NZ264876A - Lift valve closure member having annular closure seal held by groove innermost wall having return portion - Google Patents

Description

0 4 8 7 6 Patents Form# 5 Priority Date{s): Complete Specification Filod: Class: |..3.ferVfctej Publication Date:... 15.jm.1996...

P.O. Journal No: V C>V NKW7.FAT.Alsm * £. 1 *? uo-y *• f Patents Act 1953 \A > X£eenJtV COMPI.ETE SPFrtCTrATin Improved Valve Closure Member We, CON-SERV CORPORATION (AUSTRALIA) PTY LTD, an Australian company, of 5 Noble Street, Wilston, Brisbane, Queensland 4051, Australia, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: The following page is numbered "la" PF05JWP FEE CODE -1050 4 8 76 la This invention relates to a closure member for fluid valves. In particular the invention relates to an improved closure member for water taps.

Fluid valves of the lift type typically 5 comprise closure members, also called "jumper valves" or "tap seals", consisting of a disc having a stem engaged by a spindle. Rotation of the spindle in one direction drives the disc against a seat in the valve to close off fluid flow while rotation of the spindle in the opposite 10 direction allows fluid to flow through the valve by fluid pressure lifting the disc off the seat. To improve the seal between the disc and the seat, washers or annular rings of elastomeric material are fitted to the face of the disc.

A disadvantage of existing valve closure members is that wearing of the disc, elastomeric material fitted to the disc, or the seat, results in leakage of fluid past the closure member when the valve is closed. Wearing of closure member components and the seat is 20 exacerbated by overtightening of the spindle to close the valve.

The closure member disclosed in Australian Patent No. 567,174 is an example of an attempt to overcome the problem of valve leakage. While the 567,174 25 closure member improves the seal between the disc and seat, and includes protection against overtightening, the closure member cannot compensate for leakage due to misalignment of the disc and seat because of wear in the valve spindle or faulty initial manufacture. 30 Another problem with lift valves is "hammering" in the fluid system when a valve is closed, particularly when the valve is closed abruptly. Hammering can result in damage to the fluid system components. Furthermore, the noise associated with hammering is usually annoying. 35 Anti-hammer closure members are known in which resilient means are interposed between the stem face of the disc and the spindle housing. The resilient means counteracts the effect of fluid back pressure. However, 2 0 4 8 7 6 there is no known closure member which overcomes the problem of hammering and provides improved sealing characteristics.

It is an object of this invention to provide a 5 lift valve closure member with improved sealing characteristics. It is a further object of this invention to provide a lift valve closure member which reduces or eliminates hammering in the fluid system when the valve is closed.

In one aspect, this invention provides a lift valve closure member, the closure member having: a stem; a disc having a first face to which the stem is pivotally attached and a second face having an annular 15 groove therein, the groove having a radially innermost wall; and an annular seal disposed within the annular groove; wherein a portion of the annular seal projects beyond 20 the second face and wherein the innermost wall of the groove has a return portion for retaining the seal within the annular groove.

The pivotal attachment of Lne member to the disc is advantageously by way of a ball at an end of the 25 stem which is engaged in a corresponding socket in the disc. Any pivotal attachment can be used however, provided that the disc can be tilted from perpendicular to the stem axis to an angle of at least 10° in any plane.

The stem may be received by an aperture in the valve spindle. Two or more rings of elastomeric material can be fitted around the stem to improve location of the stem in the spindle aperture. Typically, annular grooves are provided in the stem to receive the rings of 35 elastomeric material.

The outer edges of the disc are preferably chamfered to reduce turbulence in fluid flowing through the valve when open. Because of the presence of the 3 2 6 4 8 7 6 return portion projecting from the innermost wall of the annular groove, the second face is stepped. The annular groove can ie of any cross-sectional shape but is typically vee-shaped.

The annular seal is typically of circular cross-section and is made of an elastomeric material. Suitable elastomeric materials include rubber, neoprene, nitrile rubber and silicones. The preferred elastic material is nitrile rubber.

In a preferred embodiment, a plurality of apertures are provided extending between the annular groove in the second face of the disc and the first face of the disc. The apertures reduce or eliminate hammering in the fluid system when the valve is closed. It is 15 believed that back pressure is absorbed by distension of the annular seal into the apertures. The number of apertures in the disc depends on the size of the valve in which the closure member is fitted and the pressure of the fluid system. In a valve such as a domestic water 20 tap, eight apertures are provided.

