GB2133504A - Fluid pressure control valve - Google Patents

Abstract

A fluid pressure control valve particularly for a vehicle braking system, using a resiliently supported balanced rigid beam. The beam 10 is supported by a vertically arranged leaf spring 11 so that the beam is capable of angular movement. The spring 11 is clamped at its lower end between a block (12) Fig. 2, (not shown) and plate (13), the block (12) being attached to the beam. At its upper end the leaf spring 11 is clamped between block (15) and plate (16) attached to the fixed structure. One end of the beam controls a ball valve and is deflected by an electromagnet. These are counterbalancing weights and springs. The angular movement is small and with this vertical spring the space between the blocks is kept very small (0.4mm). <IMAGE>

Description

SPECIFICATION Fluid pressure control valves This invention relates to afluid pressure control valve particularly suitable for use in installations such as braking systems for vehicles which may be subject to violent mechanical vibrations or shock.

In U.K. Patent Specification 2 122A there is described and claimed a fluid pressure control valve having a restricted fluid flow inlet port, a vent port provided with a variable throttle arrangement and a fluid pressure outlet port connected to a region between the inlet port and the vent port, the variable throttle arrangement comprising a force-applying means carried to one side of a support point of a substantially rigid beam which is resiliently supported for angular movement about said support point and having counter-balancing mass at the other side thereofto render the valve substantially insensitive to shockforces acting through said support point.

The preferred resilient support described in that specification is a strip of spring metal arranged horizontally at right angles to the beam so that its free ends extend out beyond the beam on eitherside ofthe beam. The strip of spring metal is clamped to the beam between blocks and its free ends are clamped between two pairs of blocks straddling the beam and attached to fixed structure. Thus the horizontal spring strip acts as a torsion bar two allow angular movement ofthe beam.

An object of this invention is to provide an alternative method of supporting the beam so as to allow this angular moement to occur, the alternative method resulting in a more compact and less expensive construction.

In accordance with the present invention the resilientsupportforthe beam is in the form of a vertically arranged leaf spring which has one end (preferably its lower end) clamped to a block attached to the rigid beam and its other end (preferably its upper end) clamped to a block attached to rigid structure.

With this arrangement the distance between the upper and lower block may be very small (of the order of0.4mm) becausetheamountofangularmovement required ofthe beam is also very small (0.17O).

The spring may be held on to the block by a second block or by a plate with fixing such as screws or rivets extending through the assembly.

In the accompanying drawings: Fig. lisa section through an electro-pneumatic convertervalve, similar to the one shown in Fig. 1 of U.K. Patent Specification 2076 1 22A, but modified in accordance with the present invention; and Fig. 2 is an enlarged isometric view of the modified beam supporting arrangement of this invention.

In Fig. 1 is shown a balanced rigid beam 10 supported byaverticallyarranged leafspring 11 so thatthe beam is capable of angular movement. The spring 11 (Fig. 2) is clamped at its lower end between a block 12 and a plate 13. The block 12 is attached to beam 10 by scres 14. The uper end of leaf spring 11 is clamped between a block 15 and a plate 16which are in turn attached to fixed structure e.g. by welding block 15to a housing 17 (Fig. 1) of an electromagnet assembly 18.

The beam carries, atone end, the coil 19 of electromagnetic assembly 18 and the lower side of this end ofthe beam controls a ball alve 20. The beam is balanced byweights 21 at the ends with a counter-balancing spring 11 below the bam. The force exerted by spring 22 is adjustable means of an adjuster 23.

The remaining details and the operation of this electra-pneumatic converter are very sirnilarto that described in Patent Specification 1 076 22A and will not be described herein except by reference to the specificatfo n.

It will be seen that, because the angular movement ofthe beam is-maII,the space between the upper and lower blocks is small, of the order of 0.4mrn-and thewholeassemblyis more compact, has less parts and is less expensive than the arrangement shown in specification 2 22A.

1. Afluid pressure control valve having a restricted fluid fiow inlet port, a vent port provided with a variable throttle arrangement and a fluid pressure outlet port connected to a region between the inlet port and the vent port, the variable throttle arrange mentcomprising aforce-applying means carried to one side of a support point of a substantially rigid beam which is resiliently supported for angular movement about said support point and having counter-balancing mass at the other side thereof to render the valve substantially insensitive to shock forces acting through said support point, in which the resilientsupportforthe beam is in the form of a vertically arranged leaf spring which has one end clamped to a block attached to the rigid beam and its other end clamped to a block attached to rigid structure.

2. Afluid pressure control valve according to Claim 1 and in which the lower end of the leaf spring is clamped to the blockandthe upper end of the leaf spring is clamped to the rigid structure.

3. Avalve according to Claim 1 orClaim2andin which the distance between the upper and lower blocks isofthe orderof 0.4mm and the angular movement required ofthe i red of the bam is ofthe order of 0.17o.

