Patent GB-514727-A (GB)
Title: Improvements in machines for welding and forging metals
IPC: B23K11/04
Filed: 1938-04-13
Abstract: 514,727. Machines for welding, forging, stretching, and breaking. GASPAR, E., and OMES, Ltd. April 13, 1938, No. 11416. [Class 83 (iv] The machine comprises a bed 11, vice electrodes 16, 17, a preliminary feeding device for moving the electrode 17, a heavy pressure feeder with a ram to engage the end of a workpiece and force it through the electrode 16 for upsetting or welding, and a transformer 15 connected to the electrodes and regulatable to suit both welding and forging operations. Voltages referred to are below four for forging and above eight for welding. Stretching to produce thinning or breakage of the workpiece and intermediate upsetting may be effected in the machine. The vice electrodes comprise water-cooled jaws, the upper jaws being coupled to the rams of double-acting hydraulic cylinders 21. The electrode 17, which may be fitted with a watercooled anvil for upsetting, is connected by rods 27 to a head 28 fitted with an abutment 30 for engaging the workpiece and a screwed feed-rod 29 engaging a tapped hole in a worm wheel 31 which may be rotated by a handwheel 38 coupled by a chain 36 and sprockets 37, 35 with the worm shaft 34. The electrode 16 is coupled by removable struts 40 with a head 41 mounted on the ram 42 of a double-acting hydraulic cylinder 43 and carrying an interchangeable abutment bar 52 for engaging a workpiece. An adjustablymounted rod 46, and a pair of rods 47 screwed into the cylinder 43 and interconnected by a chain 49 and sprockets 48, form stops for limiting the movement of the ram. One rod 47 is provided with a handle 50 for rotating the pair of rods. The primary of the transformer is provided with tappings and a selector arm 103 and is in series with a switch 106 controlled by a coil 107 connected to supply points 108, 109 in series with a push-button switch 112 and a hydraulic switch 115 supplied with pressure from the pump 117 supplying the cylinders 21, 43 through a valve box 120. The valves are controlled by levers 82, 81 which, when depressed against the action of springs, effect closure of the vices and advance of the ram 42. The levers can be operated independently or a pivoted arm 150 can be moved so that depression of lever 81 effects depression of lever 82. When depressed the levers are held down by sliding latches 135, 137 moved by springs 78, 75, until the latches are withdrawn by a striker 70 on the head 41 engaging the stops 73, 74. When released the levers move the valves to effect return of the ram and opening of the vices. The lever 81 is also controlled by a solenoid 145 in series with a switch 147, which is closed when the latch 137 is in the position shown, and a switch 148 closed by engagement of striker 60 on the head 28 with stop 64. In butt welding, the workpieces are gripped in the vices by depressing lever 82 and the electrode 17 is moved to effect the burning off of the edges, the stop 64 being adjusted so that at the correct moment switch 148 is closed and pressure is applied to the weld. When welding is completed push-button 112 is depressed, cutting off the welding current and energizing solenoid 141 to cause bell crank 139 to move latch 137 to allow lever 81 to lift and effect retraction of the ram. In upsetting, the stop 73 is adjusted to give the correct travel to the ram, but the operator may use the push-button instead. When drawing out a workpiece, the ram is fully extended before the vices are closed. The current is cut off and the ram is retracted by depressing the push-button and the stop 46 is used to limit the travel of the ram.' The solenoid 141 may be controlled by a temperature responsive device located near the workpiece. The electrode 17 may be hydraulically operated under hand control. Specifications 368,345 and 514,728 are referred to.