摘要 |
Suction-pulling devices for engaging the underside of a lifted top sheet of a stack of sheet material are carried on short carrier pieces inwardly extending from the respective front ends of two swing rods suspended above the stack near its sides. The swing rods are suspended on two crank arms, the most rearward of which is continuously driven to cause the front ends of these rods to describe an oval path in the vertical plane. The upper part of this path, which provides the forward motion, matches the speed of a suction lifter for the top sheet in a rear path portion and matches the linear speed of the drive rolls of a succeeding transport device in a forward portion. The suction-pullers are rotatable about a horizontal axis to fit the lay of the sheet being transferred and a control cam on a bearing of the rear supporting crank arm also produces a slight outward pull of the suction lifters during the forward motion to stretch the front edge of the sheet. |