In operation, the annular seal engages a chamfered edge of a seat in the body of a valve to which the closure member is fitted to close the valve. As the disc can pivot on the stem, misalignment between the 25 valve spindle and the seat is compensated for ensuring continued leak-proof closure of the valve with prolonged use. Furthermore, the annular seal cannot be damaged by overtightening of the closure member as the periphery of the second face of the disc can abut the surface of the 30 seat outside of the chamfered portion thus preventing further compression of the seal.

To provide a seat suitable for engaging the closure member of this invention there is provided in another aspect a valve body insert, the valve body insert 35 including a cylindrical member having an axial aperture therethrough, wherein at least a portion of the aperture at an end of the cylindrical member is circular and the edge of the aperture in the circular portion is 264876 4 chamfered.

The valve body Insert can be fitted to a valve as a replacement for an existing damaged valve seat or as an alternative to known seats. The chamfered edge of the 5 insert receives the annular seal of the closure member when the valve is closed. The end of the cylindrical „ member between the chamfered edge and the periphery of the member provides a surface against which the periphery of the second face of the closure member disc can abut 10 preventing over-compression of the annular seal.

Advantageously, the cylindrical member is externally threaded and is fitted into a correspondingly threaded hole in the valve. To facilitate installation of the insert, the axial aperture can have a region for 15 engaging a tool. Typically, the region is of hexagonal cross-section and engages a tool such as an "Allen wrench".

To seal the threaded insert into the valve, a collar can be provided at the end of the cylindrical 20 member adjacent the chamfered edge of the aperture and a sealing washer interposed between the collar and the outer edge of the threaded hole in the valve.

Advantageously, the portion of the aperture at the end of the cylindrical member opposite the chamfered 25 edge is similarly circular and has a constant flow regulator valve fitted therein.

The closure member components and the valve body insert can be made from any suitable material. Typically, the material is a metal or a plastic. The 30 preferred material for the closure member stem and valve body insert is dezlncation resistant (DR) brass, The preferred material for the closure member disc is acetal plastic.

In a further aspect of the invention, there is 35 provided a valve including the valve closure member described above.

In a still further aspect of the invention, there is provided a valve including the valve closure 26 4 876 member and valve body insert described above.

So that the invention may be more fully understood, particular examples of the closure member and valve body insert will now be described with reference to 5 the following drawings in which: Figure 1 is a cross section of the valve closure member and valve body insert; and Figure 2 is an exploded view of the valve closure member and valve body insert with some components 10 in cross-section.

Referring now to Figure 1, there is shown valve closure member 1 and valve body insert 2. The closure member 1 consists of stem 3 and disc 4. The stem 3 is pivotally attached to disc 4 via ball 5 engaged by socket 15 6 in first face 7 of the disc. Two elastomeric rings 8 and 8a are fitted about stem 3 in grooves 9 and 9a. Disc 4 has a second face 10 having an annular groove 11 therein. An "0-ring" elastomeric seal 12 is fitted into groove 11. Edges 13 and 14 of first face 7 and second 20 face 10 respectively are chamfered. A plurality of apertures in the form of circular holes, one of which is shown at 15, are provided between groove 11 and first face 7.

Valve body insert 2 consists of a cylindrical 25 member 16 having an aperture 17 therethrough. The aperture has a circular cross section in the region 18 adjacent the closure member and the edge 19 of the aperture is chamfered at 45°. Cylindrical member 16 has a collar 20 adjacent chamfered edge 19. Cylindrical 30 member 16 is externally threaded as shown ait 21 and a sealing washer 22 fitted between thread 21 and collar 20. A constant flow regulator valve 23 is fitted into a portion 24 of circular cross-section in aperture 17.

Referring now to Figure 2, there can be seen in 35 exploded view stem 3 and disc 4 of the closure member. Ball 5 on the stem is shown which fits into socket 6 in first face 7 of disc 4. Elastomeric rings 8 and 8a can also be seen together with grooves 9 and 9a. Ends of the 26 48 76 J35 O -f.\ apertures between the annular groove 11 of Figure 1 and first face 7 can be seen, one of which is shown at 15a. Annular seal 12 is shown in partial cross-section.

The lower part of Figure 2 depicts the valve body insert in perspective. Cylindrical member 16, circular region 18, chamfered edge 19 collar 20 and thread 21 can be seen together with sealing washer 22 and constant flow regulator valve 23. A region 25 of hexagonal cross-section can be partially seen in aperture 17 of the cylindrical member.

