Method and machine for preforming open clamps and their flat blanks

摘要

A method and apparatus for preforming a substantially flat blank of an open clamp adapted to be mechanically interconnected near the free ends thereof into a circular clamp having a configuration at least approximately the configuration of the clamp when installed about an object to be fastened onto a relatively fixed, generally circular part; as the flat blank is being fed through the machine, it is preformed into a generally circular shape with the free ends thereof axially spaced from one another; the pair of rollers feeding the blank may also be so shaped in their external contours that the lateral edges of the blank are bent out in the generally radial direction; additionally the blank is automatically stopped after an initial short feed through the machine to permit stamping of a predetermined part of the flat blank; the entire operation which is preferably pneumatically controlled is thereby automatically cyclically operated as soon as a flat blank is inserted into the machine a predetermined distance.