Patent GB-1134179-A (GB)
Title: Apparatus for individually separating ferrous metal workpieces from a stack
IPC: B65G59/04
Filed: 1966-09-13
Abstract: 1,134,179. Feeding sheets. DANLY MACHINE SPECIALTIES Inc. 13 Sept., 1966 [14 July, 1966], No. 40909/66. Heading B6B. Individual ferrous workpieces are separated from a stack and transferred to a workpiece receiving rest by an apparatus comprising a plurality of vertically-reciprocatable vacuum means, mounted in a frame, for engaging a workpiece, means for lowering and raising the vacuum means to raise the topmost workpiece from the stack positioned beneath the vacuum means, a plurality of horizontal magnetic rails positioned above the stack for receiving the workpiece from the vacuum means and supporting it in the raised position, means for moving the raised workpiece horizontally for deposit in the receiving rest and control means for operating the machine continuously. The workpiece may be a sheet or may be a piece having irregular surfaces or projections. In a preferred embodiment, Figs. 1 and 5 the apparatus 20 is arranged for removing individual sheets or blanks of ferrous metal from a stack and feeding them one by one to the input of a press or automated press line. Endless belt conveyer 30 carries stacks of sheet metal blanks 34 loaded on pallets 36 to the operating region where the leading edge of the first stack abuts against and is aligned by a plurality of vertically orientated stop blocks 40 spaced across the machine. These blocks may include magnetic strips 45 to aid horizontal alignment of the sheets in a stack. Adjustable spaced arms 46 ensure that the stacks are centred on the conveyer. Sheets are separated from the aligned stack by a plurality of pairs of transversely spaced vacuum cups 52, mounted on arms 54 connected to bar 56 which includes racks 58 driven by a plurality of spur gears mounted on a shaft 62 to effect vertical reciprocation of the cups. A number of magnetic rails 72 are suspended so that each vacuum pick-up head passes between spaced pairs of rails and is raised sufficiently beyond the rails to effect dislodgment of the raised sheet from the vacuum cups and its retention on the magnetic rails. The dislodged sheet is moved (to the right) along rails 72 assisted by rollers 81 (Fig. 4, not shown) by a pair of reciprocating plunger members 82 mounted parallel to rails 72. Members 82 carry pivotally mounted dogs 84 which engage the trailing edge of the sheet. On the return stroke of plungers 82, dogs 84 retract within the plungers. A thus moved sheet 49<SP>1</SP> passes through the nip of segmented lubricating rollers 90, 91 and drops into first rest 80. This rest comprises a plurality of adjustable slabs 100 supported by frame 102 pivotally mounted on the frame of the machine by shaft and collar 104 Guides 105, 106, 107 align the sheet on the rest. A second similar rest 112 is mounted on upright column 110. A loading arm trolley 86 with pick-up heads 114 raises a sheet in rest 80, moves horizontally (to the right) and deposits the sheet in rest 112. Simultaneously pick-up head 114 moves a preceding sheet from rest 112 to a work station or further transport device. Double feed is prevented by the provision immediately before rollers 90, 91 of a horizontal guide (120, Fig. 6, not shown) and a vertically shiftable actuator bar (122) bearing a roller, between which guide and roller the sheets pass. If the actuator bar is lifted by more than a single sheet thickness, a limit switch is actuated which in turn actuates servo cylinder 132 which rotates bell crank 130 and thus lowers rest 80 from its normal horizontal position into a position where roller ramps 134 extend above slabs 100, allowing the " double sheet " to roll off on to bed 108. When bed 108 is filled with rejected workpieces switch LS5 is actuated to stop the machine. When a pallet is empty no sheets bear against pivotally mounted lever 140 and consequently switch LS9 is actuated and the conveyer advances until the next stock is in position against lever 140. The empty pallet is pushed under stops 40 on to cart 44. Varying sizes of sheet may be accommodated and for this purpose the position of stops 140 is axially adjustable by screw jacks 100, the spacing between vacuum cups 52 and rails 72 is adjustable, and the spacing between slabs 100 of rest 80 may be changed. A switch LS2 under the control of actuator arm 144 limits the downward passage of pick-ups 50 to the level of the top sheet and the upward travel of the pick-ups is determined by switch LS1 operated by arm 146 attached to drive rack 68. Switches (LS7, LS8) are provided to detect whether the sheet has cleared the pick-up haeds and passed on the rails in an aligned position. Switch LS6 serves the return stroke of the plungers 82 and operates guides 107 to centre the sheet on rest 80.