GB2077866A

GB2077866A - Vehicle Brake Equipment

Info

Publication number: GB2077866A
Application number: GB8019350A
Authority: GB
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1980-06-13
Filing date: 1980-06-13
Publication date: 1981-12-23

Abstract

Brake equipment for a vehicle adapted to travel along a stationary rail 14 comprises a first component 1 movable with respect to the stationary rail when the brake is applied, a second component 2 slideably mounted with respect to the first component and urged towards rail 14 when the brake is applied, a third component 40 pivotably mounted to the first component, energising means 20 and 21 motivated by relative movement between the first and second components, and activating means 36 activated by motivation of the energising means to urge the third component towards the stationary rail. As shown, the energising means comprises a piston-cylinder arrangement 20, 21 which, upon said relative movement, pressurizes a piston cylinder arrangement 36 constituting the actuating means to move brake component 40, constituted by brake members 42 (see Figure 3 for details of piston cylinder arrangements). Brake application (e.g. upon overspeed) exhaust, elevating some of vehicle chassis-this moves downwards to apply pad 9 of component 1 to rail 14-and hydraulic operation of member 42 via means 20, 21, 36 applies pads 45. In a modification, chassis is fixed and brake is applied by moving part of brake equipment relative to chassis. <IMAGE>

Description

SPECIFICATION Vehicle Brake Equipment This invention relates to vehicle brake equipmeiit.

In particular, the present invention relates to vehicle brake equipment provided on vehicles which travel along a stationary rail with the brake equipment arranged to co-operate with the stationary rail. With such a vehicle when the vehicle brake is applied a brake component is urged to contact the stationary rail tending to bring the vehicle to rest.

In a typical installation in which the vehicle is mounted on the stationary rail the brake component is urged to abut the top of an outwardly projecting flange provided on the rail tending to lift the-vehicle wheels from the stationary rail. With such an installation the maximum brake effort exerted is dependant upon the weight of the vehicle. In order to obtain increased maximum braking effort it is known to provide a reaction component arranged to run along the stationary rail on the side of the outwardly projecting flange opposite to the brake component. Thus, when the vehicle brake is applied the outwardly projecting flange of the stationary rail tends to be clamped between the brake component and the reaction component and the maximum braking effort tends to be dependant upon the force urging the brake component towards the rail rather than upon the weight of the vehicle.Unfortunately, in many installations it is not possible to provide such a reaction component because of obstructions intermittently located in the desired path of the reaction component. Such abstructions would be encountered at, for example point or crossover arrangements. A further disadvantage of such brake equipment is that a special rail is required, the rail providing a horizontal outwardly projecting flange. The cost for the provision of such non-standard rails can be prohibitive.

An object of the present invention is to provide vehicle brake equipment which tends to overcome or reduce the above mentioned problems and which is suitable for use with a standard rail section.

According to the present invention vehicle brake equipment for a vehicle adapted to travel along a stationary rail comprises a first component movable with respect to the stationary rail when, in use, the brake equipment is mounted on the vehicle and the brake is applied, a second component movably mounted with respect to said first component and urgable towards the stationary rail when, in use, the brake is applied, a third component movably mounted with respect to the second component, energising means arranged to be motivated by relative movement between the first and second components, and activating means adapted to be activated by motivation of the energising means to urge the third component towards the stationary rail.

Preferably, the third component is pivotally mounted with respect to the first component.

Conveniently, the activating means is arranged to pivot the third component with respect to the first component.

Preferably, the activating means comprises a piston and cylinder arrangement.

Preferably, the energising means comprises a piston and cylinder arrangement.

Conveniently, relative movement between said first and second component tends to cause relative movement between the piston and cylinder units of the energising means.

Preferably, relative movement between the piston and cylinder units of the energising means tends to pressurise fluid in the energising means.

Advantageously, the pressurised fluid in the energising means activates the piston and cylinder arrangement of the activating means.

Preferably, a topping-up storage reservoir for fluid is provided.

Preferably, the third component comprises two pivotally mounted brake members arranged to cooperate with opposed faces of the stationary rail.

Conveniently, the activating means is arranged to act on both brake members. Preferably, resilient means tend to act against the action of the activating means. Preferably, resilient means are provided between the first and second components.

The present invention also provides a vehicle comprising brake equipment substantially as defined above.

By way of example only, one embodiment of the present invention now will be described with reference to the accompanying drawings, in which: Figures 1 and 2 are incomplete cross-sectional views taken through brake equipment constructed in accordance with the present invention, Figure 1 shows the equipment in a "brake released" mode and Figure 2 shows the equipment in a "brake applied" mode; and Figure 3 is an incomplete perspective view of a portion of the brake equipment of Figures 1 and 2.

The drawings show details of one set of brake equipment for mounting on a chassis of a rope hauled, rail mounted vehicle (not shown).

