Abstract:
A concrete gauge panel spans the gap between two parallel railroad tracks. Two concrete field panels lead from the roadway surface to the railroad tracks, one panel on each side of the railroad tracks. A spacer sits between the concrete of the concrete field and gauge panels and the railroad tracks. The spacer is affixed to the panels in a way that allows the spacer to be removed and replaced without replacing the entire panel.

Description:
RELATED APPLICATION DATA 
     This application claims priority from U.S. Provisional Application No. 60/097,439, filed Aug. 21, 1998, incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to railroad grade crossings and, more particularly, to railroad grade crossings using concrete panels with polymeric, preferably elastomeric, seals between the panels and the rails. 
     BACKGROUND OF THE INVENTION 
     Where paved roads intersect with railroad crossings, vehicles need a simple way to cross the railroad tracks. The simplest solution uses concrete panels to span the gap between the rails. When the concrete panels are positioned with respect to the railroad tracks to match the elevation of the roadway, vehicles have a nearly continuous surface on which to travel over the tracks. However, if the rails and concrete panels directly abut each other, they can do damage to each other. 
     To avoid this problem, a gap needs to be maintained between the concrete panels and the rails. But leaving this gap unfilled allows water and debris to intersect with the ballast and ties of the track, which can damage the ties and ballast (rock placed below and between the railroad ties to provide a level surface on which to lay the track). To fill this gap, a flexible substance, such as a rubber spacer, is used, both to cushion the concrete panels and the rails and to limit the entry of water and debris. 
     Originally, the spacer was a separate element. The concrete panels were positioned between and around the rails, and then the spacer was carefully inserted therewithin. This made it possible to replace the spacer when it wore out, but necessitated a more complicated installation process. Later developments included permanently attaching the spacer to the concrete panels, making the two parts into a single piece. For example, the spacer could be permanently bolted to a completed concrete panel using a T-bar, or the concrete panel could be cast around the spacer. But when the spacer wore out, the entire panel had to be replaced, an expensive proposition. 
     SUMMARY OF THE INVENTION 
     The invention is directed to spacers and panel systems which form a paved road across railroad tracks. A concrete gauge panel is located between the rails. A panel system comprising a pair of gauge flangeway spacers are attached to the concrete gauge panel and form a cushion between the concrete gauge panel and the rails. The gauge flangeway spacers are preferably made of a resilient polymeric material and are removable. The gauge flangeway spacers are preferably offset downward from the top surface of the concrete gauge panel to allow train wheels to run properly on the tracks. The gauge flangeway spacer is typically shaped to match the contour of the rail at the point of contact. The complimentary shape of the gauge flangeway spacer helps prevent water and debris from getting under the panels and rails. 
     The gauge flangeway spacer preferably defines a longitudinal cavity into which a retaining bar can be inserted for securing the gauge flangeway spacer to the concrete gauge panel. The retaining bar includes a plurality of holes through which bolts can be inserted to secure the gauge flangeway spacer to the concrete gauge panel. The gauge flangeway spacer also preferably includes complementary holes through which bolts can be inserted to secure the gauge flangeway spacer to the concrete gauge panel. 
     A pair of concrete field panel systems is located outside the rails. The panel systems comprising a pair of field flangeway spacers attached to the concrete field panel cushion, the concrete field panel and the rails. The field flangeway spacers are also preferably made of a resilient polymeric material and are removable. The field flangeway spacer is also preferably shaped to match the contour of the rail at the point of contact. The shape of the field flangeway spacer helps prevent water and debris from getting under the panels and rails. The top surface of the field flangeway spacer can also be configured to increase crossing vehicles&#39; traction. 
     The field flangeway spacer preferably defines a longitudinal cavity into which a retaining bar can be inserted for securing the field flangeway spacer to the concrete field panel. The retaining bar includes a plurality of holes through which bolts can be inserted to secure the field flangeway spacer to the concrete field panel. The field flangeway spacer also preferably includes complementary holes through which bolts can be inserted to secure the field flangeway spacer to the concrete field panel. 
     The invention also includes a method for replacing an attached gauge or field flangeway spacer. The gauge flangeway spacer is replaced by uninstalling the concrete gauge panel system. This may involve releasing the concrete gauge panel and attached spacer and lifting it from between the rails. The existing gauge flangeway spacer is removed from the concrete gauge panel, and a new gauge flangeway spacer is attached to the concrete gauge panel. An attachment mechanism, such as bolts or screws, can be used to reattach the gauge flangeway spacer to the concrete gauge panel. Finally, the concrete gauge panel and attached spacer is reinstalled between the rails. 
