High resilient direct fixation fastener in standard footprint

Abstract

A bonded, direct fixation fastener as a supportive structure for a rail on a railroad bed comprising a top member or plate having a center portion having an upper face and a lower face; the top plate defining first and second wall sections each defining an outer perimeter having an outer face defining a lower face section and an upper face section; wherein a first angle between the lower face section and a horizontal surface of the railroad bed is lower than a second angle between the upper face section and the horizontal surface of the railroad bed; a bottom plate or member having first and second anchoring sides connected by first and second elements; wherein the bottom plate or member defines an opening;wherein the bottom plate has first and second wall members each having an interior face; and an elastomeric or rubber portion disposed between the top plate and the bottom plate.

What is claimed is: 
     
         1 . A bonded, direct fixation fastener as a supportive structure for a rail on a railroad bed comprising:
 a top member or plate having a center portion having an upper face and a lower face;   the top plate defining first and second wall sections each defining an outer perimeter having an outer face defining a lower face section and an upper face section;   wherein a first angle between the lower face section and a horizontal surface of the railroad bed is lower than a second angle between the upper face section and the horizontal surface of the railroad bed;   a bottom plate or member having first and second anchoring sides connected by first and second elements; wherein the bottom plate or member defines an opening;   wherein the bottom plate has first and second wall members each having an interior face; and   an elastomeric or rubber portion disposed between the top plate and the bottom plate.   
     
     
         2 . The bonded, direct fixation fastener of  claim 1  wherein, the upper face of the center portion is flat and defines a substantially rectangular or substantially square shape. 
     
     
         3 . The bonded, direct fixation fastener of  claim 1  wherein, the first angle is about 80° and the second angle is about 88°. 
     
     
         4 . The bonded, direct fixation fastener of  claim 1  wherein, the bottom plate or member defines a substantially rectangular shape. 
     
     
         5 . The bonded, direct fixation fastener of  claim 1  wherein, an interior perimeter of the opening is defined by a plurality linear walls and two semi-circular walls each having a radius of curvature of about 1.75 inches. 
     
     
         6 . The bonded, direct fixation fastener of  claim 5  wherein, each of the two semi-circular walls has a radius of curvature of about 1.75 inches. 
     
     
         7 . The bonded, direct fixation fastener of  claim 1  wherein, the elastomeric or rubber portion disposed between the top plate and the bottom plate encapsulates all elements of the top plate except for the interior faces of open cylinders for attaching the bonded, direct fixation fastener to a railroad rail and the upper face of the center portion of the top plate and the bottom plate except for a bottom surface of the bottom plate and serrated surfaces around anchoring apertures defined by the bottom plate and the anchoring apertures. 
     
     
         8 . The bonded, direct fixation fastener of  claim 1  wherein, the lower face of the center portion defines first and second beveled edges; wherein each of the first and second beveled edges has an inner portion and an outer portion and wherein a first thickness of the rubber or elastomeric material between the outer portions and a top surface of the bottom plate is greater than a second thickness of the rubber or elastomeric material between the inner portions and the top surface of the bottom plate. 
     
     
         9 . The bonded, direct fixation fastener of  claim 8  wherein, the first thickness is about 0.85 inches and the second thickness is about 0.63 inches. 
     
     
         10 . The bonded, direct fixation fastener of  claim 1  wherein, a first thickness of the rubber or elastomeric material between the lower face section of the outer face of the top plate wall and the inner face of the bottom plate wall is less than a second thickness of the rubber or elastomeric material between the upper face section of the outer face of the top plate wall and the inner face of the bottom plate wall. 
     
     
         11 . The bonded, direct fixation fastener of  claim 10  wherein, the first thickness is about 0.88 inches and the second thickness is about 0.98 inches. 
     
     
         12 . The bonded, direct fixation fastener of  claim 1  wherein, the bonded, direct fixation fastener produces a vertical spring-rate in the range of about 45,000 lbf/in. to about 65,000 lbf/in. 
     
     
         13 . The bonded, direct fixation fastener of  claim 1  wherein, the top plate has a rail attachment means comprising open cylinders for attaching the bonded, direct fixation fastener to a railroad rail using a clip. 
     
     
         14 . The bonded, direct fixation fastener of  claim 1  wherein, each of the top plate and the bottom plate comprise one or more of the materials selected from the group of a metal, an alloy, cast steel and ductile iron. 
     
     
         15 . The bonded, direct fixation fastener of  claim 1  wherein, each of the top plate and the bottom plate comprises ductile iron grade 65-45-12. 
     
     
         16 . The bonded, direct fixation fastener of  claim 1  wherein, each of the first and second elements comprises a beam having a generally trapezoidal cross-section having at least one sharp corner and at least one round corner. 
     
     
         17 . The bonded, direct fixation fastener of  claim 5  wherein, the bottom plate defines a drainage channel from each of the semi-circular walls across the underside of each anchoring side. 
     
     
         18 . The bonded, direct fixation fastener of  claim 1  wherein, each of the anchoring sides defines an aperture surrounded by a serrated surface for use in attaching the bottom plate or member to a rail bed. 
     
     
         19 . The bonded, direct fixation fastener of  claim 1  wherein, each of the interior faces of the bottom plate is angled at about 75° with respect to horizontal. 
     
     
         20 . The bonded, direct fixation fastener of  claim 1  wherein, the elastomeric portion has a hardness in the range of 55 to 65 durometer A or Shore A. 
     
     
         21 . The bonded, direct fixation fastener of  claim 1  wherein, the elastomeric portion has a hardness of 60 durometer A or Shore A.