Patent GB-1056592-A (GB)
Title: Improvements in or relating to press feed mechanism
Inventor: NORTON HENRY
IPC: B21D43/11
Filed: 1962-07-04
Abstract: 1,056,592. Metal sheet feeds. NORTON TOOL CO. Ltd. July 4, 1963 [July 4, 1962]. No. 25693/62. Heading B3W. A feed mechanism for continuous material comprises a stationary clamp, a movable clamp, means for reciprocating the movable clamp, and cam means for opening and closing each clamp, the said cam means being mechanically coupled to the reciprocating means. The mechanism 12 is described in relation to an hydraulic punching press 1 arranged for producing washer-like components from a strip 7, Fig. 1 (not shown). The hole is cut by a punch 8 and the strip is then fed forward to a blanking punch 9 which has a pilot pin 11. The operation of the press 1 is controlled by the feed mechanism 12, which is itself driven by an electric motor 43. The mechanism is arranged on a welded structure comprising plates 13, 14 and 15, a bracket 16, and a square-section bar 17 connecting the plate 13 and the bracket 16. The stationary clamp 18, Fig. 3 (not shown), is mounted on the bracket 16 and comprises a fixed jaw 19 and a spring-loaded movable jaw 21. The guide rods 22, 23 for the movable jaw 21 are connected by a yoke 26, which carries a screw 79. The movable clamp 29, Fig. 4, is of similar construction and includes a block 36 mounted for reciprocation along the bar 17, and actuated by a variable throw crank-pin 53, Fig. 5 (not shown), rotated by a shaft 46 driven by the motor 43. The movable clamp is closed by a lever 57 which is housed in a slot 56 in the connecting rod 55. The lever is pivoted on a pin 58, and at one end has a roller 61 which runs on a face cam 63 fixed to the crank-pin 53. The other end of the lever engages a screw 64 on the yoke 38 to lower the jaw 33 on to the fixed jaw 32. The movable jaw 21 of the stationary clamp is controlled by a lever 76, pivoted on a bracket 78, and carrying at one end a roller 74 which follows a face cam 71 fixed on the shaft 45. The other end of the lever engages a screw 79 in the yoke 26. Also fixed to the shaft 45 is an edge cam 82 which operates a lever 84 and hence a cable .86 coupled to the press control, means.. In order that the strip is free to be moved by the pilot pin 11, the control of the movable jaw of the stationary clamp .provided by the face cam 71 is over-ridden by a mechanism comprising a projection 87 on the moving press member 6 which engages a lever 88 and through links 90 and 91 and a.shaft 92 operates a lever 95 and raises the yoke 26.  Operation.-During the return stroke of the movable clamp, the strip is gripped by the stationary clamp, and during the last 5 degrees of movement of the movable clamp the cam 63 causes it to grip the strip. During the first 5 degrees of the. feeding stroke the stationary clamp is opened by the face cam 71 and remains open until 5 degrees before the end of the feed stroke, when it begins to close, so that at the end of the feed stroke the strip is gripped by both clamps. The movable clamp opens during the first 5 degrees of movement of the return stroke and remains open until it begins: to close again 5 degrees before the end of the return stroke. As the movable clamp moves towards the stationary clamp the cam 82 operates the lever 84 causing the press-ram to descend. Before the pilot pin 11 reaches the strip, the projection 87 strikes the lever 88 and opens the stationary clamp to leave the strip free to move under the pilot pin. The press moves up again and the stationary clamp grips the strip again before the movable clamp reaches the end of its return stroke.