EQUAL-PASS T-PIECE FORMING APPARATUS Russian patent published in 2007 - IPC B21C37/29 

FIELD: plastic working of metals, possibly formation of T-pieces from thin-wall tube blank by forming bead on its lateral surface.

SUBSTANCE: apparatus includes die set having two die halves, inner mandrel, two punches with inclined end surfaces and insert in the form of ball arranged between punches. Parting surface of two die halves is normal relative to vertical axis of die set and it passes through axis of its opening under bead of tube blank. Insert has two inclined surfaces and two parallel end surfaces. Inclined surfaces pass through poles of ball, they are parallel to inclined surfaces of punches and inclined by the same angle relative to vertical axis of die set. Tangent of said angle exceeds friction factor value on contact surface of punches and insert. Front end surface of ball is arranged at side of opening of die set under bead of tube blank, it is normal to axis of said opening and spaced from ball center by distance whose value is determined depending upon ball radius and diameter of its front end surface. Maximum height of slope of end surfaces of punches is no more than height half of back end surface of ball plane.

EFFECT: lowered labor consumption for making T-piece with increased height of bead, decreased quantity of die set fitting.

4 dwg