US3666175A - End post insulator - Google Patents

Abstract

An improved insulated end post for use between the meeting ends of railway rails to insulate one rail from another in conjunction with insulated rail joints employed in block signal systems. The web of the end post has a greater width than the webs of the rail ends with which it is used to provide greater load-bearing capacity. The end post is preferably of a sandwich-type construction which has an elastomeric core and rigid metal face sheets. The core is preferably formed from a polyurethane compound.

Description

United States atent Gill [451 May 30, 1972 END POST INSULATOR 72 inventor: Homer R. Gill, St. Marys, Ohio The Goodyear Tire & Rubber Company, Akron, Ohio [22] Filed: Apr. 15, 1970 [21] Appl.No.: 28,889

[73] Assignee:

[52 U.S. Cl ..238/152 [51] Int. Ci. ..E01b 11/00, EOlb 11/32, EOib 26/00 [58] Field of Search ..238/152, 218, 229, 227, 283

[56] References Cited UNITED STATES PATENTS 3,312,399 4/1967 Cruikshank ..238/152 1,227,832 5/1917 Rome et al.... ..238/227 1,455,695 5/1923 Woll ..238/229 Qua ..238/227 Stamos ..238/152 Primary Examiner-Arthur L. La Point Assistant ExaminerRichard A. Bertsch Attorney-F. W. Brunner and Ronald P. Yaist [5 7] ABSTRACT 2 Claims, 6 Drawing Figures PATENTEDHAY 3 0 I972 ENTOR. HQM R. $1M. BY

INV ER A ORN EY BACKGROUND OF THE INVENTION This invention relates to end posts for use between the meeting ends of railway rails to insulate one rail from another in conjunction with insulated rail joints employed in block signal systems. This invention has particular application to an improved end post insulator which exhibits increased loadbearing capabilities.

Conventional railroad end posts are formed from insulating materials conforming to the cross-sectional shape of the ends of the rails with which they are used. For many years the railroad end posts were constructed of insulating materials, such as fibers and conventional rubbers or plastics. However, the fibrous materials have not proven adequate because of poor weather resistance and the rubber and plastics exhibit inadequate resistance to abrasion, the crushing force of rail vehicle wheels passing over them, and the pressure caused by expansion of the rail due to temperature changes. These previously used materials have also been subject to deterioration caused by oil dripping from passing trains.

Consequently, in recent years new materials and constructions have been used to overcome these disadvantages. For example, U.S. Pat. No. 3,312,399 discloses an end post of a sandwich-type construction of metal and an elastomeric core, preferably of a polyurethane elastomeric formulation, which has a profile conforming to the cross-sectional shape of the ends of the rails with which it is to be used. This construction has proven very successful in overcoming these beforementioned difficulties in service, especially when used with conventional rail section lengths of 39 or 40 feet which are bolted together, thus forming a joint every 39 or 40 feet. However, when this sandwich-type construction is used in conjunction with welded rails typically in which 1,000 foot or more lengths of rail are welded together, sometimes forming 1% mile or even up to 1 mile of continuous rail, the single rail joint has failed prematurely due to increased loading caused by the excessive concentration of pressure due to thermal expansion.

It has been found that the difficulties encountered when welded rail sections are used have been successfully overcome by a rail end post construction which will be hereinafter described.

OBJECTS OF THE INVENTION An object of this invention is to provide an improved insulated end post for rail sections which has increased load-bearing capabilities when subjected to concentrated pressure caused by increased thermal expansion.

Another important object of the present invention is to provide an improved end post insulator of a sandwich-type metal and elastomeric core construction which will withstand the increased loading caused by long lengths of welded rails.

Still another object of this invention is to provide a rail insulating structure which includes an improved end post which exhibits an increased load-bearing capacity.

Other objects and advantages of this invention will become apparent hereinafter as the description thereof proceeds, the novel features, arrangements and combinations being clearly pointed out in the specification as well as the claims thereunto appended.

