Patent GB-947194-A (GB)
Title: Sheet feeders for printing presses
Inventor: JAMESON KEITH
IPC: B65H1/14
Filed: 1961-03-10
Abstract: 947,194. Feeding sheets. LINOTYPE & MACHINERY Ltd. March 9, 1962 [March 10, 1961], No. 8897/61. Heading B6B. Pile tables and supports.-A sheet feed for a printing press includes a main pile hoist and an auxiliary pile hoist, the main pile hoist lifting a pile of sheets and residual pile-supporting means a predetermined height, whence subsequent lifting is effected by the auxiliary pile hoist, the latter comprising an auxiliary motor driving, through clutch means, gearing meshing with racks having associated hook means, each rack being carried in a guide arm depending from a sheet feeder frame extending above the sides of the sheet pile, and each guide arm and its associated rack and hook means being capable of limited pivotal movement to enable the hook means to engage and incrementally lift the residual pile-supporting means so that the main pile hoist may be lowered for reloading without interrupting the feeding of sheets to the printing press. The pile sup. port comprises spaced guide bars 20 connected by transverse members 15, on which residual pile support bars 17, and between the support bars, a board 18, rest. Metal laths 19 extend across the top of the board and rest on the support bars. The pile support is raised and lowered by cables 8, 9, as described in Specification 947,193, and is guided vertically by bars 21 passing through bearings 7 in the front ends of the guide bars. The auxiliary hoist consists of four units 16, each comprising a fixed depending member 22 and pivoted guide arm 23. The latter is channelshaped in cross-section and contains a bar 25 having a hook 26 at its lower end and a rack 27 at its upper end. A plate 32 having a rightangled flange 34 is secured to the arm 23 by a nut 36 and bolt 33, to limit pivotal movement of the arm by means of a compression spring 35 surrounding the bolt. Relative pivotal movement between the bar 25 and arm 23 is prevented by a grub screw 38 engaging a channel 37 out in one side of the bar. As the pile support is lifted during the continuous feeding of sheets, the support bars 17 are guided between the members 22 and arms 23. The arms pivot slightly as the support bars abut the hooks so that the support bars may pass the hooks 26 and then snap back under the action of the springs 35, whereby the hooks engage beneath the support bars. Longitudinal shafts 29 having pinion teeth 28 engaging the racks 27 are rotated by means of an auxiliary motor 43 to effect movement of the racks 27 to lift the support bars carrying the residual pile. Meanwhile, the members 15 and board 18 are lowered for reloading by the main motor. Microswitches 57, 60 attached to each or only one unit and actuated by the support bars, control operation of the auxiliary motor. In addition, the microswitch 57 switches off the main motor or may reverse the direction of drive of this motor to effect lowering of the main hoist. A channel 49 in the underside of the bar 25 co-operates with the plunger 50 of a microswitch 48 to operate a lamp and indicate that the auxiliary pile hoist is ready to receive the support bars 17 and/or that the auxiliary pile hoist has come into operation.