GB2200176A

GB2200176A - Rail vehicle braking

Info

Publication number: GB2200176A
Application number: GB08701151A
Authority: GB
Inventors: John Roland Gayfer
Original assignee: Becorit Ltd
Current assignee: Spare IPG 15 Ltd
Priority date: 1987-01-20
Filing date: 1987-01-20
Publication date: 1988-07-27
Anticipated expiration: 2007-01-20
Also published as: GB8701151D0; GB2200176B

Abstract

A rail vehicle for use in a mine working has a speed-responsive device for operating a braking system of the vehicle. This device comprises a weight (17) pivotally mounted in a recess (11) of the wheel and a pin (21) which normally lies entirely within the wheel but is caused to project axially from the wheel when the speed of rotation of the wheel exceeds a threshold value. A projecting end portion of the pin engages member (25) to rotate shaft (24) and thus operate a hydraulic or pneumatic valve or electric switch (23) of the brake system. <IMAGE>

Description

Title:"Vehicle and running wheel for the vehicle" Description of Invention The present invention relates to a brake control device for use in a wheeled vehicle, the device being responsive to an increase in the running speed of the vehicle to a value above a threshold value by operating a brake system of the vehicle. Brake control devices of this kind are an important contribution to the safety of vehicles used in m;nes. Known examples of such vehicles have brake control devices connected by transmission means, for example a gear train or a chain and sprocket transmission with a running wheel of the vehicle.

According to a first aspect of the present invention, there is provided a vehicle having a plurality of running wheels, a brake system for braking running of the vehicle and a brake control device responsive to an increase in the running speed of the vehicle to a value above a threshold value by operating the brake system, wherein the brake control device includes a weight arranged to rotate with one of said wheels and to move relative to the axis of rotation of the one wheel when the speed of rotation of the wheel rises above a threshold speed corresponding to the threshold value of the running speed of the vehicle.

According to a further aspect of the invention, there is provided a vehicle running wheel comprising a weight mounted in the wheel for movement relative to an axis of rotation of the wheel and biasing means for urging the weight in a direction towards the axis, the weight having an element arranged to be moved between a retracted position and a projected position when the weight moves relative to the axis.

An example of a wheel and of a vehicle embodying the invention will now be described, with reference to the accompanying drawing, wherein: FIGURE I shows a side elevation of a wheel of a vehicle, together with an arm on which the wheel is mounted, a cover of the wheel being omitted and the wheel being partly broken away to reveal components of a brake control device on the mounting arm; FIGURE 2 shows a plan view of the parts shown in Figure I and; FIGURE 3 shows a cross-section on the line Ill-Ill of Figure 1.

The vehicle, certain parts of which are illustrated in the drawings, comprises a chassis and four running wheels which, in the particular example illustrated, are adapted to run on rails such as the rails of a track laid in a mine working. Each wheel is mounted by a stub shaft on a respective mounting arm 10 which extends generally horizontally from the wheel and is pivotally connected with a chassis of the vehicle (not shown). The general arrangement of the chassis, mounting arms, wheels and bearings connecting the wheels with the mounting arms may be a known arrangement.

The wheel shown in the drawing defines an annular recess II which faces along the axis 12 of rotation of the wheel in a direction away from the remainder of the vehicle and a further, annular recess 13 which faces in the opposite direction along the axis 12. These recesses are separated by a web 14 in which there may be formed apertures through which the recesses communicate one with the other.

A guide member 15 is mounted in an opening in the web 14 and extends therefrom through the inner recess 13 to the open mouth thereof. One or more ears provided on the guide member 15 project into the outer recess 11.

There is disposed in the outer recess a weight 17 which is mounted in the wheel for movement of the centre of gravity of the weight towards and away from the axis 12. The weight is pivotally connected with the remainder of the wheel by a pivot pin 18 extending through the ear or ears 16. The pivot axis defined by the pin 18 is tangential to a pitch circle centered on the axis 12. It will be noted that the weight extends from the pivot axis generally in a direction along the axis 12.

Biasing means is provided for urging the weight to pivot about the pivot axis relative to the remainder of the wheel in a direction towards the axis 12.

In the example illustrated, the biasing means comprises a pair rf springs 19 and 20 each having one of its ends connected with the weight at a position remote from the pivot pin 18 and the other of its ends connected with the web 14 at a position remote from the weight. Pivoting of the weight 17 under the action of the springs 19 and 20 may be limited by abutment of the weight with a hub portion of the wheel.

