Patent GB-1110775-A (GB)
Title: Automatic sheet stackers
IPC: B65H29/50
Filed: 1965-06-18
Abstract: 1,110,775. Sheet stacking apparatus. M. D. MARTIN. 18 June, 1965, No. 25786/65. Heading B6H. A stacking apparatus for sheets delivered from a printing machine comprises a base 1, Fig. 3, on which is pivotally mounted a conveyer 2 one end of which is articulated to a compensating lever 4 attached to brackets 23 supported on the base . Intermediate its length the conveyer is attached to a raising and lowering device 3 comprising arms 17 articulated at their ends to the conveyer 2 and bracket 18, respectively, and the arms 17 are actuated by a pressure operated piston rod 24 in such a manner that the stacking end of the conveyer, which is raised with the increasing height of the stack deposited on an intermittently operated conveyer 6, moves in a vertical plane. Attached to the stacking end of the conveyer 2 is a sheet guide comprising abutment walls 42 and oblique guide walls 43 mounted adjustably on a cross-bar 46 which is carried on adjustable bars 48 mounted slidably on yokes 49 pivotally mounted through brackets 32 on a shaft 33. A wheel 52 in conjunction with chains 54 slides the bars 48 to adjust the abutment walls 42 to the size of printed sheets stacked. The sheet guide is maintained in a horizontal position during the vertical travel of the conveyer stacking end by a link 39 pivotally attached to the bracket 32 and actuated by a crank arm 41 operated by the arms 17. To prevent offset of printing, the stacking of the sheets is assisted by air jets blown from nozzles 34, Fig. 7, disposed between conveyer belts 15 some of the nozzles being provided with baffles 38 to promote even air distribution in the air duct 31. The duct 31 is attached to the pivotally mounted brackets 32 so that the nozzles 34 have their outlets 36 disposed in the vertical plane during the vertical movement of the conveyer 2. When a stack of sheets has reached a predetermined height which is adjustable by means of a dial 164, Fig. 3, a photo-electric-cell 93 actuates a brake 109 which arrests the sheets on the conveyer belts 15 by means of brake slats 109. The arms 17 are also connected to a timer 114, Fig. 12 (not shown), which includes cams 103, 106, 112, 134, and the pivotal movement of the arms sequentially actuates the cams so that when the stack reaches a predetermined height and the slats 109 are on the arms are subjected to additional pivotal movement to raise the sheet guide vertically sufficiently for the abutment walls 42 to clear the top of the stack, whereupon the conveyer is set in motion to remove the stack of sheets. The arms 17 are then lowered to lower the stacking end of the conveyer 2 to the level of the conveyer 6 and on release of the brake slats 109 the stacking cycle begins afresh. To prevent the printed sheets falling between the printing machine 191, Fig. 10 (not shown), and a lay boy 186 which moves laterally away from the printing machine on account of the pivotal movement of arms 4 the lay boy 186 is provided with a guard including a fixed bar 187 to which are articulated guard plates 189 extending between the conveyer belts 188 and towards the printing machine.