This term generally stands for a technical device consisting of 2 tongs which open and close in order to hold and transport objects.
Grippers on CNC-machining centres
Referring to CNC controlled tool machinery such as CNC- machining centres and CNC boring automates, grippers are the device used to hold and transport workpieces.
The grippers are used to carry out a processing movement with the workpiece on a linear axis (usually X).
Advantages
- The aggregates support only needs to be moved in one direction. The machine can thus be constructed with a much smaller, space-saving base frame which is more economic. The complete technology to move a heavy cantilever or gantry, which is comparatively complex, is no longer necessary. The technology required to move the grippers is relatively simple and can be produced economically.
Disadvantages
- In order to process the workpiece, it can only be held on a small area and has to slide over the support for the movements and processing. This can lead to damage on sensitive surfaces. Measures such as the use of flotation tables or synchronised feed-through technologies eg. conveyor belts can guard against damage.
- The workpiece has to be fixed during processing to avoid vibrations and sliding around. The grippers can be an obstruction for the fixation and also for the processing. A better, flexible fixation can be achieved with a divided beam at the pressure table and processing in the clamping area of the gripper is possible if the tongs are programme-controlled to change their gripping position. In this way there is no limit, theoretically, to the length of the workpiece to be processed.
Grippers are also used as clamping and gripping devices in other machines, please see:
