Precision-folded, high strength, fatigue-resistant structures and sheet therefor

• US 8,114,524 B2
• Filed: 01/20/2011
• Issued: 02/14/2012
• Est. Priority Date: 09/26/2002
• Status: Expired due to Fees

• Current Assignee: Industrial Origami, Inc.
• Original Assignee: Industrial Origami, Inc.
• Inventors: Durney, Max W.
• Primary Examiner(s): Zimmerman, John J
• Application Number:
  US13/010,619
• Publication Number:
  US 20110281065A1
• Time in Patent Office: 390 Days
• Field of Search: None
• US Class Current: 428/597
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: E04B 2/78 characterised by special cross-section of the frame members as far as important for securing wall panels to a framework with or without the help of cover-strips
• CPC Class Codes: E04C 2/08 of metal, e.g. sheet metal E04C2/26 takes precedence
• CPC Class Codes: E04C 2/34 composed of two or more spaced sheet-like parts E04C2/32 takes precedence; spacers for cavity walls E04B2/44
• CPC Class Codes: E04C 2003/043 the hollow cross-section comprising at least one enclosed cavity
• CPC Class Codes: E04C 2003/0447 circular- or oval-shaped
• CPC Class Codes: E04C 2003/0465 square- or rectangular-shaped
• CPC Class Codes: E04C 2003/0469 triangular-shaped
• CPC Class Codes: E04C 3/02 Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; BracesE04C3/38 takes precedence; for structures characterised by movable, separable, or collapsible parts E04B1/343; braced purlins E04B7/024
• CPC Class Codes: E04C 3/07 at least partly of bent or otherwise deformed strip- or sheet-like material
• CPC Class Codes: E04C 3/083 Honeycomb girders; Girders with apertured solid web
• CPC Class Codes: E04C 3/32 of metal E04C3/36 takes precedence
• CPC Class Codes: E04C 3/34 of concrete other stone-like material, with or without permanent form elements, with or without internal or external reinforcement, e.g. metal coverings E04C3/36 takes precedence
• CPC Class Codes: E04C 3/40 of metal E04C3/46 takes precedence
• CPC Class Codes: E04F 2019/0427 with a integrally formed hinge
• CPC Class Codes: E04F 2203/08 with a plurality of grooves or slits in the back side, to increase the flexibility or bendability of the elements
• CPC Class Codes: E06C 7/08 Special construction of longitudinal members, or rungs or other treads
• CPC Class Codes: Y10T 428/12361 having aperture or cut
• CPC Class Codes: Y10T 428/12368 Struck-out portion type
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/15 : Sheet, web, or layer weakened to permit separation through thickness
• CPC Class Codes: Y10T 428/24198 : Channel-shaped edge component [e.g., binding, etc.]
• CPC Class Codes: Y10T 428/24264 : Particular fold structure [e.g., beveled, etc.]
• CPC Class Codes: Y10T 428/24273 : including aperture
• CPC Class Codes: Y10T 428/24281 : Struck out portion type
• CPC Class Codes: Y10T 428/24314 : Slit or elongated
• CPC Class Codes: Y10T 428/24479 : including variation in thickness
• CPC Class Codes: Y10T 428/2457 : Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/24612 : Composite web or sheet
• CPC Class Codes: Y10T 428/24628 : Nonplanar uniform thickness material

Abstract

Precision-folded, high strength, fatigue-resistant structures and a sheet therefore are disclosed. To form the structures, methods for precision bending of a sheet of material along a bend line and a sheet of material formed with bending strap-defining structures, such as slits or grooves, are disclosed. Methods include steps of designing and then separately forming longitudinally extending slits or grooves through the sheet of material in axially spaced relation to produce precise bending of the sheet when bent along the bend line. 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 to be engaged and supported on faces of the sheet material on opposite sides of the slits or arcs. The edge-to-face contact produces bending along a virtual fulcrum position in superimposed relation to the bend line. Several slit embodiments suitable for producing edge-to-face engagement support and precise bending are disclosed. With these teachings, forming numerous three-dimensional load-bearing structures from a two dimensional sheet are enabled. Examples of straight and curved beams, chassis, and exoskeletons are disclosed.

Claims

1. A sheet of material formed for bending along a bend line, the sheet of material comprising:

a plurality of slits positioned along and proximate to the bend line, each slit having slit end portions diverging away from the bend line, each slit defining a tongue displaced laterally out of the plane of the sheet of material prior to bending of the sheet of material.

2. The sheet of material of claim 1, wherein the slits are positioned on alternating sides of the bend line, and the end portions of longitudinally adjacent slits define bending straps each having a central axis oriented obliquely with respect to the bend line.

3. The sheet of material of claim 2, wherein the central axes of adjacent bending straps are skewed in alternating directions.

4. The sheet of material of claim 2, wherein the bending straps each have a width dimension which increases with distance on both sides of a minimum width dimension.

5. The sheet of material of claim 1, wherein the end portions of the slits are arcuate end portions.

6. The sheet of material of claim 1 wherein edges of the slits engage and slide on opposing faces of the displaced tongues during bending.

7. The sheet of material of claim 1, wherein:

the slits are positioned on alternating sides of the bend line;

the slit end portions of pairs of longitudinally adjacent slits are arcuate slit end portions defining bending straps each having a central axis oriented obliquely with respect to the bend line; and

the central axes of adjacent bending straps are skewed in alternating directions.

8. The sheet of material of claim 1, wherein each slit comprises a central portion substantially parallel to and offset laterally from the bend line.

9. The sheet of material of claim 8, wherein the slits are positioned on alternating sides of the bend line, and the slit end portions of longitudinally adjacent slits define bending straps each having a central axis oriented obliquely with respect to the bend line.

10. The sheet of material of claim 9, wherein the central axes of adjacent bending straps are skewed in alternating directions.

11. The sheet of material of claim 9, wherein the bending straps each have a width dimension which increases with distance on both sides of a minimum width dimension.

12. The sheet of material of claim 8, wherein the end portions of the slits are arcuate end portions.

13. The sheet of material of claim 8 wherein edges of the slits engage and slide on opposing faces of the displaced tongues during bending.

14. The sheet of material of claim 8, wherein:

the slits are positioned on alternating sides of the bend line;

the slit end portions of pairs of longitudinally adjacent slits are arcuate slit end portions defining bending straps each having a central axis oriented obliquely with respect to the bend line; and

the central axes of adjacent bending straps are skewed in alternating directions.

15. The sheet of material of claim 1, wherein the slits are arcuate in shape.

16. The sheet of material of claim 15, wherein the slits are positioned on alternating sides of the bend line, and the slit end portions of longitudinally adjacent slits define bending straps each having a central axis oriented obliquely with respect to the bend line.

17. The sheet of material of claim 15, wherein the central axes of adjacent bending straps are skewed in alternating directions.

18. The sheet of material of claim 15, wherein the slits are continuous arcs.

19. The sheet of material of claim 15, wherein the slits are elongated arcuate slits.

20. The sheet of material of claim 15 wherein edges of the slits engage and slide on opposing faces of the displaced tongues during bending.

21. The sheet of material of claim 15, wherein:

the slits are positioned on alternating sides of the bend line;

the slit end portions of longitudinally adjacent slits are arcuate slit end portions defining bending straps each having a central axis oriented obliquely with respect to the bend line; and

the central axes of adjacent bending straps are skewed in alternating directions.

22. The sheet of material of claim 21, wherein the slits are continuous arcs.

23. The sheet of material of claim 21, wherein the slits are elongated arcuate slits.

24. A coil comprising the sheet of material of claim 1 co-wound with a polymer web.