GB301043A - - Google Patents

Abstract

301,043. British Thomson-Houston Co., Ltd., (Assignees of Steenstrup, C.). Nov. 23, 1927, [Convention date]. Heating by electricity.-An electric wire feed for automatic or semi-automatic metallic arc welding machines, comprises a feed roll engaging the arcs arranged to rotate on an axis inclined to the line of feed and mounted in a support rotated about this line. The feed rolls are freely mounted on pins 2 in bushings 3 that are carried by cupshaped members 4 clamped to a casing 9, which is keyed on a hollow shaft 11 rotated by a feed motor 12 through bevel gearing 13. The bushings are adjusted by screws 6 to suit the size of wire, and are forced against the electrode wire 7 by a rubber washer 8, and are prevented from rotating by pins. The rolls are tilted by angular adjustment of the members 4 after first loosening the clamping rings 10, so as to effect the feed of the wire in either direction. Welding current is fed to the terminal 23 and conducted to the electrode by a curved nozzle 22. The motor may be of the variable speed type connected with electrical circuits so that the speed varies according to the rate of electrode consumption in the arc so as to maintain the arc of constant length as described in Specification 139,919. In a modification the shaft of the motor is hollow and is in alignment with shaft 11 to which it is connected by spur gear. In a further modification, Fig. 4, the rollers 29 are carried in bushings 28 angularly adjusted by hand, during operation of the machine, in a casing 24 carried by the hollow shaft 25, 25<1> which is driven in either direction from a constant speed motor 49 by spur gear 43, 44 and friction bevel gear 46, 47, 48. The gears 46, 47 are mounted on a shaft 45 moved against the action of an adjustable spring 51 by a solenoid 50 responsive to a characteristic of the arc circuit that varies with the arc length. The rolls are radially adjustable by screws and are pressed by springs against the electrode and their bushings are rotatably adjusted so as to vary the rate of or reverse the feed by links 33 connected to a cross head 34 which is movable in a slot in the shaft 25 and is connected to a hollow rod 35 moved in a screwed bushing 39 by a nut 37. The rod is provided with a. collar 35<1> at its upper end and is held in place by a cap 38. The angularity of the rolls may also be adjusted by a solenoid.