diffuser. The minimized approach angle reduces the possibility of cross-
threading between the
contact tip and the gas diffuser.
[0038] Certain embodiments of the present disclosure also include an
internal bore at the rear
axial end of the contact tip that is large enough to fit over a welding torch
liner, which provides a
conduit through which a consumable wire electrode may travel to the contact
tip. In conventional
MIG welding systems, welding torch liners are either not in contact with, or
simply abut against an
axial rear face of a threaded contact tip. In contrast, certain embodiments of
the present disclosure
enable the welding torch liner to fit inside the axial rear portion of the
contact tip, thereby
maintaining better concentricity between the welding torch liner and the
contact tip and, thus,
improved wire electrode feedability.
[0039] Turning now to the drawings, and referring first to FIG. 1, a
welding system 10 is
illustrated as including a power source 12 coupled to a wire feeder 14. In the
illustrated
embodiment, the power source 12 is separate from the wire feeder 14, such that
the wire feeder 14
may be positioned at some distance from the power source 12 near a welding
location. However, it
should be understood that the wire feeder 14, in some implementations, may be
integral with the
power source 12. The power source 12 may supply weld power to a torch 16
through the wire
feeder 14, or the power source 12 may supply weld power directly to the torch
16. The wire feeder
14 supplies a wire electrode 18 (e.g., solid wire, cored wire, coated wire) to
the torch 16. A gas
supply 20, which may be integral with or separate from the power source 12,
supplies a gas (e.g.,
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
7
CO2, argon) to the torch 16. An operator may engage a trigger 22 of the torch
16 to initiate an arc
24 between the electrode 18 and a work piece 26. In some embodiments, the
welding system 10
may be triggered by an automation interface including, but not limited to, a
programmable logic
controller (PLC) or robot controller. The welding system 10 is designed to
provide welding wire
(e.g., electrode 18), weld power, and shielding gas to the welding torch 16.
As will be appreciated
by those skilled in the art, the welding torch 16 may be of many different
types, and may facilitate
use of various combinations of electrodes 18 and gases.
[0040] The welding system 10 may receive data settings from the operator
via an operator
interface 28 provided on the power source 12. The operator interface 28 may be
incorporated into a
faceplate of the power source 12, and may allow for selection of settings such
as the weld process
(e.g., stick, TIG, MIG), the type of electrode 18 to be used, voltage and
current settings, transfer
mode (e.g., short circuit, pulse, spray, pulse), and so forth. In particular,
the welding system 10
allows for MIG welding (e.g., pulsed MIG welding) with electrodes 18 (e.g.,
welding wires) of
various materials, such as steel or aluminum, to be channeled through the
torch 16. The weld
settings are communicated to control circuitry 30 within the power source 12.
[0041] The control circuitry 30 operates to control generation of welding
power output that is
applied to the electrode 18 by power conversion circuitry 32 for carrying out
the desired welding
operation. For example, in some embodiments, the control circuitry 30 may be
adapted to regulate a
pulsed MIG welding regime that may have aspects of short circuit transfer
and/or of spray transfer
of molten metal from the welding wire to a molten weld pool of a progressing
weld. Such transfer
modes may be controlled during operation by adjusting operating parameters of
current and voltage
pulses for arcs 24 developed between the electrode 18 and the work piece 26.
[0042] The control circuitry 30 is coupled to the power conversion
circuitry 32, which supplies
the weld power (e.g., pulsed wavefoiiii) that is applied to the electrode 18
at the torch 16. The
power conversion circuitry 32 is coupled to a source of electrical power as
indicated by arrow 34.
The power applied to the power conversion circuitry 32 may originate in the
power grid, although
other sources of power may also be used, such as power generated by an engine-
driven generator,
batteries, fuel cells or other alternative sources. Components of the power
conversion circuitry 32
may include choppers, boost converters, buck converters, inverters, and so
forth.
[0043] The control circuitry 30 controls the current and/or the voltage of
the weld power supplied
to the torch 16. The control circuitry 30 may monitor the current and/or
voltage of the arc 24 based
at least in part on one or more sensors 36 within the wire feeder 14 or torch
16. In some
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
8
embodiments, a processor 35 of the control circuitry 30 determines and/or
controls the arc length or
electrode extension based at least in part on feedback from the sensors 36.
The arc length is defined
herein as the length of the arc between the electrode 18 and the work piece
26. The processor 35
determines and/or controls the arc length or electrode extension utilizing
data (e.g., algorithms,
instructions, operating points) stored in a memory 37. The data stored in the
memory 37 may be
received via the operator interface 28, a network connection, or preloaded
prior to assembly of the
control circuitry 30. Operation of the power source 12 may be controlled in
one or more modes,
such as a constant voltage (CV) regulation mode in which the control circuitry
30 controls the weld
voltage to be substantially constant while varying the weld current during a
welding operation. That
is, the weld current may be based at least in part on the weld voltage.
Additionally, or in the
alternative, the power source 12 may be controlled in a current control mode
in which the weld
current is controlled independent of the weld voltage. In some embodiments,
the power source 12 is
controlled to operate in a constant current (CC) mode where the control
circuitry 30 controls the
weld current to be substantially constant while varying the weld voltage
during a welding operation.
[0044] FIG. 2 illustrates an embodiment of the torch 16 of FIG. 1. As
described in relation to
FIG. 1, the torch 16 includes the trigger 22 for initiating a weld and
supplying the electrode 18 to the
weld. Specifically, the trigger 22 is disposed on a handle 38. A welding
operator holds the handle
38 when performing a weld. At a first end 40, the handle 38 is coupled to a
cable 42 where welding
consumables (e.g., the electrode, the shielding gas, and so forth) are
supplied to the weld. Welding
consumables generally travel through the handle 38 and exit at a second end
44, which is disposed
on the handle 38 at an end opposite from the first end 40.
[0045] The torch 16 includes a gooseneck 46 extending out of the second end
44 of the handle
38. As such, the gooseneck 46 is coupled between the handle 38 and a welding
nozzle 48. As
should be noted, when the trigger 22 is pressed or actuated, welding wire
(e.g., electrode 18) travels
through the cable 42, the handle 38, the gooseneck 46, and the welding nozzle
48, so that the
welding wire extends out of an end 50 (i.e., torch tip) of the welding nozzle
48. Further, as
illustrated in FIG. 2, the handle 38 is secured to the gooseneck 46 via
fasteners 52 and 54, and to the
cable 42 via fasteners 52 and 54. The welding nozzle 48 is illustrated with a
portion of the welding
nozzle 48 removed to show the electrode 18 extending out of a contact tip 56
that is disposed within
the welding nozzle 48.
[0046] FIG. 3 is a cross-sectional perspective view of a portion of the
welding torch 16 of FIG. 2
in certain embodiments. As illustrated, a gas diffuser 58 receives the contact
tip 56 during
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
9
replacement of the contact tip 56, facilitates mechanical coupling of the
contact tip 56 to the welding
torch 16 for the contact tip 56, and facilitates electrical coupling to the
power source 12 for the
contact tip 56 (e.g., by creating an electrical connection between the contact
tip 56 and the
gooseneck 46 via the gas diffuser 58), as described in detail below. More
specifically, in certain
embodiments, the contact tip 56 includes external threading 60 that mate with
internal threading 62
of the gas diffuser 58 such that the contact tip 56 may be secured (e.g.,
mechanically affixed) within
the welding torch 16 (e.g., to the gooseneck 46 via the gas diffuser 58) by
creating a locking,
threaded connection between the contact tip 56 and the gas diffuser 58. It
should be noted that, in
certain embodiments, the gas diffuser 58 also includes a second set of
internal threads 65 near an
axial end 66 of the gas diffuser 58 opposite the axial end 68 near which the
first set of internal
threads 62 are located. This second set of internal threads 65 are configured
to mate with external
threads 70 on an axial end of the gooseneck 46 of the welding torch 16. The
welding nozzle 48,
contact tip 56, and gas diffuser 58 arc each commonly referred to as welding
consumables.
[0047] Furthermore, the gas diffuser 58 includes gas-through ports 64
extending through the
walls of the gas diffuser 58 to facilitate movement of shielding gas to a
welding site (e.g., through
the welding torch 16 from an interior volume 67 of the gooseneck 46 into an
internal volume 72
formed between the welding nozzle 48 and the contact tip 56), as described in
greater detail herein.
The gas diffuser 58 may also include a compressible member 74, such as a
compressible
circumferential ring, which facilitates threadless retention of the welding
nozzle 48 over the gas
diffuser 58. The welding nozzle 48 is axially pushed onto the gas diffuser 58,
as illustrated by arrow
76. In certain embodiments, the compressible member 74 may be a rubber or
steel ring mounted
about an outer circumference of the gas diffuser 58. In its relaxed state, the
compressible member
74 may have an outer diameter that is slightly larger than an inner diameter
of a portion of the
welding nozzle 48 (e.g., a welding nozzle insert 75 in the illustrated
embodiment) that abuts the
compressible member 74 when the welding nozzle 48 is secured to the gas
diffuser 58. As the
welding nozzle 48 is pushed onto the gas diffuser 58, the compressible member
74 radially
compresses, allowing the welding nozzle 48 to be installed over the
compressible member 74 and
fully onto the gas diffuser 58. The compressible member 74 remains in a
compressed state as long
as the welding nozzle 48 is installed on the gas diffuser 58. In the
compressed state, the
compressible member 74 continuously applies a radial force against the
internal bore of the welding
nozzle 48, as illustrated by arrows 78.
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
[0048] However, the embodiments described herein do not rely solely on this
radial force 78 to
provide axial friction to prevent the welding nozzle 48 from sliding off the
gas diffuser 58 during
use. One reason for this is that relying on axial friction alone to retain the
welding nozzle 48 to the
gas diffuser 58 would present certain drawbacks. For example, over time, the
friction force might
inevitably lessen, allowing the welding nozzle 48 to fall off of the gas
diffuser 58. More
specifically, the compressible member 74 may wear away over time due to
repeated installations
and/or removals encountered during normal use. To mitigate these drawbacks, as
illustrated in FIG.
3, in certain embodiments, the internal bore of the welding nozzle 48 (e.g.,
the welding nozzle insert
75 in the illustrated embodiment) does not have a constant diameter along its
engagement length
with the gas diffuser 58, but instead includes an internal bore that allows
the compressible member
74 to apply an axial retention force, as illustrated by arrows 80, in addition
to the frictional force.
More specifically, in certain embodiments, the internal bore of the welding
nozzle 48 includes an
inner circumferential rib 82 having a tapered surface 84 against which the
compressible member 74
interfaces when the welding nozzle 48 is installed onto the gas diffuser 58.
[0049] FIG. 4 is a cutaway side view of the portion of the welding torch 16
illustrated in FIG. 3.
As illustrated, when the welding nozzle 48 is secured to the gas diffuser 58,
the compressible
member 74 is radially compressed between the tapered surface 84 of the inner
circumferential rib 82
of the welding nozzle 48 (e.g., the welding nozzle insert 75 in the
illustrated embodiment) and an
outer surface 86 of the gas diffuser 58 that forms an outer circumferential
groove 88 with adjacent
walls 90, 92 that extend radially outward from opposite sides of the outer
surface 86. As such, the
compressible member 74 creates a radially outward force Frathal, which creates
an axial friction force
Ffor,õ that at least partially holds the welding nozzle 48 in place with
respect to the gas diffuser 58.
