Hydraulic deep-drawing of bowl-shapes - where blank already contains a centre-hole

摘要

A device esp. for the mfr. of metal bowls with stepped bases using blanks already provided with a centre hole, and applying liq. press. directly on the blank, forcing it over a punch. The novelty is that the centering or guide elements are located exclusively in the region between the sheet-holder and the die-ring and the area of the blank's surface which rests on, and is supported by, the punch must be at least twice the area of the centre-hole or the area of the annulus which will be pressed upwards to form the step. A high prodn. rate can be obtd. by this simple arrangement.