GB768884A - Improvements in or relating to a sheet feeder - Google Patents

Abstract

768,884. Feeding sheets. HARRISSEYBOLD CO. April 5, 1955 [April 7, 1954], No. 9910/55. Class 100(1) In sheet separating and feeding apparatus wherein sheets are separated from a pile 10 by a rotary suction wheel 16 and then fed by an endless conveyer over a feed table 43, 45 to front register stops 46, the wheel 16 and conveyer are driven synchronously at speeds varying from a minimum speed above zero to a maximum and back to a minimum during each cycle, and the taking of a sheet from the pile by the wheel 16 and the registration of a preceding sheet against the stops 46 by the conveyer recur at about the minimum speed. The distance between the stops 46 and the front edge of the top sheet of the pile 10 is equal to, or a multiple of, the circumference of the suction wheel 16. A number of nozzles 66 direct blasts of air at the top front end of the pile and tend to cause the top sheet to press against the underside of a plate 13. The sheet is then gripped by the rotating wheel 16, which protrudes through a slot in the plate 13, and is fed between a conveyer roller 40 and a gravity roller 38. The roller 40 has the same peripheral speed as that of the suction wheel 16, and drives belts 39 which pass over 'the feed table 43 and around a roller 44. The stops 46 are shown as situated adjacent an impression cylinder 47 of a printing- machine. To ensure that sheets arrive at the stops 46 at the correct time, the suction wheel 16 can be adjusted circumferentially relative to its driving shaft 17; a scale and pointer facilitate this adjustment. The wheel 16 has a series of lateral holes 31 which communicate with radial openings, the holes 31 being adapted to register one after another with a port in a suction fitting 34 mounted on a fixed bracket 35. The driving arrangement comprises a gear 50, which is secured on the cylinder 47 and has a pitch circle diameter equal to the diameter of that cylinder, adapted to drive a gear 53 through gears 51, 52. The gear 53 has a radial slot 56 therein engaged by a roller 60 secured on another gear 57 mounted on a shaft 58 which is offset from the axis of the gear 53, whereby the gear 57 is driven at varying speeds, during each revolution of the constant speed gear 53. The shaft 17 of the suction wheel 16 is driven by chain-and-sprocket gearing from the gear 57, and the latter engages a gear secured to the shaft 65 of the conveyer roller 40, the arrangement being that the surface speed of the conveyer .belts and the peripheral speed of the suction wheel 16 are the same.