GB794199A - Improvements in or relating to sheet feeding apparatus - Google Patents

Abstract

794,199. Perforating machines. BUCKLEY, M., and BUCKLEY, D., [trading as HIRST, BUCKLEY & CO.]. March 26, 1956 [March 28, 1955], No. 8941/55. Class 31 (2). [Also in Groups XVI and XXIX] In sheet feeding apparatus wherein sheets are moved in a second direction after reaching their limit of travel in a first direction, there is disposed adjacent the limit of travel a suction nozzle connected to a source of suction by means of a control device which is responsive to a pressure fall in the nozzle, and which is connected to sheet-gripping means for feeding the sheets in the second direction, the arrangement being that when a sheet overlies the suction nozzle, the control device will be actuated to cause operation of the sheet-gripping means. As shown, the invention is applied to a paper-perforating machine comprising two sets of apparatus arranged to provide perforations in two directions across sheets. Sheets 50 are separated one by one from a pile by a suction roller 51 on to the feed belts 12 in apparatus 10 which feed each sheet past perforating discs 13 up to an adjustable stop 20 where it overlies a suction nozzle 21. The nozzle is connected by a flexible pipe 24 to a control device 25 connected by a pipe 42 to a source of suction. When the end of the nozzle 21 is obturated by a sheet, suction builds up in the control device 25 to move a piston therein so that suction can be established between the pipe 45 and a pair of rotating suction rollers mounted in a cross-shaft 48, whereupon these rollers feed the sheet at right angles to the first direction on to feed belts 12<SP>1</SP> in another apparatus 11 which has further perforating discs therein. The suction rollers are in heads 43, 44; suction is applied thereto by pipes 46, 47, 41, and chambers disposed against holes in the sides of the rollers. The side holes communicate with holes in the circumference of the rollers, and top plates 49 ensure that only one axially disposed row of holes is presented at a time to a sheet. The control device 25 comprises a valve body in which a piston is slidable, against the action of gravity and a light spring, to establish communication between pipes 41, 42, when the pressure above the piston falls due to the closing of the nozzle 21 by a sheet. A by-pass is arranged between the pipe 42 and the space above the piston which communicates with the pipe 42.