Patent Publication Number: US-8123145-B2

Title: Tie plate with cam shoulder bridge

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     None 
     TECHNICAL FIELD 
     The invention relates generally to a tie plates used to secure railway rails to the cross ties. 
     BACKGROUND ART 
     In prior art, known wood tie plates and rail fastening systems have offered difficulties to insertion of rail clips. The current invention facilitates insertion of the clips to provide the desired amount of clip pressure on the rail base. 
     There is still room for improvement in the art. 
     SUMMARY OF THE INVENTION 
     In the present invention, to provide the desired amount of clip pressure on the rail base tie plates are used to secure railway rails to the cross tie where the plate is cast with vertical abutment walls each of which has a slot along the inner wall originating from the lower outside edge and rising towards the top and center of each vertical abutment member. Between each pair of abutment members on either side of the rail seat is an upwardly facing ramp to facilitate insertion of the clip. Each ramp surface has a half cylindrical button cast on top of it. The button is used to retain the clip prior to shipment and the bottom of the plate has wedge shaped projections that tapper laterally solely in the same direction as the rail seat. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an isometric view of the wood tie plate in accordance with the invention. 
         FIG. 2  is a half section of the wood tie plate in  FIG. 1 . 
         FIG. 3  is an isometric bottom view of the wood tie plate in  FIG. 1  showing the wedge shaped projections. 
         FIG. 4   a  is an isometric front view of the shoulder bridging member in accordance with this invention. 
         FIG. 4   b  is a side view of the shoulder bridging member in  FIG. 4  showing the cam profile. 
         FIG. 5  is an isometric view of a rod formed clip. 
         FIG. 6  is an isometric view of the plate in  FIG. 1  with shoulder bridging member in place and the arm of the cam lifted to receive the clips in the pre-set position. 
         FIG. 7  is an isometric view of the plate in  FIG. 6  with arm of the shoulder bridging lowered and the clips secured in the pre-install position. 
         FIG. 8  is an isometric view of a quarter cutaway of the assembly in  FIG. 7 . 
         FIG. 9  is an isometric view of the plate in  FIG. 7  now secured on a wood tie and the arm of the bridging member lifted to allow complete and final insertion of the clip onto the top of the rail base flange. 
         FIG. 10  is an isometric view of the plate in  FIG. 7  now secured on a wood tie and the arm of the bridging member lowered to secure the clip in the final position. 
         FIG. 11  is an isometric view of a rectangular bar formed clip. 
         FIG. 12  is an isometric view of the pre-installation of the clip in  FIG. 11  into the plate in  FIG. 1 . 
         FIG. 13  is an isometric view of the plate in  FIG. 12  now secured on a wood tie and the arm of the bridging member up. 
         FIG. 14  is an isometric view of the plate in  FIG. 12  now secured on a wood tie and the arm of the bridging member lowered to secure the bar formed clip in the final position. 
         FIG. 15  displays a bridging member with a split cam. 
         FIG. 16  is an isometric view of the plate in  FIG. 12  now secured on a wood tie and the arm of the bridging member lowered to secure the bar formed clip in the final position using a split cam. 
     
    
    
     In the drawings, like characters of reference indicate corresponding parts in the different figures. 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     The present invention relates to a tie plates used to secure railway rails to the cross ties. The plate  10  comprises of a base plate adapted to be applied to the tie and a pair of abutment members upstanding there from to accommodate a rail between them. The upright abutment members have an open top to accommodate a bridging member with a downward face profiled to provide a reaction to a laterally inwardly inserted rail clip, and an upwardly facing lower ramp surface inclining from a laterally outer side of each abutment member upwardly inwardly to a laterally inner side thereof for facilitating insertion of the clip to an installed position wherein an inner end of the clip bears resiliently on the top side of the rail base flange. The plate  10  has a central portion between the abutment walls that tapers laterally in thickness and has an upper side canted with respect to the lower side and the said lower side is provided with discrete wedge shaped projections that spaced inwardly from a longitudinal edge of said plate  10 . The wedge shaped projections tapper laterally solely in the same direct ion as the central portion, each wedge having an end face making an angle of approximately 90 degrees with said lower face and wherein the base plate has holes for insertion of cut spikes and/or threaded coach screws for securing said plate to the tie. 
     Whereas known wood tie plates and rail fastening systems of which the applicant is aware have offered difficulties to insertion of rail clips, the ramp surface of the present invention facilitates insertion of the clips and the removable bridging member can be profiled to provide the desired amount of clip pressure on the rail base. 
     This invention is an improvement over U.S. Pat. Nos. 6,305,613 and 6,431,463. In the present invention, the plate  10  shown in  FIG. 1  is cast with vertical abutment walls each of which has a slot along the inner wall originating from the lower outside edge and rising towards the top and center of each vertical abutment member  15 . Between each pair of abutment members  15  on either side of the rail seat is an upwardly facing ramp shown in  FIG. 2  to facilitate insertion of the clip  20 . Each ramp surface has a half cylindrical button cast on top of it. Said button is used to retain the clip  20  prior to shipment. The bottom of the plate  10  has wedge shaped projections  14  shown in  FIG. 3  that tapper laterally solely in the same direction as the rail seat. The plate  10  also has a portion laterally outward of each abutment member  15  formed with a pit in its upper side for locating the outer end of said clip  20 . 
     Each inner wall slot of the vertical abutment members  15  stops short of the top of the abutment and receives the bridging member  30  shown in  FIG. 4 . The bridging member  30  has cylindrical projections  32  on either side that fit into the vertical shoulder slots. The bridging member  30  has a cam profiled portion, referred to as the cam  34  that reacts against the clip  20  and serves to apply the appropriate pressure. The cam profile determines the clip ( FIG. 5 ) pressure. Lifting the arm of the cam  34  as shown in  FIG. 6  allows insertion of the clips  20  to the pre-install position while lowering the arm of the cam secures the clip  20  as shown in  FIG. 7  for shipping to the field. The quarter plate cut away in  FIG. 8  shows how the clip  20  interacts with the ramp surface, the clip retention button and the cam  34 . During installation in the field, the plate  10  is first secured to the tie  40  and the rail  50  inserted as shown in  FIGS. 9 and 10 . Once again, the arm of the cam  34  can be lifted to allow complete insertion of the clip  20  to the top of the rail base as shown in  FIG. 9 . Finally, the arm of the cam is lowered to apply pressure to the clip  20  and to secure it to the rail as shown in  FIG. 10 . Removal of the clip  20  for rail maintenance follows the reverse procedure. 
     This cam profiled bridge member  30  design is not limited to rod formed Clips  20 . Clips  20  formed from other shapes can also be used. An example is the clip  20  formed from the rectangular flat bar shown in  FIG. 11 . In this case, a hole is made at the nose of the clip  20  to accommodate the button on the plate ramp surface between the vertical abutment members  15 . Again, the arm of the cam  30  is lifted to pre-install the clip  20  as shown in  FIGS. 12 and 13 . The final installation procedure is the same as previously described with the final assembly for this clip  20  form shown in  FIG. 14 . 
     A bridging member  30  that has a cam split cam  34  can be also used in the current invention. In a split cam  20  the bridging member  30  has and opening on the non-cam side with holes  35  drilled into the two bridging member extensions  37  as shown in  FIG. 15 . A single vertical abutment member  16  extends from the plate  10  on to which the bridging member  30  is attached as shown in  FIG. 16 . 
     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.