Elongate plastic member and method and apparatus for providing structural strength to same

Abstract

An apparatus for increasing the rigidity of an elongate plastic member having a groove formed in an exterior surface thereof is an elongate metal reinforcing member, preferably having a generally T-shaped cross section, the member being adapted for placement into the groove so that the member fits snugly into the groove. An improved elongate plastic member has a reinforcing member formed, preferably by roll forming, into a rigid structure, preferably having a substantially T-shaped cross-section when viewed end-on. The insert fits tightly within a groove in the plastic portion of the improved elongate plastic member. An elongate plastic member is provided structural strength by forming in the plastic member a groove adapted so that a reinforcing member will fit tightly within the groove and then placing a reinforcing member into the groove.

1 . A method for increasing rigidity of an elongate plastic member, comprising: 
 supplying a metal reinforcing member having a principal axis and a cross-section perpendicular to the principal axis;    forming in an exterior surface of the elongate plastic member a groove adapted so that the reinforcing member fits tightly within the groove; and    placing the reinforcing member within the groove.    
     
     
         2 . A method for increasing rigidity of an elongate plastic member according to  claim 1 , wherein said cross-section is substantially T-shaped.  
     
     
         3 . A method for increasing rigidity of an elongate plastic member according to  claim 2 , wherein the cross-section of the reinforcing member defines a shape having: 
 a thickness t;    a starting point p 1 ;    a first segment of length L 1 , the first segment joining the starting point p 1  to a first angle a 1 ;    a second segment of length L 2 , the second segment being essentially perpendicular to the first segment and joining first angle a 1  and a second angle a 2 ;    a third segment of length L 3 , L 3  being approximately equal to two times the length (L 2 +t), the third segment running parallel and adjacent to the second segment and joining second angle a 2  and a third angle a 3 ;    a fourth segment of length L 4 , L 4  being approximately equal to L 2 , the fourth segment running parallel and adjacent to the third segment and joining third angle a 3  and a fourth angle a 4 ;    a fifth segment of length L 5 , L 5  being greater than L 1 , the fifth segment running parallel and adjacent to the first segment and joining fourth angle a 4  and a fifth angle a 5 ; and    a sixth segment of length L 6 , the sixth segment running parallel and adjacent to the first segment and joining fifth angle a 5  and an end point p 2 .    
     
     
         4 . A method for increasing the rigidity of an elongate plastic member according to  claim 2 , wherein the cross-section of the reinforcing member defines a shape having: 
 a thickness t;    a starting point p 1 ;    a first segment of length L 1 , the first segment joining the starting point p 1  to a first angle a 1 ;    a second segment of length L 2 , the second segment being essentially perpendicular to the first segment and joining first angle a 1  and a second angle a 2 ;    a third segment of length L 3 , L 3  being approximately equal to twice the length (L 2 +t), the third segment running parallel and adjacent to the second segment and joining second angle a 2  and a third angle a 3 ;    a fourth segment of length L 4 , L 4  being approximately equal to L 2 , the fourth segment running parallel and adjacent to the third segment and joining third angle a 3  and a fourth angle a 4 ;    a fifth segment of length L 5 , L 5  being greater than L 1 , the fifth segment running parallel and adjacent to the first segment and joining fourth angle a 4  and a fifth angle a 5 ; and    a sixth segment of length L 6 , L 6  being slightly less than L 5  minus L 1 , the sixth segment running adjacent to the fifth segment and forming an angle with said fifth segment of approximately 3 to approximately 5 degrees at a 5 , and joining fifth angle a 5  and an end point p 2 .    
     
     
         5 . A method for increasing the rigidity of an elongate plastic member according to  claim 2 , wherein the groove is T-shaped and is adapted such that when the reinforcing member is placed in position in the groove, the base of the cross-section of the reinforcing member is recessed with respect to the surface of the elongate plastic member.  
     
     
         6 . A method for increasing the rigidity of an elongate plastic member according to  claim 3 , wherein the reinforcing member is formed from sheet metal.  
     