In accordance with the present invention, an improved insulated end post is provided which is to be placed between and in substantial alignment with meeting ends of rail sections. The rail section ends and the end post each have a head portion, a web portion and a base portion with the web portion of the end post having a greater overall width than the corresponding web portion of the rail section ends that it is aligned with to provide the end posts with greater load-bearing capabilities to withstand increased thermal expansion.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a side elevational view of a rail insulator joint construction including the improved end post of this invention;

FIG. 2 is an enlarged section taken on line 2-2 of FIG. 1;

FIG. 3 is another form of the invention shown in FIG. 2;

FIG. 4 is a vertical elevation of the preferred form of the improved end post insulator of this invention;

FIG. 5 is a side elevation of the end post shown in FIG. 4 with a portion broken away to show the structure; and

FIG. 6 is a cross-sectional view along line 6-6 of FIG. 4.

DESCRIPTION OF THE' PREFERRED EMBODIMENTS In FIGS. 1 and 2 a rail insulator joint construction designated by numeral 10 is shown in which welded rail sections 11 having rail section ends 12 are to be joined and insulated from each other.

As best shown in FIG. 2, the rail ends 12 have head portions 13 on the top, a flanged base portion 14 on the bottom, and a web portion 15 connecting the head portion 13 and the base portion 14. An end post 16 is provided between the rail ends 12 and includes a head portion 17, flanged base portion 18 and a connecting web portion 19 which is aligned with the corresponding portions 13, 14 and 15 of the rail ends 12. The joint construction 10 also includes splice or joint bars 20 typically of a laminated insulated material which are provided on either side of the rail sections 11. The joint bars 20 are conventionally attached to the rail, for example by means of bolts 21 which extend through the rails 11. The bars 20 are customarily provided with a portion abutting against the curved bottoms of the rail heads 13 extending angularly downwardly against the flanged base portion 14 and spaced from the rail webs 15 so that a clearance space 22 is defined between the bars 20 and the rail webs 15. Preferably the space 22 is provided on both sides of the web 15 but may also be present on only one side thereof.

With this arrangement, it is possible to extend the width of the web portion 19 of the end post 16 so that it substantially fills the gap or space 22 adjacent the end post 16. The web portion 19 thus has a greater overall width than the corresponding web portion 15 of the end 12 of the rails 11 with which it is aligned. In this way, the end post 16 has a greater load-bearing capacity and capability when subjected to concentrated pressures caused particularly by thermal expansion of the welded rail sections 11. It should be appreciated that the only limiting factor to be considered in regard to the width of the end post web 19 is the amount of available clearance space 22.

Of course it is to be understood that the improved insulated end post of this invention can be used with any of the various joint bar constructions being used today. For example, FIG. 3 shows a joint bar 23 which is constructed to closely conform to the rail head portion 13 and the rail base portion 14. The bar 23 is composed basically of metal with insulation material 24 provided in the areas of contact between the bar 23 and the rail section 11. It should be noted that again a clearance space or gap 25 is provided between the bar 23 and the rail web 15 to thereby allow the width of the end post web 19 to be extended in accordance with the teachings of the present invention. This joint bar construction is fully described in U.S. Pat. No. 2,016,214.

Even though the joint structure 10 including the improved end post 16 of this invention is particularly suitable for use with welded rail sections, it of course should be obvious to one skilled in the art that the use of the invention is also contemplated with the more conventional bolted rail sections.

The preferred end post construction is shown in FIGS. 4, 5 and 6 and may be regarded as an improvement of the end post structure of U.S. Pat. No. 3,312,399. The end post designated generally by the numeral 16 is a sandwich-type construction which has an elastomeric core 26 and a face sheet 27 on each side of the core 26 to provide vertical stiffness and protect the core 26 from abrasion by the rail ends 11. The core 26 is preferably made of a polyurethane which is the reaction product of a polyester, an organic diisocyanate and a diamine as described in U.S. Pat. No. 3,107,235 and sold under the trademark Neothane, a trademark of The Goodyear Tire & Rubber Company.

