Note: Descriptions are shown in the official language in which they were submitted.
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C OMPRES S I ON TOOL
Background of the Invention ,
This invention is directed generally to ~he field of
compression tools a~d more particularly to a compression
tool for compressing or crimping generally tubular work-
pieces such as connectors or terminals utilized for
establishing electrical wiring connections.
A number of compression tools have heretofore been
proposed for compressing or crimping the generally
tu~l]ar terminal or connector members of the type
utilized in elect~ical wiring installations. Briefly,
these tubular comlectors receive a wire or bundles of
wire and mllst be crimped or compressQd in order to
securely forln both a mechanical and electrical union
between the connector or terminal and the wire.
The wire sizes and corresponding connector or terminal
sizes vary over a considerable range for achieving
different wire gauge connections. For exam?le, the
outer diameters to be compressed or crimped may range
from as small as 1/4" to as l~rge as 2".
Generally speaking, the crimping or compressing tools
heretofore proposed for accommodating this range of
sizes of connectors or terminals have been of two basic
types: 1) a tool having a tool head provided with an
interchangeable set of removable diesets, one dieset
for each connector size or for sizes within given limited
ranges; and 2) a tool having a tool head which carries
a single, permanent crimping or compression member which
is compressable to different degrees or extents in
order to accommodate a given range of sizes.
52~
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The former type of tool can be rather difficult and
timeconsuming to use, as the removable, interchangeable
diesets must be frequently changed in the field,
whenever different sized wires and the corresponding
connectors or terminals are to be installed The
lat~er type of tool is generally referred to as a
"dieless" compression tool. The term "dieless" refers
to the single, permanent die or compressiny structure
which is utilized, rather ~han the multiple, inter-
changeable, removable diesets provided with the former
-type o~ tool. Tools of this latter type have hereto-
fore proven relatively heavy and complex, and have
been relatively difficult to operate. Moreover, many
of these latter tools are prone to frequent malfunction
due to the complexities of their design.
Additionally, the tools of the second type have
generally provided an indentor-type of crimp, which
is a crimp or compression centered about a single
inden~ation, made by the tool, in the termin~l or
connector. However, a polygonal configuration of
compression or crimping is generally regarded as
s~perior in achieving both electrical and ~echanical
union of such a connector or terminal with electrical
wires.
Objects and Summary of the Invention
Accordingly, it is an object of this invention to
provide a novel and improved compression tool.
A more specific object is to provide a compression
tool of the foregoing type which is capable of accom-
modating a relatively broad range of connector or
terminal sizes.
S2~3
related object is to provide a compression tool of the foregoing
~ype which provides a polygonal compression configuration to the
connector or terminal compressed.
A further object is to provide a compression tool of the
foregoing type which is relatively simple in design and easy to
use and yet is highly reliable in operation.
The present invention thus provides a compression tool
comprising: a tool head, a die set including fi~ed and movable
die means mounted in said tool head for compressingly, surround-
ingly engaging a generally tubular workpiece, said movabl~ diemeans being continuously variably positionable for defining an
opening of variable size between a predetermined minimum opening
and a predetermined maximum opening for selectively accommodating
relatively large to relatively small workpieces over a correspond-
ing range of sizes by the same said die set, fluid operated drive
means for driving said ~ovable die means toward said predetermined
minimum opening to compress a preselected size of workpiece; and
fluid pressure control means including a control member manually
readily accessible in view to an operator in on-the-job field use
for preselecting and presetting the maximum pressure of fluid sup-
plied to said fluid operated drive means for the preselected size
of workpiece to be compressed and thereby con~rolling the force
applied by the drive means to the die means and the compressive
force applied by the die means to the selected size of workpiece;
wherein the fluid pressure control means includes a relief valve
mounted interiorly of the tool and inaccessible to an operator,
said relief valve being movable to a plurality of positions, each
position corresponding to a given relief pressure; and wherein the
528
control member comprises a manually adjustable member operatively
coupled with the relief valve and including an adjustment knob
mounted to an exterior surface of the tool and protruding from the
tool for gripping by an operator to manually achieve corresponding
movement of the relief valve to a desired one of a plurality of
positions thereof, and indicia on said knob and on an adjacent
surface of the tool for indicating each of said plurality of posi-
tions and thereby indicating each of a corresponding plurality of
relief pressures.
