Patent Application
20230110305
This invention relates to insulated rail joints and, more particularly, to an end post gap fill assembly for an insulated rail joint.
A rail system is generally divided into sections or blocks for detecting trains which permit more trains to travel on one stretch of track or railroad rails. Each section is electrically isolated from all other sections so that when no train is present, a high electrical resistance can be measured over the parallel railroad rails in that section. When a train enters the section, the train short circuits adjacent railroad rails and the electrical resistance drops, thus indicating that a train is in that section.
Railroad tracks are created generally by welding railroad rails to each other or by attaching railroad rails to each other with a steel joint. High-performance, non-metallic joints are typically used for electrically-isolating adjacent rail sections of a rail system in order to create an electrically-isolated section. However, the non-metallic joints are very expensive due to the special high-performance material needed to endure the high tensile and flexural forces exerted on a rail joint as the wheels of a locomotive or rail car pass over the joint. An alternative to a non-metallic joint is a steel rail joint having electrically-insulating material, such as epoxy or resin affixed to the rail joint surface for isolating rail sections.
However, these epoxies and resins must be able to endure the high tensile, temperature change, and flexural forces exerted on the railroad rails in order to prevent the electrically-insulating material from peeling off the rail joint. Over time, the rail wheels will cause the rail ends to deform and/or break apart, thus causing an insulation failure and incorrect signaling. This can cause significant and unnecessary delays in train journeys, thereby adversely affecting the efficiency of the rail service.
One existing repair process includes filling the joint with the epoxies or resins. However, this repair process does not provide the proper compression resistant properties and the rail joint soon fails again.
In one aspect or embodiment, an end post gap fill assembly for an insulated rail joint including a first rail, a second rail aligned with the first rail and defining an end post gap between ends of the first rail and the second rail, a first rail joint bar, and a second rail joint bar, the first rail and the second rail each including a head portion, a web portion extending from the head portion, and a base portion extending from the web portion, with the end post gap fill assembly including a gap fill member having a first end, a second end positioned opposite the first end, a first face configured to abut the end of the first rail, and a second face configured to abut the end of the second rail. The gap fill member includes a head section at the first end of the gap fill member and a stem section extending from the head section to the second end of the gap fill member, with the head section configured to be positioned between the respective head portions of the first and second rails and the stem section configured to be positioned between the respective web portions and base portions of the first and second rails. The gap fill member has a length extending along a longitudinal axis of the gap fill member, a width extending perpendicularly to the longitudinal axis of the gap fill member, and a thickness extending from the first face to the second face, with the thickness of the gap fill member consistent from the first end of the gap fill member to the second end of the gap fill member. The end post gap fill assembly also includes a sealant configured to fill a circumferential gap between an outer surface of the gap fill member and outer surfaces of the first and second rails.
The gap fill member may include a high pressure fiberglass laminate, where the gap fill member and the sealant are electrically insulating. The width of the gap fill member at the head section may be smaller than a width of the first and second rails at the head portions of the first and second rails. The width of the gap fill member at the stem section may be smaller than a width of the first and second rails at the web portions of the first and second rails. The length of the gap fill member may be smaller than a height of the first and second rails extending from a top surface of the head portions of the first and second rails to a bottom surface of the base portions of the first and second rails. The first and second rails may be 115 RE railroad rail. The first and second rails may be 136 RE railroad rail. The end post gap fill assembly may further include tape configured to be applied to the head portions of the first and second rails to contain the sealant to the circumferential gap.
In a further aspect or embodiment, a method of filling an end post gap for an insulated rail joint including a first rail, a second rail aligned with the first rail and defining an end post gap between ends of the first rail and the second rail, a first rail joint bar, and a second rail joint bar, the first rail and the second rail each including a head portion, a web portion extending from the head portion, and a base portion extending from the web portion, with the method including: inserting a gap fill member into the end post gap. The gap fill member having a first end, a second end positioned opposite the first end, a first face abutting the end of the first rail, and a second face abutting the end of the second rail, with the gap fill member including a head section at the first end of the gap fill member and a stem section extending from the head section to the second end of the gap fill member. The head section is positioned between the respective head portions of the first and second rails and the stem section is positioned between the respective web portions and base portions of the first and second rails. The gap fill member having a length extending along a longitudinal axis of the gap fill member, a width extending perpendicularly to the longitudinal axis of the gap fill member, and a thickness extending from the first face to the second face, with the thickness of the gap fill member consistent from the first end of the gap fill member to the second end of the gap fill member. The gap fill member defining a circumferential gap between an outer surface of the gap fill member and outer surfaces of the first and second rails. The method further including: filling the circumferential gap with a sealant, where the sealant is electrically insulating.
