Patent GB-1255499-A (GB)
Title: Methods and apparatus for feeding sheets to processing equipment
Inventor: VALENTINE NORMAN STANLEY
IPC: D06F67/04
Filed: 1968-09-03
Abstract: 1,255,499. Laundry feeding apparatus. POLYMARK Ltd. 2 Sept., 1969 [3 Sept., 1968], No. 41930/68. Heading D1A. A sheet feeder comprises a flat table 16 adapted, as by suction openings 17, to support and retain an edge portion of a sheet, a comer of which has been conveyed across the table adjacent a stop edge 20 by means 18, and a transfer member 81, which is parallel to the table edge and is displaceable transversely thereto to engage an adjacent portion of the sheet and transfer it in the form of a loop, the member 81 moving progressively within the loop until the sheet edge is released, when a second transfer means 95 presents the sheet edge to processing equipment (13). The feeder includes a suction box 97 across which the remainder of the sheet is drawn, in a sinuous path to increase it, by bands 13 of the processing equipment. The traversing means 18 comprises a trolley 25 which is movable by a chain 22 along rails (24) (Fig. 3 not shown) below the table 16 and has two sets of grippers 28, 29 which draw sheets from opposite ends of the table and release the sheets automatically when a roller 33 engages a cam surface 35 at the end of the travel or a rail 34 which is raised by centralising means when the sheet is centralised. The sheet centralising means includes an actuator block 44 which moves with the trolley 25 and moves a chain 41 and two measuring blocks 45 which are each moveable with the lower run of the chain 41. Each block 45 moves when a pawl 49 (Fig. 4) on the block engages a ratchet wheel on the same shaft as a sprocket 47 engaging the lower chain run. In use the pawl is released when the trailing edge of the sheet breaks the beam of a photocell 67 and the block 45 then approaches the moving block 44 until a pin 66 on the block 45 abuts an arm 56 or 57 of the block 44 to actuate a switch to raise the rail 34 and thereby raise the grippers 29 and 28, the block 44 then returning the measuring block 45 to its starting position. In operation of the feeder a sheet corner is placed below the grippers 28 or 29 and the. trolley 25 started manually or by the sheet breaking the beam from the photocell 67 when an edge portion of the sheet is drawn onto the table adjacent the stop edge 20, the rest of the sheet entering a trough 19. When the sheet has been released by the centralising means air is admitted to a cylinder 85 (Fig. 7) to move a bar 81 to the position 811 and hold the sheet against a clamping surface 84. An air cylinder 94 is then actuated to swing the transfer bar or roller 89 against the sheet and move the edge in a loop over the second transfer bar 95 into the suction box 97, the bar 81 moving to the position 812 during this movement. The second transfer bar 95, which is mounted between two chains 96 carried on pivotable side frames. 111, then carries the edge of the sheet onto the conveyer bands 13, the bar 81 meanwhile moving to the position 813, (Fig. 7). As the edge is placed on the bands 13 the roller 101 is raised and a brush 141 is pivoted away from the roller 101 to smooth the leading edge of the sheet. Switches S1 to S11 control the successive operations of the apparatus.