The weight 17 is provided with an element 21 which is arranged to lie within the wheel, when the wheel is stationary, and to project from the wheel when the rotational speed of the wheel increases to a threshold speed. In the example illustrated, the element 21 has the form of a pin and is arranged for reciprocation in a passageway defined by the guide member 15. At one of its ends, the pin 21 is pivotally connected with the weight 17 at a position spaced from the pivot pin 18 in a direction away from the taxis 12. The opposite end portion of the pin normally lies inside the passageway of the guide member 15 but is caused to project from the guide member when the weight 17 pivots against the action of the springs 19 and 20.It will be noted that there is some lateral play between the pin 21 and the surfaces of the guide member defining the passageway, to accommodate movement of the pivotal connection between the pin and the weight.

The recess II is normally closed by a cover 22 which prevents foreign matter entering the recess and contaminating the pivots associated with the weight 17.

The brake device further comprises a control unit 23 mounted on the arm 10. The control unit is incorporated in the braking system of the vehicle and may be an hydraulic valve, a pneumatic valve or electrical switch. The control unit has an operating shaft 24 which is rotatable relative to a body of the unit for changing the condition of the unit and which protrudes from the body of the unit in an outward direction parallel to the axis 12. On an end portion of the shaft 24 which is remote from the body of the control unit, there is provided a driven member 25 which can pivot relative to the arm 10 about the axis of the shaft 24. As shown in Figure I, the driven member includes a pair of arms arranged with their lengths extending away from the shaft 24 and which are mutually divergent in a direction away from the shaft.

The driven member 25 lies between the arm 10 and the wheel and is close to the mouth of the inner recess 13. During normal operation of the vehicle, the pin 21 lies entirely inside the guide member 15 and the inner recess 13, so that there is a small clearance space between the. pin and the driven member 25 when the pin moves past the driven member with each rotation of the wheel relative to the control unit and driven member. As the speed of rotation of the wheel is increased, the weight 17 pivots away from the axis 12 and causes the pin to move along the passageway of the guide member in a direction parallel to the axis 12 and towards the longitudinal centreline of the vehicle.When the speed of rotation of the wheel reaches the threshold speed, the projecting end portion of the pin engages the driven member 25 and turns the driven member about the axis of the shaft 24 to operate the control unit. This brings the braking system into operation and brakes running of the vehicle. If the speed of the vehicle falls, the weight 17 pivots towards the axis 12 and the pin 21 is withdrawn into the guide member 15 once more. However, the control unit 23 remains in the operated condition until reset. The control unit may be reset manually by exerting a force on the driven member 25 to return the driven member to its initial position.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

I. A vehicle having a plurality of running wheels, a brake system for braking running of the vehicle and a brake control device responsive to an increase in the running speed of the vehicle to a value above a threshold value by operating the brake system, wherein the brake control device includes a weight arranged to rotate with one of said wheels and to move relative to the axis of rotation of the wheel when the speed of rotation of the wheel rises above a threshold speed corresponding to the threshold value of the running speed of the vehicle.
2. A vehicle according to Claim I further comprising biasing means urging the weight in a direction towards the axis of rotation of the wheel.
3. A vehicle according to Claim I or Claim 2 wherein the weight is mounted on the wheel.
4. A vehicle according to Claim I or Claim 2 wherein the weight is pivotally mounted on the wheel.
5. A vehicle according to any preceding Claim wherein the wheel defines a cavity and the weight is disposed in the cavity.
6. A wheel according to any preceding Claim wherein the weight is provided with an element arranged to lie within the wheel when the wheel is stationary and to project from the wheel when the weight moves in response to rotation of the wheel at a speed above the threshold speed.
7. A vehicle according to Claim 6 wherein said element is arranged to move longitudinally of the axis of rotation of the wheel, when the weight moves.
8. A vehicle according to Claim 6 wherein the element is guided for reciprocation relative to the wheel.
9. A vehicle according to Claim 8 wherein said element is pivotally connected with the weight.
10. A vehicle according to Claim 6 wherein the brake control device further comprises a driven member relative to which the wheel and the weight rotate, the driven member being mounted on the vehicle near to the wheel to be engaged by said element when the element projects from the wheel.
II. A vehicle according to Claim 10 wherein the driven member is mounted for turning about an axis parallel to the axis of rotation of the wheel.
12. A vehicle according to Claim II wherein the axis about which the driven member turns lies further from the axis of rotation than does the pin.
13. A vehicle running wheel comprising a weight mounted in the wheel for movement relative to an axis of rotation of the wheel and biasing means for urging the weight in a direction towards the axis, the weight having an element arranged to be moved between a projected position and a retracted position when the weight moves relative to the axis.
14. A wheeled vehicle having a brake control device substantially as herein described with reference to the accompanying drawing.
15. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.