In addition, when the welding nozzle 48 is secured to the gas diffuser 58, the
compressible member
74 is axially compressed between the tapered surface 84 of the inner
circumferential rib 82 of the
welding nozzle 48 (e.g., the welding nozzle insert 75 in the illustrated
embodiment) and the first
wall 90 of the outer circumferential groove 88 of the gas diffuser 58. As
such, the compressible
member 74 creates an axial force Faxiai that at least partially holds the
welding nozzle 48 in place
with respect to the gas diffuser 58. It should be noted that, in other
embodiments, other nozzle
retention designs may be used, such as threading or other forms of retainer
rings.
[0050] As described above, in certain embodiments, the contact tip 56
includes external
threading 60 that mates with internal threading 62 of the gas diffuser 58 such
that the contact tip 56
may be secured within the welding torch 16 by creating a locking, threaded
connection between the
CA 03066773 2019-12-09
WO 2018/231758 PCT/US2018/037004
11
contact tip 56 and the gas diffuser 58. It is noted that the external
threading 60 of the contact tip 56
is not disposed near an axial end of the contact tip 56. Rather, the external
threading 60 is disposed
near a center portion of the contact tip 56. FIG. 5 is a cross-sectional side
view of the contact tip 56
of FIG. 3. As illustrated, in certain embodiments, the contact tip 56 includes
a non-threaded distal
end portion 94, an externally threaded middle portion 96, and a non-threaded
proximal end portion
98. The distal (e.g., downstream) axial end 100 of the contact tip 56 will be
understood to be the
axial end of the contact tip 56 that is nearest to the welding application
(e.g., where the arc 24 is
created), whereas the proximal (e.g., upstream) axial end 102 of the contact
tip 56 will be
understood to be the axial end of the contact tip 56 that is farthest away
from the welding
application (i.e., nearest to the gooseneck 46 of the welding torch 16).
[0051] For reference, in certain embodiments, a total axial length ltotai
of the contact tip 56 may
be in a range of approximately 1.000 inch and approximately 1.625 inches
(e.g., between
approximately 1.125 and approximately 1.500 inches, or between approximately
1.250 and
approximately 1.375 inches, between approximately 1.000 and approximately
1.125 inches, between
approximately 1.125 and approximately 1.250 inches, between approximately
1.250 and
approximately 1.375 inches, between approximately 1.375 and approximately
1.500 inches, or
between approximately 1.500 and approximately 1.625 inches,). For example, in
certain
embodiments, the total axial length ltõ,.1 of the contact tip 56 may be
approximately 1.000 inch,
approximately 1.125 inches, approximately 1.250 inches, approximately 1.375
inches,
approximately 1.500 inches, approximately 1.594 inches, approximately 1.625
inches, or any length
between approximately 1.000 inch and approximately 1.625 inches. Each of the
embodiments of the
contact tips 56 described herein may have a total axial length ltotai equal to
these values and/or ranges
of values such that the relative dimensions of the contact tips 56 may be used
to determine absolute
dimensions of the contact tips 56.
[0052] In certain embodiments, an axial length Idistat of the non-threaded
distal end portion 94 of
the contact tip 56 may be in a range of approximately 35% - approximately 60%
(e.g., between
approximately 40% and approximately 55%, between approximately 45% and
approximately 50%,
or approximately 47%) of the total axial length ltutai of the contact tip 56,
and an axial length 1 proximal
of the non-threaded proximal end portion 98 of the contact tip 56 may be in a
range of
approximately 25% - approximately 45% (e.g., between approximately 30% and
approximately
40%, or approximately 36%) of the total axial length 'total of the contact tip
56. As such, in certain
embodiments, an axial length imiddie of the externally threaded middle portion
96 of the contact tip 56
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
12
may be in a range of approximately 10% - approximately 25% (e.g., between
approximately 15%
and approximately 20%, or approximately 17%) of the total axial length liotai
of the contact tip 56.
Accordingly, in certain embodiments, the external threading 60 of the contact
tip 56 may be
disposed greater than approximately 25%, greater than approximately 30%,
greater than
approximately 35%, greater than approximately 40%, or greater than
approximately 45%, of the
total axial length 1w of the contact tip 56 from the proximal axial end 102 of
the contact tip 56 (i.e.,
to
at least the distance of the axial length 1proximal of the non-threaded
proximal end portion 98 of the
contact tip 56).
[0053] Similarly, a tapered outer surface 104 of the contact tip 56, which
is configured to abut a
mating tapered inner surface 106 of the gas diffuser 58 when the contact tip
56 is threaded into the
gas diffuser 58 (see, e.g., FIG. 3), may be disposed near a center portion of
the contact tip 56. More
specifically, the tapered outer surface 104 of the contact tip 56 may be
located greater than
approximately 40%, greater than approximately 45%, greater than approximately
50%, greater than
approximately 55%, greater than approximately 60%, or greater than
approximately 65%, of the
total axial length Low of the contact tip 56 from the proximal axial end 102
of the contact tip 56 (i.e.,
at least the distance of the axial length 1proximal of the non-threaded
proximal end portion 98 of the
contact tip 56 and the externally threaded middle portion 96 of the contact
tip 56). A shoulder 105
connects the tapered outer surface 104 to the externally threaded middle
portion 96. As illustrated,
in certain embodiments, the shoulder 105 is orthogonal to a central
longitudinal axis 109 of the
contact tip 56.
[0054] Because of the relatively long axial length 'proximal of the non-
threaded proximal end
portion 98 of the contact tip 56, the non-threaded proximal end portion 98 may
be referred to as a
"cooling tail". The gas diffuser 58 is configured such that when the contact
tip 56 is installed within
the gas diffuser 58, the non-threaded proximal end portion 98 of the contact
tip 56 (the "cooling
tail") protrudes into the welding gas stream and, as such, helps cool the
contact tip 56 through
convection during use, thereby helping the contact tip 56 perform better and
last longer than
conventional contact tips. For example, as illustrated by arrows 108 in FIG.
3, at least a portion of
the gas flows between the contact tip 56 and the gas diffuser 58 from the
proximal axial end 102 of
the contact tip 56 along the non-threaded proximal end portion 98 of the
contact tip 56 until the gas
reaches gas-through ports 64 of the gas diffuser 58, at which point the gas
enters the internal volume
72 formed between the welding nozzle 48 and the contact tip 56.
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
13
[0055] In certain embodiments, the external threading 60 and the exterior
surfaces of the contact
tip 56 that abut the gas diffuser 58 at axial locations downstream (i.e.,
distal) of the external
threading 60 (e.g., including the tapered outer surface 104) are the only
physical points of contact
between the contact tip 56 and the gas diffuser 58 when the contact tip 56 is
fully installed (e.g.,
threaded) into the gas diffuser 58 (i.e., the non-threaded proximal end
portion 98 does not physically
contact the gas diffuser 58 when the contact tip 56 is fully installed into
the gas diffuser 58). In
particular, the proximal axial end 102 of the contact tip 56 does not contact
the gas diffuser 58 when
the contact tip 56 is fully installed (e.g., threaded) into the gas diffuser
58. Having only the external
threading 60 and the exterior surfaces of the contact tip 56 that abut the gas
diffuser 58 at axial
locations downstream (i.e., distal) of the external threading 60 (e.g.,
including the tapered outer
surface 104), be the only physical points of contact between the contact tip
56 and the gas diffuser
58 prevents the non-threaded proximal end portion 98 of the contact tip 56
from serving as a means
of electrical conduction from the gas diffuser 58 to the contact tip 56.
Instead, electrical conduction
from the gas diffuser 58 to the contact tip 56 occurs only at the threaded
middle portion 96 and the
tapered outer surface 104 of the non-threaded distal end portion 94 of the
contact tip 56.
[0056] During the MIG welding process, electric current is transferred from
the contact tip 56 to
a welding electrode 18 that is continuously fed through an inner bore 111 of
the contact tip 56. It
has been found that a majority of this electric current transfer occurs
towards the distal end portion
94 of the contact tip 56. By conducting electric current from the gas diffuser
58 to the contact tip 56
at axial locations at or near the distal end portion 94 of the contact tip 56,
the overall electric current
path from the gas diffuser 58 to the welding electrode 18 is shortened. This
shortened path helps to
reduce resistive heating generated within the contact tip 56 during the
transfer of current from the
gas diffuser 58 to the welding electrode 18. As described herein, this current
transfer path does not
include the non-threaded proximal end portion 98 (i.e., the "cooling tail") of
the contact tip 56. The
non-threaded proximal end portion 98 (i.e., the "cooling tail") thus primarily
serves to help cool the
contact tip 56 via convective heat transfer from the surfaces of the non-
threaded proximal end
portion 98 to the welding gas as it flows over these surfaces. Another feature
of the embodiments of
the contact tip 56 and gas diffuser 58 described herein is that the gas
diffuser 58 helps shield the
non-threaded proximal end portion 98 of the contact tip 56, the threaded
middle portion 96 of the
contact tip 56, and at least a part of the tapered outer surface 104 of the
non-threaded distal end
portion 94 of the contact tip 56 from heat generated by the welding arc 24.
Specifically, as
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
14
illustrated in FIG. 3, only a portion of the non-threaded distal end portion
94 of the contact tip 56 is
external to the gas diffuser 58 when the contact tip 56 is installed within
the gas diffuser 58.
[0057] More specifically, as illustrated in FIG. 5, only a certain axial
length 'exposed of the non-
threaded distal end portion 94 of the contact tip 56 is external to the gas
diffuser 58 when the contact
tip 56 is installed within the gas diffuser 58. For example, in certain
embodiments, the axial length
lexposed of the non-threaded distal end portion 94 of the contact tip 56 that
is external to the gas
diffuser 58 when the contact tip 56 is installed within the gas diffuser 58
may be in a range of
approximately 20% - approximately 40% (e.g., between approximately 25% and
approximately
35%, or approximately 30%) of the total axial length itotal of the contact tip
56. In addition, in
certain embodiments, the axial length lexp,,,d of the non-threaded distal end
portion 94 of the contact
tip 56 that is external to the gas diffuser 58 when the contact tip 56 is
installed within the gas
diffuser 58 may be in a range of approximately 55% - approximately 75% (e.g.,
between
approximately 60% and approximately 70%, or approximately 65%) of the axial
length 'distal of the
non-threaded distal end portion 94 of the contact tip 56. Furthermore, it is
noted that the surface
area 120 of the contact tip 56 includes a rounded outer surface at the distal
axial end 100 of the
contact tip 56, further minimizing exposure to the welding arc 24. By limiting
this exposed surface
area 120 of the contact tip 56, less radiant heat is absorbed into the contact
tip 56, thereby extending
the life of the contact tip 56.
[0058] As such, the gas diffuser 58 shields the portion of the non-threaded
distal end portion 94
of the contact tip 56 that is not within the exposed axial length I exposed of
the non-threaded distal end
portion 94 from heat generated by the welding arc 24. In certain embodiments,
as illustrated in FIG.
5, an axial length ltapered of the tapered outer surface 104 of the contact
tip 56 may be in a range of
approximately 5% - approximately 15% (e.g., between approximately 5% and
approximately 10%,
or approximately 7%) of the total axial length 'total of the contact tip 56.
In addition, in certain
embodiments, the axial length Lamed of the tapered outer surface 104 of the
contact tip 56 may be in
a range of approximately 10% - approximately 25% (e.g., between approximately
10% and
approximately 20%, or approximately 15%) of the total axial length ldistai of
the non-threaded distal
end portion 94 of the contact tip 56. Specifically, in certain embodiments,
the axial length luipõed of
the tapered outer surface 104 of the contact tip 56 may be in a range of
approximately 0.094 inch to
approximately 0.141 inch (e.g., between approximately 0.094 inch and
approximately 0.125 inch, or
approximately 0.109 inch).
