AU602199B2 - Pressure control valve - Google Patents

Description

000 00 0 0 0 0 0 0 0 0 .0 00 0 000 00 00 00 0 0 0 0 0 t a 0 0 0 00 0 0 0 6O2~~'g

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Ludged: Complete Specification Lodged: Accepted: Published: Priority Related Art: APPLICANT'SREF.: C.A,P. of PI 09CO Name(s) of Applicant(s): G.S.A. INDUSTRIES (AUST.) PTY. LTD.

Address(es) of Applicant(s): C 51 Queens Street, Melbourne, Victoria, 3000f Australia.

Actual Inventor(s): MARCUS FERDINAND SCHOENHEIMER IThis clocument contains the amendments mad-- under "I and is, cor-rect for printing PHILLIPS, ORMONDE AND FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Metbourne, Australia, 3000 Address for Service is: Complete Specificatioii for the invention entitled: PRESSURE CONTROL VALVE The following statement is a funl description of this Invention, including the best method of performing it known to applicant(s): P1911/84 Thi s invention relates to valves for controlling pressure in a fluid flow system and the control may be for the purpose of either reducing or limiting the pressure in that system. It will be convenient to hereinafter describe the invention with particular reference to pressure limiting V valves, but that is not the only application of the invention.

Pressure control valves are generally of relatively bulky and complex construction. Furthermore, such valves i.sometimes requir' the inclusion of a one-way flow or .0 non-return facility, and that generally requires use of a V valve body different to that used for a valve not having such Va facility. Manufacturing costs are thereby increased.

It is an object of the present invention to provide a pressure control valve which is of relatively simple construction and which can incorporate a facility of the aforementioned kind without change to the form of its body or any other major component of the valve.

According to the invention there is provided a pressure control valve comprising a body having an inlet chamber, an cutlet chamber and a ?passage between the two chambers, a valve k .'.cseat located in the passage, a valve member located within the Sbody and being movable between a closed positibn in which it engages the valve seat to prevent fluid flow through said Spassage and an open position in which said flow is permitted, and biasing means urging the valve member towards said open position, the valve member being responsive to fluid pressure in said outlet chamber so as to move to said clcsed position when that fluid pressure is above a predetermined value, the outlet chamber being adapted to receive a non-return device therein for shutting off return flow through the pagsage.

An embodiment oE the invention is described in detail in the following passages of the specification which refer to the accompanying drawings. The drawings, however, are merely illustrative of how the invention might be put into effect so that the spec-ific form and arrangement of the various features as shown is not to be understood as limiting on the invention.

In the drawings: Figure I. shows a cross-sectional side view of a control valve according to the invention, without a non-return device located therein, and -2 ii t Figure 2 shows a similar view of a valve similar to that of Figure 1, but in which the valve is fitted with a non-return device.

The valve 1 shown in Figure 1 of the drawings, has inlet and outlet ports (numbered 2 and 3 respectively) arranged in coaxial relationship. The valve is formed of three parts which may be conveniently referred to as inlet, primary and outlet parts numbered 4, 5 and 6 respectively. That terminology, however, is not to be understood as imposing a strict relationship between each part as hereinafter described, or imposing a particular direction of flow through the valve 1 under all conditions of use.

The primary part 5 is of open-ended tubular form having o an internal transverse wall 7 between its ends. An inlet 0 0 0 o chamber 8 is defined between that internal wall and an end of a -o 0" the primary part, and an axial opening 9 is provided through o0 00 0 the internal wall 7 for a reason hereinafter made clear.

oooo. Each of the inlet and outlet parts is also preferably a tubular member which is arranged to be secured to a respective 20 end of the primary part 5 in coaxial relationship. The outlet 0 00 0000 part 6 may be open-ended to define an outlet passage o o S0oo therethrough, whereas the inlet member 4 is not, at least in the particular embodiment hereinafter described. Each of the 0 00 0o inlet and outlet parts may be serured to the primary part through cooperable screw-threads In the arrangement shown, the inlet part 4 has an o00 internal passage extending from its outer end 11 to an end ooo wall 12 at its inner end. That inner end is contained within 0 0 the inlet chamber 8 of the primary part 5, and a plurality of transfer ports extend 13 through the side wall of the inlet part 4 to provide communication between the passage of that part, and the inlet chamber 8. A resilient disc or annulus 14 is provided at the inner end of the inlet part to form a valve seat which functions as hereinafter described.

