| 摘要 |
A workpiece engaging apparatus includes a drive having a linearly reciprocal drive member. Two workpiece engaging members are arranged in opposed, inverted relationship with respect to each other and pivotally connected at one end to the drive. Each workpiece engaging member includes a workpiece engaging surface and at least one cam. In one embodiment, the cams in each of the first and second workpiece engaging members are identically constructed, but are disposed in opposed, inverted relationship with respect to the cams in the opposed one of the first and second workpiece engaging members. Cam follower members mounted on the linear drive member engage the cams during reciprocal movement of the drive member to pivot the workpiece engaging surfaces of the first and second workpiece engaging means between open and closed workpiece engaging positions. In another embodiment in which the apparatus is designed to perform a hemming operation on overlapping sheets, a first cam is formed in each of a pair of block members secured to the linear drive member. The block members are pivotally connected at a first end to the linear drive cylinder. Spaced, outer plates, each having a second cam formed therein, are also pivotally connected at one end to the linear drive cylinder and carry a workpiece engaging member at an opposite end. Linear movement of the cam follower driven by the linear drive member causes the outer plates to pivot between an open position and a closed, workpiece engaging position.
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