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
[0059] It
should be noted that, while the embodiments illustrated in FIGS. 3 and 5
include an
exposed axial length 'exposed of the non-threaded distal end portion 94 that
is less than the total axial
length 'distal of the non-threaded distal end portion 94 minus the axial
length ltat,õd of the tapered
outer surface 104, in other embodiments (see, e.g., FIG. 7A), the exposed
axial length 'exposed of the
non-threaded distal end portion 94 may be greater than the total axial length
Idisiat of the non-
threaded distal end portion 94 minus the axial length Itar,,,,d of the tapered
outer surface 104. In other
words, while the embodiments illustrated in FIGS. 3 and 5 include a tapered
outer surface 104 of the
contact tip 56 that mates with the tapered inner surface 106 of the gas
diffuser 58 internal to the gas
diffuser 58 (e.g., with a substantially constant inner diameter of the gas
diffuser 58 at the front axial
end 146 of the gas diffuser 58), in other embodiments (see, e.g., FIG. 6), the
tapered inner surface
106 of the gas diffuser 58 may be disposed at the front axial end 146 of the
gas diffuser 58 such that
the tapered outer surface 104 of the contact tip 56 may extend slightly
outside of the gas diffuser 58
when the contact tip 56 is fully installed (e.g., threaded) into the gas
diffuser 58.
[0060] As
illustrated in FIG. 5, in certain embodiments, the tapered outer surface 104
of the
contact tip 56 (as well as the mating tapered inner surface 106 of the gas
diffuser 58) may include a
taper that increases in diameter from the shoulder 105 of the contact tip 56
toward the distal axial
end 100 of the contact tip 56. For example, in certain embodiments, the
tapered outer surface 104 of
the contact tip 56 may increase in diameter from proximal end points pp,õima[
(i.e., that transitions
the tapered outer surface 104 to the shoulder 105) to distal end points
pdistai (i.e., that transitions the
tapered outer surface 104 into an adjacent, downstream portion of the non-
threaded distal end
portion 94 of the contact tip 56. More specifically, in certain embodiments,
an angle atapered formed
from the proximal end points pproxiffild to the distal end points pdistal
relative to a central longitudinal
axis 109 may be in a range of approximately 1 degrees - approximately 10
degrees (e.g., between
approximately 2 degrees and approximately 8 degrees, between approximately 3
degrees and
approximately 7 degrees, between approximately 4 degrees and approximately 6
degrees, or
approximately 5 degrees). It
will be appreciated that, when described herein, axial lengths of
components are defined as lengths along longitudinal axes for the respective
components. For
example, the axial length lia d of the tapered outer surface 104 of the
contact tip 56 is defined as
the length along the longitudinal axis 109 between the proximal end points
pprommai and the distal end
points Pdistal of the tapered outer surface 104.
[0061]
Although illustrated in FIGS. 3 and 5 as having a tapered outer surface 104
that is
substantially linear from the proximal end points n
rproximal to the distal end points pdisiai, in other
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
16
embodiments, the contact tip 56 may include a tapered outer surface 104 that
is not substantially
linear, but which may include various shapes and contours, such as convex
curved outer surfaces,
concave curved outer surfaces, stepped linear outer surfaces, stepped curved
outer surfaces, or some
combination thereof. Regardless of the specific shape or contour, the tapered
outer surface 104 of
the contact tip 56, through its interaction with the mating tapered inner
surface 106 of the gas
diffuser 58, aid in the alignment (e.g., concentricity) of the contact tip 56
when it is installed (e.g.,
threaded) into the gas diffuser 58.
[0062] Returning now to FIG. 5, in certain embodiments, the non-threaded
proximal end portion
98 of the contact tip 56 may include first and second portions 110, 112
connected by an angled
connecting portion 114. The first portion 110 may be directly connected to the
threaded middle
portion 96 of the contact tip 56, and generally has substantially similar (or,
indeed, identical) inner
and outer diameters as the threaded middle portion 96 (e.g., the outer
diameter from which the
threads 60 extend radially from the middle portion 96 may be substantially
similar, or identical, to
the outer diameter of the first portion 110), whereas the second portion 112
is disposed at the
proximal axial end 102 of the contact tip 56 and has inner and outer diameters
that are substantially
larger (e.g., greater than 100%, greater than 150%, greater than 200%, or even
larger, in certain
embodiments) than the first portion 110, necessitating the angled connecting
portion 114 between
the first and second portions 110, 112.
[0063] The internal bore 116 created by the second portion 112 of the non-
threaded proximal end
portion 98 is configured to be large enough to facilitate insertion of a
welding torch liner 118, as
illustrated in FIG. 3. The welding torch liner 118 provides a conduit through
which the wire
electrode 18 may travel to the contact tip 56. In conventional welding
torches, the welding torch
liners are either not in contact with the contact tip, or simply abut against
a proximal end of the
contact tip. In contrast, the embodiments illustrated in FIGS. 3 and 5 allow
the welding torch liner
118 to fit inside the internal bore 116 created by the second portion 112 of
the non-threaded
proximal end portion 98, maintaining better concentricity between the welding
torch liner 118 and
the contact tip 56, and thereby improving feedability of the wire electrode
18. In other
embodiments, the welding torch liner 118 may abut against the proximal axial
end 102 of the
contact tip 56. In yet other embodiments (e.g., as shown in FIG. 6), the
welding torch liner 118 may
be adapted on a first axial end 124 with a liner stop 126. In certain
embodiments, the gas diffuser 58
may be configured internally to interact with the liner stop 126 such that the
welding torch liner 118
may not abut, reside within, nor be in any physical contact with the proximal
axial end 102 of the
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
17
contact tip 56. As such, the installation and removal of the contact tip 56
may be made easier in that
the welding torch liner 118 may not exert any axial or counter-rotational
forces against the proximal
axial end 102 of the contact tip 56. In certain embodiments, as described
herein, the gas diffuser 58
may also be configured internally to interact with the liner stop 126 such
that the welding torch liner
118 maintains better concentricity between the welding torch liner 118 and the
contact tip 56.
Indeed, in certain embodiments, the liner stop 126 may be integral to the gas
diffuser 58. In other
words, the features of the liner stop 126, as described herein, may be part of
the gas diffuser 58 in
embodiments where the liner stop 126 and the gas diffuser 58 are integrated
into a single
component.
[0064] In conventional MIG welding systems, several different design types
of liner assemblies
are used to install welding torch liners in the welding torches. For example,
in a first conventional
design type (i.e., which may be referred to as rear load, captured end/free
end liners), it is common
for a liner assembly to be adapted on one axial end with a "stop", with the
other axial end being
unadapted. In such systems, the welding torch liner is often installed into
the welding torch via a
rear connector of the welding torch (often referred to as "rear load"). In
general, such rear
connectors facilitate attachment of the welding torch to a welding machine
and/or wire feeder, as
well as locating and aligning a liner assembly with the drive rolls of the
wire feeder that deliver
welding wire to the welding torch. In such conventional systems, the liner
assembly is fed into the
rear connector (e.g., located at a rear axial end of a gooseneck of the
welding torch) of the welding
torch until it is stopped by the liner stop. The liner stop locates and aligns
the liner assembly within
the rear connector of the welding torch, and provides a means with which to
retain the liner
assembly in the welding torch. In certain such designs, the liner stop may be
retained within the rear
connector of the welding torch via a threaded connection between the liner
stop and the rear
connector of the welding torch, or by a retaining "cap" that installs over the
liner stop and threads to
the rear connector of the welding torch. Another such design retains the liner
stop within the rear
connector of the welding torch by tightening a locking screw located in the
rear connector of the
welding torch, such that it applies a radial force to the liner assembly. This
retained end of the
welding torch liner may be referred to as being "captured". The opposite,
unadapted axial end of the
liner assembly commonly protrudes from the front axial end of the gooseneck,
and must be trimmed
to a specific length before installation of a gas diffuser and/or contact tip
into the welding torch. In
such designs, the gas diffuser usually has a shoulder or seat area to accept
this front axial end of the
welding torch liner. This gas diffuser feature prevents the front axial end of
the welding torch liner
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
18
from moving axially towards the contact tip once the gas diffuser is
installed, but does not prevent
the front axial end of the welding torch liner from moving axially away or
radially off-center. As
such, the front axial end of the welding torch liner may be considered "free".
[0065] In general, the length at which the welding torch liner is trimmed
is very important for
proper functioning of the welding torch. In particular, it is important to
keep the front axial end of
the welding torch liner as close to the rear axial end of the contact tip as
possible. A welding torch
liner that is cut too short may create problems feeding welding wire into the
contact tip and, thus,
affect the quality of the resulting weld.
[0066] As described above, to trim the welding torch liner in such
conventional designs, the gas
diffuser and/or and the contact tip must be removed from the gooseneck. The
correct cut location
often varies from one consumable design to another, so one must first verify
the trim length
required. Next, this trim length must be measured via some
tool/instrument/device while the torch
cable 42 is laying straight and untwisted. In general, it is relatively
difficult to hold the welding
torch in such a position while at the same time using a measuring device and
marking a cut location.
As a result, many users do not want to bother going through all this work and
just visually estimate
the length, cut the welding torch liner, and re-install the gas diffuser
and/or contact tip. Various
methods and devices have been developed to ease the measuring/cutting process,
but it still remains
relatively difficult to do correctly. In addition, with the gas diffuser
and/or contact tip re-installed,
there is no way to verify whether or not the user has trimmed the welding
torch liner too short.
More specifically, the user cannot see the free (front axial) end of the
welding torch liner because it
is hidden inside the gas diffuser.
[0067] A common phenomenon which occurs with rear load, captured end/free end
MIG welding
torch designs is referred to as "liner retraction". As the torch cable 42 is
coiled, bent, and twisted
during normal use, the free (front axial) end of the welding torch liner tends
to retract into the
gooseneck and away from the rear axial end of the contact tip. To combat this,
the welding torch
liner is often trimmed to a length that is a little longer than needed while
the torch cable 42 is
somewhat straight and not twisted. Often, though, this extra length is still
not enough to prevent the
welding torch liner from retracting away from the contact tip as the torch
cable 42 is moved around.
When this happens, it is essentially the same as if the welding torch liner
were trimmed too short to
begin with, and wire feeding problems will arise and affect the quality of the
weld.
[0068] Besides liner retraction, another problem with rear load, captured
end/free end MIG
welding torch designs is misalignment of the free (front axial) end of the
welding torch liner with
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
19
the contact tip. Perhaps just as important as keeping the front axial end of
the welding torch liner
close to the contact tip, it is also important to keep the two parts aligned
(e.g., concentrically). As
the welding wire exits the welding torch liner and enters the contact tip, any
radial misalignment
between the welding torch liner and the contact tip may cause resistance to
movement of the
welding wire. This resistance can cause wire feeding problems that may again
affect the quality of
the resulting weld. Such misalignment may also lead to premature wear and
reduced life of the
contact tip. As described above, it is common for gas diffusers to have an
internal shoulder or seat
area to accept the front axial end of the welding torch liner. Due to the
desire for "universal fit" gas
diffusers that accept various sized welding torch liners (e.g., having varying
outside diameters), the
seat area of such gas diffusers is usually of a diameter much larger than the
outer diameter of most
welding torch liners, thereby often causing the front axial end of the welding
torch liner to sit out-of-
alignment with the contact tip.
[00691 In a second conventional design type (i.e., which may be referred to
as rear load, captured
end/captured end liners), a locking screw is used to secure the liner assembly
in place at its
unadapted axial end to prevent axial movement of the welding torch liner
(i.e., liner retraction). As
such, the welding torch liner is captured on both axial ends of the welding
torch liner. In such
designs, the locking screw is often located within the gas diffuser, or in the
torch handle. These
designs are typically "rear load", similar to the aforementioned rear load,
captured end/free end MIG
welding torch designs. In addition, in such designs, the opposite (i.e., front
axial) end of the liner
assembly protrudes from the gooseneck after installation into the rear
connector and must he
trimmed to a specific length to place it as close as possible to the contact
tip. Again, the length at
which the welding torch liner is trimmed is very important for proper
functioning of the welding
torch. A welding torch liner that is cut too short may create problems feeding
welding wire into the
contact tip and, thus, affect the quality of the resulting weld being created.