Typically, at least one set of brake equipment is mounted on each side of the vehicle chassis so as to co-operate with an adjacent stationary rail as will be explained later in this specification. The brake equipment is secured to the bottom of the vehicle chassis by bolts (not shown) such that in operation when the vehicle brake is applied hydraulic rams are exhausted allowing the chassis to fall towards the rail track and brake pads on the brake equipment to contact the associated stationary rail tending to arrest the vehicle. The hydraulic rams for retaining the vehicle in a brake released mode and an overspeed device arranged to sense the vehicle speed and to exhaust the elevating rams to apply the brake in case of overspeed are not shown in the drawings.

The brake equipment comprises a first component 1 comprising a generally box-shaped body housing having an uppermost flange 4 provided with bolt holes holes 5 for the previously mentioned bolts securing the brake equipment to the vehicle chassis. The brake equipment also comprises a second component 2 constituted by a slide block slideably mounted within a vertical slot 3 defined by the first component. Downward movement of the slide block along the vertical slot is limited by two stops 6 projecting outwardly from the uppermost margins of the slide block and arranged to abut two shoulders 7 provided by the first component.

As seen in Figure 3 an elongate brake member or shoe 8 extends along the length of the slide block, the shoe being provided with a brake pad 9 bonded to the shoe, the brake shoe and pad being fixedly secured to the side block by bolts (not shown) engaging in bolt holes 12 provided in brackets 13 secured to the ends of the slide block.

From Figure 2 it can be seen that when the brake is applied the brake pad 9 is urged to abut the upward facing surface 1 5 of the associated stationary rail 14. The end portions of the elongate brake member 8, 9 are inclined upwardly to assist negoatiation of undulations in the track.

The slide block 2 is provided with two vertical cylindrical blind bores 20 for receiving piston elements 21 (only one of which is shown in Figure 1) each constituted by an inverted generally cup shaped element having a domed uppermost end 22 for abutting the downward facing surface 23 of the flange 4 of the first component 1. Each piston element is slideable along its associated bore 20 and is sealably engaged in the bore by means of a ring seal 25 provided in a groove formed in the piston element. A coil spring 26 tends to urge each piston element 21 out of the associated bore 20.

A passage 27 hydraulically connects the inside chambr 28 of the piston and cylinder arrangement 20, 21 with an elongate main pasage 29 extending along the slide block 2 to hydraulically interconnect the two piston and cylinder arrangements with a hydraulic toppingup reservoir 30 which is formed by a substantially closed third vertical bore in the slide block 2 and which is hydraulicaliy connected to the main passage 29 by a passage 32 provided with a nonreturn valve 33 allowing fluid flow from the reservoir into the main passage but preventing fluid flow from the passage into the reservoir. The ends of the main passage 29 are closed by plugs 34 and the top of the reservoir 30 is closed by a cap 31.

The slide block also comprises two generally horizontal cross bores 35 each housing a piston and cylinder arrangement 36 which is hydraulically connected to the main passage 29 by a vertical feed passage 37.

The brake equipment also comprises a third component 40 constituted by two pairs of brake members 42 (only one pair of which is shown in Figures 1 and 2). Each brake member 42 is pivotally mounted to the first component by a pivotal mounting 43 including a shaft 44.

The lower portion of each pivotally mounted brake member 40 is provided with a brake pad 45 fixedly secured to the body of the member 40 by bolts 47. As seen in Figure 2 the two brake pads 45 on each pair of brake members are arranged to co-operate with opposed surfaces 50, 51 of the stationary rail 14.

Activating means comprising the two previously mentioned piston and cylinder arrangements 36 are arranged to act in an opposite sense on relatively upper portions of the brake members 40 in each pair of brake members such that when activated the brake members in each pair are urged to pivot about the pivotal mounting 43 thereby tending to urge the brake pads 45 towards the associated surface 50, 51 of the stationary rail. Thus, when.the activating means are activated they tend to urge the brake members 42 in each pair to clamp the stationary rail.

Each brake member 42 is urged to pivot in a direction opposite to that under the action of the activated piston and cylinder arrangement 36 by resilient means comprising a coil spring 58 supported on the first component 1 and arranged to abut a vertical surface 59 formed by a cut-out in the associated brake member. The effort exerted by each coil spring 58 is adjustable via a adjustment screw 60.

In use, with the brake equipment fixedly mounted on the vehicle chassis sufficient hydraulic fluid is fed to the hydraulic system to fill the piston and cylinder arrangements constituting the energising and activating means and to fill the storage reservoir 30. The adjustment screws 60 are adjusted until the action of the coil springs 58 is sufficient to pivot the brake member 40 about the pivotal mountings 43 such that the brake pads 45 are clear of the stationary rail 14 and to force hydraulic fluid against the piston elements 21 within the bore 20.

With the brake equipment in a brake release mode the previously mentioned elevating rams raise the chassis together with the brake equipment shown in the drawings until the brake pad 9 is clear of the upper surface of the station rail.

Upon the overspeed device sensing the vehicle to travelling above a desired speed the elevating rams are connected to exhausts permitting the chassis together with the brake equipment to fall towards the stationary rails 14 until the brake pad 9 on each set of brake equipment abuts the upper surface of the associated rail. Thus, the vehicle brake rapidly starts to be applied.

