Rail fastening system

Abstract

A system for fastening a rail to a foundation such as railroad ties or sleepers to form a railroad track. The system includes L-shaped inserts which are imbedded into the foundation and extending above it, supports which are laterally located with respect to the rails, and a fastening member or clip securing the rails. The main portion of each clip is mounted between the insert and the foundation, and one end contacts the upper surface of the supports. The other end of the clip contacts the flange of the rail, and has an offset lower surface which applies vertical and lateral pressure to the edge of the flange. The clip is made of a metal material and is a resilient spring having a multiple curved cross-section in order to apply compressive forces to the rail flange, the curved portions having undulating portions which make the various contacts.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a system for fastening a rail to a foundation to form a railroad track, and primarily to a fastening member in the form of a clip for securing the rail against extreme movements. This is important in maintaining the correct gage of the track despite variations in load on the rail. While there are many types of fastening systems utilizing clips for securing the rails, the present invention is of the type wherein one end of the clip is resiliently forced against the lower flange of the rail, and the other end rests upon a support which is spaced laterally of the rail. Intermediate of the rail and support is located an insert which is cast into and embedded in the foundation, which may be a tie or a sleeper; the insert extends above the surface of the foundation and is L-shaped so that crossbar of the insert is spaced above the foundation. The main body of the clip is placed under the crossbar so that the upper surface of the clip is held by the crossbar and permits the lower surface of the ends of the clip to maintain contact with the rail flange and the support.

2. Prior Art Statement

Fastening systems of the type generally described above are known and disclosed in the following publications:

Waters' U.S. Pat. No. 3,314,605 utilizes a clip made of a straight flat plate of spring steel. When the clip is installed and under stress as in FIG. 2, the clip is bowed slightly upwardly between the support 4 and the insert 5, and is bowed slightly downwardly between the insert and the flange-contacting end. An insulator 6 is placed over the flange and the end of the clip actually contacts the insulator, rather than the flange itself.

Waters' et al U.S. Pat. No. 3,515,347 has a similar arrangement to the earlier Waters' patent, but the insulator on the flange is specially shaped to receive the bifurcated ends of the clip. In addition, the support has a specially shaped depression to receive the other end of the clip.

Serafin et al utilizes a U-shaped steel clip which has outwardly extending legs that bear against an insulator on the rail flange to secure the rail in place. The other end of the clip forming the bight of the clip contacts the support member.

Gehrke is primarily directed to a pad placed under a rail, but also discloses a metal leaf spring which acts to secure the rail. It has a configuration generally similar to the clips of the Waters' patents.

Hixson also discloses a flat clip similar to Waters', also made of metal, and shaped so that the ends resting on the support fit within recesses on the support.

A BTREC advertisement of BTREC Inc. (date unknown) illustrates a clip which is similar to Waters', and is believed to be related to Waters'.

SUMMARY OF THE INVENTION

The present invention provides an improved fastening system wherein the principal feature resides in the use of a novel fastening member or clip for securing the rail. The clip is made of a resilient metal material and is essentially in the form of an undulating multiple curved plate which acts in spring-like fashion. The rail retaining end and opposite end each have surfaces which contact the upper surfaces of the rail flange and the support which is remote from the rail, while another undulating surface fits under the insert which is cast into the foundation. The end contacting the rail is thickest in cross-section, and the remainder of the clip has a gradually decreasing cross-sectional thickness until reaching a minimum at the support-contacting end.

By devising the clip as described, it is simple to manufacture, is very easy to install or remove, and has superior retaining properties with respect to the rail. The rail-retaining end applies a constant spring tension in a downward direction at the edge of the flange, and is also provided with an offset configuration which simultaneously applies lateral pressure against the side of the flange. Thus, no intervening insulator or other type of adaptor, is required to create these pressure points.

The opposite end of the clip is in direct contact with the support, unlike the conventional construction which utilizes a bearing member between the clip and support. The undulating portion of the clip which fits under the insert, contains a groove shaped to promote a contiguous fit with the insert, or a bearing member which is placed between the insert and the groove.

Other objects, uses and advantages of the invention are apparent from the following description and accompany drawings, which set forth the preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the novel fastening system, with the fastening member in its installed position.

FIG. 2 is a sectional view taken along the lines 2--2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A typical railroad track system is known to consist of a pair of rails held in spaced parallel relationship, resting on a series of lateral ties or sleepers, usually made of concrete, and generally referred to as foundations. The drawings illustrate only sufficient portions of the system necessary to bring out the salient features of the invention.

As shown in the drawings, a typical rail 11 has the principal wheel-contacting surface 12, a vertical rib 13, and lower flanges 14 extending laterally at each side of the rib. Each flange has an upper surface 15 which slopes downwardly from the rib to an outer edge 16. The lower surface 17 of the rail rests upon a resilient tie pad 18 which is placed upon the tie 19 and acts as a cushion for the rail.