As such, it is very
important to keep the front axial end of the welding torch liner as close to
the rear axial end of the
contact tip as possible. Also, as in the rear load, captured end/free end
liners, when the gas diffuser
and/or the contact tip is re-installed, there is no way to verify whether or
not the user has trimmed
the welding torch liner too short. More specifically, the user cannot see the
free (front axial) end of
the welding torch liner because it is hidden inside the gas diffuser.
[0070] While liner retraction is not an issue for rear load, captured
end/captured end MIG
welding torch designs (as it is with rear load, captured end/free end MIG
welding torch designs),
welding torch liner misalignment (e.g., radial misalignment) with the contact
tip may be. As
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
described above, there is a desire for "universal fit" gas diffusers that
accept various sized welding
torch liners. This results in gas diffusers with liner seat areas that are
often much larger than the
outer diameter of the welding torch liner used. While a locking screw may
prevent liner retraction,
it does nothing to aid (and, in fact, may worsen) radial alignment of the
welding torch liner and the
contact tip. When the locking screw is located in the gas diffuser, the act of
tightening the locking
screw against the welding torch liner forces the welding torch liner off-
center from the contact tip.
[00711 Additional problems may arise when the locking screw resides in the
gas diffuser. In
such designs, removing and replacing a gas diffuser becomes more difficult as
the user has to
remember to loosen the locking screw from against the welding torch liner
before the gas diffuser
may be removed. Another problem with this design is that the locking screw is
often exposed to the
welding arc environment, which is extremely hot, with molten metal "spatter"
flying about and
attaching to the welding torch components. This spatter may adhere to surfaces
of the locking screw
that interact with the tool used for loosening/tightening the locking screw.
This can make it
difficult, or even impossible, to loosen the locking screw after use of the
welding torch.
Furthermore, the heat from the welding arc may cause the locking screw and
mating gas diffuser
threads to temporarily change size when hot, creating a "bind" between the two
parts that makes
loosening/tightening the locking screw more difficult.
[0072] In designs where the locking screw is located in the handle of the
welding torch, a
separate problem may occur. For example, MIG welding torches sold in Europe
are required to
meet certain specifications ("CE"), one of which deals with exposed,
electrically "live" components
within the handle of welding torches. The CE standard dictates a maximum
orifice size in a handle
of a welding torch to limit the chances of a user getting shocked. Since the
locking screw is in direct
contact with the welding torch liner, the locking screw is "live" during the
welding process. As
such, in most designs, the locking screw located in the handle of the welding
torch requires an
access hole for a tightening/loosening tool, and often this access hole may
exceed the CE
specifications.
[0073] In a third conventional design type (i.e., which may be referred to
as front load, free
end/free end liners), the welding torch liner installs via the gooseneck of
the welding torch (i.e.,
from a front axial end of the gooseneck), rather than via a rear connector of
the welding torch. This
is often referred to as "front load". In such designs, the welding torch liner
is adapted on one axial
end (i.e., a rear axial end) to mate with a receiver in the rear connector of
the welding torch. The
welding torch liner is fed into the gooseneck of the welding torch until the
adapter ends -bottoms" in
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
21
the receiver of the rear connector of the welding torch. The receiver is
affixed to the rear connector,
but the welding torch liner is not captured by the receiver. As such, the
receiver keeps the adapted
end (i.e., the rear axial end) of the welding torch liner from moving axially
out of the rear connector
towards the wire feed drive rolls (i.e., away from the contact tip and gas
diffuser), but does not
prevent axial movement in the opposite axial direction (i.e., toward the
contact tip and the gas
diffuser). Such designs do, however, keep the welding torch liner centered
(e.g., radially) within the
rear connector. As such, the adapted end (i.e., the rear axial end) of the
welding torch liner may
experience liner retraction back into the torch cable 42, similar to how a
rear load, captured end/free
end liner design may enable liner retraction in the gooseneck. For this
reason, this adapter end of
the welding torch liner may be considered "free".
[0074] In certain such designs, the receiver in the rear connector of the
welding torch may be
spring-loaded. As such, the welding torch liner again has an adapted end to
mate with the receiver
of the rear connector of the welding torch. In such designs, the welding torch
liner is fed into the
gooseneck (i.e., from a front axial end of the gooseneck) until the welding
torch liner engages with
the receiver in the rear connector of the welding torch. At this point,
further insertion of the welding
torch liner into the welding torch causes compression of a biasing spring
located behind the receiver.
The welding torch liner may be inserted to a point that the spring can no
longer be compressed. In
general, the spring and receiver are often affixed to the rear connector, but
the receiver is free to
move axially. Again, in such designs, the adapted end of the welding torch
liner is not captured by
the receiver or the spring, so the adapted end of the welding torch liner may
experience liner
retraction back into the torch cable 42. For this reason, this adapted end of
the welding torch liner
may also be considered "free".
[0075] In both of these designs, the opposite (i.e., front axial) end of
the welding torch liner is
unadapted, and protrudes from the gooseneck end of the welding torch. This
axial end of the
welding torch liner must be trimmed to a specific length before installation
of a gas diffuser and/or
contact tip. In such designs, the gas diffuser usually has a shoulder or seat
area to accept this axial
end of the welding torch liner. This gas diffuser feature prevents the welding
torch liner from
moving axially towards the contact tip, but does not prevent the welding torch
liner from moving
axially away from the contact tip or radially off-center. As such, this end of
the welding torch liner
may also be considered "free".
[0076] As described above, in general, the length at which the welding
torch liner is trimmed is
very important for proper functioning of the welding torch. In particular, it
is important to keep the
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
22
front axial end of the welding torch liner as close to the rear axial end of
the contact tip as possible.
A welding torch liner that is cut too short may create problems feeding
welding wire into the contact
tip and, thus, affect the quality of the resulting weld. Also, as in the rear
load designs, when the gas
diffuser and/or contact tip are re-installed, there is no way to verify
whether or not the user has
trimmed the welding torch liner too short. More specifically, the user cannot
see the free end of the
welding torch liner because it is hidden inside the gas diffuser. In addition,
the front load, free
end/free end liner designs are also subject to liner retraction into the
gooseneck of the welding torch
and liner-to-contact tip misalignment.
[0077] Other problems exist with these front load, free end/free end liner
designs. For example,
determining if the adapted end of welding torch liner has actually mated with
the receiver in the rear
connector of the welding torch can be difficult as there is no way to visually
inspect for engagement.
The adapted end of the welding torch liner and the receiver are both hidden
inside the rear
connector. In general, the user must assume that when the welding torch liner
can no longer be
urged into the gooseneck, it has successfully mated with the receiver. If the
adapted end of the
welding torch liner has not mated and the welding torch is used, wire feeding
problems may develop
and affect the resulting weld.
[0078] An additional problem is presented by the design with the spring-
loaded receiver. The
intent of such design is to use compression of a biasing spring to apply a
constant axial force upon
the welding torch liner in a direction towards the gas diffuser in order to
combat liner retraction into
the gooseneck. The problem is that in order for this concept to work properly,
the liner assembly
must be pushed into the welding torch until the receiver spring has been fully
compressed, then the
welding torch liner must be trimmed to a specific length while holding it
against the spring biasing
force. However, it can be difficult to determine if the spring is fully
compressed while the welding
torch liner is trimmed, again due to the fact that the receiver and spring are
hidden inside the rear
connector in such designs.
[0079] Embodiments of the present disclosure are intended to address the
shortcomings of the
three conventional liner designs described above (i.e., rear load, captured
end/free end liner designs,
rear load, captured end/captured end liner designs, and front load, free
end/free end liner designs).
The embodiments of the present disclosure may be referred to as a front load,
captured end/captured
end liner design. The front load, captured end/captured end liner embodiments
described herein
may have certain synergies with the cooling tail contact tip designs described
herein with respect to
FIGS. 3-5. However, it should be noted that the front load, captured
end/captured end liner
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
23
embodiments described herein may be used with other types of contact tips
(e.g., not just with the
cooling tail contact tip 56 illustrated in FIGS. 3-5).
[0080] FIG. 6 is a cross-sectional perspective view of a portion of the
welding torch 16 of FIG. 2
in certain embodiments. The embodiment illustrated in FIG. 6 is substantially
similar to the
embodiment illustrated in FIG. 3. However, FIG. 6 illustrates a portion of a
welding torch liner
assembly 122 in accordance with embodiments of the present disclosure. The
welding torch liner
assembly 122 described herein includes a welding torch liner 118 that is
adapted with a liner stop
126 on a first (front) axial end 124, but unadapted at a second, opposite
(rear) axial end. The liner
stop 126 is mechanically affixed to the first axial end 124 of the welding
torch liner 118. The
welding torch liner 118 is fed into the gooseneck 46 of the welding torch 16
(with the unadapted
axial end of the welding torch liner 118 fed first in an axial direction
toward a rear end of the
welding torch 16) until the liner stop 126 abuts a front axial end 128 of the
gooseneck 46. As such,
the liner stop 126 protrudes from the front axial end 128 of the gooseneck 46
similar to how
unadapted liner ends protrude in the conventional liner designs described
above.
[0081] The difference from conventional liner designs is that the adapted
axial end 124 of the
welding torch liner 118 does not get trimmed. As described above with respect
to the conventional
liner designs, the distance the welding torch liner protrudes from the front
axial end of the
gooseneck is very important for proper functioning of a welding torch. In
general, the idea is to
have the front axial end of the welding torch liner as close as possible to
the contact tip. As
described above, such conventional liner designs rely on the user to measure
and trim the front axial
end of the welding torch liner to the critical length. In contrast, in the
present embodiments, the
liner stop 126 is precisely machined to its critical length. The user simply
inserts the welding torch
liner 118 into the gooseneck 46 until a rear axial end 125 of the liner stop
126 abuts the front axial
end 128 of the gooseneck 46, then the user installs the gas diffuser 58 over
the liner stop 126 (and
the contact tip 56). The present embodiments obviate the need for the user to
assume that the liner
protrusion length is correct.
[0082] In addition, the liner stop 126 provides a means with which to
capture the adapted axial
end 124 of the welding torch liner 118. In certain embodiments, the liner stop
126 is larger in
diameter (e.g., at the rear axial end 125 of the liner stop 126) than an
internal bore 130 of the
gooseneck 46 such that the liner stop 126 prevents the welding torch liner 118
from retracting (e.g.,
axially toward a rear portion of the welding torch 16) into the gooseneck 46.
In certain
embodiments, an internal bore 132 of the gas diffuser 58 is configured to abut
both an external
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
24
surface 134 of the gooseneck 46 at the front axial end 128 of the gooseneck 46
and a first external
surface 136 (as a rear axial portion) of the liner stop 126 at the rear axial
end 125 of the liner stop
126 when the gas diffuser 58 is installed in the welding torch 16 over the
contact tip 56 and the liner
stop 126. In addition, in certain embodiments, the internal bore 132 of the
gas diffuser 58 is
configured to mate with a shoulder 138 of the liner stop 126, which is formed
at a generally
orthogonal transition from the first external surface 136 of the liner stop
126 and a second external
surface 140 (as a front axial portion) of the liner stop 126 that has a
smaller outer diameter than the
first external surface 136 of the liner stop 126, when the gas diffuser 58 is
installed in the welding
torch 16 over the contact tip 56 and the liner stop 126.
