METHOD OF HEADING INSERTED BOLTS WITH RADIAL TAGS, DEVICE FOR PRELIMINARY SHAPING OF TAGS AND DEVICE FOR FINAL SHAPING OF TAGS Russian patent published in 2001 - IPC

FIELD: cold heading of T-shaped bolts with rectangular heads and square necks intended for securing cantilevers of load-bearing guides in laying telegraph cable. SUBSTANCE: method includes two-stage shaping of tags by upsetting metal, thus forming two opposite segment lugs on one of axles at first stage; these lugs are biconical in height. Cone formed on rod under head is inverted relative to that on head. Final shaping of tags of head and square of neck is effected at second stage; tags are inclined and undercut. Then, flash is removed and rod is reduced for thread. Device for preliminary shaping of tags includes punch with working chamber consisting of two engageable taper surfaces whose guides are made in form of elongated oval; this oval is formed by two semicircles which are diametrically opposite on larger axis of oval and are equidistant relative to center of symmetry of chamber by the amount of eccentricity. Semicircle are engageable by sectional planes passing through both taper surfaces from end face of punch as far as bottom of chamber. Device for final shaping of tags includes die and punch. Working chamber of punch is made in form of truncated regular pyramid with sloping faces and square at vertex which is sunken in end face. Working chamber of die is rectangular at end face and is provided with radial recesses at ends of rectangle. EFFECT: facilitated manufacture at minimum load on tools and minimum losses on metal; attractive appearance of bolt. 4 cl, 7 dwg