A valve member 15 is mounted within the primary part so as to be disposed between the inlet and outlet parts and so as to be movable towards and away from the valve seat 14. The valve member 15 preferably has a stepped configuration including a stem section 16 which is slidably located in the aforementioned opening 9 through the internal wall 7, and an 3 I r enlarged head section 17 which is slidably mounted in the portion of the primary part bore 18 extending between the internal wall 7 and the outlet part 6. That head section 17 is at one end of the stem section 16 and divides the aforementioned bore portion 18 into a spring chamber 19 and an outlet chamber 20. Any suitable sealig means may be provided between each of those valve member sections and the surfaces over which they move, and in the preferred embodiment shown 'O'.ring seals 22 sere as the sealing means.

An axial bore 23 extends completely through the valve member 15, and that bore 23 is enlarged (as shown at numeral 24) at the head section end for a reason hereinafter made clear. The end 25 of the stem section 16 remote from the head section 17 may be chamfered or otherwise formed to provide a relatively narrow annular zone for engagement with the aforementioned valve seat 14. Such engagement limits movement of the valve member in one direction, and movement in the opposite direction may be limited by engagement of the valve member with an inwardly facing end surface 26 of the outlet part.

A coil compression spring 27 is contained within the spring chamber 19 and acts between the head section 17 and the internal wall 7 to normally urge the valve member 15 away from the valve seat 14. An air bleed hole 28 may be provided through an external wall of that chamber to facilitate i movement of the valve member Under normal conditions of operation, fluid pressure within the outlet chamber 20 acts against the piston section 17 so as to apply a closing force to the valve member 15. If that pressure is high enough, the valve member 15 will move to engage the valve seat 14 and thereby close the valve. When the outlet chamber pressure falls below a particular level, however, the spring 27 force predominates and therefore causes the valve member 15 to move away from the valve seat 14 to open the valve. As a consequence of such movement, fluid within the inlet chamber 8 is able to enter and pass through the axial passage 23 of the valve member 15 and thereby enter the outlet chamber The arrangement is such that the fluid pressure within the valve body imposes a net closing force on the valve member 4 I P That arises because the surface area of the valve member which is exposed to pressure within the outlet chamber is larger than the surface area exposed to pressure within the inlet chamber 8. In that regard, the relevant surface area is that of surfaces arranged transverse to or angularly relative to the longitudinal axis of the valve member. The closing force imposed by fluid pressure is countered by the spring force so that closing will not occur below a particular pressure, which can be predetermined. The strength of the spring 27 may be altered to alter the closing force required to close the valve 1.

As shown in Figure 2, a one-way or non-return facility can be easily incorporated in a valve as described with reference to Figure 1. In Figure 2 of the drawings, parts similar to the parts described with reference to Figure 1 are given like numerals. Outlet part 6a in Figure 2 has said non-return facility incorporated therein. The non-return facility shown includes a closure member 30 which is located within the outlet chamber 20 and is arranged to close the adjacent end of the axial passage 23 through the valve member o 15. The closure member 30 includes a spindle 31 which is slidably mounted in a support member 32 which is mounted o o8 within outlet part 6a. A head portion 34 at one end of the oo 84 S spindle 31 is engageable with a seat formed around the enlarged opening 24 of the aforementioned axial passage 23. A resilient sealing disc 35 is located on the head portion 34 so as to be engageable with the valve seat.

The support member 32 is located within the adjacent end portion of the outlet passage through the outlet part 6 and can be secured against relative movement in any appropriate fashion. That member has a central boss 36 which slidably receives the spindle and a plurality of openings 37 located radially outwardly of that boss through which the outlet passage 3 and the outlet chamber 20 communicate. A spring 38 acts between the support member 32 and the head portion 34 to normally urge the closure member 30 into a flow blocking position.

The outlet part 6a shown in Figure 2 is somewhat different to the outlet part 6 shown in Figure 1 of the drawings in that said part 6a includes the non-return -i facility. The outlet part 6a may be used in the valve of Figure 1 and, likewise, the outlet part 6 shown in Figure 1 may be used in the valve of Figure 2.

