Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates ~o multiple
passage conduits, especially for usP with welding guns
of the type wherein fumes are extracted from the
vicinity of the arc welding zone.
Arc-welding operations are known to produce
undesirable fumes during the welding process, many of
them being noxious to the welder or others in the
vicinity of the welding operation. Such fumes when
allowed to accumulate in confined spaces have long been
known to constitute a safety hazard, as well as an
interference to welder visibility and general welding
operation efficiency, and numerous means have been
employed by the welding industry to dissipate these
fumes as they are generatedO
One such procedure involves the use of a
conduit associated with the welding gun through which
undesirable product gases of the welding operation are
extracted by means of a vacuum applied to the conduit.
The conduit commonly comprises an outer shell defining
a hollow conduit through which the gases pass and in
which are located a continuous weld wire, a power cable
and also source of shield gas for the welding tip.
The welding gun is connected to vacuum
system, wire feed electrical power input, and shield
gas feed by a flexible outer corrugated sheath or hose.
While the corrugations impart considerable flexibility
to the hose, they provide no support for the weld wire,
power cable or shield gas feed pipe, can wear through
to expose the electrical power cable, with consequent
danger of shorting, tend to be bulky and heavy, and are
also prone to catch on projections, and hence are
difficult to manoeuvre.
There are also other instances where a
variety of materials must be conveyed or extended from
one location to another and no satisfactory means
exists for achieving the desired result.
In accordance wlth the present invention,
there is provided an improvement in a fume extracting
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welding gun through which a consumable electrode is
fed, comprising a head portion, a control handle
portion, a flexible connector portion, means for
removing fumes from the weld site, means for conducting
the consumable electrode wire to the head por~ion,
means for conducting shielding gas to the head portion,
and means for conducting electricity to the electrode
wire at the head portion~
The improvement is that wherein the flexible
connector portion comprises a flexible hose comprising
an outer housing defining a hollow lnterior and having
a smooth outer surface and a plurality of
longitudinally- extending baffles located in the hollow
lnterior to define a plurality of separate passageways
for conveying the fumes from the head po~tion,
conducting the consumable electrode wire and the
electricity to the head portion and for conducting
shielding gas to the head portion.
Preferably, the hose comprises an axial
cylindrical passage and a plurality of
radially-extending webs joining the outer surface of
the cylindrical passage to the inner surface, to define
separate and discrete compartments surrounding the
central cylindrical passage. The hose is preferably
constructed by extrusion of rubber or flexible
polym~ric material, so that the elements are integrally
formed.
The power cable and weld wire may be located
in the central compartment of the hose, shield gas may
be fed by one of the other compartments while fumes
from the welding site are extracted through the others.
In this way, the power cable is supported
internally of the hose and, even if the outer wall of
the hose is worn through, which is highly unlikely in
view of the robust nature of the hose, the power cable
is not exposed and shorting cannot occur. Further, the
central compartment is surrounded by flowing gas which
cools the power cable located therein.
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The invention is described further, by way of
illustration, with reference to the accompanying
drawings, wherein:
Figure 1 is a schematic representation of a
fume-e~tracting welding apparatus incorporatlng the
s hose of the present invention;
Figure 2 is a part-sectional view of portions
of the welding apparatus of Figure l;
Figure 3 is an elevational view of the
services supply end of the apparatus of Figure l;
Figure 4 is a perspective view of a detail of
the view of Figure 3;
Figure 5 is a perspective sectional view of
the flexible hose used in the structure of Figure 1 and
constructed in accordance with the present invention;
Figure 6 is an end view of the flexible hose
of Figure 5; and
Figure 7 is a perspective view of a
corrugated hose as used in the prior art in comparison
with the present invention.
Referring to the drawings, Figures 1 to 4
illustrate schematically a fume extracting welding gun
10 incorporating a hose constructed in accordance with
the present invention. The gun 10 includes a head
portion 12, a control handle portion 14 gripped by a
welder 16 during operation, a flexible connector hose
portion 18, and a services supply portion 20,
The flexible connector hose 13 terminates in
a T-adapter 22 which communicates with a vacuum pump 24
by a pipe 26. The vacuum pump 24 applies a vacuum to
the interior of the hose 18 to remove fumes from
adjacent the weld site at the head portion end o~ the
unit 10.
The services supply portion 20 comprises a
consumable welding wire feed mechanism 28 which
includes a reel 30 of welding wire 31, an electrical
connector 32 connected to a power cable 33 which
surrounds the weld wire 31, an inert gas feed pipe 34
,~ connected by pipe 35 through an electrically-operated
solenoid valve 36 to a source of inert gas 38 for
providing shield gas at the welding tip. The pipe 34
also carries electrical connector wires 40 which pass
by pipe 42 to a switched electrical power source 44,
which also serves to actuat:e the solenoid valve 36.
