METHOD AND APPARATUS FOR JOINING THERMOPLASTIC PARTS

摘要

A technique for permanently joining thermoplastic parts (10,20) in a single stroke converts kinetic energy into thermal energy. In this technique, one of the thermoplastic parts (10) includes a linear shaft (12) while the other includes a cavity (22) having the same general shape but being slightly smaller in its crosssection. The thermoplastic parts are permanently joined when the shaft is thrust into the cavity at a velocity that exceeds a predetermined minimum value which is a function of the thermoplastic materials used and the relative dimensions of the shaft and cavity. An interference fit between the shaft and cavity causes frictional heat to be generated which melts the contacting surfaces and thus welds the parts together after a brief cooling period.