The polyurethanes described in U.S. Pat. No. 3,107,385 are preferred for making the end post of this invention because of the superior quality of the polyurethanes obtained. It should be appreciated that any of the casting type polyurethanes may be utilized provided the sometimes inferior physical properties may be tolerated. For instance, the organic polyisocyanates such as methylene bis phenol isocyanate and toluene diisocyanate may be utilized as well as the other organic diamines or the glycol curatives, preferably butanediol.

Where the end posts are to be subjected to extremely cold temperatures, it is preferred that the polyester polyol be one that yields a polyurethane having excellent low temperature properties such as the polyesters obtained by reacting adipic acid with butanediol or azelaic acid with butanediol and mixtures of these, where the molecular weight are preferably about 1,000 to no more than 2,500.

It will be understood, however, that other elastomeric materials in addition to polyurethane, which have the required physical properties, can also be used for the core 26. The face sheets 27 are preferably made of steel. However, other materials which will provide adequate stiffness to the end post 16 and protect it from abrasion may also be used.

As previously stated, the end post 16 has a head section 17 on the top, a flanged base 18 on the bottom and a web 19 connecting the head section 17 and the base 18. The overall width of the web portion 19 is greater than the width of the web of the ends 12 of the rail sections 11. This is represented in broken lines in FIG. 4. This differs from conventional end posts which have a profile conforming with the cross-sectional shape of the ends of the rails with which it is used.

As is true of the end post disclosed in U.S. Pat. No. 3,312,399, it will be observed in the drawings that the face sheets 27 have the same peripheral dimensions as the core 26 in the base 18 and the lower portion of the web 19, but have smaller peripheral dimensions than the core 26 around the edge of the head 17 and approximately the upper half of the web 19 so that in this part of the end post 16, the edges of the face sheets 27, when positioned on the core 26, lay laterally inwardly from the edge of the elastomeric core 26. This means that the edges of the face sheets 27 also lay laterally inwardly from the top and sides of the rail heads 13 which abut the end post 16 and therefore will not be subjected to the crushing force and wear of the train wheels passing over the track. Only the elastomeric core 26 will be in contact with the train wheels and it will, of course, yield to the pressure of the wheels and spring back after each wheel has passed over it. In so doing, it will tend to push out metal particles which might otherwise collect in the spaces between the ends 12 of the rails 11 and short out the track circuits.

If the core 26 were completely flat, a gap would be left between the core 26 and the face sheets 27 around the edge of the end post 16 in the area where the face sheets 27 are smaller than the core 26. Such open space would trap moisture and various foreign particles and would tend to cause separation of the face sheets 27 from the core 26. To avoid such a gap an integral lip 28, perpendicular to the face of the core 26, extends outwardly from each face of the core 26 the same distance as the thickness of the face sheet 27 and fills in the space left by the smaller dimension around the ends of the face sheets 27. This is best shown in FIG. 6. The lips 28 also help to retain the face sheets 27 in position on the core 26 and aid in maintaining the bond between the face sheets 27 and the core 26.

This end post 16 may be made by casting in place the core material between the face sheets 27. If Neothane" or certain other polyurethane compounds are used, they may adhere to the metal face sheets without the need for additional bonding material. The face sheets and core may also be made separately and bonded together with some suitable adhesive. However, where the core 26 is cast in place, no appreciable stresses are created between the core 26 and the face plates 27 as might be if the core and face plates were made separately and bonded together afterwards. For this reason, the cast-in-place core gives a superior bond which is less likely to result in separation of the face sheets 27 from the core 26 then when the core is made separately from the face sheets.

The improvement resides in increasing the width of the face sheets 27 and elastomeric core 26 to provide an extended web portion 19 of the end post 16. This structure provides a signif cant increased load-bearing capacity and is particularly applicable when the end posts are used in conjunction with extremely long-length, welded rail sections in which the stresses resulting from thermal expansion from the entire length of the rails are concentrated in a single joint area.

