Patent GB-369505-A (GB)
Title: Improvements in or relating to hydraulic presses for operating upon sheet or strip material
IPC: B21D43/02
Filed: 1931-08-01
Abstract: 369,505. Punching. OILGEAR CO., 1403, West Bruce Street, Milwaukee, Wisconsin, U.S.A.-(Assignees of Ferris, W. ; 2704, North Prospect Avenue, Milwaukee, Wisconsin, U.S.A.) Aug. 1, 1931, No. 21963. Convention date, Aug. 4, 1930. [Class 83 (iv).] Metal-sheet feeds.-In a hydraulic press with feed-grippers opened, closed, and reciprocated, to effect the feed, by hydraulic cylinders, a gripper hydraulic motor 77 is connected in series with feed hydraulic motors 53, 55, and a ram cylinder 2. Liquid flows through one of feed motors, then through the gripper motor, then through the ram cylinder, and, after ram stalls at the end of the stroke it operates feed, grippers and ram in the reverse direction. An upper die 5, reciprocated by a ram 2, carries a stop-pin 22, a die 15, a pilot hole punch 16, and a pilot pin 17. In punching L-shaped pieces 20, Fig. 9, the strip 19 is positioned originally by the pin 22, and, at subsequent operations of the press, the pilot pin engages the holes to position the strip as it is fed under a stripper 18 secured to the lower die 6. Feed. Pivoted grippers 30 carried by a bar 31 on arms 32 on a crosshead 33 are reciprocated in the direction of feed through a crank 41 by plungers 52, 54, of feed motors 53, 55. The plungers are connected by a rack 51 engaging a pinion 50 on a crankshaft 42. The grippers 30 are opened by springs 63 and closed by a cam-lever 64 operated by a handlever 68 or by rods 71, 75, from a plunger 76 of gripper motor 77. The pilot pin 17 and resiliently mounted pressure pin 22 are reciprocated by a rod 79 from the plunger 76. Clutch. Depression of a pedal 94 raises a rod 100 to operate the press for one revolution. Depression of a locking pedal causes continuous operation. Operation. The cylinders are connected as shown in Fig. 11. In working for a single stroke, liquid from high-pressure pump 11 flows through pipe 133, valve 8, pipe 156, valve 9, pipes 159, 160, 161 and upper feed motor 53, pipe 164, gripper motor 77 to a pipe 166. As the ram 4 is at top of its stroke, the liquid flows through pipe 170 to lower part of valve 10, acts upon piston 176 operating plunger 106, and uncovering port 178. Liquid passes from bottom of valve 10 back to pump. Liquid in valve 10 below a piston 176 flows through a pipe 188 to top of main cylinder 2. The piston 4 is supported by a valve 168 and liquid flows through pipe 191 to port 192 of pilot valve 9 then through pipe 194 to control valve 8 and through port 135 back to pump 11. The pump 12 forces liquid through valve 10 to move the valve plunger 140, and liquid in pipe 156 is forced through valve 9 and raises piston 54 of motor 55. This causes rack 51 to rotate crank 41 and pinion 50 to move feed bar 31. As the piston 54 reaches top of its stroke high-pressure liquid flows through a port 213 to the lower end of motor 77 and raises piston 76 to open grippers 30 and to lower pilot pin 17 and pressure pin 22. When the piston 75 reaches top of its stroke high-pressure liquid passes through port 217 and pipes 218, 188 to the upper end of cylinder 2 and forces piston 4 and ram 3 down. At the bottom of stroke of ram liquid flows through valve 187 to valve 10 and raises plunger 106 The cam 129 swings arm 121 from plunger 104 and lever 107 locks plunger 110 in upper position. Liquid from pump 12 through pipe 139, and valve 10 flows to cylinder 145 forcing plunger 140 of valve 9 down. High-pressure liquid in the pipe 156 flows through valve 9, pipes 159, 160 to upper end of motor 53 to force piston 52 and rack 51 down. This moves feed bar 31 and grippers 30 to initial position. The speed of the rack 51 is retarded by a choke 224. When the piston 52 is at bottom of stroke, high-pressure liquid flows through pipe 164 to upper end of motor 77 and forces piston 76 down to close grippers 30 and to raise pilot pin 17 and pressure pin 22. When piston 76 is at bottom of stroke, highpressure liquid flows through pipe 166 to cylinder 2 and raises ram 3. When the ram reaches top of stroke, liquid tends to force rod 106 down, but is prevented by lever 107. It then passes valve 175, overcomes pressure of a detent 130 and moves plunger 104. When the piston 142 uncovers port 144 the accumulator 141 assists downward movement of the plunger 104. If the press is operated continuously, lever 117 and detent 127 are held in operation and the slide 101 is raised. The plunger 104 is raised and cam 112 holds lever 107 from plunger 106 to allow it to drop. When the pedal 94 is released the slide 101 is lowered and the press completes its cycle and stops with ram in upper position and the grippers closed. To slow down the press when introducing a fresh strip control means is provided for regulating the stroke of the pump. To stop the press instantly an emergency lever 232 is swung upwards to move the plunger 104 down to cut off the high-pressure liquid. On moving the lever downwards the plunger 104 is raised to restart the press.