Patent GB-969647-A (GB)
Title: Improvements in and relating to sheet feeding apparatus
IPC: B65H3/52
Filed: 1961-11-01
Abstract: 969,647. Feeding sheets. INTERNATIONAL BUSINESS MACHINES CORPORATION. Nov. 1, 1961 [Nov. 2, 1960], No. 39056/61. Heading B6B.  Sheet feeding apparatus which provides a substantially constant gap between successive sheets comprises two feed means spaced apart at a distance less than the length of the shortest sheet, the first means being driven impositively at one speed and the second means being driven positively at a higher speed, the arrangement being such that when sheets are gripped by the second means, the first means will slip to allow the sheets to be withdrawn therefrom at the higher speed. The first means co-operates with a restraint member driven in the opposite direction to prevent double feed. Sheet-separators; pile tables.-Sheets 13, such as cheques, are separated from the top of a pile by a belt 104 which passes over a hexagonal grooved pulley 100 supported on a pivoted arm 101. The arm 101 is extended to control a switch 106 in a motor circuit whereby the table 12 is raised periodically to keep the top sheet at a substantially constant level. The top sheet is urged along guides 14, 15 to the throat 17 between a driven disc 21 provided with a friction rim 22, and an endless friction belt 19 which travels in a direction opposed to the sheet movement. The belt 19 is mounted on a drive pulley 34 and idler pulleys 35 . . . 39, the pulley 35 being tensioned by a spring 41, and is driven at a slower rate than the periphery of the disc 21. The coefficient of friction between the belt 19 and a sheet 11 is greater than that between two sheets, but not as great as that between a sheet and the rim 22 of the disc 21; so that a single separated sheet is fed forward by the disc 21, and other sheets separated at the same time are returned by the belt 19. Sheet-forwarders.-A separated sheet is forwarded by the disc 21 along guides 45, 46 between a positively-driven roller 48 and a spring-urged idler roller 49 spaced from the bight of the disc 21 by a distance smaller than the length of the-shortest sheet. Since the periphery of the roller 48 is driven faster than that of the disc 21, the disc is arranged to be driven impositively through a clutch of the coil-spring type to enable the disc to be " overrun " by the sheet while the latter is simultaneously engaged by the roller and disc. During the speed-up of the disc 21 by the sheet, the succeeding sheet will be advanced so that its leading edge will abut the trailing edge of the first sheet. Thus, the sheets can be suitably spaced apart by selecting appropriate speeds for the disc 21 and roller 48. An electromagnetic brake could be used to effect instant reduction in speed of the disc 21 to normal speed when a sheet has left the bight thereof. The disc 21 and reversely-driven belt 19 could be replaced by an arrangement described in Specification 969,646. The sheets are fed over a rotating aligning drum 60, driven at the same peripheral speed as the feed roller 48 by a belt 64, on to a drum 75 driven by a belt 77, around a further drum 78 driven by belts 80, 81, and then between guides 82, 83 by a belt 84. The sheets are fed between the surfaces of the various drums and their drive belts, and on drum 75 they pass a " write " head 90 which magnetizes the magnetic ink characters recorded on the sheets, and a " read " head 91 which reads the characters and provides a signal to control selectors which determine which particular pocket a sheet is to be delivered. Sheet-registration.-Each sheet is fed on to the aligning drum 60 and between a driven roller 71 and a castor-roller 70 which can swivel as necessary to urge the rear edge of the sheet against a rim 65 on the drum. The sheet is then guided by an arcuate guide 72 to a second castor-roller 73 which also urges the sheet into accurate alignment with the rim 65.