Patent GB-235466-A (GB)
Title: Improvements in and relating to metal perforating machines
IPC: B21D28/26
Filed: 1924-11-19
Abstract: 235,466. Thomas, G. P. Nov. 19, 1924. Punching; metal - sheet feeds. - In a punching machine of the kind in which a member supporting the work and a templet has longitudinal and transverse movements in a horizontal plane, the work being located by a finder-pin co-operating with the templet, the work and templet rest on rollers carried by an intermediate frame and are clamped along one edge only to a carriage mounted on the intermediate frame. The work 6 and templet 63, Fig. 2, are clamped side by side by clamps 16, Fig. 7, to a plate 19 which is adjustably secured to a carriage 13 adapted to move longitudinally on grooved rollers 15 on an intermediate frame 4, the latter being provided with rollers 7 on which the work and templet rest. and having rollers 3 on which it may be moved in a transverse direction. The movements of the carriage and intermediate frame are controlled through rack and pinion gearing respectively by hand-wheels 32, 25, Fig. 2. One of the members attaching the plate 19 to the carriage may be guided to slide freely thereon to accommodate stretching of the work during punching. The work-supporting rollers adjacent the punch-head may be carried by upwardly spring-pressed pivoted arms, to free the work from the lower die after each punching operation. The punch-head is reciprocated by a shaft 36, Fig. 6, driven through spur gearing and a one-revolution clutch 40, 41 by an electric motor 43. The clutch-member 40 is normally urged into engagement with the member 41 by a spring 44, but is withheld by a pin 47 coacting with a cam surface 48. The pin is controlled through linkage by a solenoid 56 in a circuit controlled by a pointed finder-pin 64, Fig. 4. The work and templet support is first roughly positioned by the hand-wheels 32, 25, till the finder-pin partially enters one of the perforations in the templet, whereupon the circuit through the solenoid is closed by contacts 66, 67, so withdrawing the clutch-pin 47 and starting the machine. The actuation of the solenoid also rocks a shaft 60 through linkage 57, 58 and depresses a sleeve surrounding the finder-pin, through a yielding spring connection, to force the finder-pin completely into the templet perforation, thereby accurately locating the work. As the shaft 36 revolves to operate the punch, a cam 91, Fig. 6, breaks a contact 94, 95 in the solenoid circuit to allow the pin 47 to rise into contact with the cam on the clutch member, and a cam 84 actuates linkage to withdraw the finder-pin. The finder-pin may be withdrawn by a hand-lever 116 and may be retained in the disengaged position by a latch 114, Fig. 4. An auxiliary punch for punching odd holes of a different size in the work may be mounted in the head. The two punches are in this case controlled by gags actuated by links 109, 110, Fig. 6, operated by a spring- pressed hand-lever 101 which also actuates a finder-pin 100. When working non-automatica.lly, a separate circuit containing the clutchactuating solenoid may be closed to start the machine, by a foot-operated switch at the control platform. In a modification the automatically controlled finder-pin is omitted and a gang of punches is mounted in the punch-head, each punch being controlled by a gag in operative connection with a corresponding manually-operated finder-pin. In this modification the circuit containing the clutch-actuating solenoid is closed by the operation of each of the finder-pins.