Apparatus and control for angular alignment of inertia or friction welded parts

Claim 1

In a friction welding machine of the kind in which two parts are clamped in a rotatable spindle and a tailstock respectively, pressed together and rotated relative to one another until the entire interface is heated to a hot plastic condition, alignment means for rotatively aligning the parts in a desired angular alignment at the end of the weld and including actuator means for turning the tailstock part through the hot plastic interface to a desired angular orientation with respect to the other part at the end of the weld cycle, indexing means for measuring the angular orientation of the parts and for actuating the actuator means to align the parts, the indexing means including a position error circuit having synchronized position sensors associated respectively with the spindle and tailstock; and control means effective to retain the indexing means in a standby mode until the interface has been heated to the plastic condition during the weld cycle and effective to place the indexing means in an indexing mode after the interface has been heated to a plastic condition at the end of the weld cycle.