Multiple action shovel feed mechanism for stacked sheets

Abstract

A stack of sheets or blanks are supported for individual high speed feeding from the bottom of the stack on a table positioned adjacent to a feed cylinder. An air blast from a pivotal nozzle deflects the leading edge of the bottom blank downwardly into engagement by suction force with the surface of the feed cylinder. Rotation of the feed cylinder separates the bottom blank from the stack. A plurality of rocker arms are then oscillated forwardly into the gap between the stack and the separated bottom blank. The rocker arms are independently, rotatably supported transverse to the leading edge of the stack. The position of the rocker arms is adjustable to support the stack as determined by the die cut configuration of the blanks. A fast cam actuates oscillation of centrally positioned rocker arms beneath the central portion of the stack leading edge with an accompanying blast of air between the bottom blank and the stack. Slow cams oscillate the laterally positioned rocker arms beneath the lateral portions of the stack leading edge with an accompanying blast of air between the bottom blank and the stack. The lateral rocker arms move after the centrally positioned rocker arms to ensure that the lateral edge portions of the stack remain stationary and do not sag into the path of the separated bottom blank and jam the feed operation. The independently supported rocker arms are laterally adjustable across the stack leading edge for efficient conversion of the feed operation from one style of blank to another.