Briefly, and in accordance with the foregoing objects, a
compression tool according to the invention comprises a tool head,
die means mounted in said tool head for compressingly, surround-
ingly en~aginy a generally tubular workpiece, said die means
defining a minimum opening and a maximum opening therein for
accommodating workpieces over a corresponding range of si~es,
fluid operated drive means for driving said movable die means to
compress said workpiece and fluid pressure control means for con-
trollably varying the maximum pressure of the fluid supplied to
said fluid operated drive means in a predetermined fashion in
accordance wit~ the size of a workpiece to be compressed.
Brief Description of the Drawings
Other objects, features and advantages of the invention
will become more readily apparent upon reading the following
detailed description of the illustrated embodiment together with
reference to the accompanying drawings wherein:
FIG. 1 is an elevational view of a compression tool in
accordance with the present invention;
FIG. 2 is an enlarged perspective view of die portions
of the tool of FIG. l;
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FIG. 3 is a reduced view illustrating one aspect of
operation of the dies of ~IG. 2;
FIG. 4 is another reduced view illustrating another
aspect of operation of the dies of FIG. 2;
FIG. 5 is yet another reduced view illustrating a
further aspect of the operation of the dies of FIG. 2;
FIG. 6 is an enlarged sectional view, somewhat dia-
grammatic in form, of a pressure control portion of
the tool of FIG. l; and
FIG. 7 is a view similar to FIG. 6 and illustrating
lS another aspect of the operation of the pressure control
portion.
D ailed Description of the Illustrated Embodiment
Reerring now to the drawings and initially to FIG. 1,
a compression tool in accordance with the present in-
vention is designated generally by the reference
numeral 10. Broadly speaking, this compression tool
10 includes a tool head 12, a manually controlled tool
actuating portion 14.
The tool head 12 comprises a die assembly 18 and a
drive assembly 30 for actuating the die assembly 18.
In the illustrated embodiment, the die assembly 18
includes a pair of elongate guide members 20, 22 which
slidably mount a lower die member 24 therebetween. An
upper die member 26 is mounted to respective top ends
of the elongate guide members 20, 22. Between the
lower die 24 and the upper die 26 a workpiece-receiving
through opening 28 is defined. As will be more fully
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explained later, and in accordance with a feature of the
invention, these dies 24 and 26 and the guide members
20, 22 are arranged for compressing or crimping terminals
or connectors into engagement with electrical cables
or conduc~ors. Moreover, the compression tool 10
readily accommodates such connectors or terminals and
associated electrical cables over a relatively broad
range of sizes. This novel arrangement avoids the
necessity o providing a plurality of interchangeable,
removable sets of dies for accommodating such a range
of sizes of conductors and connectors or terminals.
The drive assembly 30 is mounted intermediate the die
assembly 18 and the manual actuating portion 14. This
drive assembly 30 is coupled with the lower die 24
for driving the lower die upwardly, sliding alon~ the
guides 20, 22, so as to compress a workpiece between
the lower die 24 and upper die 26. In the illustrated
embodiment, this drive assembly 30 comprises a hydraulic
piston-and-cylinder or ram arrangement, the piston 32
thereof being coupled with the lower die member 24 by
suitable means such as a pin 34 extending therethrough.
Hydraulic fluid under pressure is delivered to this
hydraulic ram assembly 30 by means of a pump 36
mounted within an upper portion of the manual
actuating portion 14. In this regard, the actuating
portion 14 includes a first handle 38 which is pivotally
mounted at a pivot point 39 to a second handle 40. This
handle 38 is also operatively collpled for energiæing
or actuating the pump 36. Accordingly3 pivotal mounting
of the handle 38 with respect to the handle 40 defines
a lever for actuating the pump 36. Hence, the pump 36
is primarily located within the handle 40 but is
actuated by the pivotal movement of the handle 38.
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The handle 40 also mounts a variable pressure control
apparatus 42 (not shown in detail in FIG. 1) for con~
trolling the maximum pressure of the fluid delivered
to the hydraulic ram assembly 30 by thle pump 36 in
response to pivotal movement of the handle 38. This
pressure control apparatus 42 is adjustable in response
to manual rotation of an adjustment knob 44 rotatably
carried in the handle 40. In the illustrated embodi-
ment, this adjustment member or knob 44 is carried at
the bottom of the handle 40. Preferably, indicia 46
are provided on the knob 44 and on the periphery of
the handle 40 immediately adjacent thereto for selectin~
the maximum fluid pressure. In operation, the maximum
pressure delivered to the hydraulic ram assembly 30 is
lS therefore controlled in accordance with the setting of
the knob 44. In this regard, the fluid pressure to be
applied to the hydraulic ram assembly will generally
incr~ase as the pump handle 38 is actuated. However,
a maximum pressure is preselected for each size of
workpiece to be compressed by the die assembly 12.
