PROCEDURE FOR FABRICATION OF HOLLOW SPHERICAL ITEMS WITH ONE OR SEVERAL AXIALLY SYMMETRICAL BENDS Russian patent published in 2011 - IPC B21D51/08 

FIELD: machine building.

SUBSTANCE: tube work-piece is positioned into punch between two matrixes with semi-spherical working cavities and with central openings. A cylinder stop with reinforcement on its middle part is inserted into the said openings of the matrixes inside the tube work-piece; diametre of the stop corresponds to internal diametre of produced bends. The work-piece is deformed by matrixes approach, ensuring contact of ends of the work-piece with the stop to make a spherical semi-finished product. Upon deformation of the work-piece one or both matrixes with a semi-spherical working cavity are replaced with outward flanging matrixes with semi-spherical working cavities havong central openings. Also, diametre of each opening corresponds to external diametre of produced bends. There is facilitated the contact between the said matrixes at specified force; the stop is transferred to the side of the central opening on the outward flanging matrix with force less, than force ensuring contact between matrixes. One or both bends on the spherical semi-finished product are made with the reinforcement of the stop.

EFFECT: expanded process functionality.

6 cl, 12 dwg