[0083] These internal spatial features of the gas diffuser 58 limit axial
movement (e.g., less than
2 mm, less than 1 mm, less than 0.5 mm, less than 0.1 mm, or even less axial
movement, in certain
embodiments) of the liner stop 126 back toward the contact tip 56 when the gas
diffuser 58 is
installed in the welding torch 16 over the contact tip 56 and the liner stop
126. In addition, these
internal spatial features of the gas diffuser 58 limit radial movement (e.g.,
less than 2 mm, less than
1 mm, less than 0.5 mm, less than 0.1 mm, or even less radial movement, in
certain embodiments)
of the liner stop 126, thus keeping the welding torch liner 118 centered
radially with respect to the
contact tip 56. However, in certain embodiments, the liner stop 126 may be
configured to freely
rotate with 360 of full rotational movement with respect to the gas diffuser
58 and the gooseneck
46. As such, the adapted axial end 124 of the welding torch liner 118 is
considered "captured". In
other words, the adapted axial end 124 of the welding torch liner 118 is not
able to retract into the
gooseneck 46 (i.e., axially rearward), move towards the contact tip 56 (i.e.,
axially forward), or to sit
radially off-center with respect to the contact tip 56. The length that the
adapted axial end 124 of
the welding torch liner 118 protrudes from the gooseneck 46 is always correct
as it is precisely
machined into the liner stop 126. As described above, in certain embodiments,
the liner stop 126
may be integral to the gas diffuser 58. In other words, the features of the
liner stop 126, as described
herein, may be part of the gas diffuser 58 in embodiments where the liner stop
126 and the gas
diffuser 58 are integrated into a single component.
[0084] In addition to illustrating an embodiment of the gas diffuser 58
that is configured to
cooperate with the liner stop 126 of the welding torch liner assembly 122
described herein, FIG. 6
also illustrates an embodiment of the contact tip 56 that is different than
the embodiment of the
contact tip 56 illustrated in FIGS. 3 and 5. In general, the contact tip 56
illustrated in FIG. 6 is also
configured to cooperate with the liner stop 126 of the welding torch liner
assembly 122 described
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
herein. In this embodiment, again, the contact tip 56 includes external
threading 60 that mates with
internal threading 62 of the gas diffuser 58 such that the contact tip 56 may
be secured (e.g.,
mechanically affixed) within the welding torch 16 (e.g., to the gooseneck 46
via the gas diffuser 58)
by creating a locking, threaded connection between the contact tip 56 and the
gas diffuser 58.
Again, the external threading 60 of the contact tip 56 is not disposed near an
axial end of the contact
tip 56. Rather, the external threading 60 is disposed near a center portion of
the contact tip 56.
[0085] FIG. 7A is a cross-sectional side view of the contact tip 56 of FIG.
6. As illustrated, in
certain embodiments, the contact tip 56 includes a non-threaded distal end
portion 94, an externally
threaded middle portion 96, and a non-threaded proximal end portion 98,
similar to the embodiment
illustrated in FIGS. 3 and 5. In certain embodiments, the axial length ldisrai
of the non-threaded distal
end portion 94 of the contact tip 56 may be in a range of approximately 30% -
approximately 50%
(e.g., between approximately 35% and approximately 45%, or approximately 40%)
of the total axial
length Itotai of the contact tip 56, and the axial length Iproximai of the non-
threaded proximal end
portion 98 of the contact tip 56 may be in a range of approximately 35% -
approximately 55% (e.g.,
between approximately 40% and approximately 50%, or approximately 45%) of the
total axial
length Iwo' of the contact tip 56. As such, in certain embodiments, the axial
length muddle of the
externally threaded middle portion 96 of the contact tip 56 may be in a range
of approximately 10%
- approximately 25% (e.g., between approximately 10% and approximately 20%, or
approximately
15%) of the total axial length ltoo of the contact tip 56. Accordingly, in
certain embodiments, the
external threading 60 of the contact tip 56 may be disposed greater than
approximately 35%, greater
than approximately 40%, greater than approximately 45%, greater than
approximately 50%, or
greater than approximately 55%, of the total axial length howl of the contact
tip 56 from the proximal
axial end 102 of the contact tip 56 (i.e., at least the distance of the axial
length 1proxima of the non-
threaded proximal end portion 98 of the contact tip 56).
[0086] The tapered outer surface 104 of the contact tip 56 may be located
greater than
approximately 50%, greater than approximately 55%, greater than approximately
60%, greater than
approximately 65%, or greater than approximately 70%, of the total axial
length llulal of the contact
tip 56 from the proximal axial end 102 of the contact tip 56 (i.e., at least
the distance of the axial
length 1prommdt of the non-threaded proximal end portion 98 of the contact tip
56 and the externally
threaded middle portion 96 of the contact tip 56).
[0087] As with the embodiment illustrated in FIGS. 3 and 5, because of the
relatively long axial
length 'proximal of the non-threaded proximal end portion 98 of the contact
tip 56, the non-threaded
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
26
proximal end portion 98 may be referred to as a "cooling tail". The gas
diffuser 58 is configured
such that when the contact tip 56 is installed within the gas diffuser 58, the
non-threaded proximal
end portion 98 of the contact tip 56 (the "cooling tail") protrudes into the
welding gas stream and, as
such, helps cool the contact tip 56 through convection during use, thereby
helping the contact tip 56
perform better and last longer than conventional contact tips. For example, as
illustrated by arrows
108 in FIG. 6, at least a portion of the gas flows between the contact tip 56
and the gas diffuser 58
from the proximal axial end 102 of the contact tip 56 along the non-threaded
proximal end portion
98 of the contact tip 56 until the gas reaches gas-through ports 64 of the gas
diffuser 58, at which
point the gas enters the internal volume 72 formed between the welding nozzle
48 and the contact
tip 56. One difference from the embodiment illustrated in FIG. 3 is that, as
illustrated in FIG. 6, in
certain embodiments, the liner stop 126 may include one or more ports 142
through which welding
gas may flow between the contact tip 56 and the gas diffuser 58, as
illustrated by arrows 108.
Welding gas is thus allowed to travel from the interior volume 67 of the
gooseneck 46 into the
internal bore 132 of the gas diffuser 58.
[0088] Again, in general, the external threading 60 and the exterior
surfaces of the contact tip 56
that abut the gas diffuser 58 at axial locations downstream (i.e., distal) of
the external threading 60
(e.g., including the tapered outer surface 104) are the only physical points
of contact between the
contact tip 56 and the gas diffuser 58 when the contact tip 56 is fully
installed (e.g., threaded) into
the gas diffuser 58 (i.e., the non-threaded proximal end portion 98 does not
physically contact the
gas diffuser 58 when the contact tip 56 is fully installed into the gas
diffuser 58). In particular,
again, the proximal axial end 102 of the contact tip 56 does not contact the
gas diffuser 58 when the
contact tip 56 is fully installed (e.g., threaded) into the gas diffuser 58.
Having only the external
threading 60 and the exterior surfaces of the contact tip 56 that abut the gas
diffuser 58 at axial
locations downstream (i.e., distal) of the external threading 60 (e.g.,
including the tapered outer
surface 104 ), be the only physical points of contact between the contact tip
56 and the gas diffuser
58 prevents the non-threaded proximal end portion 98 of the contact tip 56
from serving as a means
of electrical conduction from the gas diffuser 58 to the contact tip 56.
Instead, electrical conduction
from the gas diffuser 58 to the contact tip 56 occurs only at the threaded
middle portion 96 and the
tapered outer surface 104 of the non-threaded distal end portion 94 of the
contact tip 56.
[0089] Again, during the MIG welding process, electric current is
transferred from the contact tip
56 to a welding electrode 18 that is continuously fed through the inner bore
111 of the contact tip
56. It has been found that a majority of this electric current transfer occurs
towards the distal end
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
27
portion 94 of the contact tip 56. By conducting electric current from the gas
diffuser 58 to the
contact tip 56 at axial locations at or near the distal end portion 94 of the
contact tip 56, the overall
electric current path from the gas diffuser 58 to the welding electrode 18 is
shortened. This
shortened path helps to reduce resistive heating generated within the contact
tip 56 during the
transfer of current from the gas diffuser 58 to the welding electrode 18. As
described herein, this
current transfer path does not include the non-threaded proximal end portion
98 (i.e., the "cooling
tail") of the contact tip 56. The non-threaded proximal end portion 98 (i.e.,
the "cooling tail") thus
primarily serves to help cool the contact tip 56 via convective heat transfer
from the surfaces of the
non-threaded proximal end portion 98 to the welding gas as it flows over these
surfaces. Again,
another feature of the embodiments of the contact tip 56 and gas diffuser 58
described herein is that
the gas diffuser 58 helps shield the non-threaded proximal end portion 98 of
the contact tip 56, the
threaded middle portion 96 of the contact tip 56, and at least a part of the
tapered outer surface 104
of thc non-threaded distal end portion 94 of the contact tip 56 from heat
generated by the welding
arc 24. Specifically, as illustrated in FIG. 6, only a portion of the non-
threaded distal end portion 94
of the contact tip 56 is external to the gas diffuser 58 when the contact tip
56 is installed within the
gas diffuser 58.
[0090] More specifically, as illustrated in FIG. 7A, only a certain axial
length lexmed of the non-
threaded distal end portion 94 of the contact tip 56 is external to the gas
diffuser 58 when the contact
tip 56 is installed within the gas diffuser 58. For example, in certain
embodiments, the axial length
lexposed of the non-threaded distal end portion 94 of the contact tip 56 that
is external to the gas
diffuser 58 when the contact tip 56 is installed within the gas diffuser 58
may be in a range of
approximately 20% - approximately 40% (e.g., between approximately 25% and
approximately
35%, or approximately 30%) of the total axial length ltotai of the contact tip
56. In addition, in
certain embodiments, the axial length lexposed of the non-threaded distal end
portion 94 of the contact
tip 56 that is external to the gas diffuser 58 when the contact tip 56 is
installed within the gas
diffuser 58 may be in a range of approximately 65% - approximately 85% (e.g.,
between
approximately 70% and approximately 80%, or approximately 75%) of the axial
length ldistal of the
non-threaded distal end portion 94 of the contact tip 56. Furthermore, it is
noted that the surface
area 120 of the contact tip 56 includes a rounded outer surface at the distal
axial end 100 of the
contact tip 56, further minimizing exposure to the welding arc 24. Again, by
limiting this exposed
surface area 120 of the contact tip 56, less radiant heat is absorbed into the
contact tip 56, thereby
extending the life of the contact tip 56.
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
28
[0091] As such, again, the gas diffuser 58 shields the portion of the non-
threaded distal end
portion 94 of the contact tip 56 that is not within the exposed axial length
'exposed of the non-threaded
distal end portion 94 from heat generated by the welding arc 24. In certain
embodiments, as
illustrated in FIG. 7A, an axial length Lamed of the tapered outer surface 104
of the contact tip 56
may be in a range of approximately 10% - approximately 25% (e.g., between
approximately 10%
and approximately 20%, between approximately 10% and approximately 15%, or
approximately
13%) of the total axial length 1Lotat of the contact tip 56. In addition, in
certain embodiments, the
axial length ltapeõd of the tapered outer surface 104 of the contact tip 56
may be in a range of
approximately 25% - approximately 45% (e.g., between approximately 30% and
approximately
40%, or approximately 35%) of the total axial length Idistai of the non-
threaded distal end portion 94
of the contact tip 56. Specifically, in certain embodiments, the axial length
ltapered of the tapered
outer surface 104 of the contact tip 56 may be in a range of approximately
0.125 inch to
approximately 0.188 inch (e.g., between approximately 0.141 inch and
approximately 0.172 inch, or
approximately 0.163 inch).
