In the machining industry, when a piece of stock or a workpiece is being machined, it is desirable to securely hold the workpiece so as to prevent unwanted movement thereof during the machining operation. One approach commonly taken is to utilize any one of a variety of vise type devices for holding workpieces. Such vise devices typically include one or more jaws which can be adjusted to engage the outer surfaces of the workpiece. Often in the machining environment, it is necessary to utilize the same machine tool for machining workpieces of various configurations, that is, workpieces having different cross-sectional shapes. In the past, some vise type devices utilized for holding workpieces have allowed for the jaw or jaws to be removed in order to accommodate holding of workpieces having various configurations. In particular, it is not uncommon to use multiple sets of jaws, each set being machined to specifically hold a workpiece of a certain configuration. One set of jaws is placed on the vise type device at a time in order to hold a workpiece having a configuration which corresponds thereto. If the same vice needs to be used for holding a workpiece of a different configuration the solution is to remove the set of vise jaws currently being used and to replace the removed set with a different set of vise jaws. This type of change out operation is time consuming and therefore costly in that it reduces productivity.
An alternative to changing out jaws is to use a jaw which does not necessarily match any one of the workpiece configurations. However, this can sometimes result in inadequate holding forces, and thus workpiece movement during the machining operation, resulting in defective end products. Even where specially machined jaws are used, it is possible that some workpieces may not exactly fit the jaw. For example, a jaw might be machined having planar surfaces intersecting at an angle of 90 degrees in order to hold a workpiece of rectangular cross-section. It is possible that some workpieces may not be exactly rectangular, that is, the corners thereof may not form precise right angles. In such cases the machined jaws are unable to compensate for such variations and the effective holding power of the jaws is adversely affected with respect to such imperfect workpieces.
Further, many of the aforementioned problems arise in workpiece holding applications in which a device other than a vice is used. It would therefore be desirable to provide a workpiece holding assembly which can be adapted for inclusion in a large number of types of holding devices, and which can be scaled for use in holding both small and large workpieces.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.