4. Avalve according to any of Claims 1 to 3 and in which the spring is held on to the block by a second block or by a plate with fixing such as screws or rivets extending through the assembly.

5. Afluid pressure control valve according to any preceding Claim incorporated in a vehicle braking system.

6. Afluid pressure control valve substantially as hereinbefore particularly described and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fluid pressure control valves This invention relates to afluid pressure control valve particularly suitable for use in installations such as braking systems for vehicles which may be subject to violent mechanical vibrations or shock. In U.K. Patent Specification 2 122A there is described and claimed a fluid pressure control valve having a restricted fluid flow inlet port, a vent port provided with a variable throttle arrangement and a fluid pressure outlet port connected to a region between the inlet port and the vent port, the variable throttle arrangement comprising a force-applying means carried to one side of a support point of a substantially rigid beam which is resiliently supported for angular movement about said support point and having counter-balancing mass at the other side thereofto render the valve substantially insensitive to shockforces acting through said support point. The preferred resilient support described in that specification is a strip of spring metal arranged horizontally at right angles to the beam so that its free ends extend out beyond the beam on eitherside ofthe beam. The strip of spring metal is clamped to the beam between blocks and its free ends are clamped between two pairs of blocks straddling the beam and attached to fixed structure. Thus the horizontal spring strip acts as a torsion bar two allow angular movement ofthe beam. An object of this invention is to provide an alternative method of supporting the beam so as to allow this angular moement to occur, the alternative method resulting in a more compact and less expensive construction. In accordance with the present invention the resilientsupportforthe beam is in the form of a vertically arranged leaf spring which has one end (preferably its lower end) clamped to a block attached to the rigid beam and its other end (preferably its upper end) clamped to a block attached to rigid structure. With this arrangement the distance between the upper and lower block may be very small (of the order of0.4mm) becausetheamountofangularmovement required ofthe beam is also very small (0.17O). The spring may be held on to the block by a second block or by a plate with fixing such as screws or rivets extending through the assembly. In the accompanying drawings: Fig. lisa section through an electro-pneumatic convertervalve, similar to the one shown in Fig. 1 of U.K. Patent Specification 2076 1 22A, but modified in accordance with the present invention; and Fig. 2 is an enlarged isometric view of the modified beam supporting arrangement of this invention. In Fig. 1 is shown a balanced rigid beam 10 supported byaverticallyarranged leafspring 11 so thatthe beam is capable of angular movement. The spring 11 (Fig. 2) is clamped at its lower end between a block 12 and a plate 13. The block 12 is attached to beam 10 by scres 14. The uper end of leaf spring 11 is clamped between a block 15 and a plate 16which are in turn attached to fixed structure e.g. by welding block 15to a housing 17 (Fig. 1) of an electromagnet assembly 18. The beam carries, atone end, the coil 19 of electromagnetic assembly 18 and the lower side of this end ofthe beam controls a ball alve 20. The beam is balanced byweights 21 at the ends with a counter-balancing spring 11 below the bam. The force exerted by spring 22 is adjustable means of an adjuster 23. The remaining details and the operation of this electra-pneumatic converter are very sirnilarto that described in Patent Specification 1 076 22A and will not be described herein except by reference to the specificatfo n. It will be seen that, because the angular movement ofthe beam is-maII,the space between the upper and lower blocks is small, of the order of 0.4mrn-and thewholeassemblyis more compact, has less parts and is less expensive than the arrangement shown in specification 2 22A. CLAIMS

1. Afluid pressure control valve having a restricted fluid fiow inlet port, a vent port provided with a variable throttle arrangement and a fluid pressure outlet port connected to a region between the inlet port and the vent port, the variable throttle arrange mentcomprising aforce-applying means carried to one side of a support point of a substantially rigid beam which is resiliently supported for angular movement about said support point and having counter-balancing mass at the other side thereof to render the valve substantially insensitive to shock forces acting through said support point, in which the resilientsupportforthe beam is in the form of a vertically arranged leaf spring which has one end clamped to a block attached to the rigid beam and its other end clamped to a block attached to rigid structure.

2. Afluid pressure control valve according to Claim 1 and in which the lower end of the leaf spring is clamped to the blockandthe upper end of the leaf spring is clamped to the rigid structure.

3. Avalve according to Claim 1 orClaim2andin which the distance between the upper and lower blocks isofthe orderof 0.4mm and the angular movement required ofthe i red of the bam is ofthe order of 0.17o.

4. Avalve according to any of Claims 1 to 3 and in which the spring is held on to the block by a second block or by a plate with fixing such as screws or rivets extending through the assembly.

5. Afluid pressure control valve according to any preceding Claim incorporated in a vehicle braking system.

6. Afluid pressure control valve substantially as hereinbefore particularly described and as illustrated in the accompanying drawings.