METHOD FOR MAKING SHARPLY BENT TUBULAR PRODUCTS Russian patent published in 2002 - IPC

FIELD: plastic metal working, possibly manufacture of tubular products, for example toroidal vessels, coils, sharply bent elbows. SUBSTANCE: method comprises steps of pulling tubular blank with rod- shaped filler of easy-to-melt material simultaneously into shaping cavities of two detachable draw plates due to moving both draw plates mutually opposite until their butt jointing; preliminarily making symmetrical tapered end portions inclined relative to lengthwise axis of end portions of tubular blank and filler; upon pulling tubular blank with rod filler to draw plates at first bending tapered end portions along shaping cavities of draw plates; then stepwise pulling out-of-plate zones of tubular blank along unclamped near-draw plate portions of blank; determining length values of those portions, length of tapered zones of end portions of blank and rod according to given mathematical formulae. EFFECT: lowered labor and energy consumption at making tubular products. 2 cl, 11 dwg