GB2261472A

GB2261472A - Mounting actuators

Info

Publication number: GB2261472A
Application number: GB9124339A
Authority: GB
Inventors: A R Turner
Original assignee: Bendix Ltd
Current assignee: Honeywell UK Ltd
Priority date: 1991-11-15
Filing date: 1991-11-15
Publication date: 1993-05-19
Also published as: GB9124339D0

Abstract

In a stud-mounted compressed air brake actuator which has mounting studs 16 that project from a non-pressure wall at one end of the actuator housing, the studs are carried on an internal plate 21 which is manually depressable against a spring 13 from outside to enable the studs to be positioned to project through selected apertures. This enables adaptable mounting of the actuator with conveniently positioned control ports. <IMAGE>

Description

BRAKE ACTUATORS.

This invention relates to fluid pressure operable brake actuators especially but not exclusively compressed air operable brake actuators.

Compressed air operable brake actuators are well known in which a fluid pressure operable dish-shaped diaphragm is provided with a peripheral bead clamped between a non-pressure part and a pressurable part of an actuator housing. The non-pressure part is provided with mounting means for mounting on the chassis or axle of a vehicle and the pressurable part is provided with a fluid pressure input port. Typically the mounting means comprises two or more screw-threaded studs and nuts by which this actuator is secured in position in pre-positioned holes.Different vehicles have different requirements for the relative orientation of the pressure input port relative to the mounting studs and it has become common but undesirable practice, when fitting replacement actuators to achieve such positioning by temporarily loosening a clamping ring which clamps the two housing parts and to permit the desired orientation of pipe connection in any given installation. However such disturbance of factory-fitted clamp rings is highly undesirable.

The object of the present invention is to provide a compressed air operable actuator in which relative positioning of mounting means and the pressure input ports can be achieved without relatively rotating such body parts.

According to the present invention there is provided a fluid pressure operable actuator comprising a housing defining a fluid pressurable chamber and a pressure input port a non-pressurable chamber and a fluid pressure responsive diaphragm forming a movable wall between said chambers, said non-pressurable chamber having an end wall through which an actuator output member extends and mounting means comprising a plate like member carrying at least two mounting studs which extend through selected apertures of said end wall for mounting the actuator, said plate being inwardly manually depressable against a light spring for selectively positioning said studs in alternative apertures.

In order that the invention may be more clearly understood and readily carried into effect the same will be further described by way of an example with reference to the accompanying drawing of which1 Fig. I illustrates a combined pneumatic service diaphragm brake actuator and spring brake actuator, including a mounting arrangement in accordance with the invention and Fig. 2 illustrates an alternative view of a plate-like member and a tool to be referred to.

Referring to Fig. I of the drawings the combined compressed air operable service brake actuator and spring brake actuator comprises a middle body casting denoted by reference 1. Such casting is formed by pressure die casting and provides a dividing wall 2 between a pressure chamber 3 of the service brake portion and a pressure chamber 44 of the spring brake portion. These chambers communicate via respective passages (not shown)0 with twin input ports denoted at 5, 6 formed on the outside of the casting.

On the left hand end of the casting 1 as seen in the drawing, there is formed a peripheral lip portion 6 to receive a pressed steel clamping ring 7 to clamp the peripheral bead 9 of a dish-shaped diaphragm 10 between a lip 6 and a corresponding lip 8a of a non-pressure portion 8 of the service actuator portion. Diaphragm 10 acts against a push plate 11 carrying the screw-threaded actuator output rod. The push plate is urged towards the normal rest condition as shown by means of a light conical return spring 13 captive between the push plate and the non-pressure portion of the actuator body, the actuator rod extending outwardly through a central aperture 144 thereof for connection to a brake mechanism of a vehicle.

The wider end of the conical spring 13 is located by means of an annular locating plate 20 resting against a circular intermediate stud-mounting plate 21 which carries two diametrically positioned actuator mounting studs 16 as shown in the perspective view of Fig. 2. The stud mounting plate 21 is retainable in position by the spring 13 with the studs projecting through corresponding apertures 23 of the non-pressure plate. A plastic or rubber contaminant excluder 24 is slidingly carried between plate 20 and plate 21 as shown.

The aperture 14 of the non-pressure plate is somewhat larger than the central aperture 25 of the plate 21 to permit a tubular tool 26 as shown in Fig. 2 to be urged against plate 21 -to enable it to be pressed inwards against the spring 13 to permit it to be reoriented and released with the studs in alternative diametrically located apertures of the non-pressure plate. The tool 26 is provided with keys or dogs 27 which locate in slots 28 of plate 21 as also shown in Fig. 2 to facilitate rotation by the tool 26 On the right hand end of the middle casting 1, as seen in Fig. 1 of the drawing, there is a peripheral lip portion 31 to retain a rolled end 32 of a pressed steel cylinder 33 of the spring brake actuator portion. The rolled end 32 and lip 31 trap a retainer ring 31a in known manner and a seal 34 is provided between the casting 1 and the cylinder 33.Axially sealingly slideable in the bore 35 of cylinder 33 there is provided a piston 36 with an annular seal and piston guide assembly 37. A power spring 38 is trapped under compression between the piston 36 and a spring support member the right hand end of the cylinder 33, this spring 38 being shown in its fully compressed condition as it is in use with full pressure applied to the chamber 4. The piston 36 is formed with a central recess which accommodates seal 44 and a screwed-in spring actuator output member 400 which extends through a axial seal arrangement 41 in the central wall 2 to abut the right hand side of diaphragm 10. The output member 40 is tubular to accommodate and enclose the head 42 of a wind-off bolt 43. The wind-off bolt which is normally in the position shown, is carried in a threaded member 46 captive in the right hand end wall of the cylinder and is provided with a keyed-on nut 47. A snap-on end cover 48 has an apeture which affords access to the nut 47.

Claims

CLAIMS 1. A fluid pressure operable actuator comprising a housing defining a fluid pressurable chamber and a pressure input port a non-pressurable chamber and a fluid pressure responsive diaphragm forming a movable wall between said chambers, said non-pressurable chamber having an end wall through which an actuator output member extends and mounting means comprising a plate like member carrying at least two mounting studs which extend through selected apertures of said end wall for mounting the actuator, said plate being inwardly manually depressable against a light spring for selectively positioning said studs in alternative apertures.
2. A fluid pressure operable brake actuator substantially as described with reference to the accompanying drawing.