Patent GB-170681-A (GB)
Title: Improvements in pneumatic rivetting machines particularly adapted for rivetting the studs of driving chains
IPC: B21J15/18
Filed: 1920-07-28
Abstract: 170,681. Renold, Ltd., H., Itenshaw, A., and Grimshaw, H. E. July 28, 1920. Chains.-In a pneumatic riveting-machine for the studs of driving-chains, of the type in which a punch with localized pressure areas is rotated slowly while being subjected to the action of the piston of a pneumatic hammer, the hammer cylinder is fed forward by fluid pressure to grip the stud between the punches and then automatically open ports to admit the air to the interior of the cylinder. Two opposite riveters may be fixed on the bed, or a single riveter may co-operate with a .fixed or movable support. In the form shown, in which two riveters are used, each consists of a block supporting a hammer cylinder 16, which is provided with a piston 46 so that it may be fed forward by compressed-air into contact with the stud 11 to be riveted to the chain 12. The cylinder is returned by a spring 47 when the air pressure is cut off. The speed of the return movement and also of the feed movement is controlled by allowing air to escape from and enter a space 70 between the block and a shoulder on the piston 46 through a needle valve 72. Punches 13 of various sizes having cruciform or other shaped ends to provide two or more localized pressure areas are interchangeably secured by a screw-cap 14 in a liner 21 in the end of the cylinder, being capable of a slight longitudinal movement. Compressed air is supplied from a pipe 38 through a rotary valve 36 to a pipe 41, from which it enters the space 45 to feed forward the cylinder. When the port 49 is uncovered, pressure is admitted to the cylinder through the valve 20 to force forward the hammer piston 18. At the end of the forward stroke, the air passes through the port 19 to exhaust, and the piston is returned by the compressed-air at the forward end of the piston. The rotary valve 36 is provided with a central port through which air is supplied from the pine 38 to the pipe 41 by way of the port 40, and is provided with an inclined groove 43 which in one position connects the port 40 with the exhaust port 44. The valve is rotated by gearing 35 from a shaft 32 carrying a long pinion 31, which engages a narrow wheel 33 on the cylinder 16 so as to rotate the cylinder and punch during operation. This shaft is driven by toothed wheels 30 on a shaft 17, which is normally. rotated from an electric motor through a shaft 22, Fig. 2, worm gear, chain gear 24, spur gear 26, 27, and chain gear 28. In order that the machine may also be driven by hand or be set by hand into correct starting position, a clutch is provided between the gear 27 and the shaft on which it is mounted, which is held in open or closed positions by a hand-lever 82 provided with a spring button 84 engaging holes in a plate. When the clutch is in the open position, a shaft 66 provided with a hand-wheel 65 is pressed forward against the action of a spring 67 so as to bring the pinion 68 into mesh with one of the toothed wheels 30. The cylinders and punches may be rotated either in the same direction or in opposite directions, in which latter case one of the pinions 31 is driven from its corresponding wheel 30 through a pinion. The rotation may be communicated to the punches only, the punches being engaged in angular recesses in rings driven from the shaft 17. The chains mav be held in operative position by a heavy block 50 carried by a spring-pressed lever 51 and may be fed over the guide 10 by a hookshaped block 56, adjustably mounted in a link 58 connected to an arm 59, which may be rocked on its pivot 60 either by a handle 61 or by a cam on the shaft of the sprocket 91, which engages a lever 80 rigid with the arm, the forward movement being limited by a screw-stop 62. In a modification, Fig. 6, the feed may be effected by a chain-wheel 73 loosely mounted on the shaft 17 and operated by a ratchet 75 and pawl 74 carried by a link 76 which is mounted on an eccentric stud 78 on a shaft 77. The chain passes along a table 63 and over an incline 64 to a receiving place. The shaft 17 is lubricated by oil supplied through pipes 92.