| 摘要 |
A gripping device for an apparatus for placing electronic and/or electrical components on a substrate comprises a pair of grippers (1 and 2) which are movable relative to one another to close and open the jaws (4 and 5) of the grippers. The device is intended for use in an apparatus which is designed to handle components of different widths, and the device is constructed so that the gripper jaws can be opened wide enough to accommodate the widest component. In order to reduce the space required between the components on the substrate for the opening of the jaws to release a component (6) after it has been placed on the substrate, a stroke-limiting device is provided which is arranged for abutment with one of the grippers after an initial relative movement between the grippers in the direction to open the jaws, so that the initial stroke of the grippers in this direction is limited to a small amount which is sufficient to release the component. The gripping device is then raised above the component and the stroke-limiting device is rendered inoperative so that the jaws can be fully opened. The stroke-limiting device comprises an abutment member (7) in the form of a rod (8) which is slidable in a bore (11) in one of the grippers (1) and has a head (9) with an abutment surface (12) for cooperation with an abutment surface (14) on that gripper, a spring (16) being arranged to urge the abutment member (7) to a position in which the abutment surfaces are spaced from one another (Figure 1). The rod also extends between two clamping members (18 and 19) in the other gripper (2), which clamping members are operable by fluid pressure to clamp the rod between them to lock the abutment member to this gripper. In the locked operative condition of the abutment member the gripper jaws can be opened only by a small initial amount which is determined by the abutment of the two abutment surfaces. The abutment member is rendered inoperative by releasing the clamping members. The grippers can then be opened fully. |