In the embodiment shown in Figure 2 a stop element is provided within the outlet chamber 20 between the outlet part 6a and the valve member 15 so as to limit travel of the valve member 15 away from its valve seat 14. That element in this embodiment comprises a circlip or the like snap engaged within a circumferential groove provided in the wall of the outlet chamber A valve 1 as described is open to substantial variation. By way of example, the valve seat of the inlet part 4 and the cooperating portion of the valve member 1.5 may be formed by or include substantially complementary tapered surfaces. A resilient O-ring or other annular member may be attached to one of those surfaces so as to be engageable by the other in the manner described in relation to Figures 4 to 6 of Australian Patent Application No. 62393/86.

It will be apparent from the foregoing description that a valve according to the invention is of very simple construction and can be manufactured at a relatively low cost. It will be further apparent that the valve is able to accept a one-way or non-return facility without requiring alteration to its major components.

Finally, it is to be understood that various zlterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the. spirit or ambit of the 29 invention.

6

Claims (7)

1. 2. A valve according to claim i, wherein said valve member is in the form of a piston which is axially slidable within a cylindrical bore of said body for said movement towards and away from said closed position, the face at one end of said piston is arranged to be reacted on by fluid pressure within said outlet chamber, and the end of the piston opposite said one end is arranged to engage a valve seat when the valve member is in said t closed position and thereby prevent said communication between the chambers.
2. 3. A pressure control valve comprising a body having an inlet chamber, an outlet chamber and a passage between the two chambers, the body being formed by a primary part in conjunction with either an outlet part or a selected one of a plurality of outlet parts; a valve seat and a valve member both located within the body, the valve member being movable between a closed position in which it engages the valve seat to prevent fluid flow through the passage and an open position in which said fluid flow is permitted, and biasing means urging the valve member towards said open position, the valve member being responsive to fluid pressure in the outlet chamber so as to move to said closed position when that fluid pressure is above a predetermined value; an end portion of the valve member adjacent the outlet chamber forming a first part of a non-return facility, for preventiiig fluid flow from the outlet chamber to the inlet chamber, and a second part of the non-return facility being removably 000. locatable within the outlet chamber such that, if o present, the second part of the non-return facility is 0 0 brought into co-operative association with the first part o s 25 of the non-return facility when the or a selected outlet part of the body is attached to the primary part of the body
3. 4. A valve according to claim 3, wherein the body comprises a cylindrical bore and the valve member comprises a piston, slidable in the cylindrical bore between said open and closed positions, with at least one face at one end of the piston facing towards the outlet chamber so as to be reacted on by fluid pressure in the outlet chamber. r I ~i A valve according to claim 2 or claim 4, wherein a tubular member or inlet part is arranged substantially coaXial with said cylindrical bore and is removably attached at one end of said body so as to intrude into said inlet chamber, and said valve seat is formed at an end of said tubular member or inlet part which is located within said inlet chamber.
4. 6. A valve according to any one of claims 2, 4 o~r wherein the piston has a head portion at said one ei~d thereof and a stem which is of smaller diameter than, the head portion extending axially from said head portion, said passage means includes a passage extending axially through said piston, said head portion is slidably mounted in sai(i cylindrical bore, and said stem is slidably mo.unted in an opening formed through a transverse wall of said body.
5. 7. A valve according to any preceding claim, wherein said otitlet chambcr is fcrmed in part by the or each of the outlet parts, adaptor or substitute adaptor. 240 8. A valve according to any preceding claim, wherein said first part of the non-return facility includes an annular valve iz-ct which surrounds an end of said passage means, and said further or second part of the non-return facility is engagable with said annular Valve seat to prevent said communication through said passage means.
6. 9. A valve according to claim 8, whariein said further or second part of the non-return facility includes a closure memtber and closure member biasing means which uirges said cl~osure member into engagement with said annular valve seat, said closure member biasing means acting between said closure member and said or said selected outlet part, adaptor or substitute adaptor. A valve accordingq to claim 9, wherein slid closure member includea a closure disc, which is engagab,e wit$ said annular valve seat, and a extending axially w
7. 11. A pressure control valve substantially as hereinbefore described with reference to either one of the accompanying drawings. -T- DATED: 1 May 1990 PHILLIPS ORMONDE FITZPATRTCK Attorneys for; GSA INDUSTRIES (AUST.) PTY. LTD, VW Aci '7 0, t C IAN .4h~ -10