The head portion 12 of the welding gun 10
comprises a curved tubular housing 46 and a tubular
sheath 48 of the control handle portion 14, which
enclose a hollow power connector 50.
Fume extraction is provided by
interconnecting annular fume extracting passageways 52
and 54 disposed between the tubular casings 46 and 48
and the power connector 48, which provide a conduit for
fumes entering the head portion 12 through an annular
opening 56 to the hose 18 and thence, through
passageways therein, described below, to the T-adapter
22 under the influence of vacuum applied thereat.
The annular opening 56 is provided between an
outer sleeve 55 and inner sleeve 57. The outer sleeve
55 is slidable relative to the inner sleeve 57 to move
the annular opening 56 towards or away from the welding
site. In this way, the actual vacuum applied to the
welding site for fume extraction may be varied.
An inert gas flow pipe 58 cQnnects with the
hose 18 and terminates in a collar 60 which establishes
communication between the inert gas feed pipe 34 and
the interior of the power connector 50, to feed
shielding gas to the welding tip 62. The control
handle portion 14 of the gun 10 includes an operator
switch 64 connected to the downstream end of the
connector wires 40 for operating the gun 10.
The connecting hose 18 of the invention has a
novel construction, as illustrated in particular in
Figures 5 and 6. As seen therein, ~he hose 18,
preferably formed by extrusion of rubber or othex
flexible polymeric material, has a smooth outer surface
60. The smooth nature of the outer surface 60 prevents
th~ hose 18 from becoming caught on projecting surfaces
68, such as occurs with the prior art corrugated
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surface hoses 70, as seen by comparison of Figures 7A
and B.
The hose 18 has a plurality of radial webs 72
which extend from integral connection with the inner
surface 74 of the hose 18 to integral connection with
the outer sur-face 76 of a cylindrical tube 78
concentric with the pipe 18. The cylindrical tube 78
defines an inner passageway or compartment 80 extending
for the length of the hose 18 and in which the
electrical cable 33 and the concentric weld wire 31 are
loca-ted.
The radial webs 72 define a plurality of
cornpartments 82 which extend for the length of the hose
18.
One passageway 82 is used to convey inert
gas, such as, carbon dioxide from the servlces supply
to the head ~2, and to house the electrical
connecting wires 40. As may be seen in Figures 2, 4 and
5, at each end of the compartment 82 which feeds the
inert gas a short length of pipe is received therein.in
gas tight fit to convey the inert gas to the
compartment (pipe 34~ at the services end and to convey
the inert gas from the compartment ~pipe 58) at the
head portion end. Alternatively, the compartment 82
may house a continuous pipe through which the inert gas
is flowed.
The electrical connecting wires 40, which
extend from the electrical power source 44 to the
operator-activated switch 64, pass through the same
compartment as the inert gas and, as may be seen in
Figures 2, 4 and 5, enter the compartment internally of
the pipe 34 at the services end and exit the
compartment externally of the pipe 58.
The remainder of the compartments 82 serve to
convey fumes from the head portion 12. The
compartments 82 communicate with the annual passageway
54 at the head portion and with the pipe 26 at the
services end.
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In contrast with the prior art hose
connectors 70, not only is the outer surface 66 smooth,
but also the power cable 33 is supported remote from
the wall of the hose in its own passageway 80, so that,
even in the unlikely event of the outer wall being worn
through, the power cable 33 is not exposed and shorting
cannot occur.
Further, the power cable compartment 80 is
completely surrounded by a flow of gas, in the form of
the extracted fumes and the inert gas, and this
provides cooling to the power cable 33.
Although the structure of the hose 18 which
is illustrated represents the preferred embodiment of
the invention, nevertheless modifications may be made
thereto without departing from the invention. For
example, the compartment 82 conveying the inert gas
feed pipe 34 is illustrated to be of much smaller
dimensions than the other compartments 82, but al] the
compartments 82 may have the same dimensions, if
desired. Further the number and form of the
compartments may be varied, as desired. Central
compartment 80 may be omitted, if desired, and the
power cable 33 and welding wire 31 then are located in
one of the remaining compartments 82.
The illustrated hose 18 is integrally formed
and is most expeditiously formed by extrusion. As
noted earlier, the utility of the hose 18 is not
limited to fume extracting welding guns, but rather has
broad applicability to any situation where it is
desired to provide, within a single en~losed elongate
structure, the passage of materials out of contact one
with another. The passageways 80 and 82 provided in
the hose 18 may be used to convey liquids or gases or
utilities of various types.
In summary of this disclosure~ the present
invention provides an improved flexible hose having
wide utility and particularly useful in connection with
fume extracting welding guns. Modifications are
rs ~ possible within the scope of the invention.
