GB721297A - Improvements in press feeds - Google Patents

Abstract

721,297. Metal sheet feeds; blank punching. ALUMINUM LABORATORIES, Ltd. March 25, 1953 [Feb. 28, 1952], No. 5312/52. Class 83 (4). Means for feeding sheet material past a press punch includes a carriage, to which the sheet is clamped, moved intermittently past the punch by a chain driven through gear means including a coupling adapted to be disconnected and connected to provide the intermittent movement and means actuated by the carriage to reverse its movement and to move the sheet holding member transversely to the direction of movement of the carriage so that a return row of blanks may be punched. A metal sheet 1, held by a pneumatic clamp 5 on a vertically movable part 4 of a carriage 2 movable along horizontal guideway 3 by a chain 6, is carried intermittently past a crank-operated punch adapted to punch out successive blanks in horizontal rows from the sheet. The chain 6 is intermittently driven by a sprocket on an output shaft 61 of a gear-box 10, an input shaft 32 of which is driven from a sprocket on the drive shaft of the punch crank. Drive from the shaft is taken from a bevel gear 39 thereon to one of two bevel gears 40, 41 on a shaft 42 and from a pinion 50 on the shaft 42 to a pinion 51 on a shaft 52 and thence through changeable gearing 55-59 to a shaft 54 and through clutch members 62, 67 to the output shaft 61. The clutch 62, 67 is intermittently allowed to disengage by an arm 70 on a shaft 74 rocked, by a cam 38 on the input shaft 32, against spring means 72 and a dashpot 81, which latter serves also to lubricate the bearings. The output shaft 61, which is capable of slight axial movement, is braked by the engagement of a brake member 102 thereon, under the action of springs 108, with a fixed brake member 101. The drive to the carriage 2 is automatically reversed, after a row of blanks has been punched from the sheet 1, by a stop 114, Fig. 2, on the carriage hitting a stop 112 on a rod 110 linked to a rod 90 carrying a cam follower 91 engaging a cam 37 on the shaft 32. The cam follower 91 is thus moved, still in engagement with the cam 37, from a position engaging one of two tappets 87, 88 to a position engaging the other. These tappets, through links 86, 85, rock a yoke 49 on a shaft 83 to move the shaft 42 axially so that a driving dog 47 thereon disengages a pin 45 on one bevel gear 40, 41, and engages a pin 45 on the other. The operation of the cam 37 is so timed that the pins are 180 degrees apart when the drive is disconnected, thus allowing the shaft 32 to rotate half a turn before the drive is reconnected so that the next row of holes is staggered relative. to the previous row. Rocking of the shaft 83 also rocks a lever 96 connected to a rod 111, Fig. 2, to move this rod in a direction opposite from that of the rod 110 and cause a stop 112 thereon to strike a lever 118 on the carriage to release the movable part 4 and allow it to descend a distance equal to one line spacing.