WO1980000682A1

WO1980000682A1 - A mounting arrangement for a railway vehicule brake actuator

Info

Publication number: WO1980000682A1
Application number: PCT/SE1979/000196
Authority: WO
Inventors: A Stjaerne; B Stensson
Original assignee: Sab Ind Ab; A Stjaerne; B Stensson
Priority date: 1978-09-28
Filing date: 1979-09-28
Publication date: 1980-04-17
Also published as: JPS55500723A; FR2437330B3; GB2051982B; IT7925470A0; FR2437330A1; SE7810162L; GB2051982A; IT1122965B

Abstract

An Arrangement on a railway vehicle for enabling a block brake actuator (1) to coact with the tread of a corresponding wheel (2) irrespective of lateral movements thereof. The actuator (1) is suspended (by members 3-6) so as only to be laterally movable and is guided in the lateral direction by a member (7) moving together with the wheel (2) and/or by the wheel itself.

Description

A mounting arrangement for a railway vehicle brake actuator

Technical Field This invention relates to an arrangement on a rail¬ way vehicle for enabling a block brake actuator to coact with the tread of a corresponding wheel irrespec¬ tive of lateral movements thereof. Background Art A block brake actuator, normally including a slack adjuster and in such a case called a block brake unit, is normally rigidly mounted in the vehicle underframe in the vicinity of the corresponding wheel. This is satisfactory as long as the wheel or wheelset is only laterally movable to a limited extent.

However, in certain cases, for example if a rail vehicle without bogies is to negotiate small-radius curves, greater lateral wheelset movements must be allowed, which means that the brake block of the actuator can no longer be laterally rigid, as in such case proper brake applications cannot be guaranteed. The problem is thus, simply speaking, to allow the brake block to follow the lateral wheelset movements without lowering the efficiency of the brake actuator. Disclosure of the Invention

This problem is according to the invention solved in that the actuator is suspended so as only to be laterally, movable and is guided in the lateral direc- tion by a member moving together with the wheel and/or by the wheel itself.

In a practical embodiment the actuator suspension is of the parallelogram-type with mounting rods extend ing substantiallyparallel with each other and the actuator from the latter to attachments in the vehicle underframe, the rods being arranged only to allow lateral movements. In this way the brake actuator will be able to move laterally but not be angularly dis- placed, and the brake reaction forces will be transmit ted through the rods.

In a preferred embodiment each mounting rod con¬ sists of one or more flat strips piled together, but it is also possible to have a rigid rod suitably pivoted at each end to bring about only the lateral movement.

The lateral guiding in one direction may be accomplished'by the cooperation between the brake bloc and the wheel flange, but for the guiding in the opposite direction a pull means (a rod or wire) may connect two^"actuators at a wheelset with each other. Another possibility is to connect the actuator with a part (for example a motor or a bearing) moving laterally with the wheelset. Brief Description of the Drawing

The invention will be described in further detail below reference being made to the accompanying drawing, in which Fig. 1 is a side view of a preferred embodi¬ ment of an arrangement according to the invention and Fig. 2 is a top view of the same arrangement with a suspension link deleted.

Detailed Description of a Preferred Embodiment A conventional block brake actuator for a railway vehicle, in the shown case a brake unit including a slack adjuster, a hanger, a brake block holder and

OMPI brake blocks, has the designation 1 and is outlined with thick lines.

This brake actuator 1 is to be attached to a vehicle underframe, which for the sake of clarity is only indicated as fix-points for certain parts of the arrangement. The brake actuator 1 is to apply a brake force to a tread of a wheel 2 indicated in broken lines in Fig. 2. A wheelset including this wheel 2 may under service move laterally with respect to the vehicle underframe due to its suspension.

In the shown case the actuator 1 is provided with a mounting bracket 3 at its rear wall (opposite the brake blocks) .

Four mounting rods 4 - two above and two below the actuator - are attached to the bracket 3 and extend for¬ ward substantially parallel with each other and the actuator 1. They are attached to the vehicle underframe by means of attachments 5.

In the preferred embodiment each of these mounting rods 4 consists of a number of piled thin flat steel strips having a certain flexibility and thus allowing movements in the plane of Fig. 2 but not perpendicular thereto. Only one flat strip is also conceivable.

The mounting arrangement may be supplemented by a suspension link 6 only shown in Fig. 1. This link will take up brake forces and provide a further suspension from the underframe. It will allow actuator movements in the plane of Fig. 2.

Due to the existence of the link 6, having a certain arch height, a limited actuator movement perpendicular to said movements in the plane of Fig.2 must be allowed, which may be accomplished by the piled strips 4 having a limited width.

A lateral movement downwards in Fig.2 of the wheel 2 will cause the brake actuator 1 to move along with it due to the engagement between the wheel flange and the brake blocks. The mounting arrangement of the parallelogram-type will have to effect that the whol actuator will move laterally without any angular dis placement.

This means that irrespective of any lateral move ment downwards in Fig.2 of the wheel 2 the brake app cations from the actuator 1 will occur on the tread the wheel 2. A corresponding arrangement is provided for the brake actuator at the other wheel of the wheelset, causing that actuator to move in the opposite direct at lateral wheelset movements. If these two actuator are connected by means of a pull means 7 (a rod, wir or the like) they will move in parallel in both dire tions together with the wheelset.

In order to ensure a proper neutral position for the actuator 1 one or two helical tensions springs 8 may be arranged between the mounting bracket 3 and t vehicle underframe.

Many modifications are possible within the scope the appended claims. The mounting rods 4 may, for ex ple, be rigid rods pivotally attached at their respec tive ends so as only to allow movements in the plane of Fig.2. It would also be possible to have a somewha different practical arrangement of the rods 4, for example two rods above the actuator and only one belo or vice versa. Another important modification would b not to connect the two actuators on a common wheelset with each other by means of the pull means 7 but to connect each actuator with a part laterally moving to gether with the wheelset. If this connection is rigid no guiding contact between the wheel flanges and the brake blocks will occur. In the claims the suspension is said only to allow lateral movements. The word "only" is not meant to ex¬ clude the very limited movements perpendicular thereto if a link 6 is provided. To the contrary, the preferred embodiment with the piled strips 4 is advantageous in this respect.

Claims

CLAIMS :

1. An arrangement on a railway vehicle for enabli a block brake actuator to coact with the tread of a corresponding wheel irrespective of lateral movements thereof, characterized in that the actuator is suspended so as only to be latera ly movable and is guided in the lateral direction by a member moving together with the wheel and/or by the wheel itself.

2. An arrangement according to claim 1, characterized in that the actuator suspension is of the parallelogram- type with mounting rods (4) extending substantially parallel with each other and the actuator (1) from the latter to attachments (5) in the vehicle underframe, the rods being arranged only to allow lateral movement

3. An arrangement according to claim 2, characterized in that each mounting rod (4) consists of one or more fla strips piled together.

4. An arrangement according to claim 2, characterized in that each mounting rod (4) is a rigid bar pivotally journalled at the actuator (1) and the attachment (5) , respectively.

5. An arrangement according to claim 2, characterized by a pull means (7) connecting two actuators at a wheel¬ set with each other.

6. An arrangement according to claim 2, characterized by means connecting an actuator with a part moving laterally with the wheelset.

/_- WIP