Patent GB-1058561-A (GB)
Title: Friction welding apparatus and method
IPC: B23K20/12
Filed: 1964-10-19
Abstract: 1,058,561. Welding by pressure. ROCKWELL-STANDARD CORPORATION. Oct. 19, 1964 [Dec. 23, 1963], No. 42629/64. Heading B3R.  In friction-welding metal workpieces wherein relative rotation is established between the workpieces engaged under pressure, the relative rotation is arrested after metal has become fusible and pressure is retained on the integral article during cooling to control its length. A friction welder comprises a drive unit (24), Fig. 1 (not shown), including a motor (124), a clutch (26) and a belt (28), an input shaft drive mechanism (30) including a brake (32), a workpiece belt drive unit (34) for rotating one workpiece against a second workpiece or between two stationary workpieces, workpiece alignment and bearing support assemblies (36), a fixed end workpiece clamping unit (38), a non-rotatable but axially slidable end workpiece clamping unit (40) and a force applying assembly (42) to press the workpieces into engagement. The belt (28) is driven by motor (124) through clutch (26) to rotate an input shaft (128) having a portion (130) in which a splined section of the shaft is slidable in a section (131). The shaft (128) which carries a shoe and drum brake (32) is supported adjacent the belt drive unit (24) by bearings (137), (139). The belt drive unit (34) comprises a pulley (142) fixed on the shaft (128) and located in an open recess between legs (170), (172), Fig. 6 (not shown), of a frame (161) formed by spaced parallel members (176), (178), which extends upwardly to the level of a pair of tracks (66), which extend on opposite sides of a gap into which the frame projects. The frame carries adjustable idler pulleys (180), (182), (188) and (586), Fig. 6, (not shown), closely adjacent the pulley (142) and carries idler pulleys (200) and (202) on a fixed jaw (196) and a movable jaw (194) respectively. A wide belt (162) engages all these pulleys and is looped around a workpiece located between the jaws (194), (196). The movable jaw is operated by a cylinder and piston and the whole frame is pivoted and adjustable by a cylinder and piston. The adjustment and bearing support assemblies (36) are arranged on the tracks (66) on each side of the frame (161) and each comprises three adjustable rollers (97) to engage and rotatably support the workpiece engaged by the belt (162). The workpiece clamping unit (38) is clamped to the track (66) and the clamping unit (40) is slidable on the track (66) and each unit comprises a number of parts bolted to a frame to support non-symmetrical parts. The force-applying assembly (42) includes a doubleacting cylinder (280), the ram (281) of which drives a push-rod (282) into engagement with a bearing plate (264) on the movable clamping unit (40). In operation irregular non-symmetrical steering axle and pieces butcircular at their end surfaces to be welded are clamped in the members (38), (40) and the central section a seamless tubular element is cradled in the loop of belt (162) in the jaw recess and supported in the rollers of supports (36). The start " button on a control device (46) is now pressed to energize the jaw piston and cylinder device of the movable jaw (194) to close the jaw and operate limit switches which release the brake (32) and engage the clutch (26) to rotate the control workpiece. The clutch engagement causes solenoid valve energization  which applies hydraulic pressure to the cylinder (280) to move the push-rod (282) to the left, an abutment associated with the push-rod tripping a switch to cause the end surfaces of the workpiece, to nearly abut. A further abutment trips a switch to permit a gradual hydraulic pressure build up in the cylinder (280). to gradually bring the workpieces into frictional contact when the metal becomes plastic, further advance of the rod (282) trips another switch to disengage the clutch (26) and in turn engage the brake (32). Upon stoppage of the shaft (128) a speed sensor device causes operation of the cylinder controlling the movable jaw (194) to release the workpiece from the belt (162). A limit switch operation causes high pressure to enter cylinder (280) to forge the workpieces together and the forward movement of the rod (282) causes another switch to trip to reduce the pressure in the cylinder (280) to that required for cooling. It is stated that only two workpieces may be welded, that the forging pressure need not be decreased prior to shut-off and that the pressure applied may be constant throughout the welding cycle. A reference to preheating by induction is also included and the use of metal or metal alloy coating on the surfaces to be joined. Metals which may be joined are carbon steel, alloy steel, aluminium, titanium, copper, brass and bronze. Dissimilar metals may be joined after pre-heating one of the members.