Bonded electrically insulated joint system for railway rails, method for fabricating such, method of modifying at least one starting type switch rail and use of two switch rails modified in accordance with said modifying method

Abstract

A bonded, electrically insulated rail joint (IRJ) assembly for railways or subways is realized by machining two standard switch rails and subsequently coupling them by use of a lower bolted cover plate.

The invention claimed is: 
     
         1 . A bonded insulated rail joint (IRJ) system comprising:
 a first switch rail ( 1 );   a second switch rail ( 2 );   wherein both said first and said second switch rails ( 1 ,  2 ) have a first portion ( 1 ″;  2 ″) of predetermined longitudinal length with a standard rail structure that connects to a second portion, lowered with respect to the first portion, said second portion comprising, at one of its sides, a conjugate coupling surface (S) and having, on an opposite side, a portion of a switch blade structure; and   wherein said conjugate coupling surfaces (S) are such that, when said first and said second switch rails are coupled together by said two conjugate coupling surfaces (S) placed in contact with each other, the structure of a switch blade or rail is restored in a coupling section, said switch blade or rail having a foot, a web and a head; and   further comprising a bolted cover plate ( 8 ) forming a second foot, to which at least part of said foot of the switch blade or of the rail restored as a result of said coupling is fixed.   
     
     
         2 . The bonded insulated rail joint system, according to  claim 1 , wherein, following their coupling, said conjugate coupling surfaces (S) generate a transition line (L) which forms, for at least a section of its length or for several sections of its entire length or for its entire length, a predetermined angle with respect to a longitudinal axis of the switch rail on which said transition line is provided. 
     
     
         3 . The bonded insulated rail joint system, according to  claim 1 , wherein said first and second switch rails ( 1 ,  2 ) are of standard type and said conjugate coupling surface (S) is a surface obtained by choice of:
 chip removal of said second portion of a starting standard switch rail;   forging said second portion of the starting standard switch rail; or   a combination of both of the preceding options.   
     
     
         4 . The bonded insulated rail joint system, according to  claim 1 , further comprising a first layer of electrically insulating material ( 15 ) inserted between the conjugate coupling surfaces (S) which couple together, and a second layer ( 11 ′,  11 ″) of the electrically insulating material inserted between the bolted cover plate and said second foot which connects to the bolted cover plate. 
     
     
         5 . The bonded insulated rail joint system, according to  claim 1 , further comprising first connecting means ( 3 ,  4 ,  5 ,  6 , F) for connecting said first switch rail with said second switch rail through said conjugate coupling surfaces. 
     
     
         6 . The bonded insulated rail joint system, according to  claim 1 , further comprising second connecting means for connecting said second portions to each other coupled to said plate ( 8 ). 
     
     
         7 . The bonded insulated rail joint system, according to  claim 6 , wherein said second connecting means further comprise one or more blocking elements ( 10 ′,  10 ″) shaped so as to overlap for a part thereof with the foot of the rail restored by the coupling of said conjugate coupling surfaces (S) and, for another part thereof, abutting plate ( 8 ) so as to be fixed to said cover plate by bolts or screws. 
     
     
         8 . The bonded insulated rail joint system, according to  claim 1 , wherein said first and said second switch rails comprising said conjugate coupling surfaces (S) are arbitrary and mutually identical. 
     
     
         9 . The bonded insulated rail joint system, according to  claim 1 , wherein said conjugate coupling surface (S) extends longitudinally for a predetermined length so as to form, following coupling, a transition (L) having a longitudinal length extending further for a full height of said second portion. 
     
     
         10 . A method for fabricating a bonded, electrically insulated rail joint (IRJ) assembly comprising:
 providing a first starting standard type switch rail ( 1 ) having a first portion ( 1 ″) of a predetermined longitudinal length with a standard rail structure that connects to a subsequent second blade portion that is asymmetrical and lowered with respect to the first portion;   providing a second starting standard type switch blade bar ( 2 ) having a first ( 2 ″) portion of a predetermined longitudinal length with the standard rail structure that connects to a subsequent second blade portion that is asymmetrical and lowered with respect to the first portion;   machining at least part of said second portion for both said first and second starting switch rails in such a way as to modify said second portion by obtaining on one side of said second portion a conjugate coupling surface (S) and maintaining an original structure on an opposite side;   jointing of said first and second switch rails together by bringing said two conjugate coupling surfaces (S) into contact with each other in such a way as to restore, following coupling, a structure of a switch blade or rail, said switch blade or rail having a foot, a web and a head; and   fastening the foot relative to the said restored switch blade or restored rail with a bolted cover plate ( 8 ) arranged underneath said foot.   
     
     
         11 . The method, according to  claim 10 , wherein said machining is:
 a machining operation on machine tools for chip removal;   machining by forging; or   a combination of both.   
     
     
         12 . The method, according to  claim 10 , wherein, as a result of coupling said two conjugate coupling surfaces (S), a transition line (L) is generated which forms, for at least a section of its length or for several sections of its entire length or for its entire length, a predetermined angle with respect to a longitudinal axis of the switch rails on which said transition line is provided. 
     
     
         13 . The method, according to  claim 12 , wherein the jointing of said first and said second switch rails is performed by drilling the two conjugate coupling surfaces with one or more holes passing transversely through an entire thickness and applying first connecting means. 
     
     
         14 . The method, according to  claim 10 , wherein said coupling conjugate surface (S) extends longitudinally for a predetermined length so as to form, following the coupling, a transition of a longitudinal length extending over an entire height of said second portion from the head to the foot of said second portion. 
     
     
         15 . The method according to  claim 10 , wherein the jointing provides a joint that is electrically insulated and bonded at least by insertion of a layer of electrically insulating material and assisted with adhesive material at least between the two conjugate coupling surfaces (S) and between the foot and the bolted cover plate. 
     
     
         16 . A method of modifying a starting standard type switch rail ( 1 ) having a first portion ( 1 ″) of predetermined longitudinal length with a standard rail structure which connects to a subsequent second portion asymmetrical and lowered with respect to said first portion, said method comprising:
 machining at least one portion of said second portion of said starting switch rail in such a manner as to modify a side of said at least one portion of said second portion by obtaining on said side a conjugate coupling surface (S) and maintaining an original structure on an opposite side. 
 
     
     
         17 . The method according to  claim 16 , further comprising a step of coupling said first portion and said second portion together by bringing the conjugate coupling surfaces (S) into contact with each other to form a bonded insulated rail joint (IRJ) assembly.