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

Abstract

A sheet of material formed for bending along a bend line comprises a plurality of slits positioned proximate and along the bend line. The slits each have opposite end portions which diverge away from the bend line. The slits are configured and positioned to produce bending of the sheet of material along the bend line. The diverging slit end portions reduce stress in the sheet of material during bending.

1 - 21 . (canceled) 
     
     
         22 . A sheet of material formed for bending along a bend line, the sheet of material comprising:
 a plurality of slits positioned proximate and along the bend line, the slits each having opposite end portions which diverge away from the bend line, the slits being configured and positioned to produce bending of the sheet of material along the bend line, the diverging slit end portions reducing stress in the sheet of material during bending.   
     
     
         23 . The sheet of material of  claim 22 , 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. 
     
     
         24 . The sheet of material of  claim 23 , wherein the central axes of adjacent bending straps are skewed in alternating directions. 
     
     
         25 . The sheet of material of  claim 23 , wherein the bending straps each have a width dimension which increases with distance on both sides of a minimum width dimension. 
     
     
         26 . The sheet of material of  claim 22 , wherein the end portions of the slits are arcuate end portions. 
     
     
         27 . The sheet of material of  claim 22 , wherein:
 the slits are positioned on alternating sides of the bend line;   the slit end portions of longitudinally adjacent slits define 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.   
     
     
         28 . The sheet of material of  claim 22 , wherein each slit comprises a central portion substantially parallel to and offset laterally from the bend line. 
     
     
         29 . The sheet of material of  claim 28 , 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. 
     
     
         30 . The sheet of material of  claim 28 , wherein the central axes of adjacent bending straps are skewed in alternating directions. 
     
     
         31 . The sheet of material of  claim 28 , wherein the bending straps each have a width dimension which increases with distance on both sides of a minimum width dimension. 
     
     
         32 . The sheet of material of  claim 28 , wherein the slits have arcuate end portions. 
     
     
         33 . The sheet of material of  claim 28 , wherein:
 the slits are positioned on alternating sides of the bend line;   the slit end portions of longitudinally adjacent slits define 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.   
     
     
         34 . The sheet of material of  claim 22 , wherein the slits are arcuate with convex sides facing the bend line. 
     
     
         35 . The sheet of material of  claim 34 , 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. 
     
     
         36 . The sheet of material of  claim 34 , wherein the central axes of adjacent bending straps are skewed in alternating directions. 
     
     
         37 . The sheet of material of  claim 34 , wherein the slits are continuous arcs. 
     
     
         38 . The sheet of material of  claim 34 , wherein the slits are elongated arcuate slits. 
     
     
         39 . The sheet of material of  claim 34 , wherein:
 the slits are positioned on alternating sides of the bend line;   the slit end portions of longitudinally adjacent slits define 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.   
     
     
         40 . The sheet of material of  claim 39 , wherein the slits are continuous arcs. 
     
     
         41 . The sheet of material of  claim 39 , wherein the slits are elongated arcuate slits. 
     
     
         42 . A coil comprising the sheet of material of  claim 22  co-wound with a polymer web.