Method for precision bending of sheet of materials, slit sheets fabrication process

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.

1 . A sheet of material formed for bending along a bend line comprising:
 a sheet of material having a plurality of slits formed therethrough, the slits being configured and positioned relative to a desired bend line to produce bending of the sheet of material along the bend line and to produce edge-to-face engagement of the material on opposite sides of the slits along substantially the full length of the slits.   
   
   
       2 - 24 . (canceled) 
   
   
       25 . A method of slitting a sheet of material for bending along a bend line comprising the step of:
 forming a plurality of slits through the sheet of material which are configured and positioned relative to the bend line to produce bending along the bend line and to produce edge-to-face engagement of the material on opposite sides of the slits.   
   
   
       26 . A method of slitting a sheet of material for bending as defined in  claim 25  wherein, during the forming step each slit is formed with slit end portions diverging away from the bend line, with a pair of adjacent slit end portions on opposite sides of the bend line defining a bending strap extending across the bend line, and during the forming step, forming the slits with a kerf width dimensioned for producing interengagement of the sheet of material on opposite sides of the slits during bending. 
   
   
       27 . The method of slitting a sheet of material for bending as defined in  claim 26  wherein, the forming step is accomplished by forming each of the slits with slit end portions at oblique angles to the bend line to define an obliquely extending bending strap. 
   
   
       28 . The method of slitting a sheet of material for bending as defined in  claim 26  wherein, the forming step is accomplished by forming each slit as a circular segment. 
   
   
       29 . The method of slitting a sheet of material for bending as defined in  claim 26 , and the step of:
 prior to the forming step, selecting a solid sheet of elastically and plastically deformable material for slitting.   
   
   
       30 . The method of slitting a sheet of material for bending as defined in  claim 26  wherein, the forming step is accomplished by forming each of the slits in a position to longitudinally overlap along the bend line. 
   
   
       31 . The method of slitting a sheet of material for bending as defined in  claim 29  wherein, the forming step is accomplished by forming each slit with an arcuate end portion at each end of the slit to define an obliquely extending bending strap between the end portions of longitudinally adjacent slits. 
   
   
       32 . The method of slitting a sheet of material for bending as defined in  claim 31  wherein, the forming step is accomplished by forming the slits to be laterally offset on opposite sides of the bend line with central slit portions substantially parallel to the bend line. 
   
   
       33 . The method of slitting a sheet of material for bending as defined in  claim 32 , the forming step is accomplished by forming the slits with a kerf producing sliding of edges on one side of the slit on faces on the other side of the slit during bending to position the edges in supporting relation to a face of the sheet of material on opposite sides of the slits. 
   
   
       34 . The method of slitting a sheet of material for bending as defined in  claim 32 , wherein the forming step is accomplished by forming a plurality of slits as defined in  claim 25  on opposite sides of the bend line along substantially the full length of the bend line. 
   
   
       35 . The method of slitting a sheet of material for bending as defined in  claim 26 , and the step of:
 after the forming step, bending the sheet of material about the bend line.   
   
   
       36 . The method of slitting a sheet of material for bending as defined in  claim 32 , and the step of:
 after the forming step, bending the sheet of material about a virtual fulcrum aligned with the bend line to produce plastic and elastic deformation of the bending strap.   
   
   
       37 . The method of slitting a sheet of material for bending as defined in  claim 25  wherein,
 the forming step is accomplished at a first location, and the steps of:
 after the forming step, transporting the sheet of material from the first location to a second location remote of the first location; and 
 after the transporting step, bending the sheet of material along the bend line at the second location. 
   
   
   
       38 . The method of slitting a sheet of material for bending as defined in  claim 37  wherein, the transporting step is accomplished by transporting the sheet of material in one of:
 (a) a flat condition;   (b) a coiled condition; and   (c) a partially formed condition.   
   
   
       39 . The method of slitting a sheet of material for bending as defined in  claim 37  wherein,
 after the forming step and prior to the transporting step, rolling the sheet of material into a coil, performing the transporting step while the sheet of material is coiled, and the step of:   uncoiling the sheet of material at another location prior to performing the bending step.   
   
   
       40 . The method of slitting a sheet of material for bending as defined in  claim 39 , and the step of:
 during the uncoiling step, performing the bending step.   
   
   
       41 . The method as defined in  claim 40  wherein, the transportation step is accomplished by transporting the coiled sheet of material from a first location on the surface of the surface of the earth to a second location in outer space. 
   
   
       42 . The method as defined in  claim 41  wherein,
 the bending step is accomplished by bending the sheet of material along a plurality of bend lines to produce a structure having three mutually intersecting planes; and   the step of securing the structure against unbending.   
   
   
       43 . The method as defined in  claim 35  wherein,
 during the forming step, forming a plurality of slits on each of a plurality of intersecting bend lines;   during the bending step, bending the sheet of material along at least two bend lines to produce a structure having three mutually intersecting and abutting planar sheet panels; and the step of:   securing the three mutually intersecting panels in abutting relation for mutual support.   
   
