Patent GB-686454-A (GB)
Title: Improvements in mechanism for the feeding of sheets from a pile to printing, folding or other sheet operating machines
IPC: B65H7/18
Filed: 1949-09-01
Abstract: 686,454. Feeding sheets. SPIESS, G. Sept. 1, 1949, No. 22709/49. Class 100 (i). Faulty feed control devices.- In sheet-feeding apparatus wherein a feeler device 9 is operated by a faulty sheet, or the absence of a sheet, to stop the feeding of further sheets, a single shaft 36, operated by a handle 40 after a stoppage, reestablishes the suction to suction separators 2, 3, and the drive to the conveyer roll 4, and operates means to release clamps 46, 47, 50 holding the sheets on the conveyer and pile, respectively. The sheets are lifted from a pile 1 by suckers 2, 3, and forwarded by the suckers 3, to a driven roller 4. Tapes 5 on the roller 4 convey the sheets, in overlapping formation, over a table 6 to front stops 7 with which the feeler 9 is associated. The feeler 9 is adapted, when a faulty sheet is at the front stops 7, to energize an electromagnet 16 to release a catch 18 so that a spring 20 can move a rod 19 to the right (Fig. 2). One end of the rod 19 is connected to the movable part of a clutch 24 through a crank lever 21, rod 22, and crank lever 23, so that when the rod 19 is moved to the right the clutch cannot drive the conveyer roll 4 through gearing 30-33. The other end of the rod 19 is connected to a lever 25 fast on a shaft 26 coupled by gears 27, 28 to the shaft 36, .whereby the latter is rotated on movement of the rod 19. The shaft 36 has a piston thereon operating inside a valve bore 37 to which an air pipe line 39 for the suckers 2, 3, and an air pressure line 38 leading to an airblast nozzle at the front edge of the pile 1, are connected; movement of the rod 19 thus causes the air supply to these pipes to be cut off, and further sheets cannot be removed from the pile 1. The clamps 50 for the pile 1 are cylinders having pistons therein which are urged towards the sheets on the pile 1, against the action of springs, on the establishment of suction to the cylinders when the shaft 36 is rotated due to a stoppage. The clamps 46, 47 are adapted to clamp the sheets, by suction, to the heads of spring-urged pistons in air-bores connected by pipes 48, 49 to the valve bore 37, when the shaft 36 is rotated. After a stoppage, and the defective sheet has been removed, it, is only necessary to rotate the shaft 36 by the handle 40. This conditions the valve bore 37 to establish suction to the suckers 2, 3 and cuts off suction to the clamps 46, 47, 50, and moves back the rod 19 to the left to allow the conveyer roll 4 to be driven. Synchronism between the suckers and conveyer is established after a stoppage by providing a single tooth engagement between the two parts of the coupling 24, and by arranging that the shaft 36 cannot be turned until the suckers are in a particular position. The shaft 29 which operates the suckers has a cam 41 thereon engaged by a roller 42 on a pivoted lever 43, 44. The other end of this lever co-operates with a segment 45 fast on the shaft 36, the arrangement being such that the shaft 36 cannot be turned unless the cam 41 has rocked the end of the pivoted lever away from the segment 45. An auxiliary device, which is manually-operated, for stopping the sheet-feed mechanism, comprises a system of levers 52-54 adapted to press up the catch 18 to release the rod 19. A further device, which prevents sheets being separated from the pile but allows those on the conveyer to be fed, comprises a casing 56 to which the pipes 38, 39 are connected, and a spring-pressed piston 57 therein which can be hand-pressed to cut off suction from the pipe 39 to the suckers 2, 3; the mechanism is then stopped automatically, as described above, when the last sheet has been fed.