Auxetic locking pin

Abstract

A method of inserting a pin in a bore of an article may include first providing an article with a bore, the bore having an inside diameter. The method may then include providing a pin having a hollow body, the hollow body having a diameter with a profile with a pattern of voids. The method may then include applying an axial force on an end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article. The method may further include aligning the pin inside of the bore of the article, and then removing the axial force on the end of the hollow body.

1 .- 16 . (canceled) 
     
     
         17 . A method of inserting a pin in a bore of an article comprising the steps of:
 providing an article with a bore, the bore having an inside diameter;   providing a pin having a hollow body, the hollow body having a diameter with a profile with a pattern of voids, the hollow body having an end;   applying an axial force on the end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article;   aligning the pin inside of the bore of the article; and   removing the axial force on the end of the hollow body.   
     
     
         18 . The method as claimed in  claim 17 , wherein the step of removing the axial force causes the diameter of the pin to increase. 
     
     
         19 . The method as claimed in  claim 17 , further comprising the step of providing a fixture, the fixture has a driver that applies the axial force on the end of the hollow body. 
     
     
         20 . The method as claimed in  claim 17 , wherein the pin is made by:
 providing a sheet of metal,   stamping a pattern of shapes into the sheet of metal, and   rolling a stamped sheet of metal into a cylindrically shaped structure.   
     
     
         21 . The method as claimed in  claim 19 , further comprising:
 loading the article on to a shaft of the fixture; and   loading the pin in to the fixture, where an end of the shaft impinges upon an end of the pin.   
     
     
         22 . The method as claimed in  claim 21 , wherein the axial force is applied by the shaft. 
     
     
         23 . The method as claimed in  claim 17 , further comprising:
 applying an axial force on the end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article; and   removing the pin from inside of the bore of the article.   
     
     
         24 . The method as claimed in  claim 17 , wherein the pattern of voids includes axial ellipses and circumferential ellipses, the axial ellipses each having a smaller short axis and larger long axis on an inside diameter of the hollow body than on an outside diameter of the hollow body, and the circumferential ellipses each having a larger short axis and a shorter long axis on the inside diameter than on the outside diameter. 
     
     
         25 . The method as claimed in  claim 17 , wherein said pattern of voids is distributed over an entire circumference of the hollow body for an entire axial length of the hollow body. 
     
     
         26 . The method as claimed in  claim 21 , further comprising:
 applying an axial force on the end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article;   removing the pin from inside of the bore of the article; and   removing the pin from the fixture.   
     
     
         27 . A method comprising:
 loading an article having a bore onto a shaft of a fixture;   loading a pin into the fixture, the pin having a hollow body, the hollow body having a diameter with a profile with a pattern of voids;   applying, by an end of the shaft, an axial force on an end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article;   aligning the pin inside of the bore of the article; and   removing the axial force on the end of the hollow body.   
     
     
         28 . The method as claimed in  claim 27 , wherein the step of removing the axial force causes the diameter of the pin to increase. 
     
     
         29 . The method as claimed in  claim 27 , wherein the pin is made by:
 providing a sheet of metal;   stamping the pattern of voids into the sheet of metal; and   rolling a stamped sheet of metal into a cylindrically shaped structure.   
     
     
         30 . The method as claimed in  claim 27 , wherein the pattern of voids includes axial ellipses and circumferential ellipses, the axial ellipses each having a smaller short axis and larger long axis on an inside diameter of the hollow body than on an outside diameter of the hollow body, and the circumferential ellipses each having a larger short axis and a shorter long axis on the inside diameter than on the outside diameter. 
     
     
         31 . The method as claimed in  claim 27 , wherein said pattern of voids is distributed over an entire circumference of the hollow body for an entire axial length of the hollow body. 
     
     
         32 . The method as claimed in  claim 27 , further comprising:
 applying an axial force on the end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article;   removing the pin from inside of the bore of the article; and   removing the pin from the fixture.   
     
     
         33 . An assembly of a pin and an article formed by the process comprising the steps of:
 providing an article with a bore, the bore having an inside diameter;   providing a pin having a hollow body, the hollow body having a diameter with a profile with a pattern of voids, the hollow body having an end;   applying an axial force on the end of the hollow body to cause the diameter of the pin to reduce in size to a point where the diameter of the pin is less than the inside diameter of the article;   aligning the pin inside of the bore of the article; and   removing the axial force on the end of the hollow body.   
     
     
         34 . The assembly as claimed in  claim 33 , wherein the pattern of voids includes axial ellipses and circumferential ellipses, the axial ellipses each having a smaller short axis and larger long axis on an inside diameter of the hollow body than on an outside diameter of the hollow body, and the circumferential ellipses each having a larger short axis and a shorter long axis on the inside diameter than on the outside diameter. 
     
     
         35 . The assembly as claimed in  claim 33 , wherein said pattern of voids is distributed over an entire circumference of the hollow body for an entire axial length of the hollow body. 
     
     
         36 . The assembly as claimed in  claim 33 , wherein the pin is made by:
 providing a sheet of metal;   stamping the pattern of voids into the sheet of metal; and   rolling a stamped sheet of metal into a cylindrically shaped structure.