GB662947A - Improvements in or relating to a sheet delivery mechanism for machines such as printing machines - Google Patents

Abstract

662,947. Sheet-delivery mechanism. STEVENS, A. H. (Harris-Seybold Co.). Feb. 2, 1949, No. 2852/49. Class 100 (i). A sheet-delivery mechanism for machines such as printing machines includes a sheet conveyor adapted to be driver at different selected speeds and having means for gripping the sheets at their forward ends, and suction means having a sheet - contacting surface over which the sheets are drawn by the gripping means, and adapted to move in the direction of sheet travel for slowing down the sheets upon their being released by the gripping means and imparting to them a final advancing motion on to the pile, and means is provided adapted to variably control the suction means for causing the surface thereof tc move at any one of a plurality of speeds. Sheets are conveyed from a machine such as a printing press by grippers 17, Fig. 1, on endless chains 15, 16, Figs. 1 and 2, their leading edges being released by the grippers when the sheets are over a pile 26 on a vertically adjustable table 25. Bars 32, 33 are reciprocated by crank arms 31 having a complete oscillation for each sheet handled, and carry jogger-plates 59, Figs. 1, 2 and 6, for the rear of the pile. Side jogger-plates and front pile guides 27 are also provided. The plates 59 are each carried by jibs 60 on an arm 62 clamped to a pipe 5-5 and having an extension 63 carrying an adjusting screw 64 bearing against an angle bar 57, to allow vertical and lateral adjustment and removal of the plates. The angle bar 57 is secured at its ends to brackets 35, 39 carried by the bars 32, 33, and is attached to the ends of a series of flexible tapes 65 extending over idlerwheels 66' and having weights on their free ends, to support the sheets. The pipe 55 is rigidly secured to the brackets 35, 39, is plugged at one end at 56 and is connected by a pipe 53 to a suction chamber 50 connected to a source of suction by a flexible hose 52. A shaft 67 rotatably mounted in the brackets 35, 39 is driven by a constant-speed motor 96 through a manually-operated speed-controller 90, chain 88, shaft 78 and bevels 77, 76. The shaft 78 is reciprocated with the bars 32, 33, connection being maintained by a wide gear 83, and the bevel 77 is adjustable on the shaft 78 as the brackets 35, 39 are adjusted along the bars 32, 33 to accommodate sheets of different lengths. The shaft 67 carries rotating suction wheels 66, each having in its periphery a series of slots which register when in uppermost position with a hole in the wall of a stationary suction box 70. The box 70 is secured to the pipe 55 by means of an arm 73 whose bifurcated end straddles the pipe, collars 74 securing it thereto and allowing adjustment laterally of the machine. The box 70 is connected by flexible tubing 75 to the pipe 55. The sheets are drawn by the grippers over the suction wheels, and the rear part of the sheet is blown down into contact therewith by air blasts from holes 46 in a pipe 44, plugged at one end at 45, carried on the brackets 35, 39 and connected to a source of compressed air by a flexible tube 49. The wheels rotate forwardly at a slower peripheral speed than the linear speed of the grippers, and tauten and retard the sheet. The grippers release the sheet midway of the forward movement of the bars 32, 33. After the suction wheels release the sheet, the bars 32, 33 are retracted to allow the rear of the sheet to drop on to the pile. While the mechanism is operating, the force of the sheet against the guides 27 is adjustable by adjusting the speed of the suction wheels by the speed-controller 90.