| 摘要 |
1328710 Bending; punching; nibbling B & R PRODUCTS PTY Ltd 16 Aug 1971 [20 Aug 1970] 38284/71 Headings B3E and B3W A bending, punching or nibbling press has its upper die holder 15 actuated by an intermittently rotating eccentric 22 through a toggle connection 23 to effect part of the working stroke of the press and the toggle is also actuated by a hydraulic cylinder 32 to effect the remaining part of the working stroke. The piston of the cylinder acts on a guide arm 34, pivoted on the same shaft 18 as the eccentric and provided with a guide slot 35 for a roller 36 on the pivot pin of the toggle. The guide arm 34 has an abutment (40), Fig. 7 (not shown), which engages one of a set of screw adjustable plungers 50, Fig. 5, to adjustably limit the stroke of the piston. The plungers 50 are mounted on a rotatable disc 44 which is indexed to present different plungers for a sequence of different length working strokes. The disc 44 is indexed by a pawl actuated by a cam 58, Fig. 3, on the shaft 18. An arm 76 has a pin 78 which can move a cam follower pin 61 away from the cam to render the pawl inoperative if the same length working stroke is required repeatedly. The press is driven through a clutch operated by a pedal which also actuates a two-way switch (99), Fig. 6 (not shown), to control a double-acting solenoid valve (91), Fig. 7 (not shown), in the supply line to the cylinder 32. The press has two cylinders, one at each end of the die holder and respective eccentrics, toggles and rotatable discs with screw adjustable plungers indexed from a common cam. |
