公开(公告)号：US4822234A

公开(公告)日：1989-04-18

申请号：US121422

申请日：1987-11-16

申请人： Peter E. Johnson ,  David A. Johnson ,  George W. Kahl

发明人： Peter E. Johnson ,  David A. Johnson ,  George W. Kahl

IPC分类号： B65G47/84 ,  B65G59/04 ,  B65G59/08 ,  B65H3/08 ,  B65H3/42

CPC分类号： B65G47/848 ,  B65G59/04 ,  B65G59/08 ,  B65H3/0891 ,  B65H3/42

摘要： The present invention comprises a rotary carrier which carries a plurality of semi-spherical gripping heads having concave gripping surfaces. The gripping heads are positioned such that the gripping surfaces become flush with the forwardmost plate in a vertically arrayed stack of plates as the carrier rotates. Each gripping head is mounted to the carrier through a hollow bellows and vacuum air drawn into a hole in the gripping face passes through the bellows. When the vacuum increases, due to the forwardmost plate in the stack being pulled up against the gripping head, the bellows collapses and pulls the forwardmost plate away from the stack. Rollers, which extend beyond the periphery of the carrier, urge the stack away from the gripping head immediately before they become aligned. The vacuum then pulls the forwardmost plate away from the stack and into contact with the gripping head before the bellows collapses thereby increasing the gap between them. Vacuum is provided to the gripping head through a passageway which opens out of an opening in the carrier. A first sector plate, which is journaled on the carrier axle but does not rotate with the carrier, has a slot passing through it which overlies the opening in the carrier when they are aligned. A second sector plate, which overlies and is attached to the first sector plate, has a hole in it which opens into the slot in the first sector plate. A vacuum tube extends between this opening and a vacuum source.