The rail fastening system is generally designated by reference number 20, and includes an insert 21 which is L-shaped and is formed of a crossbar 22 extending parallel to the track, and a vertical leg 23 which is cast into the foundation. The insert is located a short distance laterally from the rail. The system further includes a support 24 which is in the shape of a generally rectangular cross-section block of steel or concrete, located outwardly of the insert 21. The support is mounted within a groove 25 to secure it from lateral movement. The support has an upper surface which tapers laterally downward toward the rail, and has an insulating bearing 26 mounted on the upper surface which provides good electrical insulation. The bearing is made of a friction-resistant plastic material such as phenolic, nylon or glass fiber reinforced resin. The principal member of the fastening system is a clip 27, which is in the form of a spring-like metal member having a multiple-curved cross-section in which the curved members undulate. The material of which the clip is made is preferably a high quality spring steel.

The clip 27 is designed to fit under the insert 21, and has a downwardly extending undulating lower surface 28 which is below the insert, and a groove 29 in the upper surface. An insulating bearing 30, also providing a good electrical insulation, is made of the same material as bearing 26, shaped to fit within the groove to receive the crossbar 22 of the insert. The clip is capable of insertion under the insert because the insert has been originally cast into the foundation just far enough to allow the crossbar to assume the position shown. One end 31 of the clip is designed to contact the rail flange directly, without the need for intervening insulators or adaptors. The end 31 has an offset portion creating an internal shoulder 32 on the lower surface, with the shoulder retaining the edge 16 and tapered surface 15 of the flange to prevent displacement of the rail relative to the foundation. The upper surface of the end 31 has an undulating segment 33 which provides a downwardly compressive force to assist in retaining the flange. The opposite end 34 of the clip has a further downwardly undulating cross-section 35, the lower surface of which bears against the bearing 26 of the support 24. This section 35, coupled with a further upwardly undulating section 36, provides a spring-like action which provides downward compression of the end 34 against the support 24. The overall thickness of the clip varies from a maximum at end 31, decreasing generally constantly to a minimum at the other end 34. This creates the desirable spring effect needed for retaining the rail flange, and the rail, in place.

The installation of the clip 27 may be accomplished by several methods. For example, the clip may first be placed under the insert 21 so that the shoulder 32 bears against the edge 16 and surface 15 of the flange. Next, the opposite end 34 is lifted and the support 24 is placed in position under that end. Finally, the end 34 is released to bear against the bearing 26 on the support.

Another method of installation might consist of the same first step, namely placing the clip under the insert 21 to permit shoulder 32 to bear against the flange of the rail. However, instead of lifting the end 34, the support 24 may simply be driven into position inder the end 34.

The above description refers to installation of a single clip, insert and support system as best shown in FIG. 2. However, it is normal to apply an opposite identical clip 27 and insert 21A as shown in FIG. 1, to be used with an identical bearing (not shown). Preferably, the insert 21A is mounted in an opposite but parallel direction to insert 21; that is, the insert 21A is rotated 180 degrees so that the leg 23A is at the other end of the insert. This is shown in FIG. 1.

Other modifications are contemplated; for example, the bearings 26 and 30 may be omitted, and the shape of internal shoulder 32 may be varied to fit a specific configuration in the edge of the rail flange. The specific configuration of the clip and its relationship to the other components of the fastening system may also be modified within the scope of the invention and the appended claims.

Claims

1. In a method of fastening a flanged rail to a foundation to form a railroad track system, comprising the steps of; mounting a support on said foundation laterally of said rail, embedding an insert in said foundation between said rail and said support, providing a fastening member, disposing said fastening member under said insert having opposed ends thereof contacting said support and a flange of said rail, the improvement comprising the steps of, forming said fastening member having a multiple curved cross-section with a plurality of undulating portions, and a rail flange securing end having a thicker cross-section than said support contacting end, and disposing said fastening member under said insert placing a first undulating portion downwardly at one end thereof on said support, placing a second undulating portion upwardly at the other end thereof on said flange of said rail, placing a third undulating portion having a groove formed in its upper surface and a bearing member located within said groove, under said insert so as to receive a portion of said insert within said bearing member to secure said fastening member, and driving a support under said first undulating portion, thereby securing said rail in place.

2. The method of claim 1 wherein said rail flange has an upper surface and an outer edge, the further steps of forming retaining means in the lower surface of said second undulating portion, and placing said retaining means in direct contact with said upper surface and outer edge to provide said securing step.

3. The method of claim 1 wherein said insert has a cross-bar and said fastening member is installed by inserting said member under said cross-bar on said insert, placing said second undulating portion against said rail flange, and driving said support under said first undulating portion.