From the drawings, it can be appreciated that valve body insert 2 is fitted into a threaded hole in the body of a valve utilising the closure member. Region 25 can be utilised to install the insert by fitting an appropriately shaped tool into the region. Sealing washer 22 ensures leak-proof sealing of the insert into the valve body.

It can be further seen from the drawings that closure member 1 closes off fluid flow through a valve by mating of annular seal 12 with a chamfered edge of a valve seat, or the chamfered edge 19 of insert 2 in a valve to which the insert is fitted. If the stem axis is not aligned with the axis of the seat or the axis of aperture 17 of insert 2, pivoting of the disc 4 on stem 3 nevertheless allows complete sealing of the valve.

The stem 3 of the closure member 1 and cylindrical member 16 plus collar 20 of insert 2 are preferably made from brass. The disc 4 of closure member 1 is preferably acetal plastic. Rings 8 and 8a, annular seal 12 and sealing washer 22 are preferably nitrile rubber.

It will be appreciated by one skilled in the art that many changes and modifications can be made to the closure member and valve body insert exemplified above without departing from the ambit of this invention which is limited only by the appended claims.

■\ MAY 1996 26 4 8 76

Claims (8)

1. WHAT WE CLAIM IS: 1. A lift valve closure member, said closure having: a stem; a disc having a first face to which said stem is pivotally attached and a second face having an annular groove therein, the groove having a radially innermost wall; and an annular seal disposed within said annular groove; wherein a portion of said annular seal projects beyond the second face and wherein the innermost wall has a return portion for retaining the seal within the groove.
2. 2. The closure member of claim 1 wherein said pivotal attachment of said stem to said disc is by a ball at an end of said stem engaged in a corresponding socket in said disc.
3. 3. The closure member of claim 1 or claim 2 wherein two or more annular grooves are provided along said stem to receive elastomeric rings.
4. 4. The closure member of any one of claims 1 to 3 wherein the edges of said disc are chamfered.
5. 5. The closure member of any one of claims 1 to 4 wherein said annular groove in said second face of said disc has a vee-shaped cross section portion.
6. 6. The closure member of any one of claims 1 to 5 wherein a plurality of apertures are provided between said first face of said disc and said annular groove in said second face of said disc.
7. 7. The closure member of claim 6 wherein eight apertures are provided.
8. 8 . A lift valve assembly comprising a closure member according to any one of claims 1 to 7 and a valve body insert having a cylindrical member with an axial aperture therethrough, wherein at least a portion of said aperture *^t , :an end of said cylindrical member is circular and the dge of said aperture in said circular portion is amfered. i The lift valve assembly of claim 8 wherein said to 26 4 8 76 8 cylindrical member of said valve body insert is externally threaded. 10. The lift valve assembly of claim 8 or claim 9 wherein a collar is provided at the end of said cylindrical 5 member of said valve body insert adjacent said chamfered aperture edge. 11. the lift valve assembly of claim 10 wherein a sealing washer is interposed between said collar of said valve body insert and the valve body into which said insert 10 is fitted. 12. The lift valve assembly of any one of claims 8 to 11 wherein said aperture of said valve body insert comprises a region for receiving an installation tool. 13. The lift valve assembly of claim 12 wherein said 15 region of said valve body insert for receiving an installation tool has an hexagonal cross-section. 14. A valve closure member substantially as hereinbefore described with reference to the accompanying drawings. 20 15. A lift valve assembly substantially as hereinbefore described with reference to the accompanying drawings. 16. A valve including the valve closure member of any one of claims 1 to 7 or 14. 25 17. The valve of claim 16 wherein closure of said valve causes the periphery of said closure member second face to abut the surface outside of a chamfer at the inner edge of an annular seat in said valve and prevents over compression of said annular seal in said second face. 30 18. A valve including the lift valve assembly of any one of claims 8 to 13 or 15. 19. The valve of claim 18 wherein closure of said valve causes the periphery of said closure member second face to abut the surface outside of said chamfered edge of 35 said valve body insert inner edge to prevent over ^ t t compression of said annular seal in said second face. V The valve according to any one of claims 16 to 19 J wrarein said valve is a water tap. ^10 MAY 1996 Tjjf James W Piper Co Attorneys For: . w Con-Serv Corporation (Australia) Tty Ltd V