GB564876A - Improvements in and relating to sheet feeders - Google Patents

Abstract

564,876. Feeding sheets. HARRIS-SEYBOLD-POTTER CO. July 14, 1943, No. 11471. Convention date, June 10, 1942. [Class 100 (i)] A sheet - feeding device which is especially applicable for feeding small sheets from a pile in overlapped form to a printing or like machine is constructed with a sheet gripper preferably in the form of a suction roller 178 which acts on the rear edge of the pile in conjunction with fixed air-blast devices 116, Fig. 19, and 118, Fig. 2 (not shown), and an oscillating presser - foot 147 which also is fitted with means for forming an air blast. The suction roller 178 is mounted on a pivot 170 carried by an oscillating arm 164, and a gear-wheel 180 on the roller is connected by a gear 181 to a gear sector 184 which is oscillated by a cam on the same shaft 95 which carries the cam for oscillating the arm 164. The roller 170 is constructed as shown in Fig. 10 with two sets of suction apertures 199, 201, and the roller can be secured in either of two positions on its shaft so as to cause either set of apertures to be operative to grip the top sheet of the pile 37 which is controlled by adjustable guides, the pile being kept at a level by hand or automatically controlled means. The roller 178 is provided with two spaced sets of suction apertures, or spaced suction nozzles of different sizes, 208, 260, Fig. 8 (not shown), so as to prevent lateral shifting of the separated sheets. A complete series of separating actions for each sheet is started by fluffing up of the top sheets by the blast devices 116, followed by attraction of the top sheet to the apertures 201 when these are in the position shown in Fig. 17. The roller 178 is then moved upwards and forwards in an epicycloidal path as indicated in Fig. 26 by the line a, b, the sheets being prevented from forward movement by, pivoted front guides 258. The roller 178, after gripping the top sheet, rotates counter-clockwise and the presser-foot 147 moves into the space between the top sheet and the pile, and delivers a blast of air under the top sheet, the blast being cut off from the devices 116, 118. The guides 258 are now moved away from the front edge of the pile and the roller 178 is rotated clockwise to advance the sheet into engagement with sectional feed rollers 56 co-operating with an idle roller 62 mounted in pivoted arms 64. The suction and blast are cut off as the roller 178 and presser-foot 147 return to their starting position, and the blast devices 116, 118 come into action before this return is completed. For overlapping feeds, the separation of the next sheet starts before the prior sheet is withdrawn from the pile. The sheets are finally advanced by tapes 57 to the front stops 33 of a printing or like machine. The machine is adapted for dealing with sheets of different sizes, the pile being controlled by guides adjustable on a cross-bar 240, and the separating devices being adjustable longitudinally of the pile and having splined connection with a drive shaft 85 driven by helical gearing.