   
       44 . The method as defined in  claim 32 , and the step of:
 after the bending step, filling the bent sheet of material at the slits by one of a welding, brazing, soldering and adhesive filling.   
   
   
       45 . The method as defined in claim  24 , and the step of varying the cross sectional area of the bending strap by changing at least one of the jog distance between slits and the position of the slits along the bend line. 
   
   
       46 . A method of slitting a sheet of material for bending along a bend line comprising the steps of:
 selecting a solid elastically deformable sheet of material for slitting; and   forming a plurality of slits along a desired bend line with alternate slits along the bend line being positioned on alternating sides of the bend line and during the forming step, forming each slit with a central portion substantially parallel to and offset laterally from the bend line and with arcuate slit end portions on each end of the slit curving away from the bend line so that adjacent pairs of arcuate slits define bending straps extending obliquely across the bend line.   
   
   
       47 . The method as defined in  claim 46  wherein, the forming step is accomplished using a laser cutting apparatus to cut slits having a kerf width dimensioned to produce interengagement of the sheet on opposite sides of the slits during bending. 
   
   
       48 . The method as defined in  claim 46  wherein, the forming step is accomplished using a water jet cutting apparatus to cut slits having a kerf width dimensioned to produce interengagement of the sheet on opposite sides of the slits during bending. 
   
   
       49 . The method as defined in  claim 46 , and the step of:
 after the forming step, bending the sheet of material along the bend line.   
   
   
       50 . The method as defined in  claim 49  wherein,
 the forming step is accomplished by forming the slits with a kerf width dimension producing sliding interengagement of an edge of the sheet of material on one side of the slit with a face of the sheet of material on the other side of the sheet of material; and   the bending step is accomplished by bending the sheet of material about a virtual fulcrum substantially aligned with the bend line so that sliding interengagement of edges and faces of the sheet of material produces plastic and elastic deformation of the bending straps.   
   
   
       51 . The method as defined in  claim 50  wherein,
 the forming step is accomplished by forming the slits along a plurality of intersecting bend lines; and   the bending step is accomplished by bending the sheet of material into a three-dimensional structure having three intersecting planar areas extending into abutting relation; and the step of securing the three intersecting planar areas are secured together.   
   
   
       52 . The method as defined in  claim 50  wherein,
 the bending step includes bending the sheet of material into a three-dimensional structure having three planar areas; and   the step of securing the three planar areas in abutting relation to rigidify the structure.   
   
   
       53 . The method as defined in  claim 49 , and the step of:
 after the bending step, filling the slits with a material producing a sealed joint at the bend line.   
   
   
       54 . The method of  claim 53  wherein, the filling step is accomplished by one of:
 (a) welding;   (b) brazing;   (c) soldering; and   (d) adhesive filling.   
   
   
       55 . The method of  claim 46  wherein, the forming step is accomplished to provide slits defining bending straps oriented relative to the bend line in oppositely extending oblique angles. 
   
   
       56 . The method of  claim 55  wherein, the forming step is accomplished to provide bending straps oriented relative to the bend line at angles of about 45° and about 135° at opposite ends of a slit. 
   
   
       57 . The method of  claim 49 , and the step of:
 after the bending step, unbending the sheet of material.   
   
   
       58 . A method of forming a three dimensional structure comprising the steps of:
 forming bend-facilitating structures in a sheet of material formed and positioned to produce bending of the sheet of metal precisely along a first bend line;   bending the sheet of metal precisely along the first bend line;   bending the sheet of metal along at least one additional bend line until two portions of the sheet of metal are abutting; and   coupling together two abutting portions of the sheet of metal to produce a rigid load bearing three-dimensional metal structure capable of supporting three-dimensional loading.   
   
   
       59 . The method as defined in  claim 58  wherein, the forming step is accomplished by forming a plurality of slits through the sheet of material configured and positioned relative to the bend lines to produce bending of the sheet of material along the bend lines and produce edge-to-face support of the material on opposite sides of the slits along the level lines. 
   
   
       60 . A sheet of material formed for bending along a bend line comprising:
 an elastically and plastically deformable solid sheet of material having two elongated slits through the sheet of material with each slit being laterally offset on opposite sides of a desired bend line and being longitudinally displaced relative to the other slit along said bend line, said slits having a jog distance dimensioned to produce interengagement of solid edges of said sheet of material on opposite sides of said slits during bending,   wherein said jog distance is less than the material thickness of said sheet of material.   
   
   
       61 . The sheet of material as defined in  claim 60  wherein, said jog distance is less than 0.5 times the material thickness of said sheet of material. 
   
   
       62 . The sheet of material as defined in  claim 60  wherein, said jog distance is less than 0.3 times the material thickness of said sheet of material.