Patent GB-932003-A (GB)
Title: Improvements relating to paper cutting and sorting machines
IPC: B65H43/04
Filed: 1962-03-13
Abstract: 932,003. Feeding webs; deliverying sheets. S. D. WARREN CO. March 13, 1962 [March 13, 1961 (2)], No. 9613/62. Class 100 (1). A paper cutting and sorting machine comprises an unwinding stand 12 for supporting a roll of paper 11, a pair of retarding rollers 18, 19 over which the paper web passes, means 24 for inspecting the paper and producing a signal if a defect in the paper web passes it, feed rollers 26 for the paper web, means positioned between the retarding and feed rollers responsive to the tension in the web for controlling the degree of braking applied to the retarding rollers, a rotary cutter 28 for cutting the web into sheets, means for conveying sheets from the cutter to a reject gate 36 controlled by the signal from the defect detector 24 and two conveyer systems for conveying good and defective sheets respectively to separate layboys. Feeding webs.-The paper roll 11 is elevated in the stand 12 by an hydraulically actuated elevator mechanism 13 to a position where the axis of the roll coincides with chucks 14. The chucks are then hydraulically moved into the axis of the roll and expanded within the roll core to support the roll, the mechanism 13 being then retracted. The tension control comprises a pendulum 21 pivoted at its upper end about the axis of an idler roller 22. A second roller is rotatably mounted on the lower end of the pendulum and the web is guided round the two rollers, as shown in Fig. 1. Increase and decrease of the tension in the web at 16<SP>1</SP> causes deflection of the pendulum from the vertical, such deflection opening and closing a valve 106 in an air line to a pneumatic brake control 108 which applies braking force to the rollers 18, 19. Switches and strippers.-The leading edge of a cut sheet is stripped off a drum 29 carrying the cutter 28 by a Venturi head 31, and is directed into a high-speed tape transport system 33 which delivers the sheet either to a high-speed conveyer system 41, or, if the sheet is defective, to another conveyer system 42, depending upon the position of the reject gate 36. Delay means are inserted in the electrical control circuit of the gate 36 to ensure that it is not raised so as to direct a sheet on to the conveyer system 42 until immediately before a sheet containing a defect detected by the device 24 reaches the gate. When the gate is raised blasts of air are directed downwards through ports 128, Fig. 8, on the underside of the gate and deflect the leading edge of a faulty sheet downwards before it strikes the underside of the gate. The gate 36 is divided transversely into four parts which may be moved separately (for dealing with a web which has been divided longitudinally into four strips before being cut into sheets) or together. Compressed air is supplied to the interior of one gate part by a pipe 121 and from there to the other parts via flexible connecting pipes 217. The machine parts near the gate 36 are so dimensioned that a sheet passing over or under the gate as it moves from one position to the other is not trapped. Delivering sheets.-The conveyer system 41 comprises a set of upper tapes 47 and a set of lower tapes 53. Discs 52 adjacent to one end of the tapes 53 are driven from a roller 48 over which the 'tapes 47 pass, and co-operate with corrugating rollers 40. A sheet passes from the conveyer system 41 between the discs 52 and rollers 40 and is thereby stiffened by temporary corrugations. As it leaves the nip of the discs and rollers the leading end of the sheet is blown upwards by a blast of air from a nozzle 68 which holds it in contact with the tapes 47 until it has overlapped the trailing end of the preceding sheet. The sheet continues to move at the speed of the conveyer system 41 until the leading edge passes into the nip of discs 65 and rollers 66 which decelerate it to the speed of a further set of tapes 61 driven at a slower speed than those of the conveyer system 41. Simultaneously the trailing end of the sheet is urged downwards into contact with the tapes 61 and with a rotating, braking, suction roller 64 by a blast of air from the nozzle 68 directed at the underside of the succeeding sheet which is deflected downwards from the underside of that sheet. The overlapped sheets are finally deposited by the tapes 61 in a layboy 50 of the type described in Specification 932,004. The discs 65 and rollers 66, together with a tensioning roller 67, for the tapes 61, are mounted on brackets 89 slidable on rails 90 and may be adjusted between the full- and dotted-line positions by a rack-and-pinion drive so as to accommodate different lengths of sheet. Two photo-electric detectors 75, 76 are positioned below the upper run of the tapes 53 spaced apart a distance slightly greater than the normal space between sheets in the conveyer system 41. When the detectors simultaneously register absence of a sheet above them on the tapes 53 a magnetically controlled brake and clutch device in the drive to the tapes 61 is actuated so as to stop the low-speed conveyer. As soon as one of the detectors registers the presence of a sheet above it the drive to the tapes 61 is re-engaged. The rejected sheets are carried by the conveyer system 42 round a turnaround roller 43 from which the sheets run to a high-speed conveyer system 44 which is substantially identical with the conveyer system 41. A set of tapes 61<SP>1</SP> corresponds to the tapes 61 and co-operates with the system 41 to produce an overlapped stream of rejected sheets which is finally stacked in a layboy. Detectors 75<SP>1</SP>, 76<SP>1</SP> correspond to the detectors 75, 76.