METHOD OF MAKING DOUBLE-LOOP STRAP FROM CIRCULAR CORD AND APPARATUS FOR PERFORMING THE SAME Russian patent published in 1997 - IPC

FIELD: plastic metal working. SUBSTANCE: method of making double-loop strap from circular cord comprises steps of winding circular cord of predetermined number of turns, twisting ends of filament of material around cord body, deforming circular cord to intermediate figure and then deforming said figure to double-loop endless helix. At first transition circular cord is deformed to figure in the form of half-moon; at second transition inner portion of said figure in the form of semicircle is turned by 180 degrees and outer portion of article is held. Apparatus for performing the method includes mounted in frame: mandrel, die joined with drive unit and bending rollers, guides and tie rod connected with drive unit of mandrel being in the form of hinge parallelogram secured by two opposite points. Die is in the form of movable shoulder equidistant relative to horseshoe-like mandrel having three jointly connected members. Mean member is rigidly connected through shoe with tie rod contained in guiding sleeves mounted in tube. Terminal arch-shaped members of mandrel by their one ends are jointly connected with said shoe, by their mean portions they are joined with levers jointly secured to tube. Said tie rod is mounted with possibility of axial motion and rotation together with tube. Said tube is kinematically connected with drive unit with possibility of rotation around its axis. Said mandrel has groove along its outer contour. EFFECT: improved design of apparatus, simplification of method. 3 cl, 10 dwg