As soon as the brake pad 9 contacts the stationary rail further downward movement of the brake member of the second component 2 is prevented. However, the weight of the vehicle tends to move the first component 1 downward relative to the second component compressing the spring 17 and urging the slide block to slide upwards in the slot 3. The relative movement of the piston and cylinder units 20, 21 brought about by relative movement of the first and second components pressurises the hydraulic fluid in the hydraulic circuit. This motivation of the energising means to pressurise the fluid activates the activating means such that the piston and cylinder arrangements 36 extend to urge apart the upper portions of the brake member 40 of each pair.The brake members 40 thereby are pivoted about the pivotal mountings 43 and the brake pads 45 are brought into engagement with the opposed surfaces of the stationary rail. Thus the rail is clamped by the brake equipment and the vehicle tends to be quickly brought to rest. It is anticipated that such a clamping brake effort will be particularly beneficial in wet rail conditions where the braking effort of the brake pad 9 may be relatively low.

In order to release the brake, the previously mentioned elevating rams are activated to take the vehicle weight from the brake member 2 and the return springs 26, 58 in the system restore the brake progressively to the brake release mode as the jacking up procedure proceeds. The fully brake release mode is achieved when the pad 9 breaks contact with the rail 14.

In other embodiments of the invention for use with vehicles in which the chassis is fixedly mounted with respect to the wheel mountings and the brake is applied by moving a part of the brake equipment downwards relatively to the chassis, the first component 1 is fixedly mounted to the movable part of the brake equipment. Said movable part may be urged towards the rail by resilient means upon the de-activation of hydraulic rams means or by a piston and cylinder arrangement which is activated to apply the brake.

In either of these two cases the operation of the braking equipment shown in the accompanying drawings is substantially the same as that described above. Upon the brake initially being applied the movable part of the brake equipment is moved downwards relatively to the non-movable brake part fixedly mounted on the vehicle chassis. Downward movement of the movable part is accompanied by downward movement of the first and second components until the brake pad 9 of the second component 2 contacts the rail to start to apply the brake.

Further downward movement of the first component relatively to the second component against the action of the resilient bias causes the energising means to be motivated to thereby pressurise the hydraulic system to activate the activating means to urge the brake member 40 to pivot abut the mounting 23 causing the brake pads 45 to clamp the rail and quickly bring the vehicle to rest.

In other embodiments the action of the brakes is controlled from a locomotive control cabin. In such embodiments the brakes can be repeatedly applied and released without need of conducting the setting up procedure.

From the above description it will be appreciated that the present invention provides relatively simple and vehicle brake equipment which tends to be relatively efficient.

A feature of the present brake is that the degree of braking effort is proportional to the load, thus automatically accommodating for the conditions between an empty and fully laden vehicle. A further feature of the present brake is that the side brake members can adjust to rail displacement from the nominal centre line position, due to the floating characteristics of the horizontal pistons.

Claims

1. Vehicle brake equipment for a vehicle adapted to travel along a stationary rail, comprising a first component movable with respect to the stationary rail when, in use, the brake equipment is mounted on the vehicle and the brake is applied, a second component movably mounted with respect to said first component and urgable towards the stationary rail when, in use, the brake is applied, a third component movably mounted with respect to the second component, energising means arranged to be motivated by relative movement between the first and second components, and activating means adapted to be activated by motivation of the energising means to urge the third component towards the stationary rail.

2. Equipment as claimed in claim 1, in which the third component is pivotally mounted with respect to the first component.

3. Equipment as claimed in claim 2, in which the activating means is arranged to pivot the third component with respect to the first component.

4. Equipment as claimed in claim 3, in whjch the activating means comprises a piston and cylinder arrangement.

5. Equipment as claimed in claim 4, in which the energising means comprises a piston and cylinder arrangement.

6. Equipment as claimed in claim 5, in which relative movement between said first and second components tends to cause relative movement between the piston and cylinder units of the energising means.

7. Equipment as claimed in claim 6, in which relative movement between the piston and cylinder units of the energising means tends to pressurise fluid in the energising means.

8. Equipment as claimed in claim 7, in which the pressurised fluid in the energising means activates the piston and cylinder arrangement of the activating means.

9. Equipment as claimed in claim 6 or 7, in which a topping-up storage reservoir for fluid is provided.

10. Equipment as claimed in any one of the preceding claims, in which the third component comprises two pivotally mounted brake members arranged to co-operate with opposed faces of the stationary rail.

11. Equipment as claimed in claim 10, in which the activating means is arranged to act on both brake members.

12. Equipment as claimed in any one of the preceding claims, in which resilient means tend to act against the action of the activating means.

13. Equipment as claimed in claim 12, in which resilient means are provided between the first and second components.

14. Vehicle brake equipment for a vehicle adapted to travel along a stationary rail, substantially as described herein and substantially as shown in the accompanying drawings.

1 5. A vehicle adapted to travel along a stationary rail and comprising brake equipment as claimed in any one of the preceding claims.