GB2031084A

GB2031084A - Track brake for rail vehicles

Info

Publication number: GB2031084A
Application number: GB7930966A
Authority: GB
Original assignee: Thyssen Industrie AG
Current assignee: ThyssenKrupp Technologies AG
Priority date: 1978-09-13
Filing date: 1979-09-06
Publication date: 1980-04-16
Also published as: SE7907482L; FR2436051A1; FR2436051B1; DE7827184U1; GB2031084B

Abstract

A plurality of brake bars (1a, 1b) of elastomeric material or rubber are arranged end-to-end in a row so that adjacent ends of neighbouring bars abut and the upper surface of each end portion (2) of each bar (1a, 1b) has a chamfer (3) so that each end portion (2) slopes downwardly towards the adjacent end of its neighbouring bar. When a rail vehicle passes over the track brake the chamfered end portions (2) are subjected to less deformation, and thus fewer potentially damaging edge stresses, than a non chamfered end portion. The chamfer (3) preferably has a length (4) to height (5) ratio of approximately 3.5:1. <IMAGE>

Description

SPECIFICATION Rubber track brake for rail vehicles The present invention relates to a rubber track brake for rail vehicles.

In one known form of track brake, a plurality of brake blocks or bars consisting of rubber, or an elastomeric material having proper ties similar to rubber, are disposed one behind the other with their ends abutting directly on one another along the course of a rail of a track. Two to five such brake bars are usually arranged in a row adjacent one another in the longitudinal direction.

Such rubber track brakes are either interposed in gaps in the rails of a track in such a manner that the steel rail or its head is interrupted for a length of several metres and the brake bars take over the supporting functions of the rail in the region of the interruption, or they are situated beside the track rail.

In either case the action of the rubber track brake involves the wheels of the vehicle running on to the relevant section of track and sinking into the elastomeric brake bars to an extent dependent on the wheel loads. In the former case the running surface of the wheels contacts the rubber track and in the latter case the wheel flanges run on the brake. In each case the braking effect of the rubber track brake is determined by the depth of penetration of the wheels which depends on the magnitude of the wheel load. The maximum depth of penetration of the wheels into the elastomeric material of the brake bars is limited by a guide rail which is situated beside the track brake and which includes a base portion arranged at such a height that the wheel flanges of the wheels negotiating the track brake roll on it when the intended maximum penetration depth is reached.The vertical position of the brake bars can be made adjustable, but such a facility has no bearing on the present invention.

In order to achieve the quietest and steadiest wheel travel possible when passing from the rail to the rubber track brake and vice versa, the mutually facing end portions of the rail and the end brake bar are each provided with a chamfer extending downwardly respectively towards the brake bar end or the rail end so that when changing-over to the track brake or moving off the brake on to the adjoining rail the vehicle wheels roll smoothly onto and off the brake bar.

It has been found that the elastomeric brake bars become damaged or destroyed, particularly by cracking, at the ends where the brake bars abut one another so that the rubber track brake has to be taken out of use temporarily in order to replace the relevant brake bars.

Research has shown that such damage to the brake bars is due to edge stresses which occur when the bars are negotiated by vehicles with relatively heavy wheel loadings e.g.

when loaded goods trucks pass over the track brake.

According to the present invention there is provided track brake for rail vehicles comprising a plurality of brake bars made of rubber or an elastomeric rubber-like material and arranged end-to-end in a row so that adjacent ends of neighbouring bars abut, the upper surface of each end portion of each bar having a chamfer such that, in each neighbouring pair of bars, each end portion slopes downwardly towards the adjacent end of the neighbouring bar.

The chamfers at the abutting adjacent ends of the brake bars can result (particularly when in combination with a guide rail situated laterally of the brake bars to limit the maximum penetration depth of the wheels) in the elastomeric material of the brake bars in the region of the abutting ends being subjected to considerably less deformation than would be the case with non-chamfered abutting ends.

Consequently the edge stresses possible at the abutting ends can be reduced to such an extent as to remove substantially any cracking and destruction of the elastomeric material in these regions so as to improve very considerably the working life of the brake bars. In practice the working life can be prolonged to more than twice the hitherto attained working life. It has been found particularly advantageous to give the chamfer of each end portion sloping downwardly towards the adjacent end of a neighbouring bar an inclination the length of which relative to height is in the ratio of approximately 3.5:1.

It is to be understood that the invention extends to a rail track incorporating one or more track brakes of the present invention.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawing; wherein Figure 1 is a perspective view of a rubber track brake seen in the direction of arrow I of Fig. 2; and Figure 2 shows the section along the line Il-Il of Fig. 1.

Referring to Figs. 1 and 2 the rubber track brake comprises five brake bars 1 a and 1 b of elastomeric material arranged end-to-end in the longitudinal direction with their ends abutting directly on one another. The brake bars 1 a and 1 b are each provided at their end portions 2 with a downwardly extending chamfer 3. The ratio of the length 4 of the chamfer 3 to its height 5 is approximately 3.5:1. The end brake bar 1 also includes a conventional chamfer 7 sloping downwardly to its outer end 6. Situated parallel to the brake bars 1 a and 1 b in a manner known per se is a guide rail 8 supported on a supporting structure 9. The brake bars 1 a and 1 bare adapted to be moved, in a conventional man ner, hydraulically upwardly and downwardly in the direction of arrow 11 by a supporting structure 10 and are guided between the supporting structure 9 and special guides 1 2.

The broken lines in Fig. 2 show how the brake bars 1 a, 1 b are deformed under the pressure of a wheel 1 3.

The bars need not be in contact with each other in the rest condition.

Claims

1. Track brake for rail vehicles comprising a plurality of brake bars made of rubber or an elastomeric rubber-like material and arranged end-to-end in a row so that adjacent ends of neighbouring bars abut, the upper surface of each end portion of each bar having a chamfer such that, in each neighbouring pair of bars each end portion slopes downwardly towards the adjacent end of the neighbouring bar.

2. Track brake according to claim 1 wherein the chamfer of each portion sloping downwardly towards the adjacent end of a neighbouring bar has a length to height ratio of approximately 3.5:1.

3. Track brake according to claim 1 or claim 2 wherein the upper surfaces of the outer end portions of the endmost bars have chamfers.

4. Track brake substantially as herein described with reference to Figs. 1 and 2 of the accompanying drawing.

5. Rail track incorporating a track brake according to any one of the preceding claims.