Inline stacker with non-interrupt gap generator and integrated drive control and jam response

Abstract

An inline stacker receives a shingled stream of printed sheet products from a printing press, or finishing equipment, at line speed. A sheet counter at an infeed conveyor section controls the operation of the inline stacker. The infeed conveyor can pivot to a divert position where it feeds the stream to a bi-directional conveyor. A following gap generator section of the stacker has two conveyors with opposed movable ends that are physically separated in the conveying direction by a small gap. The infeed conveyor and gap generator conveyor sections carry the stream at a substantially constant speed, which can be the line speed. To produce a gap in the shingled stream that defines a bundle size, the movable conveyor ends defining the gap between the conveyor gap generator sections move downstream in unison at the speed of the upstream conveyor. At the same time, the speed of the downstream conveyor is briefly increased. The movable ends and the increased conveyor speed then return to their initial status. Stacks of a predetermined size are collected on a forked elevator with mirror movement side walls and other product movement and position controls. Ball-screw-driven and cam-driven side joggers (at the infeed) align the stack and infeed stream laterally. The ball screw jogger, under control of a central controller and an associated servo motor rotates continuously in one direction to open the side walls in response to a sensed jam. The stacker is portable and mechanized for side lay adjustment to align with the press or finishing equipment.

1 . An inline stacker that receives a stream of shingled sheet products moving at a fist speed and forms the shingled sheet products into a succession of stacks each containing a predetermined number of the sheet products, comprising: 
 an infeed conveyor section that receives and conveys said stream at generally the first speed,    a counter that counts the number of products thus received at said infeed section, and generates an output control signal when said predetermined number is reached, and    a controller for the stacker that coordinates the operation of the online stacker at least in part in response to said counter output control signals.    
     
     
         2 . The inline stacker of  claim 2  further comprising a gap generator section and a stacker section, said gap generator section receiving said stream from said infeed section and conveying it to said stacker section at generally the first speed with a gap in said stream between successive adjacent groups of the predetermined number of sheet products.  
     
     
         3 . The inline stacker of  claim 2  wherein said gap generator has upstream and downstream conveyor sections with adjacent, movable ends that are 1) physically separated in the direction of movement of the stream, and, 2) move in unison in the direction of said conveying generally at said first speed, while the speed of said downstream section is increased to a value in excess of said first speed to create said gap in the shingled product stream.  
     
     
         4 . The inline stacker of  claim 1  or  2  further comprising a diverter that has a bi-directional conveyor disposed adjacent said infeed section that, upon detection of a jam, receives and transports the stream of shingled sheet products received at said infeed section before it reaches and is conveyed by said gap generator section.  
     
     
         5 . The inline stacker of  claim 4  wherein said diverter further includes a mechanism for moving the infeed conveyor between a first position where it feeds the stream to the gap generator section and a second position where it feeds the stream to the diverter.