GB2106571A

GB2106571A - Insulated rail clip

Info

Publication number: GB2106571A
Application number: GB08128240A
Authority: GB
Inventors: David Julian Allen; Owen Hanson
Original assignee: KARMIC Ltd
Current assignee: KARMIC Ltd
Priority date: 1981-09-18
Filing date: 1981-09-18
Publication date: 1983-04-13

Abstract

A spring steel rail clip 1 of circular section has a foot 3 which, in use, is adapted to engage an upper surface 4 of a rail base flange 5, the foot 3 being provided with a polyurethane shoe 9 secured by adhesive 10 thereto, whereby the clip 1, in use, engages the upper surface 4 via the insulating shoe 9. In manufacture, the clip is shot-blasted before applying the adhesive. <IMAGE>

Description

SPECIFICATION Rail clip This invention relates to a rail clip for sections of rail track and to a method of manufacturing such a clip.

A known clip is manufactured from spring steel, of circular section and is adapted to urge a rail into firm seating engagement with a sleeper, with an electrical insulating pad interposed between the underside of the foot of a railway rail and an upper surface of a sleeper.

Conventionally, such metal clip is provided with non-metallic, electrical insulation and every clip installation requires four components viz. an insulating spring steel clip, two additional insulators and a pad. In practice this produces a requirement for some 20,000 components per mile of track. Whilst past use has shown this prior art arrangement to be technically satisfactory, the life expectancy of such insulated clips is relatively short-normally twelve insertions/removals, due to the relatively fragile nature of the electrical insulation.

According to a first aspect of the present invention, there is provided a spring steel rail clip of circular section material having a foot which, in use, is adapted to engage an upper surface of a base flange of a conventional railway rail section, the foot being provided with a polyurethane shoe secured by adhesive thereto, whereby the clip, in use, engages the upper surface via the shoe.

By employing the clip in accordance with the invention, which avoids the provision of fragile insulating material on the clip, the clip life is substantially extended beyond the twelve insertions/removals previously considered acceptable, to provide for a virtually limitless number of insertions/removals. Even if a shoe should become detached, damaged or unacceptably worn, there is no difficulty in reshoeing and hence re-using the clips in question.

Furthermore, the clip in accordance with the invention obviates the need for the two conventionally required insulators, hence reducing the number of components per mile of track by 50%, which reduces installation, maintenance and transportation costs. It also eliminates the possibility of improperly fitting, or even omitting insulators.

Conveniently, the show is of Adiprene (Registered Trade Mark) a Du Pont product, or this may form the basis for an admixture of different polyurethanes and/or other ingredients, to suit particular service conditions and/or adhesives. For an Adiprene (R.T.M.) shoe, a suitable adhesive is Loctite (R.T.M.) a cyanacrylate adhesive.

According to a second aspect of the present invention, there is provided a method of manufacturing a clip as defined above, comprising the step of shot blasting the relevant portion of the clip foot to which the shoe is to be applied, to remove any loose particles and generally to produce an adequately prepared surface to receive the adhesive.

In principle, a layer of adhesive may be applied either to the shoe or to the clip, but the latter is preferable in an automatic clip forming and clip shoeing line. In such a line, the shoes may be cartridge fed from a magazine, with the adhesive applied to the clip foot by a roller or spray, the Loctite adhesive having a setting time of some 3-6 seconds.

The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an end elevation of a clip in accordance with the invention; Figure 2 is a side elevation of the foot portion of Figure 1; and Figure 3 is an underneath plan view of the foot portion of Figure 1.

In the drawings, a spring steel rail clip 1 is of circular section and is bent to a known shape which has been used extensively in at least the U.K. rail system. The clip terminates at one end in a head 2 adapted to engage a retaining aperture in a rail chair (not shown) and a foot 3 adapted to engage an upper surface 4 of a base flange 5 of a rail 6 of conventional cross-section, the rail 6 having a web 7 carrying a head 8. Engagement of the clip foot 3 with the upper surface 4 is in fact via a polyurethane shoe 9 secured by a layer of adhesive 10 to a suitably shot blasted surface of the clip foot. Preferably, the shoe 9 is of Adiprene (R.T.M.) and the adhesive is Loctite (R.T.M.).

Claims

1. A spring steel rail clip of circular section material having a foot which, in use, is adapted to engage an upper surface of a base flange of a conventional railway rail section, the foot being provided with a polyurethane shoe secured by adhesive thereto, whereby the clip, in use, engages the upper surface via the shoe.

2. A clip as claimed in Claim 1, wherein the shoe is of Adiprene (Registered Trade Mark).

3. A clip as claimed in Claim 1, wherein the polyurethane of the shoe is an admixture containing a major proportion of Adiprene (Registered Trade Mark) and a minor proportion of different polyurethanes and/or other ingredients, to suit particular service conditions and/or adhesives.