     
         7 . A method for increasing the rigidity of an elongate plastic member according to  claim 4 , wherein the reinforcing member is formed from sheet metal.  
     
     
         8 . A method for increasing the rigidity of an elongate plastic member according to  claim 6 , wherein the reinforcing member is formed from sheet metal by a process comprising rolling.  
     
     
         9 . A method for increasing the rigidity of an elongate plastic member according to  claim 7 , wherein the reinforcing member is formed from sheet metal that is formed by a process comprising rolling.  
     
     
         10 . A method for reinforcing an elongate plastic member according to  claim 4 , further comprising the step of incorporating the reinforced elongate plastic member into a structure.  
     
     
         11 . A method of reinforcing an elongate plastic member according to  claim 10 , wherein the reinforced plastic member is incorporated into the structure so as to bear a load.  
     
     
         12 . A method of reinforcing an elongate plastic member according to  claim 11 , wherein the structure is a fence.  
     
     
         13 . A method of reinforcing an elongate plastic member according to  claim 12 , wherein the reinforced elongate plastic member forms at least one fence post.  
     
     
         14 . A method of reinforcing an elongate plastic member according to  claim 12 , wherein the reinforced elongate plastic member forms at least one segment of the fence rail.  
     
     
         15 . A method of reinforcing an elongate plastic member according to  claim 10 , wherein the plastic member is made from recycled plastic material.  
     
     
         16 . A method of reinforcing an elongate plastic member according to  claim 10 , wherein the metal reinforcing member is made of steel.  
     
     
         17 . An apparatus for increasing the rigidity of an elongate plastic member having a groove formed in an exterior surface thereof, comprising: 
 an elongate metal member, the member being adapted for placement into the groove so that the member fits snugly into the groove.    
     
     
         18 . An apparatus for increasing the rigidity of an elongate plastic member according to  claim 17 , wherein the elongate metal member has a cross-section perpendicular to its principal axis, the cross-section being generally T-shaped.  
     
     
         19 . An apparatus for increasing the rigidity of an elongate plastic member according to  claim 18 , wherein the elongate metal member has a cross-section perpendicular to its principal axis, the cross-section defining a shape having: 
 a thickness t;    a starting point p 1 ;    a first segment of length L 1 , the first segment joining the starting point p 1  to a first angle a 1 ;    a second segment of length L 2 , the second segment being essentially perpendicular to the first segment and joining first angle a 1  and second angle a 2 ;    a third segment of length L 3 , L 3  being approximately equal to twice the length (L 2 +t), the third segment running parallel and adjacent to the second segment and joining second angle a 2  and a third angle a 3 ;    a fourth segment of length L 4 , L 4  being approximately equal to L 2 , the fourth segment running parallel and adjacent to the third segment and joining third angle a 3  and a fourth angle a 4 ;    a fifth segment of length L 5 , L 5  being greater than L 1 , the fifth segment running parallel and adjacent to the first segment and joining fourth angle a 4  and a fifth angle a 5 ; and    a sixth segment of length L 6 , the sixth segment running parallel and adjacent to the first segment and joining fifth angle a 5  and an end point p 2 .    
     
     
         20 . An apparatus for increasing the rigidity of an elongate plastic member according to  claim 18 , wherein the elongate member has a cross-section perpendicular to its principal axis, the cross-section defining a shape having: 
 a thickness t;    a starting point p 1 ;    a first segment of length L 1 , the first segment joining the starting point p 1  to a first angle a 1 ;    a second segment of length L 2 , the second segment being essentially perpendicular to the first segment and joining first angle a 1  and a second angle a 2 ;    a third segment of length L 3 , L 3  being approximately equal to two times the length (L 2 +t), the third segment running parallel and adjacent to the second segment and joining second angle a 2  and a third angle a 3 ;    a fourth segment of length L 4 , L 4  being approximately equal to L 2 , the fourth segment running parallel and adjacent to the third segment and joining third angle a 3  and a fourth angle a 4 ;    a fifth segment of length L 5 , L 5  being greater than L 1 , the fifth segment running parallel and adjacent to the first segment and joining fourth angle a 4  and a fifth angle a 5 ; and    a sixth segment of length L 6 , L 6  being slightly less than L 5  minus L 1 , the sixth segment running adjacent to the fifth segment and forming with said fifth segment an angle of approximately 3 to approximately 5 degrees at a 5 , and joining fifth angle a 5  and an end point p 2 .    
     
