Wire vise

A device for facilitating the welding together of pieces of welding wire comprises a pair of complementary vise units which are connected together for relative linear movement and are spring-loaded toward a limit position in contact with each other. In use, two pieces of welding wire are clamped in the respective vise units in such relative positions that they are in end to end contact while the vise units are separated from their limit position against their spring loading. Welding current is then applied to the junction of the wires until they are sufficiently softened for the spring-loading of the device to force their softened ends together and thereby to complete the welded joint therebetween.

BACKGROUND OF THE INVENTION 
In heliarc and similar types of welding, it is common to use what the 
industry calls "exotic metal" welding wire which not only is comparatively 
expensive, but also is usually marketed in relatively short lengths rather 
than in a coil such as is conventional practice with relatively low cost 
welding wire. For example, Stellite welding wire is normally marketed only 
in 12-inch lengths and at a cost of the order of $40 per pound, and 
welding wire containing titanium is normally sold only in 20-inch lengths 
at a cost of the order of $100 per pound. Even less expensive stainless 
steel welding wire is usually marketed only in lengths of 20-24 inches, at 
a cost in the range of $15-$20 per pound. 
There is a practical limit to the extent to which a single piece of welding 
wire can be used before it becomes too short for safe handling at the 
temperatures to which it is heated during welding. For example, the usual 
practical limit is of the order of 3 inches. Any shorter piece can be used 
only if the welder adopts the cumbersome procedure of holding the stub 
wire with a pair of pliers, but that is not practically possible for a 
piece shorter than 2 inches, because of the excessive heat problem. Thus 
with welding wires of the materials and costs outlined above, the unusable 
portion of each piece may constitute as much as from 10% to 25% of the 
original length, and this necessarily means the loss of the corresponding 
percentage of the original cost of the wire. 
The desirability of attempting to reduce or eliminate this built-in loss of 
welding wire and money has been recognized in the past, but to the extent 
of the knowledge of the present inventor, no satisfactory solution has 
been proposed or found. For example, it has been a usual practice for 
welding shops to collect the stub pieces of welding wire which were too 
short to use until a substantial number had been accumulated, and then to 
weld them in end-to-end relation into a single longer piece. However, the 
present inventor knows of no satisfactory technique or equipment, prior to 
the present invention, for carrying out such an operation. 
More specifically, if the operation is attempted by arranging two pieces of 
welding wire on a welding table and then welding them together, it is 
difficult and cumbersome to hold the wire pieces in aligned and abutting 
relation, and the result will commonly be a relatively zig-zag length of 
wire which includes misshapen and/or over-sized weld joints. Further, this 
technique is so time-consuming that the labor cost would substantially 
reduce, or even fully offset, the savings represented by the value of the 
reclaimed pieces as compared with the cost of new full length wire pieces. 
SUMMARY OF THE INVENTION 
The present invention provides a device designed for the specific purpose 
of facilitating the welding together of pieces of welding wire under 
controlled conditions which will give maximum assurance of a straight and 
smooth welded joint. The device of the invention comprises a pair of 
complementary vise units which are connected together for relative linear 
sliding movement and are spring-loaded toward a limit position in contact 
with each other. 
In the use of this device, the two pieces of welding wire to be joined are 
clamped in the respective vise units in such relative positions that they 
are in end to end contact with each other while the vise units are 
separated from their limit position against their spring loading. Welding 
current is then applied to the junction between the wires until they are 
sufficiently softened for the spring-loading of the device to force their 
softened tips together, thereby completing the welded joint therebetween. 
These and other features and advantages of the invention will be pointed 
out in greater detail in connection with the description hereinafter of a 
preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The device of the invention comprises two complementary vise units 10 and 
11 fabricated from initially identical blocks 12 and 13 respectively. The 
block 12 is provided in its upper surface with a V-groove 15 between side 
walls 16, each of which is provided with a bevel 17 at one end, and at 
that end, the block is provided with a rabbet 18 which extends below the 
level of the bottom of the groove 15. 
A clamping screw 20 is mounted on top of the block 12 by threading through 
a member 22 which bridges the groove 15. The bridging member 22 is secured 
to block 12 by a pair of screws 23 which pass freely through slots 24 in 
the bridging member 22 and are threaded into the block walls 16. The slots 
24 are open on opposite sides of the bridging member 22 to facilitate 
quick release of the clamping screw 20 under some conditions of operation 
as described hereinafter. 
The block 13 has the same configuration as the block 12 and is provided 
with an identical V-groove 25 between walls 26 having beveled ends 27, and 
the rabbet 28 on block 13 is of the same configuration as the rabbet 18 on 
block 12. The clamping mechanism on block 13 is also identical with that 
on block 10, and it similarly comprises a clamping screw 30 threaded 
through a bridging member 32 which is mounted on block 13 by screws 33 in 
slots 34. 
The vise units 10 and 11 are interconnected for relative linear movement in 
line with their respective V-grooves 15 and 25. More specifically, two 
smooth guide pins 40 are fixed in block 12, as by means of a roll pin 41, 
and are slidably received in cylindrical bores 42 extending through the 
full length of block 13. As shown in FIG. 2, when the two blocks are at 
their limit position of movement towards each other, in which they are in 
abutting contact, the pins 40 project beyond the outer end of block 13 by 
a predetermined amount, preferred results having been obtained with the 
maximum projection of pins 40 being 0.090 inch. 