4. A clip as claimed in Claim 2 or Claim 3, wherein the adhesive is a cyanacrylate adhesive.

5. A clip as claimed in Claim 4, wherein the adhesive is Loctite (Registered Trade Mark).

6. A method of manufacturing a clip as defined above, comprising the step of shot blasting the relevant portion of the clip foot to which the shoe is to be applied.

7. A method as claimed in Claim 6, wherein adhesive is applied to the clip and the shoe is thereafter applied to the adhesive.

8. A method as claimed in Claim 6, wherein adhesive is applied to the shoe and the latter subsequently brought into contact with the clip.

9. A method as claimed in Claim 7, wherein the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Rail clip This invention relates to a rail clip for sections of rail track and to a method of manufacturing such a clip. A known clip is manufactured from spring steel, of circular section and is adapted to urge a rail into firm seating engagement with a sleeper, with an electrical insulating pad interposed between the underside of the foot of a railway rail and an upper surface of a sleeper. Conventionally, such metal clip is provided with non-metallic, electrical insulation and every clip installation requires four components viz. an insulating spring steel clip, two additional insulators and a pad. In practice this produces a requirement for some 20,000 components per mile of track. Whilst past use has shown this prior art arrangement to be technically satisfactory, the life expectancy of such insulated clips is relatively short-normally twelve insertions/removals, due to the relatively fragile nature of the electrical insulation. According to a first aspect of the present invention, there is provided a spring steel rail clip of circular section material having a foot which, in use, is adapted to engage an upper surface of a base flange of a conventional railway rail section, the foot being provided with a polyurethane shoe secured by adhesive thereto, whereby the clip, in use, engages the upper surface via the shoe. By employing the clip in accordance with the invention, which avoids the provision of fragile insulating material on the clip, the clip life is substantially extended beyond the twelve insertions/removals previously considered acceptable, to provide for a virtually limitless number of insertions/removals. Even if a shoe should become detached, damaged or unacceptably worn, there is no difficulty in reshoeing and hence re-using the clips in question. Furthermore, the clip in accordance with the invention obviates the need for the two conventionally required insulators, hence reducing the number of components per mile of track by 50%, which reduces installation, maintenance and transportation costs. It also eliminates the possibility of improperly fitting, or even omitting insulators. Conveniently, the show is of Adiprene (Registered Trade Mark) a Du Pont product, or this may form the basis for an admixture of different polyurethanes and/or other ingredients, to suit particular service conditions and/or adhesives. For an Adiprene (R.T.M.) shoe, a suitable adhesive is Loctite (R.T.M.) a cyanacrylate adhesive. According to a second aspect of the present invention, there is provided a method of manufacturing a clip as defined above, comprising the step of shot blasting the relevant portion of the clip foot to which the shoe is to be applied, to remove any loose particles and generally to produce an adequately prepared surface to receive the adhesive. In principle, a layer of adhesive may be applied either to the shoe or to the clip, but the latter is preferable in an automatic clip forming and clip shoeing line. In such a line, the shoes may be cartridge fed from a magazine, with the adhesive applied to the clip foot by a roller or spray, the Loctite adhesive having a setting time of some 3-6 seconds. The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an end elevation of a clip in accordance with the invention; Figure 2 is a side elevation of the foot portion of Figure 1; and Figure 3 is an underneath plan view of the foot portion of Figure 1. In the drawings, a spring steel rail clip 1 is of circular section and is bent to a known shape which has been used extensively in at least the U.K. rail system. The clip terminates at one end in a head 2 adapted to engage a retaining aperture in a rail chair (not shown) and a foot 3 adapted to engage an upper surface 4 of a base flange 5 of a rail 6 of conventional cross-section, the rail 6 having a web 7 carrying a head 8. Engagement of the clip foot 3 with the upper surface 4 is in fact via a polyurethane shoe 9 secured by a layer of adhesive 10 to a suitably shot blasted surface of the clip foot. Preferably, the shoe 9 is of Adiprene (R.T.M.) and the adhesive is Loctite (R.T.M.). Claims

9. A method as claimed in Claim 7, wherein the shoes are cartridge fed from a magazine.

10. A method as claimed in any one of Claims 6 to 9, wherein the adhesive is applied by a roller.

11. A method as claimed in any one of Claims 6 to 9, wherein the adhesive is applied by spraying.

12. A spring steel rail clip substantially as hereinbefore described with reference to the accompanying drawings.

1 3. A method of manufacturing a clip as defined in any one of Claims 1 to 5 and 12, substantially as hereinbefore described with reference to the accompanying drawings.