Patent Publication Number: US-2010127091-A1

Title: Rail joint bar with transferred load

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     None 
     TECHNICAL FIELD 
     The invention relates generally to devices for joining or splicing railroad rails. 
     BACKGROUND ART 
     The standard joint often comprises of two joint bars sandwiching the rail on either sides of the web and connected by a series of bolts. Joints are used to: connect rail strings before they are welded, hold the rail plugs in place when defects are removed from the track before the plugs are welded onto the main rail, relieve thermal tension stresses in the rail and prevent rail pull-apart, connect different sized rails (compromise joints), and provide isolation for signal blocks. 
     While being utilized in the manner described above, the joint is expected to: provide semi-continuous rail girder action, minimize overall vertical deflection of track, reduce movement of rail ends, and be simple, user friendly and effective and of sound design. 
     There is still room for improvement in the art. 
     SUMMARY OF THE INVENTION 
     The present invention is a joint bar where the load is transferred from the wheel thread and top of rail onto the wheel flange through the use of a ramp built into the inside joint bar. The increasing ramp height ensures that the wheel does not impact the receiving rail. When the wheel has crossed the joint, the decreasing ramp action transfers the load back to the wheel thread and onto the top of the rail. 
     A similar ramp can also be incorporated into the outside joint bar. The thread can be lifted over the joint by means of an increasing ramp height and then lowered on the other side of the joint by the decreasing ramp height. Both of the ramps described herein can also be used together. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1 : Isometric view of the standard joint. 
         FIG. 2 : Cross section of the standard joint. 
         FIG. 3 : Isometric view of the insulated joint. 
         FIG. 4 : Flange bearing wheel, wheel flange carried by the inside joint bar over the joint. 
         FIG. 5 : Flange bearing wheel, wheel flange carried by the inside joint bar over the joint. 
         FIG. 6 : Isometric view from inside of the embodiment shown in  FIG. 3 . 
         FIG. 7 : Thread bearing wheel, wheel thread carried by the outside joint bar over the joint. 
         FIG. 8 : Flange and thread bearing wheel, wheel flange and thread carried by the inside and outside joint bars over the joint. 
         FIG. 9 : View from outside (field side) of the joint showing the outside ramp higher than the rails top. 
         FIG. 10 : View from inside (gauge side) of the joint showing the inside ramp that picks up the wheel flange. 
         FIG. 11 : Top view of the ramped joint system. 
         FIG. 12 : Isometric view from inside (gauge side) of the joint showing both ramps. 
     
    
    
     In the drawings, like characters of reference indicate corresponding parts in the different figures. 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     There are two types of joints; the insulated joints  2  ( FIGS. 1 &amp; 2 ) used to isolate railway signal blocks and non-insulated joint  4  ( FIG. 3 &amp; 4 ) simply used to connect two rails  10 . Each of these joints has their use and place in today&#39;s railway track. No matter in what form, the current railway joint constitutes a weakness in the system providing only a fraction of the bending strength of the continuous rail section at the joint. As a result, there have been joint failures that have caused the spilling of dangerous commodities polluting the environment, taken human lives, led to evacuation of communities, and made news headlines. The demise of the joint begins with the impact loads that are generated as the wheel crosses over the gap at the joint and is transferred from one rail  10  to the other. This chips and damages the edge of the receiving rail, causes the joint to flex and pump; a process that feeds on itself leading to either fracture or the bar or the rail and derailment. 
     This invention provides a joint bar  9  ( FIG. 5 &amp; 6 ) wherein the load is transferred from the wheel thread and top of rail  12  onto the wheel flange by means of a ramp  15  built into the inside joint bar  19 . The increasing ramp  15  height ensures that the wheel  20  does not impact the receiving rail. When the wheel  20  has crossed the joint, the decreasing ramp action transfers the load back to the wheel thread and onto the top of the rail. 
     A similar ramp  25  can also be incorporated into the outside joint bar. In this case, the thread is lifted over the joint  9  ( FIG. 7 ) by means of an increasing ramp height and then lowered on the other side of the joint by the decreasing ramp height. Both of the ramps described herein can also be used together ( FIG. 8 ). 
     The ramps  20  can be cast into the joint bars or can be inserts put into the joint assembly. The benefit of using inserts is that they can be replaced when they are worn out. On the other hand, to avoid over use of the joint bars and potential for joint bar failure due to fatigue, it might be safer to cast the ramps onto the bars and replace the entire bar when the ramp is worn.  FIGS. 9 to 12  show different views of the new flange and thread bearing joint assembly  13 . 
       FIG. 9  shows the view from outside (field side) of the joint showing the outside ramp  25  higher than the rails top.  FIG. 10  shows the view from inside (gauge side) of the joint showing the inside ramp  15  that picks up the wheel flange with  FIG. 11  showing the top view of the ramped joint system.  FIG. 12  shows an isometric view from inside (gauge side) of the joint showing both ramps. 
     A specific embodiment of the present invention has been disclosed; however, several variations of the disclosed embodiment could be envisioned as within the scope of this invention. It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.