AU652883B2 - Resilient fastening aid for concrete railway sleepers - Google Patents

Description

65288

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION S F Ref: 231812 FOR A STANDARD PATENT

ORIGINAL

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S

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Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: ASSOCIATED PROVISIONAL (313 Application No(s) PL1354 General and Railway Supplies Pty. Ltd.

Institute Road Montacute South Australia 5134

AUSTRALIA

Robert J. Rex Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Resilient Fastening ~5~K for Concrete Railway Sleepers APPLICATION DETAILS [33] Country

AU

[323 Application Date 13 March 1992 The following statement is a full description of this invention, including the best method of performing it known to me/us:- *2- IN t~ 2 RESILIENT FASTENING SY-9+T FOR CONCRETE RAILWAY SLEEPER FIELD OF THE INVENTION The invention pertains to rail fastening systems and more particularly to resilient rail fastening systems. The invention has particular application to rail fastening systems which include concrete sleepers.

BACKGROUND OF THE INVENTION Many rail fastening systems rely on concrete sleepers. Some of these systems use resilient clips to position and restrain the railway rails. In one such known system, the concrete sleeper includes a pair of recesses located on either side of the intended rail location. A metal plate is cast in place or otherwise located toward the bottom of each recess. The metal plate has a slot formed In it. The slot lockingly engages an enlarged portion formed on the bottom of an insert or stud.

15 The upper end of the insert is threaded. A threaded fastener is provided for the top of the insert. To retain and restrain the rail which passes between the two recesses, a resilient clip is inserted beneath the threaded portion of the insert. The clip extends between the concrete sleeper and the foot of the rail. The force exerted by the resilient clip onto the foot of the rail can be adjusted by loosening or tightening the threaded fastener at the end of the insert.

It has been observed that if improperly adjusted, the threaded fastener can work loose. This weakens the connection between the rail and the sleeper. In addition, the resilient clip may be over-tensioned S".i 25 or under-tensioned unless the threaded fastener is adjusted correctly.

Achieving the proper level of tension requires some skill.

OBJECTS AND SUMMARY OF THE INVENTION Accordipgly, it is an object of the invention to provide a rail fastening 6cystewhich does not require threaded fasteners and which strives to ameliorate some of the disadvantages associated with prior art rail fastening systems.

There Is disclosed herein a rail fastening .syteicomprising: an insert, the insert having a T-shaped head at one end, a key located at a second end and a shaft extending between the key and the head; and a spacer, comprising a plate having a central aperture adapted to admit the head of the insert.

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Preferably, the y-lestm\further comprises a resilient clip, the clip adapted to impinge against the T-shaped head and a foot of a rail when the rail is located adjacent the spacer.

The insert, spacer and resilient clip may be used in conjunction with a single recess formed in a concrete sleeper. Generally two such arrangements are required for each sleeper and many such pairs are required for a stretch of railway line. However, even a single set of the three aforementioned elements can be used to convert an existing rail fastening location and thereby provide the above benefits.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Figure 1 is a partially cross section side elevation of a concrete sleeper supporting a railway rail, spacer, insert and resilient clip.

15 Figure 2 is a top plan view of the spacer depicted in Figure 1.

Figure 3 is a front elevation of the insert depicted in Figure 1.

BEST MODE AND OTHER EMBODIMENTS OF THE INVENTION As shown in Figure 1, the fastening system 10 of the present invention generally comprises a spacer 11, an insert 12 and a resilient clip 13. The system 10 is particularly adapted to concrete sleepers 14.

Some concrete sleepers are formed with a recess 15 on each side of the location which supports the rail 16. A steel plate 17 is embedded in or cast in the concrete sleeper 14, As can be appreciated from Figure 1, vertical movement of the rail 16 is transmitted to the resilient clip 13 25 which in turn transmits a force to the insert 12, which force is resisted by the steel plate 17.

As seen in Figures 1 and 2, a spacer 11 with a central opening 18 is provided. The illustrated spacer 11 has a generally semi-cylindrical base portion 19 and a foot 20 which projects from the bottom surface.

The semi-cylindrical base 19 is adapted to rest within a similarly curved portion of the recess 15. In some rail retaining systems, this similarly curved portion was provided to support a different resilient clip. In this instance, the small foot 20 and the generally semi-cylindrical base portion 19 serve to locate the spacer 11 above the recess 15. The spacer inhibits lateral movement of the rail 16. Depending on the configuration of the concrete sleeper 14 the spacer may be shaped to practically any S configuration so long as it serves to support the clip and/or locate the 4 shaft 21 of the insert 12 adequately. In preferred embodiments the spacer will also serve to inhibit lateral movement of the rail 16.

