Method and arrangement to insulate rail ends

A rail joint arrangement comprises two rails. The rails have adjacent rail ends separated and thereby forming a gap. The rails have a top end containing a rail head and a bottom end. The gap is defined between the top end and the bottom end of the rails, and the width of the gap is non-uniform throughout its entire length. In addition, the rail joint arrangement comprises at least one electric insulator positioned within the gap. The rail joint arrangement is fastened together by a rail joint bar attaching the two rails together.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rail joint arrangement and a method of forming a rail joint.

2. Description of Related Art

A rail system, which permits more than one train to travel on one stretch of track of rail, is generally divided into sections or blocks. The purpose of dividing railroad rails of a rail system into sections is to detect the presence of a train on a section of rail at any given time. Each rail section is electrically isolated from all other sections so that a high electrical resistance can be measured over the rail section when no train is present in that section. When a train enters a rail section, the train will short circuit adjacent railroad rails in which the electrical resistance in the rail section drops, thereby indicating the presence of a train.

Railroad rails are generally welded to each other or attached to each other by a rail joint. Referring toFIG. 1A, a typical rail joint2having a rail end4of a first rail R1and another rail end6of a second rail R2is shown. Rail joint2is shown having an electrical insulator8and is connected by rail joint bar12and rail joint bar10. Rail joint2also shows a gap between E-E where the electrical insulator8is placed. With reference toFIG. 1B, a cross section of rail joint2is shown illustrating a uniform gap width between the rail end4and rail end6.

There are other different uniform gap shapes. InFIG. 2A, an illustration is shown of another rail joint16having angled rail ends at 45°. Rail joint16has a rail end18of a first rail R1′ and a rail end20of a second rail R2′, with an electrical insulator22within the gap that is formed between rail end18and rail end20. A cross-sectional view of rail joint16shows the rail joint having rail end18and rail end20, with a gap between E′-E′ and an electrical insulator22within the gap. As shown inFIG. 2A, the width of the gap is still uniform throughout the angled gap. Some prior art arrangements utilize 45° chamfers or small radii along upper and lower rail end edges to prevent sharp edges. Typically, these chamfers and radiused surfaces have a depth and width in the ranges of 0.030″-0.090″.

Presently, ends of rails are connected together by rail joints. Typically, as shown inFIGS. 1A,1B,2A, and2B, rail ends abut each other with flat surfaces that form a uniform gap between the rail ends. Over time, the tensile and flexural forces are higher at a center portion of the rail joints where the two railroad rails are joined. Eventually, the forces acting upon the rails deteriorate the insulator between the rails and they become non-insulated and rub up against each other and form short circuits in the rails. Therefore, it is an object of the present invention to overcome this problem.

SUMMARY OF THE INVENTION

The present invention provides for a rail joint arrangement comprising two rails. The rails have adjacent rail ends separated and thereby forming a gap. The gap has a non-uniform width and can be radiused at the top and bottom. The rails have a top end containing a rail head and a bottom end. The gap is defined between the top end and the bottom end of the rails, and the width of the gap is non-uniform throughout its entire length. In addition, the rail joint arrangement comprises at least one electric insulator positioned within the gap. The rail joint arrangement is fastened together by a rail joint bar attaching the two rails together.

The present invention also provides for a rail for use in a rail joint arrangement. The rail includes a rail body, which comprises a first end having a first rail end surface and a second end having a second rail end surface. The rail body contains a cross-sectional profile comprising a head attached to a web portion and the web portion connected to a base. The head is positioned on an opposite side of the web from the base. The rail contains a cross-sectional profile that extends along a vertical axis and the first rail end surface is not completely contained in any flat plane that contains an axis that is parallel to the vertical axis.

The present invention further provides for a method for forming a rail joint that includes providing two rails. Each rail includes a rail body, which comprises a first end having a first rail end surface and a second end having a second rail end surface. The rail body contains a cross-sectional profile comprising a head attached to a web portion and the web portion connected to a base. The head is positioned on an opposite side of the web from the base. The rail contains a cross-sectional profile that extends along a vertical axis and the first rail end surface is not completely contained in any flat plane that contains an axis that is parallel to the vertical axis. The method includes positioning respective rails having a top end and a bottom end adjacent each other to form a gap. The rail ends define a gap between the top end and the bottom end of the rails and the gap width is non-uniform throughout its entire length. Finally, insulating material is placed within the gap and the rails are attached by fasteners, thereby forming a rail joint.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 3, a rail joint arrangement made in accordance with the present invention shows rail joint30having a rail32and a rail34, with rail end surface36and rail end surface38, respectively. The two rails32,34are positioned having the rail end surfaces36,38adjacent each other to form a gap40having a width in between them. Rail32is a typical rail having a top end42and a bottom end44. The rail joint arrangement is fastened together once an insulator is placed within the gap by a rail joint bar46or46′, which extends along the length of the gap40in which the insulator is to be placed.