     The field flangeway spacer is replaced by uninstalling the concrete field panel system. This typically involves releasing the concrete field panel and sliding it away from the rail. The existing field flangeway spacer is removed from the concrete field panel and a new field flangeway spacer is attached thereto. An attachment mechanism, such as bolts or screws, can be used to attach the field flangeway spacer to the concrete field panel. Finally, the concrete field panel system is reinstalled next to the rails. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a sectional view of the concrete gauge panel and one field panel at their point of contact with a rail. 
     FIG. 2 shows a plan view of the concrete gauge panel and the field panels installed with respect to the rails. 
     FIG. 3 shows a perspective view of the gauge flangeway spacer and field flangeway spacer. 
     FIG. 4 shows a schematic of the method for installing the concrete gauge panel. 
     FIG. 5 shows a schematic of the method for installing the concrete field panels. 
     FIG. 6 shows a perspective view of how the gauge flangeway spacer is attached to the concrete gauge panel in the preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 2 shows a concrete gauge panel  100  and a concrete field panel  105  at their point of contact with a railroad track  110 . The concrete gauge panel  100  and the concrete field panel  105  sit on the railroad tie  115  that supports the railroad track  110 . Located between the concrete gauge panel  100  and the railroad track  110  is a gauge flangeway spacer  120 . In the preferred embodiment, the gauge flangeway spacer  120  is typically made of a resilient polymeric material such as styrene-butadiene rubber, preferably having the following specifications: a Durometer of about 75-85 on the Shore “A” scale, a modulus of about 300%, a tensile strength of about 1600 psi, and an elongation of about 350%. However, other materials with similar cushioning properties may be used. In FIG. 1, the gauge flangeway spacer  120  is attached to the concrete gauge panel  100  by means of a bolt  125  and washer  130 . However, other means can be used to attach the gauge flangeway spacer  120  to the concrete gauge panel  100 . 
     The field flangeway spacer  135  is located between the concrete field panel  105  and the railroad track  110 . In the preferred embodiment, the field flangeway spacer  135  is made of a resilient polymeric material as described above. In FIG. 1, the field flangeway spacer  135  is attached to the concrete field panel  105  by means of a bolt  140  and washer  145 . However, other means can be used to attach the field flangeway spacer  135  to the concrete field panel  105 . Also provided in the concrete gauge panel  100  and the concrete field panel  105  are tie holes  150  through which pins (not shown) can be driven to secure the panel to the railroad tie  115 . 
     The advantage of affixing the spacer to the concrete panels as shown in FIGS. 1 and 2 is that it retains the installation ease of a single panel with attached cushioning without the disadvantage of having to replace the entire panel when the spacer wears out (saving money). When the spacer wears out, it is removed from the concrete panels and a new spacer is affixed to the concrete panels. 
     As shown in FIG. 1, the field flangeway spacer  135  can have a grooved surface. Longitudinal-grooves in the top surface of the field flangeway spacer provide passing vehicles better traction as they cross the railroad tracks and limit the entry of water and debris under the ties and ballast of the tracks. 
     As shown in FIG. 1, the gauge flangeway spacer  120  is offset downward from the upper surface of the concrete gauge panel  100 . This offset is necessary to allow trains to run properly on the tracks. 
     FIG. 3 shows a perspective view of the gauge flangeway spacer  120  and field flangeway spacer  135 . The gauge flangeway spacer  120  includes a top surface  200 . The top surface  200  is offset  205  downward to provide to allow trains to run properly on the tracks  110 . One side  210  of the gauge flangeway spacer  120  is contoured to match the inside counter of a rail  110 . When properly installed, the contour of the gauge flangeway spacer  120  will exactly match the inside contour of the rail  110 . This prevents water and debris from getting underneath the panels  100  and  105  and rails  110 . 
     Opposite the contoured side  210 , the gauge flangeway spacer  120  includes a mechanism  215  to attach the gauge flangeway spacer  120  to the concrete gauge panel  100 . In the preferred embodiment, the mechanism  215  is a series of positioned holes that allow the gauge flangeway spacer  120  to be bolted to the concrete gauge panel  100 . However, other mechanisms for removably securing the gauge flangeway spacer  120  to the concrete gauge panel  100  can be used. 
     The field flangeway spacer  135  includes a top surface  220 . As discussed above, the top surface  220  can have longitudinal grooves to increase vehicle traction and to prevent water and debris from getting under the panels  100  and  105  and rails  110 . One side  225  of the field flangeway spacer  135  is contoured to match the outside counter of a rail  110 . When properly installed, the contour of the field flangeway spacer  135  will exactly match the outside contour of the rail  110 . This also prevents water and debris from getting underneath the panels  100  and  105  and rails  110 . 
