Hydrostatic bending and die forming

Claim 1

A process for forming and bending strip material into a shape having a point generatrix cross section by drawing said strip material through a series of spaced die orifices comprising: a. axially aligning the orifices of a plurality of spaced dies of varying orifice shape ranging between the initial crosssectional shape of said strip material to and including the final shape with said point generatrix cross section, said alignment being sequential from the die having an orifice most closely approximating the initial cross-sectional shape of said strip material to the final shape with said point generatrix cross section; and b. providing a pressurized liquid surrounding the entire sequence of dies providing one equilibrium hydrostatic pressure in the range of 5,000 p.s.i. to 400,000 p.s.i. over the entire length of said strip material in addition to the forming and bending pressures mechanically induced by the working faces of said dies; and c. pulling said strip material continuously through the orifices of said dies to form the strip into the point generatrix crosssectional shape, said strip passing sequentially from said die orifices most closely approximating the initial shape of said strip to said die substantially of said point generatrix shaped cross section while liquid hydrostatic pressure is applied to the entire length of said strip while being continuously formed into said shape of point generatrix cross section

Claim 5

An apparatus for forming and bending strip material into an article with a point generatrix cross section comprising: a. a chamber; b. a plurality of dies of varying orifice shape ranging between the initial cross-sectional shape of said strip material to and including said point generatrix cross section aligned within said chamber, said alignment being sequential from the die having an orifice most closely approximating the initial cross-sectional shape of said strip material to a die substantially of said point generatrix cross-sectional shape; c. means for the orifices of the end dies of said alignment to communicate through the walls of said chamber so that said strip material may be pulled through said chamber and said die orifices; d. means for providing hydrostatic pressure within said chamber to subject said strip material to said hydrostatic pressure along its entire length in addition to the mechanically induced forming and bending pressures exerted by the working faces of said die orifices while being pulled through said chamber and orifices and sequentially formed into said point generatrix cross-sectional shape; and e. means for pulling said strip material through said chamber and said plurality of dies to form said strip into the point generatrix cross-sectional shape while liquid hydrostatic pressure is applied to the entire surface of said strip material in addition to the mechanical forming and bending forces exerted by said dies.

Claim 6

An apparatus for forming and bending strip material into an article with a point generatrix cross section comprising: a. a chamber; b. a plurality of dies of varying orifice shape ranging between the initial cross-sectional shape of said strip material to and including said point generatrix cross section aligned within said chamber, said alignment being sequential from the die having an orifice most closely approximating the initial cross-sectional shape of said strip material to a die substantially of said point generatrix cross-sectional shape; c. means for the orifices of the end dies of said alignment to communicate through the walls of said chamber so that said strip material may be pulled through said chamber and said die orifices; d. means for providing hydrostatic pressure within said chamber to subject said strip material to said hydrostatic pressure along its entire length in addition to the mechanically induced forming and bending pressures exerted by the working faces of said die orifices while being pulled through said chamber and orifices and sequentially formed into said point generatrix cross-sectional shape; and e. means for pulling said strip material through said chamber and said plurality of dies to form said strip into the point generatrix cross-sectional shape while liquid hydrostatic pressure is applied to the entire surface of said strip material in addition to the mechanical forming and bending forces exerted by said dies.