Hence, the range of relative movement of the die members
24 and 26, and the range of maximum pressure selectable
by the knob 44 and pressure control apparatus 42 together
define a range of sizes of workpieces which may be
accommodated for compression by the tool 10.
Referring now to FIG. 2, th~ die assembly 18 including
the guide members 20, 22, the lower die 24 and the
upper die 26 will now be described in greater detail.
Also illustrated in FIG. 2 is a typical electrical con-
nector or terminal member 50 and an electrical conductor
or wire 52 which is to be compressingly engaged or
crimped within the tubular conductor or terminal 12
by ~he action of the tool 10 of the invention.
In accordance with a feature of the invention, a
composite die is defined by the lower die member 24
and the upper die member 26, which comprises a plurality
of in~ermeshing die surfaces, indicated generally by
the reference numeral 51. These intermeshing die sur-
faces 51 define a relatively broad range of compression,
th.ereby accommodating a corresponding ran~e of sizes of
connectors or termlnals such as the terminal 50 for
compression. In the illustrated embodiment, the inter-
meshing die surfaces 51 are defined by a plurality ofdie surfaces an~ intervening recesses on each of the
lower die member and upper die member 26.
In this latter regard9 in the lllustrated embodiment,
the l.ower die member 24 deines three substantially
similar and parallel die surfaces 54, 56 and 58 which
are separated by a pair of recesses 60, 62. Similarly,
the upper die member 26 defines foux die surfaces 64,
56, 68 and 70 which are substantially similar and parallel
and are separated by three recesses 72, 74 and 76. The
guides 22 and 20 hold the lower die member 24 and upper
die member 26 in alignment such that the die surfaces
54, 56 and 58 of the lower die member 24 are in align-
ment with, and as the die member 24 advances, intermesh
or interfit with the recesses 72, 74 and 76 of the
upper die member 26. Correspondingly, the die surfaces
66 and 68 of the upper die member 26 are aligned with
and, as t~e die member 24 advances, interfit with the
recesses 60 and 62 of the lower die member 24. The
remaining die surfaces 64 and 70 of the upper die member
26 align with and slidably engage over the outer sides
of the die surfaces 54 and 58 of the lower die mem~er
24.
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In operation, and referring to FIG~ 3, FIG. 4 and FIG.
5, the foregoing intermeshing of the respective die
members 24 and 26 as the lower, movable die member 24
is advanced by the ram 30, is illustrated. It will be
seen from an inspection of these three illustrations
that the die assembly 12 as thus far described defines
a range of sizes of the through opening 28 from a fully
- opened position illustrated in FIG. 3 to a fully closed
position illustrated in FIG. 5. In this latter, fully
closed position, the respective die surfaces and re-
ceiving recesses described above are fully interengaged
and bottomed out with respect to each other. Hence,
a corresponding range of sizes of workpieces such as
the electrical connector or terminal 50 and associated
cable 52 may be accommodated for compression by the die
assembly of the invention as thus far described.
Reference is next invited to FIG. 6 and FIG. 7, wherein
further details of the variable pressure control appara-
tus 42 are shown. Preferably, this pressure controlappara~us 42 comprises an adjustable relief or bypass
valve, In the illustrated embodiment, this pressure
relief or bypass valve comprises a generally cylindrical
valve chamber 80 which terminates in a conical section
82 defining a valve seat, A correspondingly cylindrical
valve member 84 terminates in a generally conical end
86 for seating on the valve seat 82. The valve member
84 and in particular, the end 86-thereof is normally
urged into seating engagement with the valve seat 82
by a compression spring 88 which is carried internally
o the cylindrical valve portion 84. The opposite end
of the spring 88 abuts an adjustable screw or sto~ member
90 which is threadably movable with respect to the valve
chamber 80.
~ S 2~
In operation, as the threaded stop member 90 is
advanced with respect to.the valve chamber 80J the com-
pressive for.ce.applied.to the spring 88 increases,
tending to urg~ the valve portion.86.into seating
engagement wlth.the valve seat 82 with increasing
force Conv~rsel.y, as..the threaded stop member 90
is threadabl.y retracted with.respect to the valve
chamber 80, a lesser such force is supplied by the
spring 88. The stop member 90 is rotated for either
threadable advancement or retraction by an elongate
rod 92 which extends axially through the handle 40
~see FIG. 1) and is coupled at its opposite end to
the adjustment knob 44.
