GB729892A - Improvements in or relating to paper feeding devices - Google Patents

Abstract

729,892. Feeding sheets. BRITISH TABULATING MACHINE CO., Ltd. Oct. 15, 1953, No. 28497/53. Class 100 (1). Pile supports; sheet-separators.-Apparatus for separating sheets from a stack comprises two or more hollow suction tubes, such as 14, 15, provided each with one or more suction nozzles, a pinion secured to each tube and meshing with the internal teeth 18 of a fixed annular gear, and means for driving the pinions to cause them to roll around the inner face of the fixed gear. As shown, a motor-driven shaft 1. running in ballbearings in a housing 4, is carried by a bracket 5 attached to a main side-plate 6, the housing having a suction drum 8, 9, 10 thereon which communicates with a source of vacuum through an inlet 7 and pipe 31. A hub disc 11 secured to one end of the shaft 1 carries ball-bearings 12, 13 which support one end of each of two suction tubes 14, 15 which carry pinions 16, 17, respectively, meshing with the internallytoothed gear 18 which is secured by brackets 19 on the bracket 5. The other ends of the tubes 14, 15 run in ball-bearings in a hub disc 24 secured to a shaft 25 and mounted in a housing 28. The tubes 14, 15 have short nozzles 20, 21, respectively, extending therefrom. Rotation of the shaft 1 and disc 11 causes the pinions 16, 17 to roll inside the gear 18, and the ends of the nozzles 20, 21 trace out a hypocycloidal path having three cusps. A hopper 35 for sheets is located adjacent one cusp, and a pair of feed rolls 36 is adjacent another cusp, so that by controlling the vacuum in the nozzles, sheets are taken up from the hopper and delivered to the feed rolls for removal by a conveyer belt 63. At one end, the tubes 14, 15 abut a side wall 9 of the suction drum, and communicate with the interior of the drum through an arcuate slot in the wall 9; the other ends of the tubes abut a plate 40 also having an arcuate slot therein which, at the appropriate time, opens the tubes to atmosphere. The end of a nozzle moves nearly vertically towards and away from the stack and the edge of each sheet is lifted nearly vertically and then bent sharply. Each sheet is drawn past the hooked end of a spring 64 to prevent two sheets being separated. The ratio of teeth on the pinions and gear 18 can be varied, and the disposition of the stack and feed rolls 36 adjusted correspondingly; or three pinions and suction tubes could be used so that three sheets may be separated for each revolution of the shaft 1. The stack of sheets is supported on a plate 44 mounted on a pillar 45 on which is secured a cord 46 which passes over a pulley 47 and has a weight 48 attached thereto. A ratchet-wheel 49 secured to the shaft of the pulley 47 is held against rotation by a pawl 50 controlled by an electromagnet 55 and armature 62 in a circuit including a switch 56 and a switch 61. The switch 61 is controlled by a bell-crank 58 having at one end a roller 57 resting on the top of the pile of sheets. The switch 61 is closed when the pile diminishes more than a predetermined amount, whereby the armature 62 is attracted by the magnet 55 to swing the pawl 50 away from the ratchet 49 and to engage a pawl 53 with the ratchet; this allows the ratchet to turn through an angle equivalent to half a tooth. At the same time, the movement of the armature also causes the switch 56 to open, and this results in the above operations being reversed and allows the ratchet 49 to move a further half tooth. The stack is thus raised one step, and if this is not sufficient to open the switch 61, the operations are repeated. In modifications, the sheets are stacked on edge and pressed forward by a weight, or the sheets are separated from beneath the stack.