With continuing reference toFIG. 3, rail joint30is formed by a Z-cut48of the rails32and34. The Z-cut48includes an angled surface82cut along an angled surface axis A and transverse cuts T and T′. Alternatively, the rail joint can be formed by just an angled cut, without the transverse cuts T and T′, similar to the 45° angled cut shown inFIG. 2A. The angle range R is defined between a longitudinal axis L and the angled surface axis A.

As shown inFIGS. 3A-3H, a U-shaped profile45is formed in the top end42when the rail end surfaces36and38are placed together. Each of the rail end surfaces36,38define a profile at the top end42that is recessed relative to a portion of the end surfaces36,38corresponding to the web portions60of the rails32,34such that the end surfaces36,38define the U-shaped profile45when placed together. The gap40is non-uniform. In other words, given a vertical axis V, the rail end surfaces36and38of the gap40in the top end42form the U-shaped gap45and the rail end surfaces36and38of the remaining gap40cannot be entirely contained in any vertical axis V.

In another preferred embodiment shown inFIG. 4, a top gap width70can have a different shaped profile. The cross section inFIG. 4is taken in a rail joint arrangement having a rectangular-shaped profile74. The cross section can have a top portion64, a middle portion66, and a bottom portion68. The top portion64is shown to have a top gap width70wider than intermediate gap width71of middle portion66. In addition, bottom portion68is shown having a bottom gap width72, shown in phantom. When bottom gap width72is not present, intermediate gap width71of middle portion66merely extends down to bottom end B and, therefore, top gap width70is wider than the gap width in the bottom portion68.

Bottom portion68is shown having a bottom gap width72in phantom, which, when optionally present, is wider than the intermediate gap width71of the middle portion66. The profile of gap G as shown in the top portion64and the bottom portion68is rectangular-shaped profile74and74′ (shown in phantom). The gap in the bottom if optionally present can be any shape, not limited to the shape of the rectangular-shaped profile74. The gap G is non-uniform in width. In other words, given a vertical axis V and a horizontal axis H, edges S1or S2of gap G in the top portion64and remaining gap G cannot be entirely contained in any vertical axis V chosen along horizontal axis H. In addition, when present, the edges S1or S2of a gap containing optional rectangular-shaped profile74′ in the bottom portion68and gap G of the middle portion66cannot be contained in any vertical axis V. Additionally, inFIGS. 3A-3H, rail joint30comprises a head58, a web portion60, and a base62.

FIG. 5shows a cross section of a rail joint of another preferred embodiment of the present invention having a trapezoidal-shaped profile78and78′ (shown in phantom). Like reference numerals are used for like parts. InFIG. 5, the rail joint is shown having a top portion64, a middle portion66, and a bottom portion68. As shown, the top portion64has a top gap width70′ wider than the intermediate gap width71′. The bottom portion68shows, in phantom, a bottom gap width72′, which is also wider than the intermediate gap width71′. Top gap width70′ and bottom gap width72′ are shown inFIG. 5to have a trapezoidal-shaped profile78and78′. Additionally, the top gap width70′ can be larger than the bottom gap width72′ or, alternatively, the bottom gap width72′ can be larger than the top gap width70′. Lastly, top gap width70′ can be equal to bottom gap width72′. When bottom gap width72′ is not present, intermediate gap width71′ of middle portion66merely extends down to bottom end B and, therefore, top gap width70′ is wider than the gap width in the bottom portion68. It should be noted that profiles72′,74′, and76′ are optional and that, in lieu of these profiles, the intermediate gaps71,71′, and71″ can extend to the bottom of the rail as shown.

FIG. 6illustrates a cross section of another embodiment having a U-shaped profile76and76′ (shown in phantom). InFIG. 6, the numerals are the same for like parts. The cross section is shown having a top T and a bottom B. The cross section is divided into a top portion64, a middle portion66, and a bottom portion68to illustrate that the top gap width70″ is wider than the intermediate gap width71″, and bottom gap width72″, shown in phantom, can be wider than the intermediate gap width71″ of middle portion66. When bottom gap width72″ is not present, intermediate gap width71″ of middle portion66merely extends down to bottom end B and, therefore, top gap width70″ is wider than the gap width in the bottom portion68.

The gap widths as shown inFIGS. 4-6of the rail joint are larger near the top T and the bottom B so that an epoxy can be applied to the cavity to strengthen the bond.