[0092] As illustrated in FIG. 7A, in certain embodiments, the tapered outer
surface 104 of the
contact tip 56 (as well as the mating tapered inner surface 106 of the gas
diffuser 58) may include a
taper that increases in diameter from the shoulder 105 of the contact tip 56
toward the distal axial
end 100 of the contact tip 56. For example, in certain embodiments, the
tapered outer surface 104 of
the contact tip 56 may increase in diameter from proximal end points Pproximal
(i.e., that transitions
the tapered outer surface 104 to the shoulder 105) to distal end points
pdistat (i.e., that transitions the
tapered outer surface 104 into an adjacent, downstream portion of the non-
threaded distal end
portion 94 of the contact tip 56. More specifically, in certain embodiments,
an angle atapered formed
from the proximal end points pproõinid to the distal end points pdisw relative
to the central longitudinal
axis 109 may be in a range of approximately 1 degrees - approximately 5
degrees (e.g., between
approximately 2 degrees and approximately 4 degrees, or approximately 3
degrees).
[0093] Although illustrated in FIGS. 6 and 7A as having a tapered outer
surface 104 that is
substantially linear from the proximal end points pp,õ,iõ,ai to the distal end
points pdistai, in other
embodiments, the contact tip 56 may include a tapered outer surface 104 that
is not substantially
linear, but which may include various shapes and contours, such as convex
curved outer surfaces,
concave curved outer surfaces, stepped linear outer surfaces, stepped curved
outer surfaces, or some
combination thereof. Regardless of the specific shape or contour, the tapered
outer surface 104 of
the contact tip 56, through its interaction with the mating tapered inner
surface 106 of the gas
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
29
diffuser 58, aid in the alignment (e.g., concentricity) of the contact tip 56
when it is installed (e.g.,
threaded) into the gas diffuser 58.
[0094] Returning now to FIG. 7A, as opposed to the embodiments illustrated
in FIGS. 3 and 5,
the non-threaded proximal end portion 98 of the contact tip 56 does not
include first and second
portions 110, 112 connected by an angled connecting portion 114. Rather, the
non-threaded
proximal end portion 98 has substantially constant inner and outer diameters
along the entire axial
length 1proximal of the non-threaded proximal end portion 98, except for a
tapered inner diameter 144
at the proximal axial end 102 of the contact tip 56, which facilitates feeding
of the welding wire into
the contact tip 56. Indeed, it is noted that the substantially constant inner
and outer diameters of the
non-threaded proximal end portion 98 are substantially similar to
substantially constant inner and
outer diameters of the externally threaded middle portion 96. It is noted that
the outer diameter of
the externally threaded middle portion 96 is defined herein as the
substantially constant outer
diameter from which the external threading 60 extends radially. As such, the
externally threaded
middle portion 96 and the non-threaded proximal end portion 98 include
substantially constant inner
and outer diameters along a total axial length (lmiddie + 1proximal) Of the
externally threaded middle
portion 96 and the non-threaded proximal end portion 98, except for the
tapered inner diameter 144
at the proximal axial end 102 of the contact tip 56. In certain embodiments,
the external threading
60 of the threaded middle portion 96 may be directly adjacent the non-threaded
distal end portion
94, abutting (e.g., extending from) the shoulder 105. However, in other
embodiments, the external
threading 60 of the threaded middle portion 96 may be spaced apart from the
non-threaded distal
end portion 94 by a small distance, as illustrated in FIGS. 5 and 7A, such
that the external threading
60 is not directly adjacent the non-threaded distal end portion 94, and does
not abut (extend from)
the shoulder 105. In addition, in certain embodiments, as illustrated in FIG.
7A, the external
threading 60 of the threaded middle portion 96 may be directly adjacent the
non-threaded proximal
end portion 98 (i.e., the external threading 60 may end at an axial location
at a proximal axial end of
the threaded middle portion 96, directly adjacent a distal axial end of the
non-threaded proximal end
portion 98). FIGS. 7B through 71 illustrate various views of the contact tip
56 of FIG. 7A to better
illustrate the features of the contact tip 56.
[0095] The embodiments of the contact tip 56 illustrated in FIGS. 7A
through 71 includes certain
relative and absolute dimensions. However, other embodiments may include other
combinations of
relative and absolute dimensions. For example, in certain embodiments, the
axial length ldistai of the
non-threaded distal end portion 94 of the contact tip 56 may be in a range of
approximately 40% -
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
approximately 60% (e.g., between approximately 45% and approximately 55%, or
approximately
50%) of the total axial length ltraa, of the contact tip 56, and the axial
length 1pm,õ,,,a1 of the non-
threaded proximal end portion 98 of the contact tip 56 may be in a range of
approximately 25% -
approximately 45% (e.g., between approximately 30% and approximately 40%, or
approximately
35%) of the total axial length Low of the contact tip 56. As such, the axial
length la-addle of the
externally threaded middle portion 96 of the contact tip 56 may be in a range
of approximately 10%
- approximately 25% (e.g., between approximately 10% and approximately 20%, or
approximately
15%) of the total axial length 'total of the contact tip 56. In addition, the
axial length 'exposed of the
non-threaded distal end portion 94 of the contact tip 56 that is external to
the gas diffuser 58 when
the contact tip 56 is installed within the gas diffuser 58 may be in a range
of approximately 30% -
approximately 50% (e.g., between approximately 35% and approximately 45%, or
approximately
40%) of the total axial length 'total of the contact tip 56. In addition, the
axial length ',posed of the
non-threaded distal end portion 94 of the contact tip 56 that is external to
the gas diffuser 58 when
the contact tip 56 is installed within the gas diffuser 58 may be in a range
of approximately 70% -
approximately 90% (e.g., between approximately 75% and approximately 85%, or
approximately
80%) of the axial length Id,stal of the non-threaded distal end portion 94 of
the contact tip 56. In
addition, the axial length 'tapered of the tapered outer surface 104 of the
contact tip 56 may be in a
range of approximately 10% - approximately 25% (e.g., between approximately
10% and
approximately 20%, between approximately 10% and approximately 15%, or
approximately 13%)
of the total axial length 'total of the contact tip 56. In addition, the axial
length ltapered of the tapered
outer surface 104 of the contact tip 56 may be in a range of approximately 15%
- approximately
35% (e.g., between approximately 20% and approximately 30%, or approximately
26%) of the total
axial length 'distal of the non-threaded distal end portion 94 of the contact
tip 56. Specifically, the
axial length ltapered of the tapered outer surface 104 of the contact tip 56
may be in a range of
approximately 0.125 inch to approximately 0.188 inch (e.g., between
approximately 0.141 inch and
approximately 0.172 inch, or approximately 0.163 inch). In addition, the angle
atapered formed from
the proximal end points Ppruximal to the distal end points pdistel relative to
the central longitudinal axis
109 may be in a range of approximately 1 degrees - approximately 5 degrees
(e.g., between
approximately 2 degrees and approximately 4 degrees, or approximately 3
degrees).
'0096" In other embodiments, the axial length ldistai of the non-threaded
distal end portion 94 of
the contact tip 56 may be in a range of approximately 55% - approximately 70%
(e.g., between
approximately 60% and approximately 65%, or approximately 63%) of the total
axial length kraal of
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
31
the contact tip 56, and the axial length Iproximni of the non-threaded
proximal end portion 98 of the
contact tip 56 may be in a range of approximately 15% - approximately 30%
(e.g., between
approximately 15% and approximately 25%, (Jr approximately 20%) of the total
axial length ltotai of
the contact tip 56. As such, the axial length liniddte of the externally
threaded middle portion 96 of
the contact tip 56 may be in a range of approximately 15% - approximately 25%
(e.g., between
approximately 15% and approximately 20%, or approximately 17%) of the total
axial length "total of
the contact tip 56. In addition, the axial length ',posed of the non-threaded
distal end portion 94 of
the contact tip 56 that is external to the gas diffuser 58 when the contact
tip 56 is installed within the
gas diffuser 58 may be in a range of approximately 40% - approximately 60%
(e.g., between
approximately 45% and approximately 55%, or approximately 49%) of the total
axial length ltotai of
the contact tip 56. In addition, the axial length 'exposed of the non-threaded
distal end portion 94 of
the contact tip 56 that is external to the gas diffuser 58 when the contact
tip 56 is installed within the
gas diffuser 58 may be in a range of approximately 70% - approximately 90%
(e.g., between
approximately 75% and approximately 85%, or approximately 79%) of the axial
length ldistai of the
non-threaded distal end portion 94 of the contact tip 56. In addition, the
axial length ltapered of the
tapered outer surface 104 of the contact tip 56 may be in a range of
approximately 10% -
approximately 25% (e.g., between approximately 10% and approximately 20%,
between
approximately 12% and approximately 18%, or approximately 16%) of the total
axial length ltotal of
the contact tip 56. In addition, the axial length ltapered of the tapered
outer surface 104 of the contact
tip 56 may be in a range of approximately 15% - approximately 35% (e.g.,
between approximately
20% and approximately 30%, or approximately 25%) of the total axial length
'distal of the non-
threaded distal end portion 94 of the contact tip 56. Specifically, the axial
length ltapered of the
tapered outer surface 104 of the contact tip 56 may be in a range of
approximately 0.125 inch to
approximately 0.188 inch (e.g., between approximately 0.141 inch and
approximately 0.172 inch, or
approximately 0.159 inch). lit addition, the angle ottapt,t formed from the
proximal end points
Pproximal to the distal end points pdiso relative to the central longitudinal
axis 109 may be in a range of
approximately 1 degrees - approximately 5 degrees (e.g., between approximately
2 degrees and
approximately 4 degrees, or approximately 3 degrees).
[0097] As such, in general, in certain embodiments, the axial length Listal
of the non-threaded
¨
distal end portion 94 of the contact tip 56 may be in a range of approximately
30% - approximately
70% (e.g., between approximately 35% and approximately 65%, between
approximately 40% and
approximately 60%, or between approximately 45% and approximately 55%) of the
total axial
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
32
length ltotal of the contact tip 56, and the axial length 'proximal of the non-
threaded proximal end
portion 98 of the contact tip 56 may be in a range of approximately 15% -
approximately 55% (e.g.,
between approximately 20% and approximately 50%, between approximately 25% and
approximately 45%, or between approximately 30% and approximately 40%) of the
total axial
length 'total of the contact tip 56. As such, the axial length 'middle of the
externally threaded middle
portion 96 of the contact tip 56 may be in a range of approximately 10% -
approximately 25% (e.g.,
between approximately 10% and approximately 20%, or between approximately 15%
and
approximately 20%) of the total axial length ltotai of the contact tip 56. In
addition, the axial length
'exposed of the non-threaded distal end portion 94 of the contact tip 56 that
is external to the gas
diffuser 58 when the contact tip 56 is installed within the gas diffuser 58
may be in a range of
approximately 15% - approximately 60% (e.g., between approximately 20% and
approximately
55%, between approximately 25% and approximately 50%, or between approximately
30% and
approximately 45%) of the total axial length Itotai of the contact tip 56. In
addition, the axial length
legosed of the non-threaded distal end portion 94 of the contact tip 56 that
is external to the gas
diffuser 58 when the contact tip 56 is installed within the gas diffuser 58
may be in a range of
approximately 55% - approximately 90% (e.g., between approximately 60% and
approximately
85%, or between approximately 65% and approximately 80%) of the axial length
'distal of the non-
threaded distal end portion 94 of the contact tip 56. In addition, the axial
length ltapered of the tapered
outer surface 104 of the contact tip 56 may be in a range of approximately 5% -
approximately 25%
(e.g., between approximately 10% and approximately 25%, or between
approximately 10% and
approximately 20%) of the total axial length Loud of the contact tip 56. In
addition, the axial length
'tapered of the tapered outer surface 104 of the contact tip 56 may be in a
range of approximately 10%
- approximately 45% (e.g., between approximately 15% and approximately 40%, or
between
approximately 20% and approximately 35%) of the total axial length LAistai of
the non-threaded distal
end portion 94 of the contact tip 56. Specifically, the axial length ltapered
of the tapered outer surface
104 of the contact tip 56 may be in a range of approximately 0.094 inch to
approximately 0.188 inch
(e.g., between approximately 0.109 inch and approximately 0.172 inch, or
between approximately
0.125 inch and approximately 0.156 inch). In addition, the angle atapõed
formed from the proximal
end points n
r proximal to the distal end points Pdistal relative to the central
longitudinal axis 109 may be
in a range of approximately 1 degrees - approximately 10 degrees (e.g.,
between approximately 2
degrees and approximately 8 degrees, between approximately 3 degrees and
approximately 7
degrees, or between approximately 4 degrees and approximately 6 degrees).