     Opposite the contoured side  225 , the field flangeway spacer  135  includes a mechanism  230  to attach the field flangeway spacer  135  to the concrete field panel  105 . In the preferred embodiment, the mechanism  230  is a series of positioned holes that allow the field flangeway spacer  135  to be bolted to the concrete field panel  105 . However, other mechanisms for removably securing the field flangeway spacer  135  to the concrete field panel  105  can be used. 
     FIG. 4 shows how the concrete gauge panel  100  is installed between two rails. In step  405 , one of the attached gauge flangeway spacers  120   a  is put in position underneath the lip of the rail  110   a.  Then in step  410  the concrete gauge panel  100  is lowered into position until the other gauge flangeway spacer  120   b  is touching the other rail  110   b.  In step  415  the other gauge flangeway spacer  120   b  is rolled under the lip of the rail  110   b.  Using a lubricant can make it easier to roll the gauge flangeway spacer  120   b  under the lip of the rail  110   b.  Finally, the concrete gauge panel  100  is centered between the rails  110   a  and  110   b  and secured in position. In the preferred embodiment, the concrete gauge panel  100  is secured to the railroad ties through lag screws, but other methods can be used to secure the concrete gauge panel  100 . 
     FIG. 5 shows how the concrete field panels  105  are installed. In step  505 , the concrete field panel  105  is positioned a few inches away from the rail  110 . Then in step  510 , the concrete field panel  105  is slid toward the rail until the field flangeway spacer  135  touches the rail  110 . The contour of the field flangeway spacer  135  should match the contour of the outside contour of the rail  110 . Then the concrete field panel  105  can be secured. In the preferred embodiment, the concrete field panel  105  is secured by driving lag screws into railroad ties, but other methods of securing the concrete field panels  105  can be used. 
     FIG. 6 shows a perspective view of how the gauge flangeway spacer  120  is removably attached to the concrete gauge panel  100  in the preferred embodiment. (The field flangeway spacer  135 , not shown, is attached to the concrete field panel  105 , not shown, in a similar manner.) Embedded within the concrete gauge panel  100  is a ferrel loop  600  (alternatively spelled as ferrule loop insert). The ferrel loop  600  includes a steel frame  605  to which concrete nuts  610  are welded. The concrete gauge panel also has holes  615  that lead into the concrete nuts  610 . A retainer bar  620  is part of the mechanism that attaches the gauge flangeway spacer  120  to the concrete gauge panel  100 . The retainer bar  620  has holes  625  drilled through the retainer bar. The holes  625  can be slot-shaped to allow the retainer bar to be adjusted after the gauge flangeway spacer  120  is placed in position. Finally, the gauge flangeway spacer  120  has holes  630  drilled through. (Only holes in the outer wall  632  of the gauge flangeway spacer  120  are shown, but there are corresponding holes in the inner wall  633 .) These holes  630  allow bolts  635  to be used to secure the gauge flangeway spacer  120  to the concrete gauge panel. The holes  630  can be oversize holes, both to allow the bolts  635  and a wrench (not shown) to be used to secure the gauge flangeway spacer  120  to the concrete gauge panel  100  and to allow the gauge flangeway spacer  120  to be adjusted. Preferably, the holes  630  in the inner and outer walls  633  and  632  are the same diameter. The concrete nuts  610  and the holes  625  and  630  are preferably spaced every 12 inches on center. 
     To secure the gauge flangeway spacer  120  to the concrete gauge panel  100 , first the retainer bar  620  is placed in the longitudinal cavity  640  of the gauge flangeway spacer  120 . The bolts  635  pass through the holes  630  in the outer wall  632  of the gauge flangeway spacer  120 , then through the holes  625  in the retainer bar  620 , and lastly through the holes  630  in the inner wall  633  of the gauge flangeway spacer  120 . The bolts  635  are tightened on the concrete nuts  610  to secure the gauge flangeway spacer  120  to the concrete gauge panel  100 . 
     To replace an old gauge flangeway spacer  120  on a concrete gauge panel  100 , first the concrete gauge panel  100  is uninstalled from between the railroad tracks. Next, the old gauge flangeway spacer  120  is removed from concrete gauge panel  100 . This is accomplished by removing the bolts  635  securing the gauge flangeway spacer  120  to the concrete gauge panel  100 . Then a new gauge flangeway spacer  120  is attached to the concrete gauge panel  100  as discussed above. Finally, the concrete gauge panel  100  is reinstalled between the railroad tracks. The method for replacing a field flangeway spacer is similar to that for replacing the gauge flangeway spacer. 
     Having illustrated and described the principles of our invention in a preferred embodiment thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. We claim all modifications coming within the spirit and scope of the accompanying claims.