Apparatus for slowing down and preventing edge damage on moving sheets

Apparatus for two-stage overlapping of cut-size sheets passing in seriatim flow between a high-speed tape conveyor system and a low-speed tape conveyor system, said low-speed tape conveyor system having sheet carrying surfaces disposed at a level substantially lower than sheet carrying surfaces for said high-speed tape conveyor system, comprising:

• a drop-off area having a support plate generally level with the carrying surfaces of said low-speed conveyor and onto which sheets drop in transit between a delivery end of said high-speed conveyor and a receiving end of said low-speed conveyor and having a slowdown assembly having upper nip wheel and lower slowdown roll means defining therebetween a nip for receiving sheets therethrough passing from said support plate to said low-speed conveyor,
• said lower slowdown roll means being aligned with the carrying surfaces of said low-speed conveyor and driven by a constant-speed motor means to run at a speed less than the speed of said high-speed tape conveyor but greater than the speed of said low-speed conveyor,
• said upper nip wheel means being mounted to selectively nip each sheet against said lower roll means for delaying the trailing edge of the nipped sheet on said support plate such that the leading edge of the next succeeding sheet overlaps onto the nipped sheet trailing edge as the next succeeding sheet passes from the delivery end of said high-speed tape conveyor system, and
• stop roll means rotatably disposed over said low-speed sheet carrying surfaces to slow each sheet down to the speed of said low-speed tape conveyor system while the next succeeding sheet is being nipped in said slowdown assembly, thus causing the next succeeding sheet to further overlap the stop roll slowed sheet as the next succeeding sheet is passed through said slowdown assembly nip.

A method for overlapping cut-size sheets passing in seriatim flow from a relatively high-speed tape conveyor system to a relatively low-speed tape conveyor system, wherein said low-speed tape conveyor has sheet carrying surfaces at a level substantially lower than sheet-carrying surfaces for said high-speed tape conveyor system, comprising:

• dropping sheets off a delivery end of said high-speed tape conveyor system onto a support plate such that the leading edge of each sheet extends horizontally outward initially and then gently curves toward said support plate and the trailing edge of each sheet bends off said delivery end so as to be snapped down flush with said support plate,
• delaying each sheet downstream of said support plate by passing each sheet through a slowdown nip formed at the level of the carrying surfaces of said low-speed conveyor by upper and lower roll means such that the trailing edge of each sheet is overlapped by the leading edge of the next succeeding sheet as the leading edge of the next succeeding sheet drops off said high-speed delivery end,
• slowing each sheet down to the speed of said low-speed tape conveyor system after each sheet has passed through said slowdown nip with a stop roll means rotatably disposed over said low-speed tape conveyor system, and
• directing each sheet through said slowdown nip at a constant speed less than speed of said high-speed tape conveyor system but greater than the speed of said low-speed tape conveyor such that the trailing edge of each slowed sheet is further overlapped by the leading edge of the next succeeding sheet passing through said slowdown nip.