METALLIC SPHERICAL ENVELOPE PRODUCING METHOD Russian patent published in 2007 - IPC B21D51/08 

FIELD: plastic working of metals, namely manufacture of spherical articles.

SUBSTANCE: method comprises steps of making petals; securing petals to upper disc; bending petals and mutually joining them; securing lower disc to petals, finishing up shape of formed envelope to spherical one by hydraulic inflation; forming meridian ribs. Petals are formed by securing limiting members to inner side of even petals discretely along their lengthwise edges at mutual spacing between them consisting of 50 thickness values. Odd and even petals are alternatively assembled at forming lap joint of lengthwise edges of odd petals with limiting members of even petals. Petals are laid in radial direction relative to disc and cross edges of even petals are adjoined to disc cutouts whose number is equal to number of odd petals. Filler such as light concrete or polyurethane foam is fed into meridian ellipsoidal ribs at deforming lap joints between even and odd petals and supplying said filler to formed cavity.

EFFECT: lowered labor consumption, increased rigidity of meridian ribs.

5 dwg