Collator for printed sheets

Claim 1

In a collator which includes an endless gathering chain provided with spaced carriers to deliver collated printed sheets for binding, and a series of printed sheet supply boxes aligned beside the conveyor chain for feeding printed sheets forwardly onto said carriers as the latter move past said boxes, in combination: a supply box frame; a hopper on top of said frame with horizontal support means to hold a small stack of generally horizontally disposed printed sheets, said hopper having a front wall provided with slots in its lower portion; a plurality of stack lifter hooks each of which has an upright shank and a finger at the lower end of the shank, each of said hooks being pivotally suspended from its upper end forward of said front wall with its finger extending rearwardly in alignment with one of said slots; means for simultaneously raising and lowering all of said hooks substantially endwise with no effective motion of said hooks toward said supply of box; cam means including a follower roller on each hook shank and a cam track forward of the front wall having parallel surfaces between which each said roller is confined and travels as the hooks are raised and lowered, each said cam track and follower cooperating to modify said substantially endwise motion so as to project the hook finger rearwardly through the slot into engagement with the stack as the hook is raised and to retract the finger as the hook is lowered; and gripper means beneath the hopper for engaging the bottom printed sheet in the stack near its leading edge to pull said sheet downwardly and forwardly out of the stack for feeding onto a conveyor chain carrier.