Wire Feeder

Abstract

In a wire feed system as used, for example, to feed weld wire, there is a positively driven roll in a fixed location and a complementary pressure roll which, together with the means providing the wire feed track, floats to and from the feed roll rectilinearly on the common diameter of the two rolls to accommodate variations in wire dimension, the pressure roll and wire guides being subject to spring bias pre-set at the proper value for a given wire diameter.

Description

BACKGROUND OF INVENTION

Wire feed systems which have yieldable pressure rolls are normally so designed that the rolls move in an arc about a point located outside of the center line of the drive roll. The instant device with rectilinear diametrical movement is believed to be superior in its accuracy of feed. It is independent of orientation. Normally, the direction of yield is vertically upward but the device will function inverted or in any other relative position of the parts. It functions independently of the wire supply system. That is to say, it is immaterial whether the wire comes from a spool, a coil, a reel, or a pay-off pack.

SUMMARY OF INVENTION

A power-driven feed roll and its bearings are mounted in a fixed position with respect to a base upon which the drive motor is preferably fixed. A drive housing is completed by an interlocking complementary housing element which includes guide means (preferably bolts or rods) and pressure biasing means for a floating unit which includes a bearing support consisting of a block having bearings for a pressure roll and having means to support wire inlet and outlet guide tubes. Spring bias means urges the floating wire track unit toward the drive roll upon a rectilinear path established by the drive housing in a direction which is diametrical with respect to both rolls.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a general view of the device in front elevation, portions being broken away.

FIG. 2 is a plan view thereof.

FIG. 3 is a view taken in section on the line 3--3 of FIG. 1.

FIG. 4 is a view showing in perspective the separated parts of the housing and base and the intervening floating unit, portions of the latter being broken away.

FIG. 5 is a fragmentary detail view in section showing one of the spring biasing means and its seat.

FIG. 6 is a fragmentary view in section taken on the line 6--6 of FIG. 1.

DETAILED DESCRIPTION

The base 8 comprises the lower part of a housing completed by a removable upper part 10 with its top overlying the base. The base has standards 12 and 14 for which the upper part of the housing is provided with notches such as that shown at 16 in FIG. 4. The standard 12 of the base member 8 has a ball bearing 17 and the standard 14 has a sleeve bearing 18 for a drive shaft 20 upon which the knurled or toothed feed roll 22 is mounted. The motor 24 may be in direct connection with shaft 20 and may be attached externally of the housing to the standard 14.

Wire track means includes a tubular input wire guide 26 and an aligned output wire guide 28 disposed at opposite sides of feed roll 22 with their bores substantially tangential with respect to the feed roll.

The guide tubes are sized in general accordance with the wire size. At their opposite sides, the guide tubes extend close to the bite of the rolls on the wire and have their terminal portions transversely beveled or relieved at 30, 31 and at 32, 33 (FIG. 1) to receive the feed roll and a floating pressure roll 34. The latter is mounted on a shaft 36 for which bearings are provided at 38 in the ends of a floating block 40. A plurality of bolts 42, one of which is shown in FIG. 5, are threaded into the top 45 of the upper housing unit 10 and have stop means such as the split collar 44, in supporting relation to block 40. The block can move rectilinearly along the bolts 42, being biased toward the drive roll 22 by compression springs 46 for which seats are provided against the upper housing unit 10 and the floating block 40. A relatively slight movement of the floating block against the bias of springs 46 accommodates movement of the pressure roll 34 to and away from the drive roll, responsive even to the most minute variations in wire size. It is contemplated that guide tube dimensions and the bias of springs 46 and range of movement permitted the floating unit can be predetermined according to the size of the wire handled by the device at any given time.

Since the tubular guides 26 and28 are rigidly fixed in depending arms 48 and 50 belted to block 40 (FIG. 4), it will be apparent that the block 40 and the wire guides and the pressure roll 34 constitute an assembly which has floating movement as a unit subject to the bias of the springs 46. The direction of that movement is not arcuate but is rectilinear upon the common diameter of the pressure roll 34 and feed roll 22, this being an important feature of the instant invention.

The invention has particular value in welding equipment, wherein the guide tubes provide a floating wire track that maintains the weld wire substantially on center. The welding torch can be mounted on the floating unit as diagrammatically shown at 55 in FIG. 4, to maintain a fixed relation to the weld wire, thereby assuring accurate uniformity.

Claims

I claim:

1. A wire feed system which includes in combination a power-driven feed roll, and a track unit comprising a coacting pressure roll, a floating wire track unit comprising a bearing support for the pressure roll and including wire guide tubes with substantially aligned axes mounted on the floating bearing support substantially tangent to the feed roll and the pressure roll at opposite sides thereof, and means for guiding the floating wire track unit for rectilinear movement along a path substantially diametrical with respect to both rolls.

2. A wire feed system according to claim 1 in which biasing means urges one of said rolls toward the other to engage between them a wire in the guide tubes.

3. A wire feed system according to claim 1 in which the guide tubes extend into close proximity to the bite of the rolls on wire engaged thereby, the respective tubes having relieved terminal portions between the rolls.

4. A wire feed system according to claim 1 in which a base has bearing support means for the feed roll, and a complementary housing means mounted on the base carries the means for guiding the floating wire track unit.

5. A wire feed system according to claim 4 in which the means for guiding the floating unit comprises bolts on the housing means and for which the floating unit has bearing apertures, and compression spring means confined between the floating unit and the housing means.

6. In a wire feed system, in combination, a base having spaced upstanding supports, a drive shaft having bearings mounted on said supports, a motor on one of said supports and in operative connection with said shaft, a wire-feed roll on the shaft between the supports, a housing element connected with the base and including a top overlying the base, a pressure roll for holding to the feed roll the wire to be fed, a floating unit on which the pressure roll is mounted, and means guiding said unit for rectilinear movement of the pressure roll regarding the feed roll, the floating unit including wire guide tubes beveled to extend between said rolls, said tubes being substantially tangential to the feed roll and movable with said unit.

7. A wire feed system according to claim 6 in which the means guiding the floating unit comprises rods fixed in the housing top and for which the floating unit has guide bearings, and springs yieldably biasing the floating unit in a direction to urge the pressure roll toward the feed roll rectilinearly along said rods.