Abstract A rigid curved sheet element, such as a helicoidal screw conveyor blade, is curved by being formed with a series of triangular segments bounded along their sides and alternately disposed so that their apexes alternate from one edge (the longer side) of the sheet element to the opposite edge (the shorter side); in addition the plane of each triangular segment forms an obtuse angle with respect to that of the next succeeding one, and alternates in direction with respect to successive ones. In a preferred method of making same, a flat sheet blank, preferably in the shape of a circle, is bent along a plurality of lines in alternate directions to form the triangular segments. In another method, a plurality of separate triangular segments are fixed together, as by welding, to form the curved sheet element.
A method of making a rigid curved sheet element, characterized in preparing a flat sheet blank having a pair of opposed edges one of which is longer than the other, defining a longer-edge side of the blank and a shorter-edge of the blank, and bending said sheet along a plurality of lines and in alternate directions for successive lines to form a series of consecutive triangular segments bounded along their sides and alternately disposed so that their apexes alternate from the longer-edge side of the blank to the shorter-edge side of the blank, said triangular segments being so bent that each forms an obtuse angle with respect to that of the next succeeding one.
Claim 2
Independent Claim
114 words
A method of making a rigid curved sheet element, characterized in preparing a flat sheet blank having a pair of opposed edges one of which is longer than the other, defining a longer-edge side of the blank and a shorter-edge of the blank, and bending said sheet along a plurality of lines and in alternate directions for successive lines to form a series of consecutive triangular segments bounded along their sides and alternately disposed so that their apexes alternate from the longer-edge side of the blank to the shorter-edge side of the blank, said triangular segments being so bent that each forms an obtuse angle with respect to that of the next succeeding one.
Claim 3
Dependent Claim
27 words
The method as defined in claim 1, wherein said flat sheet blank is substantially in the shape of a circle and includes a substantially circular central opening.
Claim 4
Dependent Claim
23 words
The method as defined in claim 1, wherein said sheet is curved by said series of obtused-angled triangular segments to form a helicoid.
Claim 5
Dependent Claim
58 words
The method as defined in claim 1, wherein said obtuse angle is the same between all the triangular segments; the dimensions of the triangular segments whose apexes face the shorter-edge side of the blank are all the same; and the dimensions of the triangular segments whose apexes face the longer-edge side of the blank are all the same.