Concrete Tie Fastener

Abstract

This invention addresses issue of rail seat abrasion by completely removing all elastomers from directly contacting the rail by utilizing a shoulder post with a lower portion that is coated or encapsulated with a nonconductive material and a rolled or cast tie plate design that introduces a tie plate to the rail seat of the concrete tie. The coated or encapsulated lower portion of the shoulder is then cast into the concrete. By having the pad between the plate and the tie, it is subjected to vertical compression only with no rubbing action.

Description

CROSS REFERENCE TO RELATED APPLICATION

None

TECHNICAL FIELD

The invention relates generally to a Concrete Tie Fastener more particularly one that removes all elastomers from directly contacting the rail.

BACKGROUND ART

Concrete ties used in railway track have to be protected from contact with the rail to maintain track circuit signal isolation and to prevent pulverization of the concrete at the rail to tie interface. Current concrete tie fastening systems use an elastomeric pad beneath the rail and elastomeric insulators sandwiched between the edge of the rail base and the shoulder post to isolate the track signal carried along the rail. Under lateral wheel loading, the rail is often pushed to the field side of the track causing the edge of the rail base to bear against the inside of the insulator. The lateral wheel loading also cause the rail to rotates about its longitudinal axis. During this rotation, the base of the rail that is pressed against the insulator gnaws away at the inside elastomer of the insulator. With time, the insulators wear down and the rail is allowed to move laterally from side to side at the tie connection. In the presence of vertical wheel loading, the sideways movement will generate significant heat due to friction demising the pad under the rail. Once the elastomers are damaged, the rail seat becomes unstable and the concrete tie is exposed to direct contact with the rail which will proceed to chip and grind the seat away. The addition of hydraulic action from rain water to the phenomenon described above further accelerates the degradation leading to what is known in the rail industry as “rail seat abrasion”.

There is still room for improvement in the art.

SUMMARY OF THE INVENTION

In the present invention, the improvement is achieved by utilizing a shoulder post with a lower portion that is coated or encapsulated with a nonconductive material and a rolled or cast tie plate design that introduces a tie plate to the rail seat of the concrete tie. The coated or encapsulated lower portion of the shoulder is then cast into the concrete. After curing of the concrete, an elastomeric tie pad with two holes made through it is placed over the rail seat. Use of the pad under the plate increases the pad foot print and significantly reduces the compression stresses in the pad. The tie plate is then slid over the shoulders and tie pad. By having the pad between the plate and the tie, it is subjected to vertical compression only with no rubbing action from the rail. Elastomers are most efficient under this type of loading. Finally, the clip is slid through the window created by the tie shoulder to its initial position, locking the system in place. At this stage, the tie with pre-assembled fastening system is ready for shipment to the installation site. At the installation site, the rail is placed on the seat provided atop the tie plate and the clips driven to their final position to secure the rail in place.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1(a) and 1(b) displays the current concrete tie fastening systems.

FIG. 2 displays a shoulder post with a lower portion that is coated or encapsulated with a nonconductive material.

FIG. 3 displays a cast or rolled tie plate.

FIGS. 4(a) and 4(b) displays the shoulder then cast into the concrete.

FIG. 5 displays an elastomeric tie pad that is slid over the shoulders.

FIG. 6 displays a tie plate slid over the shoulders and tie pad.

FIG. 7 displays the clip inserted through the shoulder window to hold the assembly together.

FIG. 8 displays the rail placed on the seat provided atop the tie plate.

FIG. 9 displays the clips driven to their final position to secure the rail in place.

FIGS. 10(a) and 10(b) displays an insert coated with a non-conductive material that is cast into the concrete tie or slab.

FIGS. 11(a) and 11(b) displays an insert with an insulating boot.

FIG. 12 displays where the inserts are connected to.

FIG. 13 displays an elastomeric tie pad that is slid over the shoulders.

FIG. 14 displays the tie plate that is slid over the shoulders and tie pad.

FIG. 15 displays the clip being slid through the window created by the tie shoulder to its initial position, locking the system in place.

FIG. 16 displays the seat provided by the tie plate.

FIG. 17 displays the clip as driven to their final position to secure the rail in place (FIG. 17).

In the drawings, like characters of reference indicate corresponding parts in the different figures.

BEST MODE FOR CARRYING OUT THE INVENTION

Concrete ties used in railway track have to be protected from contact with the rail to maintain track circuit signal isolation and to prevent pulverization of the concrete at the rail to tie interface. In the Current Art, concrete tie fastening systems (FIG. 1) use an elastomeric pad beneath the rail and elastomeric insulators sandwiched between the edge of the rail base and the shoulder post to isolate the track signal carried along the rail. This prior art can cause rail seat abrasion.

