Abstract: A method of preparing a sheet of material for bending along a bend line includes the step of forming at least one displacement in the thickness direction of the sheet of material, the displacement including a flat zone substantially parallel to the sheet of material with a portion of the periphery of the flat zone extending along and adjacent to the bend line, and including an angled transition zone interconnecting the flat zone with a remainder of the sheet of material. The forming step is preferably accomplished using one of a stamping process, a punching process, a roll-forming process and an embossing process. A sheet of material suitable for bending using the process also is disclosed, as are the use of coatings, shin guards and displacing the area of the sheet between bending inducing slits.

Abstract: A process for designing and manufacturing precision-folded, high strength, fatigue-resistant structures and a sheet therefore. The techniques include methods for precision bending of a sheet of material (41, 241, 341, 441, 541) along a bend line (45, 245, 345, 445,543) and a sheet of material formed with bending strap-defining structures, such as slits or grooves (43, 243, 343, 443, 542), are disclosed. Methods include steps of designing and then separately forming longitudinally extending slits or grooves (43, 243, 343, 443, 542) through the sheet of material in axially spaced relation to produce precise bending of the sheet (41, 241, 341, 441, 541) when bent along the bend line (45, 245, 345, 445, 543). The bending straps have a configuration and orientation which increases their strength and fatigue resistance, and most preferably slits or arcs are used which causes edges (257, 457) to be engaged and supported on faces (255, 455) of the sheet material on opposite sides of the slits or arcs.

Abstract: A sheet of material (21, 61, 81) formed for control bending along a bend line (23, 63) while maintaining a continuous web of material (26) across the bend line (23, 63). The sheet has at least one groove (22, 62, 82) formed therein with a central groove portion (24, 64, 84) extending in the direction of and positioned proximate to a desired bend line (23, 63). The groove is formed with a continuous web of material (26) at a bottom of the groove (22, 62, 82) and has a configuration defining at least one bending strap (27, 67) extending across the bending line (23, 63) at the end of the groove with a centerline (28) of the bending strap (27, 67) oriented obliquely across the bend line (23, 63) so that a balancing of the forces during bending of the web along the central portion (24, 64, 84) of the grooves and bending of the oblique bending strap occur and control the location of bending of the sheet.

Abstract: A process of forming bend-controlling structures, such as slits, grooves or displacements (22), in a sheet of material (21, 121, 221, 321, 421, 521, 621,721). The bend-controlling structures (22) have central portions (26) extending substantially parallel to a desired bend line (23) on the sheet and end portions (27) which diverge away from the bend line (23). In one embodiment the process includes the step of forming the bending straps (24) between pairs of slit end portions (27) at a desired spaced apart distances along the bend line (23) with the straps (24) having a desired configuration, and the step of forming central portions (26) which connect the end portions (27) to complete the slits (22) using a separate die set. A plurality of end portion dies (51/54) can be used to produce end portions (27) of various shapes and straps (24) of various widths, and a single set of central portion forming dies (71/74) are used to connect the end portions (27).

Abstract: A method for precision bending of a sheet of material (41, 241, 341, 441) along a bend line (45, 245, 345, 445) and the resulting sheet are disclosed. A method includes a step of forming longitudinally extending slits (43, 243, 343, 443) through the sheet of material in axially spaced relation to produce precise bending of the sheet (41, 241, 341, 441) along the bend line (45, 245, 345, 445) with edges (257, 457) engaged and supported on faces (255, 455) of the sheet material on opposite sides of the slits. The edge-to-face contact produces bending along a virtual fulcrum position in superimposed relation to the bend line (45, 245, 345, 445). Several slit embodiments (43, 243, 343, 443) suitable for producing edge-to-face engagement support and precise bending are disclosed, as is the use of the slit sheets to enhance various fabrication techniques.

Abstract: A method of designing fold lines in sheet material includes the steps defining the desired fold line in a parent plane on a drawing system, and populating the fold line with a fold geometry including a series of cut zones that define a series of connected zones configured and positioned relative to the fold line whereby upon folding the material along the fold line produces edge-to-face engagement of the material on opposite sides of the cut zones.