The valve 42 is coupled in hydraulic circuit for
varying the ma~imum pressure applied to the hydraulic
ram assembly 30 by the pump 36. In this regard, a
first hydraulic fluid line 94 carries hydraulic fluid
from the pump 36 to the hydraulic ram assembly 30.
The valve seat 82 communicates with this first fluid
passageway 94 by way of a through bore or passa~eway
96. This bore or passageway 96 is normally held in
a closed condition by the seating of the conical
valve 86 upon the con~cal valve seat 82. However,
when the fluid pressure in the passageway 94 applies
a force to the end 86 of the valve member 84 at the
passageway 96 which exceeds the force applied by the
spring 88 to hold the valve 86 seated, the valve body
84 will be forced back, compressing the spring 88 and
permitting fluid from the passageway 94 to enter into
and through the passageway 96 to the interîor of the
valve body 80. In this regard a second, return bore
or passageway 98 is provided in the valve body and is
coupled for returning fluid to a suitable fluid
reservoir (not shown).
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A fluid return line ~not shown~ from the ram 30 is
also preferably provided, including a suitable valve
~not shown) to permit the ram to return the die 24
to its fully open posi~ion following compression.
The conduit 94 preferably includes a suitable ball
check element lO0 for preventing back flow. The
relative pressure in the line 94 at which the valve
84 unseats may be referred to as a relief pressure
or by-pass pressure of the valve. This relief or
by-pass pressure is adjusted to correspond to a
predetermined or desired maximum pressure to be
applied to workpieces or connectors o:E given sizes.
In this regard, the indicia 46 on the handle 40 and/or
~djustment knob 44 preferably indicate ~he desired
positions of the adjustment knob 44 for a plurality
of sizes of connectors or terminals compressable by
the tool lO of the invention.
In operation, when a connector or a terminal such as
the terminal 50 is to be coupled with a cable such
as the cable 50 by compression in the tool of the
invention, the adjustment 44 is first set to an indicia
46 corresponding to the size of the terminal or con-
nector 50. Thereupon, the handle 38 may be manually,
pivotally actuated toward the handle 40 to energize
the pump 36 and hence hydraulic ram assembly 30,
driving the movable or slidable lower die member 34
upwards towards the relatively fixed or stationary
upper die member 26. When the selected maximum or
relief pressure has been reached, pressure will be
relieved by the v~lve arrang~ment 42 of FIG. 6 and
~IG~ 7, permitting the lo~er die 34 to return to its
open condition, whereupon the compressed and joined
connector or terminal 50 and wire or cable 52 may be
removed from the die opening 28.
~2~25~1!3
In accordance with one practical and prefe~red form
of the invention and referring again to FIG. 2, the
upper die member 26 is preferably coupled with the
top or upper portion of the respective guides 20, 22
by a pair of suitable pins 102, 104. Preferably, one
of these pins 102~ 104 is removable, whereby the upper
die member 26 is hingedly movable with respect to one
of the two guide members 20, 22. Consequently, a
connector for joining a pair of wires in serial fashion
may ~e ~ccommodated by the tool 10 of the invention.
In this illustrated embodiment, the die surfaces 5~,
56 and 58 of the lower die member are all generally
V-shaped, whereby their outermost leading edges inter-
mesh with like inwardly-formed portions of the recesses
in the upper die member 26. Similarly, the die surfaces
6~, 66, 68 and 70 of the upper die member 26 are also
generally V-shaped to intermesh with similar recesses
of the lower die member 24. Preferably, the leading
edges of the respective die surfaces of both upper
die member 26 and the lower die member 24 are generally
flat or horizo~tal, that is, generally perpendicular
to the direction of movement of the die 24, for defining
a firm and definite seat with the respective and
similar receiving recesses and thus positively defining
the ma~imum extent of compression of the die assembly
12.
While the invention has been illustrated and described
hereinabove wlth reference to a preferred embodiment,
the invention is not limited thereto. Those skilled
in the art may devise various alternatives, changes
and modifications upon reading the foregoing descriptions.
Accordingly, the invention includes such alternatives,
changes and modifications insofar as they fall within
the spirit and scope of the appended claims.
