Welded friction clamp collar

Claim 1

IN A STOP COLLAR WHICH IS CLAMPED TO ENCIRCLE A WELL CASING BY USE OF AN APPARATUS TO CAUSE CIRCUMFERENTIAL TENSIONING OF THE COLLAR, THE COMBINATION OF: A COLLAR HAVING JUXTAPOSED END PORTIONS, ONE END PORTION HAVING A CIRCUMFERENTIALLY EXTENDING ELEMENT, THE OTHER END PORTION HAVING A SLOT FOR RECEIVING SAID ELEMENT, SAID SLOT HAVING A CIRCUMFERENTIAL EDGE ADJACENT SAID ELEMENT, SAID ELEMENT HAVING A CIRCUMFERENTIAL EDGE ADJACENT TO AND ENGAGING SAID SLOT EDGE, EACH END PORTION HAVING AN APERTURE FOR RECEIVING THE TENSIONING APPARATUS WHEREBY THE SAID COLLAR IS CIRCUMFERENTIALLY TENSIONED ON THE WELL CASING BY ADVANCING SAID END PORTIONS TOWARD EACH OTHER FOR CAUSING FRICTIONAL FORCES BETWEEN THE COLLAR AND THE WELL CASING TO RESIST RELATIVE MOVEMENT THEREBETWEEN, AND WELD MEANS JOINING SAID EDGES WHEREBY SAID TENSIONING IS RETAINED AFTER WITHDRAWAL OF THE TENSIONING APPARATUS.