GB786695A - Underdriven metal blanking and drawing presses - Google Patents

Abstract

786,695. Stamping. BLISS CO., E. W. Jan. 16, 1956 [Jan. 28, 1955], No. 1388/56. Class 83(4). The drive mechanism for the press slide of a metal blanking or drawing press comprises a pair of parallel crank-shafts, a drive shaft parallel to said crank-shafts and having a first pinion engaging a gear on one of the crankshafts and a second pinion engaging a reversing pinion which engages a gear on the other crankshaft, a pair of rock-shafts rotatably supported outwardly and parallel to said crank-shafts, connecting rods arranged between throw portions on adjacent crank-shafts and rock-shafts and links extending from other throw portions on said rock-shafts to said press slide. The press comprises a base 10 and side walls provided with steps 20 and 22 which rest on beams 24 and 26. The mechanism is accommodated in a pit 30 and, with the exception of the motor 74 and flywheel 88, is immersed in an oil bath. Two pairs of slide operating links 40 and 42, and 58 and 60 are pivoted to the slide 50 and to rock-shafts 56 and 68 respectively (Fig. 3). The rock-shafts rotate in opposite directions. The main drive shaft 86 carries a pinion 94 engaging a gear 102 on an idler shaft 100 carrying idler pinions 104 and 106 on either side of the idler gear 102. The idler pinions 104 and 106 drive the gears on the parallel crank-shafts 108 and 146 (Fig. 3). The rock-shaft 56 adjacent the crank-shaft 108 has eccentrics 126 and 128 and a crank-pin 130. A pair of rock pins 132 are angularly displaced approximately 120 degrees from crank-pin 130 and support the lower ends of operating links 40 and 42. A parallel crankshaft 146 (not shown) is driven from the idler pinion 104 via a reversing pinion 144 and its adjacent rock-shaft 68 is similar to rock-shaft 56. Connecting rods 170 and 174 connect adjacent crank-shafts and rock-shafts. Rotation of the main drive shaft causes the links to pull down the slide 50 towards the bolster 200, but the return of the slide upwardly is assisted by pairs of piston-rods 186 and 191 (Fig. 2) connected to pistons on pneumatic cylinders 187 and 192. The lower die face of the slide is vertically adjustable by a motor 178 operating adjustable heads 185.