METHOD AND APPARATUS FOR FORMING CAN END WITH CONTROLLED THINNING OF FORMED PORTIONS OF CAN END Russian patent published in 2019 - IPC B21D51/44 

FIELD: metallurgy.

SUBSTANCE: group of inventions relates to metal forming and can be used to form a can. Can end blank is initially cupped and a central portion of the cup is rolled up with an annular portion of the cup being free formed with limited contact with any tooling. Free forming is performed by controlling the motion of a pre-panel punch using a double action piston so that the pre-panel punch is selectively moved between an extended position for formation of a cup of a cupped can end blank and a retracted position for free forming material between a central portion of the cup and a clamped portion of the cupped can end blank.

EFFECT: higher strength of the can.

13 cl, 16 dwg