In addition to the pins 40, the blocks 12 and 13 are also interconnected by 
a cap screw 44 which passes freely through a bore 45 in block 13 and is 
threaded into block 12. A counterbore 50 in the outer end of block 13 
receives the head of screw 44 therein and is of substantially greater 
depth than the axial extent of the head of screw 44 to provide space for a 
coil spring 52 which can thus be compressed between the head of screw 44 
and the inner end of counterbore 50. The action of spring 52 is therefore 
to bias the two blocks towards each other, to the position of abutting 
contact between their opposed inner ends shown in FIG. 1. 
Manual means are provided for easily separating the two blocks against the 
biasing action of spring 52. More specifically, a lever 55 comprises two 
arms 56 pivoted on opposite sides of block 13, on a pin 57 extending 
through the block. The lever arms 56 are also connected by a metal pad 58 
and a spacer 59, which is shown as of hexagonal section and as so located 
on lever arms 56 that when they are pressed downwardly about their common 
pivotal mounting, the spacer 59 will directly engage the projecting ends 
of the guide pins 40. 
FIG. 2 illustrates the relative positions of the vise units 10 and 11 at 
the start of the operation of welding together two short pieces of welding 
wire 60 and 61 which are clamped in these respective vise units. The first 
step in this set-up operation is to clamp one piece of wire, e.g. piece 
60, in the vise unit 10 with the end of this wire approximately in 
vertical line with the inner end face of block 12. The operator then moves 
the lever 55 down, by finger pressure on pad 58, to its lower limit 
position shown in FIG. 2. During this movement, the spacer 59 will act as 
a cam in forcing the outer ends of guide pins 40 are substantially flush 
with the outer end face of block 13, thereby opening a gap 65 between the 
opposed inner ends of the two vise units. The second wire piece 61 is then 
clamped in vise unit 11 with its end abutting the previously clamped wire 
piece 60, after which the lever 55 released. 
The two pieces of wire are now ready for the application of welded current, 
since they are being biased into firmly abutting end to end relation by 
the compressed spring 52. Welding current is then applied to the junction 
between the wires, as represented by the fragmentary showing of a torch 66 
in FIG. 5. As soon as this current has developed enough heat at the 
junction of the two wires to soften the metal there, the continued biasing 
action of spring 52 will force the softened ends of the wires together, 
thereby completing the welded connection therebetween. 
An important feature of the invention is that those portions of the two 
wires which are being welded together are spaced out of contact with any 
part of the vise units 10 and 11, by reason of both the bevels 17 and 27 
and especially the rabbets 18 and 28 on the blocks 12 and 13, which define 
a channel-like space 68 underlying the abutting ends of the wires. 
Therefore, even if more metal should accumulate around the welded 
connection than is desired, as for example if the operator holds the torch 
in position too long, with most sizes of welding wire, the welded joint 
can still be pulled under one of the bridging members 22 and 32 to free it 
from the device. 
If, however, this should not be the case, as may occur with welding wire of 
the larger diameters for which the device is designed, release after 
welding can still be effected very quickly by loosening the screws 23 or 
33 and removing the associated clamp screw and bridging member. This 
operation is facilitated by the open ended slots 24 and 34, since the 
operator need only loosen one set of screws and then turn the associated 
bridging member about 45.degree. and lift it out of the way. Replacement 
of the bridging member is equally quick and easy, by reengaging the slots 
with their associated screws and tightening the screws. 
The proportions of the vise units 10 and 11 can of course be selected to 
handle any desired range of wire sizes, the commonest such range being 
from 0.062 to 0.250 inch in diameter. In a device as shown in the drawings 
capable of handling this range of wire sizes, each of blocks 12-13 may be 
2 inches in length, 1.25 inches in width and also in maximum height, with 
each of the V-grooves having an angular extent of 90.degree. and a maximum 
of 5/16 inch. With these dimensions, the beveled surfaces 17 and 27 may be 
at 90.degree. to the vertical, and each of the rabbets 18 and 28 may be 
3/16 inch deep and 5/16 inch wide to provide a minimum width of 5/8 inch 
for the channel-like space 68 when the blocks 12-13 are in contact with 
each other. 
The distance to which the two vise units 10 and 11 can be separated is not 
critical, although it is desirable that this distance, and therefore the 
width of gap 65, be relatively small in order to limit the amount of 
movement which the two pieces of wire can make towards each other while 
their ends are softened, thereby to limit the amount of softened metal 
which can be forced out to the side of the welded joint. As noted above, a 
satisfactory maximum such dimension is 0.090 inch, and this dimension is 
subject to some adjustment, by turning the screw 52 in its threaded 
mounting in block 12, to effect corresponding adjustment of the distance 
which the head of this screw can move in bore 45 before it fully 
compresses the spring 52. A practical limitation on this adjustment is 
that if the head of the screw projects beyond the surrounding end face of 
the block 13, it would act as a stop for the spacer 59 and correspondingly 
prevent the ends of pins 40 from being pushed fully into bores 42. 
While the form of apparatus herein described constitutes a preferred 
embodiment of the invention, it is to be understood that the invention is 
not limited to this precise form of apparatus and that changes may be made 
therein without departing from the scope of the invention which is defined 
in the appended claims.