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
33
[0098] FIG. 21A is a cross-sectional side view of another embodiment of the
contact tip 56 of
FIG. 6. As illustrated in FIG. 21A, the contact tip 56 is substantially
similar to the contact tip 56
illustrated in FIG. 7A. However, the contact tip 56 illustrated in FIG. 21A
includes a plurality of
cooling fins 206 that extend radially from the non-threaded proximal end
portion 98 of the contact
tip 56 about a circumference of the non-threaded proximal end portion 98. In
particular, in the
embodiment illustrated in FIG. 21A, a common outer diameter of the cooling
fins 206 is
substantially similar to the substantially constant outer diameter of the
externally threaded middle
portion 96 from which the external threading 60 extends radially. As such,
grooves 208 are located
between the cooling fins 206, as well as between the externally threaded
middle portion 96 and the
most distal (e.g., front) cooling fin 206. As with the embodiment of the
contact tip 56 illustrated in
FIG. 7A, none of the non-threaded proximal end portion 98 of the contact tip
56 illustrated in FIG.
21A makes physical contact with the gas diffuser 58 when the contact tip 56 is
fully installed (e.g.,
threaded) into the gas diffuser 58. Rather, again, the external threading 60
and the exterior surfaces
of the contact tip 56 that abut the gas diffuser 58 at axial locations
downstream (i.e., distal) of the
external threading 60 (e.g., including the tapered outer surface 104) are the
only physical points of
contact between the contact tip 56 and the gas diffuser 58 when the contact
tip 56 is fully installed
(e.g., threaded) into the gas diffuser 58. The cooling fins 206 increase the
convective heat transfer
potential of the "cooling tail" (i.e., the non-threaded proximal end portion
98) of the contact tip 56
insofar as the cooling fins 206 (and the adjacent grooves 208) increase the
surface area of the non-
threaded proximal end portion 98. FIGS. 21B through 211 illustrate various
views of the contact tip
56 of FIG. 21A to better illustrate the features of the contact tip 56.
[0099] As described above, returning now to FIG. 6, the welding torch liner
118 may be adapted
on the first axial end 124 with the liner stop 126. In certain embodiments,
the gas diffuser 58 may
be configured internally to interact with the liner stop 126 such that the
welding torch liner 118 may
not abut, reside within, nor be in any physical contact with the proximal
axial end 102 of the contact
tip 56. For example, as illustrated in FIG. 6, the contact tip 56 and the
liner stop 126 do not
physically interact when both are installed in the welding torch 16. In fact,
the axial distance
between the contact tip 56 and the liner stop 126 when both are installed in
the welding torch 16
may be less than approximately 1/8", less than approximately 1/16", less than
1/32", or even
smaller, in certain embodiments. However, in certain embodiments, the contact
tip 56 and the liner
stop 126 each have an outer diameter that is substantially similar to the
other such that the axial flow
of welding gas is not impeded in any way, as illustrated by arrow 108.
Specifically, the outer
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
34
diameter of the non-threaded proximal end portion 98 of the contact tip 56 may
be substantially
similar to the outer diameter of the second external surface 140 of the liner
stop 126.
[00100] As such, again, the installation and removal of the contact tip 56 may
be made easier in
that the welding torch liner 118 may not exert any axial or counter-rotational
forces against the
proximal axial end 102 of the contact tip 56. In certain embodiments, as
described herein, the gas
diffuser 58 may also be configured internally to interact with the liner stop
126 such that the welding
torch liner 118 maintains better concentricity between the welding torch liner
118 and the contact tip
56. Indeed, in certain embodiments, the liner stop 126 may be integral to the
gas diffuser 58. In
other words, the features of the liner stop 126, as described herein, may be
part of the gas diffuser 58
in embodiments where the liner stop 126 and the gas diffuser 58 are integrated
into a single
component.
[00101] FIG. 8A is a cross-sectional side view of the gas diffuser 58 of FIG.
6. As illustrated, in
certain embodiments, the gas diffuser 58 includes the tapered inner surface
106 at a front axial end
146 of the gas diffuser 58, which decreases in inner diameter moving away from
the front axial end
146 of the gas diffuser 58. As described herein, the tapered inner surface 106
is configured to mate
with the tapered outer surface 104 of the contact tip 56 when the contact tip
56 is installed in the gas
diffuser 58. Adjacent the tapered inner surface 106, the gas diffuser 58
includes the internal threads
62 that are configured to mate with the external threads 60 of the contact tip
56 to secure the contact
tip 56 within the gas diffuser 58. Adjacent the internal threads 62, the gas
diffuser 58 includes a
second tapered surface 1 50 that increases in inner diameter moving away from
the front axial end
146 of the gas diffuser 58 until it reaches a portion of inner bore 152 of the
gas diffuser 58 that has a
substantially constant inner diameter, and through which the gas-through ports
64 extend to
facilitate the flow of welding gas from the interior volume 67 of the
gooseneck 46, through the one
or more ports 142 of the welding stop 126, and into the internal volume 72
formed between the
welding nozzle 48 and the contact tip 56. As illustrated, the internal bore
132 of the gas diffuser 58
is configured to mate with the external surface 136 of the liner stop 126, and
also includes an
internal shoulder 148 configured to mate with the internal shoulder 138 of the
liner stop 126 to hold
the liner stop 126 in place with respect to the gas diffuser 58 when the gas
diffuser 58 is installed
onto the gooseneck 46 (e.g., threaded onto the gooseneck 46 via the mating
threads 65, 70, as
illustrated in FIG. 6) over the contact tip 56 and the liner stop 126. In
addition, as illustrated, the gas
diffuser 58 includes the groove 88 (e.g., formed by the adjacent walls 90, 92
and the outer surface
86 of the gas diffuser 58, as illustrated in FIG. 4) into which the
compressible member 74 may be
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
inserted to facilitate threadless retention of the welding nozzle 48 over the
gas diffuser 58. FIGS.
8B through 8E illustrate various views of the gas diffuser 58 of FIG. 8A to
better illustrate the
features of the gas diffuser 58.
[00102] FIG. 9A is a cross-sectional side view of the liner stop 126 of FIG.
6. As illustrated, in
certain embodiments, the liner stop 126 includes the first external surface
136 and external shoulder
138 configured to mate with the internal bore 132, including the internal
shoulder 148, of the gas
diffuser 58 to hold the liner stop 126 in place with respect to the gas
diffuser 58 when the gas
diffuser 58 is installed onto the gooseneck 46 (e.g., threaded onto the
gooseneck 46 via the mating
threads 65, 70, as illustrated in FIG. 6) over the contact tip 56 and the
liner stop 126. In addition, as
described herein, in certain embodiments, the second external surface 140 of
the liner stop 126
facilitates the flow of welding gas through the welding torch 16 by having an
outer diameter that
generally matches (e.g., is substantially similar to) the outer diameter of
the non-threaded proximal
end portion 98 of the contact tip 56 illustrated in FIGS. 7A though 71.
Furthermore, as illustrated, in
certain embodiments, the liner stop 126 includes one or more ports 142 that
facilitate the flow of the
welding gas from the interior volume 67 of the gooseneck 46 into the internal
volume 72 formed
between the welding nozzle 48 and the contact tip 56. FIGS. 9B through 9D
illustrate various views
of the liner stop 126 of FIG. 9A to better illustrate the features of the
liner stop 126. Again, as
described herein, in certain embodiments, the liner stop 126 of FIG. 9A and
the gas diffuser 58 of
FIG. 8A may be combined into a single, integrated component.
[00103] As illustrated in FIG. 10, embodiments of the welding torch liner
assembly 122 described
herein also include a rear connector 152 disposed at a rear axial end of the
welding torch cable 42,
which is adapted with a liner receiver 154 of the welding torch liner assembly
122. In certain
embodiments, the liner receiver 154 may be affixed to the rear connector 152
and has a liner
receiver orifice 156 into which the unadapted (rear) axial end of the welding
torch liner 118 may be
inserted. As the welding torch liner 118 is fed into the gooseneck 46, the
unadapted axial end 158 of
the welding torch liner 118 will enter the liner receiver orifice 156 and pass
through it. When the
welding torch liner 118 has been fully installed into the welding torch 16
(i.e., when the liner stop
126 abuts the gooseneck 46), the unadapted axial end 158 of the welding torch
liner 118 will extend
through the end of the rear connector 152. The liner receiver 154 serves to
align the welding torch
liner 118 with a centerline of the rear connector 152.
[00104] In certain embodiments, the liner receiver 154 is fitted with a
locking screw 160, which
may be tightened against the welding torch liner 118 to secure the welding
torch liner 118 in place
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
36
with respect to the liner receiver 154. As such, the locking screw 160
prevents axial movement of
the unadapted axial end 158 of the welding torch liner 118 in both axial
directions. The liner
receiver orifice 156 is designed to be only slightly larger than an outer
diameter of the welding torch
liner 118 that passes through it. The small difference in diameters allows the
welding torch liner
118 to stay centered within the rear connector 152 even when the locking screw
160 applies a radial
force against the welding torch liner 118. As such, the unadapted axial end
158 of the welding torch
liner 118 is also considered to be "captured" when the locking screw 160 is
tightened against the
welding torch liner 118. In other words, the unadapted axial end 158 of the
welding torch liner 118
is not able to retract into the torch cable 42, move out of the rear connector
152 (i.e., axially
forward), or to sit radially off-center with respect to the rear connector
152. The unadapted axial
end 158 of the welding torch liner 118 that protrudes from the rear connector
152 must be trimmed.
However, no measuring is required, as with conventional liner designs. Rather,
when the locking
screw 160 is tightened against the welding torch liner 118, the welding torch
liner 118 is simply
trimmed approximately flush with the end of the liner receiver 154. As
described in greater detail
herein, in other embodiments, instead of using the locking screw 160 in the
liner receiver 154, a
collet or other feature may be used to capture the welding torch liner 118 at
the rear connector 152.
[00105] As previously described, the rear connector 152 serves to locate and
align the welding
torch liner assembly 122 with the drive rolls that deliver welding wire into
the welding torch 16.
The welding torch liner assembly 122 serves as an entry point of the welding
wire into the welding
torch 16. Ideally, this entry point should be as close to the drive rolls as
possible. The welding
torch liner assembly 122 provides a welding torch liner 118 with an adjustable
entry point-to-drive
roll distance. The liner receiver 154 is of a "universal" protrusion length,
but due to the design, the
welding torch liner 118 may be adjusted to protrude further, if needed. Once
the welding torch liner
118 has been trimmed approximately flush with the end of the liner receiver
154, the locking screw
160 may be loosened, and with a twist of the torch cable 42, the welding torch
liner 118 will extend
outward. The amount of extension can be fine-tuned by manipulation of the
torch cable 42 and/or
pushing/pulling on the exposed liner end. Once the desired length has been
determined, the user
simply re-tightens the locking screw 160. No re-trimming of the welding torch
liner 118 is required.