As depicted in Figures 1 and 3, the insert 12 can be seen as comprising a T-shaped head 22 at one end, an enlarged or flattened key 23 at the other end and a shaft 21 extending between the head 22 and the key 23. The key 23 may have rounded top edges 30 to prevent binding. It will also be observed that the steel plate 17 has a slot or central opening 24 formed in it. The slot 24 in the plate 17 admits the key 23 when it is inserted in one orientation but resists withdrawal of the key (and therefore the insert 12) when the insert is rotated, for example, by In both Figures 1 and 3, the insert is depicted in the locked orientation. When the insert is in the locked orientation, any effort to withdraw the insert is resisted by the plate 17. In particular, forces impinged upon the T-shaped head 22, by the resilient clip 13, are resisted by the plate 17.

The resilient clip 13 Is more or less of the type depicted in the applicant's co-pending Australian patent application No. 66581/90, which disclosure is incorporated herein by reference. The clip is formed from steel plate in generally the cross sectional shape depicted in Figure 1.

The clip 13 includes a top leg 25, a bottom leg 26 and a generally U-shaped bend extending between the two legs 25, 26. Each of the legs 25, 26 is bifurcated so as to straddle the shaft 21 of the insert. The top leg 25 includes a detent portion 27 which engages the rounded underside of the T-shaped head 22. The bottom leg 26 also Includes a 25 central bend 28 which may be tailored to provide a specific restraining force against the foot 28 of the rail 16.

It will be understood that the insert and resilient clip may be varied to suit particular rail applications and that a variety of head configurations and clip configurations fall within the scope and spirit of the invention. Further, the spacer size and configuration are variable to suit various configurations of concrete sleeper, gauge, rail sizes, etc.

To instal the apparatus of the present invention, the insert is lowered to the bottom of the sleeper recess and passed through the opening 24 and the plate 17. The insert is rotated through 900 ensuring that the Insert head is correctly oriented. In particular it should be noted that the clip guide angle 29 is oriented outwards or away from the STAi1697m 5 rail 16. The next step is to lower the spacer so that the insert head protrudes through the opening 18 paying particular attention that the spacer sits on the sleeper surface. With the insert held upright the clip is located on the sleeper and spacer. The clip can be tensioned using a purpose-made clip inserter, if required.

Hhile the present invention has been described with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope or spirit of the invention.

STA/1697m

Claims (7)

1. 2. The rail fastening aid of claim 1, further comprising a resilient clip, the clip adapted to impinge against the T-shaped head and a foot of a rail when the rail is located adjacent the spacer.
2. 3. The rail fastening aid of claim 2, wherein: the resilient clip further comprises two legs, each leg bifurcated so as to allow each leg to receive the insert, the legs attached by an integral U-shaped bend.
3. 4. The rail fastening aid of any one of the preceding claims, wherein: the spacer further comprises a semi-cylindrical base portion which projects from a bottom surface of the spacer.
4. 5. The rail fastening aid of any one of claims 2-4, wherein: a bottom surface of the T-shaped head includes an angled portion which serves as a guide to the insertion of the clip.
5. 6. The rail fastening aid :f any one of claims 2-5, wherein: a top leg of the clip includes a bend, the bend acting as a detent portion for the T-shaped head to engage. 25 7. The rail fastening aid of any one of claims 2-6, wherein: a bottom leg of the clip includes a central bend for increasing a force exerted by the clip against the foot of the rail.
6. 8. The rail fastening aid of any one of claims 1-6, wherein: the key comprises a flattened portion which, after insertion, cannot be removed from a similarly configured slot when rotated at
7. 9. A rail fastening aid substantially as hereinbefore described with reference to the accompanying drawings. DATED this SEVENTH day of JULY 1994 General and Railway Supplies Pty Ltd Patent Attorneys for the Applicant SPRUSON FERGUSON ABSTRACT RESILIENT FASTENING SYSTEM FOR CONCRETE RAILWAY SLEEPERS A rail fastening system comprises an insert (12) having a T-shaped head (22) at one end, a key (23) located at a second end and a shaft extending between the key (23) and the head The system also comprises a spacer (11) comprising a plate having a central aperture (18) adapted to admit the head (22) of the insert Also included is a resilient clip (13) adapted to impinge against the T-shaped head (22) and a foot (28) of a rail (16) when the rail is located adjacent to the spacer (11). Fig. 1 S t 6* 50«5 STA/1697m