The Prediction of Plate-Deflection and Radial Gripping Force for a Three Jaw Diaphragm Chuck

Summary

Since the conception of the diaphragm chuck, little work of an analytical nature has been carried out with regard to its functional aspects. Consequently, both designers and users have been restricted to empirical data, when considering the efficiency or usefulness of such work holding devices. In the paper, the diaphragm chuck is analysed as an encastre circular plate of varying radial thickness, with a central hole and jaws fixed to its outer surface acting as radial stiffening ribs. By applying formulae derived from the general differential equation of a flat circular plate and assuming an equivalent thickness, it is possible to predict the maximum deflection of the plate. Using the expression established for predicting plate deflection as a basis, a relationship between the deflecting load and the radial gripping force is derived.