In some instances, this procedure may be performed with the welding torch 16
fully coupled to the
wire feeder 14 via the torch cable 42.
[00106] In addition, if the user has difficulty trimming the welding torch
liner 118 approximately
flush with the end of the liner receiver 154, the locking screw 160 may be
loosened, and the
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
37
protruding portion of the welding torch liner 118 may be pushed into the liner
receiver 154 until it is
flush. The locking screw 160 may then be re-tightened, with no re-trimming
needed. Again, in
some instances, this procedure may be performed with the welding torch 16
fully coupled to the
wire feeder 14 via the torch cable 42. Welding gas is present inside the rear
connector 152 during
the welding process, and must not leak outward. As such, as illustrated in
FIG. 11, in certain
embodiments, the liner receiver 154 includes seals 162 (e.g., on opposites
axial sides of the locking
screw 160) that seal welding gas from leaking out from the rear connector 152.
[00107] FIG. 12 is a cross-sectional side view of the liner receiver 154 and
the rear connector 152
of FIGS. 10 and 11. As illustrated, in certain embodiments, the locking screw
160 may include
external threading 164 configured to mate with internal threading 166 through
the liner receiver 154
to enable the locking screw 160 to be screwed down against the welding torch
liner 118 to fixedly
secure the welding torch liner 118 within the liner receiver 154. In addition,
as illustrated, in certain
embodiments, the liner receiver 154 may include internal threading 168
configured to mate with
external threading 170 on the rear connector 152, which enable the liner
receiver 154 to be fixedly
secured to the rear connector 152.
[00108] The liner receiver 154 illustrated in FIGS. 10-12 is but one possible
embodiment that may
be used to receive the welding torch liner 118, and to secure the welding
torch liner 118 within the
liner receiver 154. For example, FIGS. 13-16 illustrate another embodiment of
the liner receiver
154, which may be used to receive the welding torch liner 118, and to secure
the welding torch liner
118 within the liner receiver 154. However, as illustrated in FIGS. 13-16,
this embodiment of the
liner receiver 154 does not include a locking screw 160 for securing the
welding torch liner 118
within the liner receiver 154. Rather, as described in greater detail herein,
the embodiment of the
liner receiver 154 illustrated in FIGS. 13-16 may instead include a washer 172
(e.g., a rubber
washer, in certain embodiments) disposed within the liner receiver 154 (e.g.,
which may be a brass
cap, in certain embodiments). As such, the liner receiver 154 and the washer
172 may collectively
function as a "cap assembly" that may be installed over the rear connector 152
(e.g., which may be
comprised of brass, and referred to as a brass pin, in certain embodiments),
as illustrated in FIG. 14.
[00109] As the cap assembly (i.e., the liner receiver 154 and the washer 172)
is installed onto
(e.g., threaded onto via mating internal threading 168 of the liner receiver
154 and external
threading 170 of the rear connector 152) the pin (i.e., the rear connector
152), the unadapted end 158
of the welding torch liner 118 passes through the orifice 156 of the liner
receiver 154. As illustrated
in FIG. 15, as the cap assembly is threaded onto the pin, a tapered external
axial end face 174 of the
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
38
washer 172 eventually contacts a mating tapered internal axial end face 176 of
the pin. As the cap
assembly is further threaded onto the pin, the washer 172 begins to compress
both axially (e.g.,
between the tapered axial end face 176 of the pin and a radially extending
orthogonal inner wall 180
of the liner receiver 154) and radially (e.g., via interaction of the mating
tapered axial end faces 174,
176), thereby reducing the inner diameter of the washer 172, as illustrated by
arrows 178. This
reduced inner diameter causes the washer 172 to grip the welding torch liner
118, which prevents
axial movement of the welding torch liner 118 relative to the washer 172 (and,
hence, the cap
assembly). In addition, the reduced inner diameter of the washer 172 provides
a seal between the
outer diameter of the welding torch liner 118 and the inner diameter of the
washer 172, which
prevents leakage of welding gas out through the orifice 156 of the liner
receiver 154. Similarly, a
gas seal is created at the interface between the washer 172 and the tapered
axial end face 176 of the
pin, which prevents welding gas from leaking through the threaded connection
between the mating
threads 168, 170 of the liner receiver 154 and the pin.
[00110] FIGS. 17-20 illustrate yet another embodiment of the liner receiver
154, which may be
used to receive the welding torch liner 118, and to secure the welding torch
liner 118 within the liner
receiver 154. However, in the embodiment illustrated in FIGS. 17-20, the liner
receiver 154 may
instead include a washer 182 (e.g., a flat, rubber washer, in certain
embodiments) and a collet 184
(e.g., a plastic collet, in certain embodiments) disposed within the liner
receiver 154 (e.g., which,
again, may be a brass cap, in certain embodiments). As such, the liner
receiver 154, the washer 182,
and the collet 184 may collectively function as a "cap assembly" that may be
installed over the rear
connector 152 (e.g., which may, again, be comprised of brass, and referred to
as a brass pin, in
certain embodiments), as illustrated in FIGS. 17 and 18.
[00111] Again, as the cap assembly (i.e., the liner receiver 154, the washer
182, and the collet
184) is installed onto (e.g., threaded onto via mating internal threading 168
of the liner receiver 154
and external threading 170 of the rear connector 152) the pin (i.e., the rear
connector 152), the
unadapted end 158 of the welding torch liner 118 passes through the orifice
156 of the liner receiver
154. As illustrated in FIG. 19, as the cap assembly is threaded onto the pin,
an external tapered
surface 186 of the collet 184 eventually contacts an axial end face 188 of the
pin. As the cap
assembly is further threaded onto the pin, the washer collet 184 begins to
compress both axially
(e.g., between the axial end face 188 of the pin and the washer 182) and
radially (e.g., via interaction
of the external tapered surface 186 of the collet 184 and the axial end face
188 of the pin), thereby
reducing the inner diameter of the washer collet 184, as illustrated by arrows
190. This reduced
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
39
diameter causes the collet 184 to grip the welding torch liner 118, which
prevents axial movement of
the welding torch liner 118 relative to the collet 184 (and, hence, the cap
assembly).
[00112] In the illustrated embodiment, the washer 182 has an inner diameter
slightly smaller than
the outer diameter of the welding torch liner 118 such that it foul's a seal
against the welding torch
liner 118 to prevent welding gas from leaking from the interior of the welding
torch 16. In addition,
as illustrated, in certain embodiments, an o-ring 192 may be disposed in an
external circumferential
groove 194 of the pin at the end of the threading 170 of the pin. In
particular, the o-ring 192 is
disposed in the external circumferential groove 194 at the thread end opposite
the axial end face 188
of the pin. As the cap assembly is fully threaded onto the pin, an axial end
face 196 of the liner
receiver 154 interacts with the o-ring 192, and compresses it slightly to
foal' a gas seal. thereby
preventing welding gas from leaking through the threaded connection between
the mating threads
168, 170 of the liner receiver 154 and the pin. It should be noted that, in
certain embodiments, the
collet 184 may include an orthogonal external shoulder 198 adjacent the
external tapered surface
186, which may interact with a mating internal shoulder 200 of the liner
receiver 154, wherein the
internal shoulder 200 is adjacent the internal threading 168 of the liner
receiver 154, and such that
the mating shoulders 198, 200 ensure that the collet 184 (as well as the
washer 182) are always
retained within the liner receiver 154.
[00113] FIG. 20 illustrates a perspective view of the collet 184 by itself. As
illustrated, in certain
embodiments, the collet 184 may include multiple, separate sections 202 (e.g.,
four sections, in the
illustrated embodiment) attached to a common cylindrical axial end portion
204. It will be
appreciated that the multiple, separate sections 202 of the collet 184 at
least partially enable the
compression of the collet 184 via interaction with the axial end face 188 of
the pin, as described
with respect to FIG. 19.
[00114] In summary, the welding torch liner 118 forms a long, tubular section
through which
welding wire may travel. The welding torch liner assembly 122 described herein
may be installed
into the welding torch 16 via the gooseneck 46 of the welding torch 16. The
front axial end 124 of
the welding torch liner 118 is fitted with the liner stop 126, which has a
larger outer diameter than
the front axial end 128 of the gooseneck 46. The liner stop 126 functions to
limit how far the
welding torch liner assembly 122 may be inserted into the gooseneck 46. An
additional benefit is
that the gas diffuser 58 also limits axial movement of the welding torch liner
assembly 122 (e.g.,
back toward the front axial end of the welding torch 16) insofar as the gas
diffuser 58 remains in a
fixed position when installed in the welding torch 16. Therefore, the liner
stop 126 cannot move
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
toward the front axial end of the welding torch 16. Furthermore, the gas
diffuser 58 serves to
radially align (e.g., center) the welding torch liner assembly 122 with the
contact tip 56.
[00115] In addition, embodiments of the present disclosure include a separate
liner receiver 154
that is not affixed to the welding torch liner assembly 122, but rather may be
removably affixed to
(e.g., threaded onto) the rear connector 152 of the welding torch 16. The
welding torch liner
assembly 122 is fitted on one axial end with the liner stop 126 while the
opposite axial end is either
"bare" or fitted with "shrink tubing" that covers a portion of the tubular
section. The liner receiver
154 includes an orifice 156 through which this axial end of the welding torch
liner 118 may pass as
it is installed through the gooseneck 46 of the welding torch 16. In certain
embodiments, the liner
receiver 154 includes a locking screw 160 that may be tightened to secure the
welding torch liner
assembly 122 within the liner receiver 154. In other embodiments, the liner
receiver 154 includes a
washer 172 that may be used to secure the welding torch liner assembly within
the liner receiver
154. In yet other embodiments, the liner receiver 154 includes a collet 184
that may be used to
secure the welding torch liner assembly within the liner receiver 154.
[00116] The liner receiver 154 thus serves to prevent axial movement of the
welding torch liner
assembly 122 within the rear connector 152 of the welding torch 16. The liner
receiver 154 further
serves to axially align the welding torch liner assembly 122 within the rear
connector 152 of the
welding torch 16.
[00117] As described herein, the front load, captured end/captured end
embodiments described
herein eliminate, or at least reduce, problems relating to liner trimming at
the gooseneck, liner
retraction at the gooseneck, misalignment of the liner with the contact tip,
gas diffuser removal (e.g.,
when using a locking screw in the gas diffuser), tightening/loosening locking
screws located in the
gas diffuser, determining if a front loaded liner is fully seated in a
receiver, liner retraction at the
rear connector, liner trimming at the receiver, wire entry point-to-drive roll
distance, and so forth.
The disclosed embodiments also include a contact tip 56 that promotes longer
tip life by helping to
cool the contact tip 56 through convection. In addition, the amount of surface
area of the contact tip
56 that is exposed to the welding arc is minimized to reduce radiant heat
input from the welding arc
and, thus, also promote long tip life. Furthermore, the disclosed embodiments
show improved
nozzle retention over conventional systems. There is less wear on nozzle
retention surfaces for
maintained retention over time.
[00118] As used herein, when referring to certain property values, the terms
"approximately",
"substantially similar", and "substantially constant" may be interpreted as
meaning properties
CA 03066773 2019-3.2-09
WO 2018/231758 PCT/US2018/037004
41
having values within 2%, within 1%, within 0.5%, or even less, depending on
manufacturing
tolerances, of the stated value (or comparative property).
[00119] While only certain features of the subject matter have been
illustrated and described
herein, many modifications and changes will occur to those skilled in the art.
It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall
within the true spirit of the disclosure.