This invention addresses the issue of rail seat abrasion by completely removing all elastomers from directly contacting the rail. This eliminates the rubbing action on the insulator and pad due to rocking of the rail and eventual instability at the rail seat. The improvement is achieved by utilizing a shoulder post (FIG. 2) with a lower portion that is coated or encapsulated with a nonconductive material and a rolled or cast tie plate (FIG. 3) design that introduces a tie plate to the rail seat of the concrete tie. The coated or encapsulated lower portion of the shoulder is then cast into the concrete (FIG. 4). After curing of the concrete, an elastomeric tie pad with two holes made through it (FIG. 5) is placed over the rail seat. Use of the pad under the plate increases the pad foot print and significantly reduces the compression stresses in the pad. The tie plate is then slid over the shoulders and tie pad (FIG. 6). By having the pad between the plate and the tie, it is subjected to vertical compression only with no rubbing action. Elastomers are most efficient under this type of loading. Finally, the clip (FIG. 7) is slid through the window created by the tie shoulder to its initial position, locking the system in place. At this stage, the tie with pre assembled fastening system is ready for shipment to the installation site. At the installation site, the rail is placed on the seat provided atop the tie plate (FIG. 8) and the clips driven to their final position (FIG. 9) to secure the rail in place.

A variant of this concept utilizes a hook-in shoulder. The concept of hook-in shoulders has been applied to steel ties but to the inventor's knowledge, it has never been applied to concrete ties or slab track. In this variant, an insert (FIG. 10) that is completely coated on its outside with epoxy or non-conductive material is cast into the concrete tie or slab. The top of the insert has a hole through which the shoulder (FIG. 11a and FIG. 11b) can be hooked in (FIG. 12). The concrete is then cured with the insert in place. The leg of the hook-in shoulder is also coated with a non-conductive or fitted with a boot. The shoulder is stabilized by a protrusion at the rear that anchors to the underside of the plate when the plate is placed above it. Again, an elastomeric tie pad with two holes made through it (FIG. 13) is placed over the rail seat to increases the pad foot print and significantly reduces the compression stresses in the pad. The tie plate is then slid over the shoulders and tie pad (FIG. 14). Finally, the clip (FIG. 15) is slid through the window created by the tie shoulder to its initial position, locking the system in place. At this stage, the tie with pre assembled fastening system is ready for shipment to the installation site. At the installation site, the rail is placed on the seat provided by the tie plate (FIG. 16) and the clips driven to their final position to secure the rail in place (FIG. 17).

Current concrete and steel tie fasteners transfer lateral loading from the shoulder to only one shoulder. With a plated system, the plate transfers half of the lateral load to the opposite shoulder. The distribution of lateral loads reduces stresses and wear at the shoulder to plate interface. The tie plate also has a raised surface on either sides of the shoulder that extends to the edge of the plate to reduce contact stresses and abrasion of the shoulder. Both systems described above can be used in direct fixation systems where the shoulder is cast into a slab base.

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.

Claims

1. A tie fastener system comprising wherein there is no direct contact between the rail and elastomers in a track that uses rail borne signal circuitry.

2. A tie fastener system as in claim 1 further comprising having a direct fixation fastening system.

3. A tie fastener system as in claim 2 where said direct fixation fastening system is concrete.

4. A tie fastener system as in claim 1 further comprising having the rail in direct contact with a tie plate.

5. A tie fastener system as in claim 1 further comprising having the pad placed beneath a tie plate.

6. A tie fastener system as in claim 1 further comprising having an insulator post with an electrically inert coating cast into the concrete tie making the shoulder electrically isolated from the concrete tie.

7. A tie fastener system as in claim 1 further comprising having a plurality of electrically isolated shoulder hooks into an electrically isolated receptacle that is cast into the tie.

8. A tie fastener system as in claim 1 further comprising having an electrically isolated receptacle for accepting a hook-in shoulder is cast into the tie.

9. A tie fastener system as in claim 1 further comprising having a tie plate with a hole through which it receives the shoulder post.

10. A tie fastener system as in claim 1 further comprising having clip locks that are preassembled system together prior to being delivered to the installation site.

11. A tie fastener system comprising wherein there is no direct contact between the rail and elastomers in a track that uses rail borne signal circuitry having a direct fixation fastening system having the rail in direct contact with a tie plate, having the pad placed beneath a tie plate, having an insulator post with an electrically inert coating cast into the concrete tie making the shoulder electrically isolated from the concrete tie, having a plurality of electrically isolated shoulder hooks into an electrically isolated receptacle that is cast into the tie having the electrically isolated receptacle for accepting a hook-in shoulder is cast into the tie.

12. A tie fastener system as in claim 11 where said direct fixation fastening system is concrete.

13. A tie fastener system as in claim 11 further comprising having a tie plate with a hole through which it receives the shoulder post.

14. A tie fastener system as in claim 11 further comprising having clip locks that are preassembled system together prior to being delivered to the installation site.

15. A tie fastener comprising wherein a fastener with no direct contact between the rail and elastomers in a track that uses rail borne signal circuitry having a direct fixation fastening system having the rail in direct contact with a tie plate, having the pad placed beneath a tie plate, having an insulator post with an electrically inert coating cast into the concrete tie making the shoulder electrically isolated from the concrete tie, having a plurality of electrically isolated shoulder hooks into an electrically isolated receptacle that is cast into the tie having the electrically isolated receptacle for accepting a hook-in shoulder is cast into the tie.

16. A tie fastener as in claim 15 where said direct fixation fastening system is concrete.

17. A tie fastener as in claim 15 further comprising having a tie plate with a hole through which it receives the shoulder post.

18. A tie fastener as in claim 15 further comprising having clip locks that are preassembled system together prior to being delivered to the installation site.