     
         21 . An apparatus for increasing the rigidity of an elongate plastic member according to  claim 20 , wherein the reinforcing member is formed from sheet metal.  
     
     
         22 . An apparatus for increasing the rigidity of an elongate plastic member according to  claim 21 , wherein the reinforcing member is formed from sheet metal that is formed by a process comprising rolling.  
     
     
         23 . An apparatus for increasing the rigidity of an elongate plastic member according to  claim 22 , wherein the apparatus is made of steel.  
     
     
         24 . An improved elongate plastic member having a principal axis, comprising: 
 an elongate plastic member having a groove in one exterior surface thereof parallel to the principal axis of the elongate plastic member; and    an elongate metal member adapted for insertion into and inserted into the groove so that the elongate metal member fits tightly within the groove.    
     
     
         25 . An improved elongate plastic member according to  claim 24 , wherein said reinforcing member has a cross-section perpendicular to its principal axis, the cross-section being generally T-shaped.  
     
     
         26 . An improved elongate plastic member according to  claim 25 , wherein the elongate metal member has a cross-section perpendicular to its principal axis, the cross-section defining a shape having: 
 a thickness t;    a starting point p 1 ;    a first segment of length L 1 , the first segment joining the starting point p 1  to a first angle a 1 ;    a second segment of length L 2 , the second segment being essentially perpendicular to the first segment and joining first angle a 1  and a second angle a 2 ;    a third segment of length L 3 , L 3  being approximately equal to twice the length (L 2 +t), the third segment running parallel and adjacent to the second segment and joining second angle a 2  and a third angle a 3 ;    a fourth segment of length L 4 , L 4  being approximately equal to L 2 , the fourth segment running parallel and adjacent to the third segment and joining third angle a 3  and a fourth angle a 4 ;    a fifth segment of length L 5 , L 5  being greater than L 1 , the fifth segment running parallel and adjacent to the first segment and joining fourth angle a 4  and a fifth angle a 5 ; and    a sixth segment of length L 6 , the sixth segment running parallel and adjacent to the first segment and adjoining fifth angle a 5  and an end point p 2 .    
     
     
         27 . An improved elongate plastic member according to  claim 25 , wherein the elongate metal member has a cross-section perpendicular to its principal axis, the cross-section defining a shape having: 
 a thickness t;    a starting point p 1 ;    a first segment of length L 1 , the first segment joining the starting point p 1  to a first angle a 1 ;    a second segment of length L 2 , the second segment being essentially perpendicular to the first segment and joining first angle a 1  and a second angle a 2 ;    a third segment of length L 3 , L 3  being approximately equal to twice the length (L 2 +t), the third segment running parallel and adjacent to the second segment and joining second angle a 2  and a third angle a 3 ;    a fourth segment of length L 4 , L 4  being approximately equal to L 2 , the fourth segment running parallel and adjacent to the third segment and joining third angle a 3  and a fourth angle a 4 ;    a fifth segment of length L 5 , L 5  being greater than L 1 , the fifth segment running parallel and adjacent to the first segment and joining fourth angle a 4  and a fifth angle a 5 ; and    a sixth segment of length L 6 , L 6  being less than L 5  minus L 1 , the sixth segment running adjacent to the fifth segment and forming an angle with said fifth segment of approximately 3 to approximately 5 degrees, and joining fifth angle a 5  and an end point p 2 .    
     
     
         28 . An improved elongate plastic member according to  claim 28 , wherein the reinforcing member is formed from sheet metal.  
     
     
         29 . An improved elongate plastic member according to  claim 28 , wherein the reinforcing member is formed by a process comprising rolling.