GB940198A - Improvements in and relating to the separating of sheet metal cuttings from a stack - Google Patents

Abstract

940,198. Feeding sheets. L. SCHULER A.G. Jan. 25, 1960 [June 26, 1959], No. 2598/60. Heading B6B. Suckers 9, 10 are raised to engage the bottom sheet of a pile of metal sheets, e.g. can blanks, are moved to the right to slide the sheet off lefthand support 2 and into right-hand slot 3a, are moved to the left to slide the left-hand edge of the sheet under support 2 and to withdraw the sheet from slot 3a, and are finally lowered to deposit the sheet on conveyer 20. The stack of metal sheets is enclosed at each corner by angle rails such as 1, 1a and the lowest sheet rests upon holder members 2, 3, the middle parts of the sheet being supported by serrated jaws such as 4. The upper portion of the stack is held in an inclined position by a pawl 5 to prevent undue pressure on the bottom sheet. The guide rail 1 has a slot 3a the width of which is adjusted by means of a vertically movable slide 18 so as to be slightly greater than the thickness of one of the sheets. A conveyer 20 comprising two spaced apart gripper chains passes beneath the stack of sheets. Suckers 9, 10 are mounted on hollow rods 9a, 10a which are located between the chains of conveyer 20, being vertically slidable in guides in a platform 8 and biased upwards by springs 23, 24. The platform 8 is carried by a rod 28 pivoted to two links 29, 30 forming a parallelogram drive, power being supplied by a crank-shaft 34, so that as the shaft 34 rotates the platform is reciprocated over an arcuate path. Abutments 15, 15a carried by the rods 9a, 10a co-operate with rollers 16, 17 to arrest upward movement of the suckers 9, 10, the roller 17 being mounted on a bracket secured to the machine frame and the roller 16 on one end of a lever 25 pivoted at 26 and which at its other end carries a cam follower roller 27. As the platform 8 moves upwards the suckers engage the bottom sheet of the stack, a valve 12 is opened by means of a cam 14 so that the suckers are put in communication with a source of vacuum, the springs 23, 24 are compressed and the suckers carry the bottom sheet a short distance to the right so that one end thereof projects through the slot 3a and the other end is clear of the holder member 2. As the platform starts its downward movement the roller 16 is moved downwards by a cam 19 so that the sucker 9 is at a lower level than the sucker 10 and the left-hand end of the sheet lies below the holder member 2. The suckers then move horizontally to the left and downwards whereby the right-hand end of the sheet is pulled out of the slot 3a and the other end slides under a guide face 40. As soon as the suckers reach the level of the conveyer 20 the valve 12 is closed and the sheet separated from the pile by the suckers is carried away by the conveyer. The platform 8 completes its downward movement and then commences another cycle. When the machine is running idly the suction is cut off by a valve 13, operation of which actuates a solenoid 22 which moves a slide 21 into position to close the slot 3a.