GB1367482A - Work transfer devices for indexing workpieces between successive stations in a die mounted in a press - Google Patents

Abstract

1367482 Feeding blanks; transfer devices B J WALLIS 27 Aug 1971 [28 Aug 1970] 40251/71 Headings B3W and B3H A device for indexing workpieces between stations of a press mounted die in which carriages 10, 10<SP>1</SP> are reciprocated in the feed direction and finger bars 16, 16<SP>1</SP> carried by them are reciprocated between workingaging and retracted positions includes an overload disconnect means 38 in a drive train for the finger bars, which drive train is independent of a drive train for the carriages, and a safety mechanism 78 actuated in timed relation with downward movement of the press ram for retracting the finger bars should the drive train fail to do so. Cam tracks 24, 26 rotated about a pivot 28 by motor 22 control reciprocation of the carriages 10, 10<SP>1</SP> and finger bars 16, 16<SP>1</SP> through cam followers 56 and 30 respectively. The drive train for the carriages includes a rack 58, shafts 62, 66 and 74, a rack 75 and an overload disconnect device 64 which uncouples the shaft 62 if the drive train is subjected to excessive driving force. The drive train to the finger bars includes a rack 32, shaft 36, racks 44, 48 and 50 and an independent overload disconnect device 38. The safety retraction mechanism comprises a rack 80 which meshes with a pinion 82, coupled with a shaft 54 which connects the rack 44 with racks 48 or 50, and has a chamfered end portion 94 which, if the finger bars have not been fully retracted when the press ram descends, is engaged by a cam 90 on the ram 92. As the rack moves to the right (Fig. 2) the shaft 54 is rotated anticlockwise which retracts the finger bars. In an alternative embodiment, Fig. 13, a drive shaft is (a) moved axially through a cam track 110, lever 112 and shaft 114 to reciprocate a carriage 106 and (b) rotated through a cam track 118, gear 120 and rack 121 to reciprocate the finger bars. There is an overload disconnect device (not shown) between a shaft 132 which drives the cam-carrying tracks 110 and 118 and the means driving the shaft 132. A second overload disconnect device (not shown) is located in the rotary drive between the cam and the shaft 102. The safety retraction mechanism comprises a pinion 122 rotated by the shaft 102 and meshing with a pinion 124 to which is attached a crank 126. If the finger bars have not been retracted when the press ram descends, an actuator 130, Fig. 14, attached to the ram engages a roller 128 on the crank and pivots the crank which rotates the shaft 102 and thus retracts the finger bars.