Patent GB-1067534-A (GB)
Title: Improvements in or relating to bonding machines
IPC: B23K20/12
Filed: 1966-03-04
Abstract: 1,067,534. Welding by pressure. CATERPILLAR TRACTOR CO. March 4, 1966 [April 23, 1965], No. 9639/66. Heading B3R. [Also in Division B5] A machine for bonding parts WP-1, WP-2 of unspecified material by engaging the parts in rubbing contact under pressure to heat and to work the interface between the parts to a bondable condition comprises a rotary and a non-rotary chuck to hold the parts WP-1, WP-2, a weight 21 connecting to the rotary chuck to a motor 14 and drive means 16, 17 between the motor 14 and the weight 21 to drive the rotary chuck, the drive means including coupling means 17 for decoupling the motor 14 from the weight 21 when sufficient energy has been stored in the weight to perform the weld, the means 17 including a slip-type coupling (26), Fig. 2 (not shown), to absorb the shock of engaging the motor 14 with the weight 21 where by the motor can be continuously operated and can be connected in drive relation with the stationary weight 21 at the end of a bond cycle to accelerate the weight 21 to the desired speed in a minimum length of time and without imposing excessive shock on the drive means between the motor 14 and the weight 21. A belt 16 drives a rotary spindle of the coupling 17 the output of which is connected to a chuck mechanism 18 which clamps the part WP-1 between jaws 19. The part WP-2 is held between jaws 22 similar to the jaws 19 and which are movable axially of a mechanism 23 by an hydraulically operated ram 24. A member 63 is slidably supported in the mechanism 23 by three machineways 64, see also Fig. 6 (not shown). The coupling (17), Fig. 2 (not shown), comprises an hydraulic coupling (26) of which the impeller member (27) is keyed to a shaft (28) driven by the belt pulley (29) and the rotor (31) is keyed to a shaft (32) connected through a splined connection (33) to a member carrying friction discs (34) of a clutch (36). An output member (41) is connected to be driven by the shaft (32) by applying hydraulic fluid to a piston (37) to press the discs (34) against interleaved discs (39). When fluid is not applied to the piston (37), the shaft (32) is freely rotatable with respect to the member (41). In a modification (not shown), the coupling (26) and the clutch (36) are replaced by a single eddy current or magnetic coupling. The replaceable chuck mechanism (18), Fig. 3 (not shown), plugs into the end of the member (41) by a splined connection and includes a rotary spindle (42) to which a carrier (46) for the weights (21) is secured. The jaws (19) are loaded by a spring (49) towards the clamping position and are released by plungers (51) engaging the inner end of the spring (49) to flex it outwardly. The plungers (51) are moved by a plate (52) actuated by a piston (54) in an hydraulic cylinder (56). Seals (61) prevent fluid leakage. Tangs on the part WP-1 are received by serrations (62) in the chuck. The tension of the belt 16 is adjusted by means, Figs. 4 and 5 (both not shown), comprising a motor mounting plate (76) extending parallel to the axis (A) of the motor (14), a crank arm (83) to rotate the plate (76) within pivot connections (79), (81) at each end thereof and a turnbuckle (86) to move the arm (83) angularly to permit the axis (A) to be swung in an arc (C)-(C) of very small curvature. In use, the motor 14 is energized for continuous operation or is operated intermittently starting at the beginning of each bond cycle. The parts WP-1, WP-2 are clamped by the jaws 19, 22, respectively. The ram 24 advances the part WP-2 towards the rotary chuck and the clutch (36) is engaged. The rotating chuck is then accelerated to a speed in excess of that desired for the bonding operation and limit switches (not shown) de-actuate the clutch (36). Further travel of the ram 24 depresses another limit switch (not shown) to cause the ram to dwell slightly until chuck deceleration, sensed by a transducer 30, shifts the ram 24 to bring the parts WP-1, WP-2 into contact. After a suitable dwell period, the ram 24 returns rapidly to its initial position and the finished assembly is unclamped. A control circuit for the operation is described, Fig. 7 (not shown).