Patent GB-1283553-A (GB)
Title: Improvements in and relating to stock feeding devices
Inventor: SCRIBNER ALBERT WILLIS
IPC: B21D43/11
Filed: 1969-10-17
Abstract: 1283553 Metal strip feeds A W SCRIBNER 17 Oct 1969 [17 Oct 1968] 51108/69 Heading B3W  Apparatus for feeding strip metal to a punch press comprises a pair of feed slides mounted one on each side of the strip, first fluid-operated means for reciprocating the slides alternately in the feed direction, a gripper mechanism, including a pivoted lever for gripping the strip, on each slide, and second fluid-operated means for actuating the gripper mechanisms alternately. Identical feed units 110a and 110b are secured by plugs 111a, 111b and 113a, 113b in brackets 104, 105 upstanding from a base 103 provided with slots 98, 99 for mounting on a press. Referring chiefly to unit 110b, a slide 117b, Fig. 5, screwed to an enlarged end of piston-rod 116b and within a tubular piston 115b slides a buffer piston 123b mounted on a piston-rod 125b sliding within piston-rod 1166. A threaded plug 126b at the rear end of piston 115b has a narrow fluid-supply passage 127b which connects the buffer cylinder 124b with the main cylinder 132b to which fluid is supplied, as at 131a, Fig. 4. The slide is returned by a spring 136 or by fluid means (not shown). The gripper mechanism comprises a lever 150b mounted on a screw 142b for limited pivotal movement in a vertical plane to and from a plate 151b. When fluid is supplied through a tube 161b and an axial bore 160b through pistonrod 157b and piston 156 to the lower end of cylinder 155b, the outer end of the lever is lifted and the inner end depressed to grip the strip stock 165. The supply of fluid to the slide cylinders and the gripper cylinders is controlled by four-way ball valves 180 and 181 respectively operated by cams 186, 187 on a shaft 190, Fig. 3. The cam-shaft 190 is driven via gears 195, 196 from a drive shaft 197 driven by an electric motor 200. The speed of rotation of the drive shaft is governed by the rate of reciprocation of the ram 202 of the press through engagement of a cam follower roller 206 fixed to a disc 204 rigid with the shaft 197 with horizontal parallel rails 207, 208 on an arm 210 mounted for vertical adjustment on the ram 202. The arrangement is such that for each cycle of the press one of the feed slides executes a feed stroke, the length of the stroke being adjustable by means of screws 121a or 121b threaded through plugs 113a or 113b. The disc 204 may have several alternative fixing points for the roller so that it may be coupled to presses of different stroke lengths. Guides 171 are laterally adjustable for different stock widths and either or both feed units 110a, 110b are laterally adjustable in brackets 104, 105. In an alternative form of fluid supply control, Figs. 8 and 9 (not shown), a predetermined number of feed strokes take place between cycles of the press. A cam-shaft (222), for actuating cams and valves (180a), (181a) similar to valves 180, 181, is rotated through oscillation of a lever (224) fixed to shaft (222) by a double-acting air actuator (225). Each oscillation operates the valves (180a), (181a), the respective mounting of the cams on the shaft causing gripping to take place slightly ahead of slide movement. After a predetermined number of strokes of actuator (225) a control unit (236) puts out a signal to initiate the next cycle of the press.