Patent GB-1481325-A (GB)
Title: Press for working materials
IPC: B30B1/26
Filed: 1974-08-09
Abstract: 1481325 Cutting; mechanical presses P VINSON 9 Aug 1974 35201/74 Headings B4B and B5F [Also in Division B3] A press comprises a frame, a press platen 99 connected by draw rods 101, reciprocable relative to the frame, to a draw platen 85 driven by rotary cams 51, 53 mounted on the frame. As shown, Fig. 1, a cam 51 is angularly displaced relative to similar cams 53 about a shaft 37 driven via a clutch and brake 33 and belt 35 from the main motor (31) to respectively raise and lower a cam housing 59 and thus the platen 85. Cam followers 55 and 57 are in constant contact with their respective cams throughout cam rotation and one rotation of the cam-shaft moves the platen through a plurality of cycles. The housing is adjustably connected to the platen 85 by a screw 87 in a nut adjustable by a motor-driven worm 95. The platen 99 carries tools (not shown) for working, e.g. sheet metal, cloth or ceramic material. An air cylinder 119 counterbalances the weight of the platen 99, cam housing 59 &c. Further tools for working transversely to the direction of platen movement, such as tools 159 for curling a part 163, Fig. 6, are supported by guides 161 on the press bed 111 and driven by pairs of cams 129, 131. Both cam-shafts 133 and 135 are driven by the main motor 31, the shaft 133 via the shaft 37, gears 137, 139, 141, 147, 153 and 155 and a belt 151 and shaft 135 via a portion of a stock feed device 29. The feed device, shown in Fig. 7 in use with a punch 209 mounted on platen 99, comprises movable grippers 201, 203 and 205, 207. Both grippers preferably grip stock 208 during punching and stripping and each carriers out a feed stroke while the other carries out a return stroke. The drive to the grippers is from the main motor via a shaft 149 on which the gears 147, 153, referred to in connection with the drive to the cams 129, are mounted. Through a coupled shaft (177), Fig. 4 (not shown), and a belt and gear arrangement the shaft 149 also drives the cams 131. A shaft 187, on which one of the last mentioned gears is mounted, is coupled by a spring coupling 219 to a shaft 213 carrying a cam 225 which drives the feed device. Cam followers 229, 231 are secured to a slide 233, Figs. 14 and 17, a key 243 rigid with the slide being slidable in a slot 247 in a bellcrank 227. The bellcrank is pivotable about an adjustable pivot 253 which is engaged in a slot 259 in the bellcrank. Rotation of the cam 225 causes the slide 233 to reciprocate between bearings 249 and the bellcrank to pivot. Connected to the end of the bellorank remote from the slide is a reciprocable rack 261 which via gears 277, 279 and 281 causes racks 287 and 289 to reciprocate in opposite directions. Each rack 289 is connected via a respective sleeve 307, Fig. 13a, with the gripper member 203. Further sleeves 309 connect the racks 287 to the gripper member 207. Rods 315 and 317 connect the gripper members 201 and 205 to gripper members 203 and 207 respectively. The rods follow cams 319 and 321 timed to cause clamping and unclamping of the stock 208 in synchronism with the feed and return strokes of the respective grippers. The gripper stroke length is adjustable by moving the pivot 253 of the bell crank 227. Stops 335, 337 engageable by an abutment 143 on the rack 261 are adjustable to suit the selected stroke length. The grippers may be given different stroke lengths by driving the rack 287 through reduction gearing.