It will be seen that this sandwich-type, wide web end post structure of the present invention combines the advantages enumerated in US. Pat. No. 3,312,399 with the increased load-bearing capabilities of the extended web feature. In other words, the end post structure combines the resilient characteristics of an elastomeric material with the stiffness and abrasion resistance of metal and provides an elastomeric core which will be resistant to crushing by the train wheels and, unlike fiber end posts, will not delaminate and permit moisture to penetrate and cause further deterioration thereof and further will more satisfactorily resist the severe stresses caused by thermal expansion of the rails. Due to the composition of the material from which the core is made, it will also resist solvents, oil and ultraviolet rays. This is particularly true when the core is made ofNeothane. The core is also abrasion and tear resistant and these qualities are further enhanced by the protective metal face sheets of extended width which stifien the core and protect it from the abrasion against the rail ends. The face sheets are in such a position in the rail joint that they remain free of contact with the trail wheels and therefore are not damaged thereby.

While certain representative embodiments and details have been shown for the purpose of illustrating this invention, it will be apparent to those skilled in the an that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What is claimed is:

1. An improved insulated end post to be placed between and in substantial alignment with meeting ends of rail sections, said rail section ends and said end post each having a head portion, a web portion and a base portion with the web portion of said end post having a continuously tapering width with the greatest width thereof being adjacent to the base of said end post so that said web portion of said end post has a greater overall width than the corresponding web portions of the rail section that it is aligned with to provide said end post with greater load-bearing capabilities, said end post including:

A. a non-conductive elastomeric core having on both sides thereof, an integral lip along at least a portion of the edge of the core, said lip being substantially perpendicular to the face of the core; and

B. a pair of substantially identical face plates attached to each face of the core, said plates being of the same general contour as the core but having that portion of their edge removed which corresponds to the position of the lips on the core so that when both face sheets are positioned against each face of the core, the lips enclose a portion of the edge of each face sheet and help to retain the face sheets in proper alignment on the core.

2. In a rail insulating structure including the combination of rail end sections having meeting rail ends including a head portion, a web portion and a base portion, a rail joint between the rail ends including an insulated end post in substantial alignment with said rail ends, said end post including a head portion, a web portion and a face portion corresponding to the similar named portions of the rail, and rigid joint bars extending from the head portions to the base portions of said rail sections and spaced from the webs of the rail sections to define a clearance space between at least one of the joint bars and the rail web, the improvement comprising the web portion of said end post extending into and substantially filling the clearance space adjacent said end post and having a continuously tapering width with the greatest width thereof being adjacent to the base of said end post so that the width of the web portion of said end post is greater than the width of the corresponding web portion of said rail to provide said end post with greater load-bearing capabilities.

Claims (2)

1. An improved insulAted end post to be placed between and in substantial alignment with meeting ends of rail sections, said rail section ends and said end post each having a head portion, a web portion and a base portion with the web portion of said end post having a continuously tapering width with the greatest width thereof being adjacent to the base of said end post so that said web portion of said end post has a greater overall width than the corresponding web portions of the rail section that it is aligned with to provide said end post with greater load-bearing capabilities, said end post including: A. a non-conductive elastomeric core having on both sides thereof, an integral lip along at least a portion of the edge of the core, said lip being substantially perpendicular to the face of the core; and B. a pair of substantially identical face plates attached to each face of the core, said plates being of the same general contour as the core but having that portion of their edge removed which corresponds to the position of the lips on the core so that when both face sheets are positioned against each face of the core, the lips enclose a portion of the edge of each face sheet and help to retain the face sheets in proper alignment on the core.

2. In a rail insulating structure including the combination of rail end sections having meeting rail ends including a head portion, a web portion and a base portion, a rail joint between the rail ends including an insulated end post in substantial alignment with said rail ends, said end post including a head portion, a web portion and a face portion corresponding to the similar named portions of the rail, and rigid joint bars extending from the head portions to the base portions of said rail sections and spaced from the webs of the rail sections to define a clearance space between at least one of the joint bars and the rail web, the improvement comprising the web portion of said end post extending into and substantially filling the clearance space adjacent said end post and having a continuously tapering width with the greatest width thereof being adjacent to the base of said end post so that the width of the web portion of said end post is greater than the width of the corresponding web portion of said rail to provide said end post with greater load-bearing capabilities.

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