METHOD OF MANUFACTURING SHELL CIRCUIT OF PROTECTION CASING Russian patent published in 2017 - IPC B21C37/20 B21K21/06 B21J5/12 

FIELD: weapon and ammunition.

SUBSTANCE: on the inner surface of the tubular blank with the bottom forming multi-spiral scrolls of the opposite direction, forming a grid of protuberances of a rhombic shape. The formation is carried out in two successive operations of reducing the broach. The first operation is performed using a central spindle with instrumental spiral projections having an inclination angle of 32-33°. In the second operation, a central rod is used with an angle of inclination of the instrumental spiral projections of 30-31°. The processed tubular blank is removed by unscrewing the central rod from it when the workpiece is braked on the ring stripper. The puller is made in the form of radially movable half rings. The diameter of the rings when closing is less than the outer diameter of the processed billet. The puller is placed under the die.

EFFECT: increasing the accuracy of the products received.

2 cl, 6 dwg