초록 ▼

A cold-forming method is disclosed for thinning localized, longitudinally extending portions of sheet metal by lateral shear deformation without any substantial longitudinal deformation. With such method, it is possible to produce elongated members which are thinned in zones of low stress and are th

A cold-forming method is disclosed for thinning localized, longitudinally extending portions of sheet metal by lateral shear deformation without any substantial longitudinal deformation. With such method, it is possible to produce elongated members which are thinned in zones of low stress and are thicker in zones of higher stress so as to provide high metal use efficiency. The method is performed by an apparatus including a rotating mandrel providing opposed conical surfaces and pressure rolls operable to apply forces substantially perpendicular to the axis of rotation of the mandrel to cause a portion of the sheet metal to yield in shear to reduce the thickness of longitudinally extending portions of the sheet metal. The forces are applied in a plane normal to the length of the strip in order to avoid longitudinal elongation.

대표청구항 ▼

A cold-forming method of longitudinally thinning an elongated sheet of metal having an original thickness (T1) to reduce the thickness of at least one longitudinally extending band portion thereof having a predetermined width comprising: (a) applying opposed localized shear forces to said opposite s

A cold-forming method of longitudinally thinning an elongated sheet of metal having an original thickness (T1) to reduce the thickness of at least one longitudinally extending band portion thereof having a predetermined width comprising: (a) applying opposed localized shear forces to said opposite surfaces along a selected portion of said strip, said forces being inclined relative to said opposite surfaces of said strip by an angle B substantially less than 90°and being applied in a plane substantially normal to the length of said strip so that said forces have no significant longitudinal component, thereby causing shear deformation and consequent thinning of the metal of selected portions without substantial thinning of the laterally adjacent part of said strip; (b) causing relative movement of said shear force along the length of said strip to produce a narrow thin lengthwise extending band portion having a width substantially less than said predetermined width and having substantially flat and substantially parallel opposing surfaces within said width of said band; (c) thereafter applying similar opposed localized shear forces to said opposite surfaces along an unthinned portion of said strip immediately adjacent to said lengthwise extending band portion, said similar localized shear forces being inclined relative to said opposite surfaces of said strip by an angle substantially equal to said angle B and being applied in a plane substantially normal to the length of said strip so that said forces have no significant longitudinal component, thereby causing shear deformation and consequent thinning of the metal of said unthinned portion of said strip immediately adjacent to said lengthwise extending band portion without substantial lengthwise deformation and without substantial thinning of a laterally adjacent part of said strip; and (d) causing relative movement of said similar opposed localized shear forces along the length of said strip to increase the width of said narrow thinned lengthwise extending band portion and having substantially flat and substantially parallel opposing surfaces within said width of said band.