The method may further include applying tape to at least a portion of the first and second rails prior to filling the circumferential gap with sealant, with the tape configured to contain the sealant to the circumferential gap. The method may further include trimming the gap fill member to size prior to inserting the gap fill member into the end post gap. The stem section at the second end of the gap fill member may be trimmed to reduce the length of the gap fill member.
For purposes of the description hereinafter, the words “upward” and “downward”, and like spatial terms, if used, shall relate to the described embodiments as oriented in the drawing figures. However, it is to be understood that many alternative variations and embodiments may be assumed except where expressly specified to the contrary. It is also to be understood that the specific devices and embodiments illustrated in the accompanying drawings and described herein are simply exemplary embodiments of the invention.
Referring to
Referring again to
In one aspect or embodiment, one or more gap fill members 14 are utilized to fill the end post gap 22 between the ends of the first and second rails 18, 20. As discussed in more detail below, the sealant 16 is configured to fill a circumferential gap 70 between an outer surface of the gap fill member 14 and outer surfaces of the first and second rails 18, 20.
The sealant 16 may be liquid or liquid-like when applied, but solidifies during installation. The sealant 16 may be configured to bond to the first and second rails 18, 20, the gap fill member 14, and/or the first and second rail joint bars 24, 26. The sealant 16 may be an adhesive material, including polyurethane-based materials. The sealant 16 may be a polymer based material, polyurethane, epoxy, silicone, acrylics, or curing acrylic or epoxy. The sealant 16 may bond and solidify within the circumferential gap 70. The sealant 16 may be selected by virtue of its properties, such as adhesion, strength, time to solidify, and flexibility to withstand tensile and compressive stresses. In one aspect or embodiment, the gap fill member 14 and the sealant 16 are electrically insulating.
In one aspect or embodiment, the gap fill member 14 is formed from a pressure resistant material, such as a high pressure fiberglass laminate, although other suitable materials may be utilized. In one aspect or embodiment, the gap fill member 14 is formed from G10 fiberglass material.
Referring to
Referring to
In one aspect or embodiment, the method includes applying the tape 72 to at least a portion of the first and second rails 18, 20 prior to filling the circumferential gap 70 with sealant 16, with the tape 72 configured to contain the sealant 16 to the circumferential gap 70. For example, the tape 72 may be applied to a portion of the head portions 28 of the first and second rails 18, 20 and/or the base portions 32 of the first and second rails 18, 20 to act as a form as the sealant 16 is pumped or delivered to the circumferential gap 70.
In one aspect or embodiment, the method further includes trimming the gap fill member 14 to size prior to inserting the gap fill member 14 into the end post gap 22. The stem section 62 at the second end 54 of the gap fill member 14 may be trimmed to reduce the length of the gap fill member 14. The gap fill member 14 may be trimmed to accommodate the size or configuration of the insulated rail joint 12 or to accommodate any portions of an end post that may remain in the end post gap 22 between the first and second rails 18, 20.
The first and second rails 18, 20, particularly the head portions 28, may be altered prior to inserting the gap fill member 14 into the end post gap 22. Altering may include grinding or shaping to better form the appropriate structure needed for proper installation. The gap fill member 14 may be installed by inserting it downward between the first and second rails 18, 20 at the end post gap 22. The tape 72 may be removed after filling the circumferential gap 70 with the sealant 16, and the sealant 16 may be altered to conform to the shape of the first and second rails 18, 20.
The end post gap fill assembly 10 is configured to at least temporarily fill the end post gap 22 between the first and second rails 18, 20 after the insulated rail joint 12 has failed and/or lost at least a portion of its end post. The end post gap fill assembly 10 is configured to maintain the electrical insulation between the first and second rails 18, 20 until the insulated rail joint 12 can be entirely replaced. The end post gap fill assembly 10 is configured to provide a solid compression stop when the rails 18, 20 warm up and compress together, thereby preventing the sealant from being pushed out of the end post gap 22 or deteriorated due to such compression.
Further, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only, and are not limiting to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.
This application claims benefit of U.S. Provisional Application No. 63/253,761, filed on Oct. 8, 2021, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63253761 | Oct 2021 | US |
