As is well known, it is necessary to firmly clamp workpieces on machine tools of various kinds so that they can be machined, ground, or otherwise shaped. In some such devices, it is common practice to support the workpieces on members which are designed to support specific workpieces, particularly where the workpieces themselves have an irregular lower surface. Thus, supporting devices are produced to accompany specific workpieces and are therefore unchangeably adapted to support the specific workpieces with which they are associated. This requires that different support devices are needed for different workpieces, and the costs of production and storage of the support devices imposes a disproportionately high load on the total production cost of the workpieces, particularly when it develops that a relatively small number of each differently shaped workpiece is to be produced.
A more flexible approach in common use is to clamp the individual workpieces on clamping tables of machine tools of various kinds, such as milling machines, wherein clamping shoes are longitudinally adjustable in slots having the shape of an inverted T, the undersurfaces of the workpiece being caused to rest on the upper surfaces of the clamping table on individually adapted or movable loose supports. While this is a usable approach, the process of clamping each workpiece requires a long adjusting time and the procedure is suitable only for the finishing of single pieces or relatively small numbers of pieces.
Yet another approach, which has similar disadvantages, is disclosed in British Pat. No. 237,996, wherein clamping elements can be variably disposed in a plate having threaded holes.
USPTO Backgrounds
USPTO Backgrounds