HOLLOW PRODUCT FORMING APPARATUS Russian patent published in 1996 - IPC

FIELD: plastic working of metals. SUBSTANCE: apparatus has multiplying unit 2 made from separate sections connected with hydraulic distributing system through pipelines, mechanism for feeding billets to working zone and withdrawing ready product, pressing tool having die 10 fixed in working cylinder 1 and stamp 9 with needle 12, with die 10 and stamp 9 being made integral. One working stroke of one working cylinder out of four-five working cylinders is provided by simultaneous supplying of high-pressure working liquid from all sections of multiplying unit. Pressing force is created by supplying high-pressure working liquid from multiplying unit to stamp with needle. In the process of stamp advancement, billet is urged into gap between needle and die. EFFECT: increased efficiency, simplified construction and improved quality of hollow products. 3 dwg, 1 tbl