In addition to the three aforementioned shapes, there can be other types of variations of shapes. For example, one rail end surface could be uniform while the other is angled and, therefore, still forms a non-uniform gap in the top gap width70or the bottom gap width72or both. Intermediate gap widths71,71′, or71″ of the middle portion66is typically about 1/16″, which is the typical thickness of the electrical insulator41. Preferably, the top gap widths70,70′, and70″ and bottom gap widths72,72′, and72″, and the widest portions of top gap widths70′ and70″ and bottom gap widths72′ and72″, should be ⅛″ or greater than intermediate gap width71,71′, or71″. More preferably, top gap widths70,70′, or70″ and bottom gap widths72,72′, or72″, and the widest portions of top gap widths70′ and70″ and bottom gap widths72′ and72″, should be within the range of ⅛″- 3/16″ greater than intermediate gap width71,71′, or71″ and, even more preferably, 3/16″ or greater than intermediate gap width71,71′, or71″. The gap depth of top portion64is preferably ½″ or greater and, more preferably, within the range of about ½″ to 1″ and, even more preferably, within the range of 1″ or greater. The gap depth of bottom portion68preferably is greater than ¼″, more preferably within the range of ¼″ to ½″ and, even more preferably, greater than ½″.

Shown inFIG. 9Ais a sectional view of the cross section inFIG. 4having a rectangular-shaped profile74′ in a bottom portion94of the gap40. The rectangular-shaped profile74′ is shown having an insulator90extending into the gap40of the bottom portion94. As shown inFIG. 9A, the rectangular-shaped profile74′ is in the bottom portion94of the cross section ofFIG. 4, however, a rectangular-shaped profile could alternatively be placed in the top end. An epoxy92can be dispersed to the cavity surrounding the extending insulator90. The epoxy can fill the gap around the extending insulator and thereby provide protection from elements and from flexural forces. The epoxy is electrically insulating.

Similar toFIG. 9A,FIG. 9Bshows an end sectional view of the embodiment shown inFIG. 5having a trapezoidal-shaped profile78′. Trapezoidal-shaped profile78′ is shown with epoxy92surrounding the extending insulator90. Again, inFIG. 9C, a keystone-shaped profile80′ is shown, with bottom portion94containing extending insulator90surrounded by dispersed epoxy92.

Returning toFIG. 3, the rail joint30has an angled gap40extending along an angled axis. The angle R as shown can be any angle which is less than 90° between the longitudinal axis L and the angled surface axis A. More preferably, the angle R should be less than 45° and, even more preferably, within the range of 0° to 15°.FIGS. 7A and 7Bshow two types of gaps that are formed when the rail end surface36and rail end surface38of rails32and34are cut having angled surfaces. InFIGS. 7A and 7B, an angled surface82and82′ are shown having an angled surface axis84.FIG. 7Ashows a slightly different gap fromFIG. 7B.

InFIGS. 8A and 8B, a straight cut is shown having an S-shape or Z-shape.FIGS. 8A and 8Bshow a rail32and a rail34adjacent each other to form a gap40. Rail end surface36and rail end surface38are S-shaped or Z-shaped. Rail end surfaces36and38form an S-shaped or Z-shaped gap88between rail32and rail34.

With further reference toFIG. 3, rail32is shown having a rail end surface36on first end50and a first rail end surface52. In addition, rail32has a second end54and a second rail end surface56. Rail32is shown in the cross section ofFIG. 3Ato have a head58, a web portion60attached to a base62, the web portion connected to a base and the head is positioned on the opposite end as shown. The rail end surface36extends from first rail end surface52along gap40. Rail end surface36extends across the complete width of the rail. In other words, rail surface36extends across the complete width of the head58, the web portion60, and the base62. As previously stated, at no time does a flat plane P contain the complete first rail end surface36. For that matter, straight vertical line V′ does not contact the complete rail cross-sectional profiles, such as shown inFIG. 3A.

The present invention provides for a method of securing two rails32and34, having rail end surface36and rail end surface38. As shown inFIG. 3A, the rail end surface is not contained in a flat plane P parallel to any cross section along an axis for either rail32or rail34.

Next, the respective rails are placed adjacent each other, with a top end42and a bottom end44of each rail adjacent to the top end42and bottom end44of the other. The gap40formed therein is defined by the rail end surfaces36and38, which are placed adjacent each other. The gap40forms a profile at the top and, optionally, at the bottom. Examples of the profile can be rectangular, trapezoidal, or keystone in shape.

As discussed earlier, the gap40can also be wider in the top than the bottom and, alternatively, the gap can be wider in the bottom than the top. After the rails are positioned adjacent each other, an insulating material is placed within the gap. The insulating material can be as shown inFIGS. 9A,9B, and9C as an epoxy placed in the top gap or bottom gap to fill the hole that has an extended fiberglass insulator. Next, the rails are attached together, thereby forming a rail joint. InFIG. 3, a rail joint bar46is used to fasten the rail joint together. However, any fastener known in the art can be used.