AU2008252027A1

AU2008252027A1 - A valve

Info

Publication number: AU2008252027A1
Application number: AU2008252027A
Authority: AU
Inventors: Troy David Wagstaff
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-12-21
Filing date: 2008-11-21
Publication date: 2011-04-07

Description

- 1 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT ORIGINAL Name of Applicant: Troy David Wagstaff Actual Inventor: Troy David Wagstaff Address for Service is: SHELSTON IP 60 Margaret Street Telephone No: (02) 9777 1111 SYDNEY NSW 2000 Facsimile No. (02) 9241 4666 CCN: 3710000352 Attorney Code: SW Invention Title: A VALVE Details of Associated Provisional Application No(s). 2007907015 (dated 21 December 2007) The following statement is a full description of this invention, including the best method of performing it known to me: File: 56841AUP00 -2 A VALVE FIELD OF THE INVENTION 5 The present invention relates to valves and in particular to ball valves for controlling fluid flow. The invention has been developed primarily for use as a tap valve and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use. 10 BACKGROUND TO THE INVENTION Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. 15 Conventional tap valves are often unsuitable for applications in areas in which the source of water is supplied at low pressure. In particular, the construction of these conventional tap valves provide undesirable reductions in the flow rate. Furthermore, the undesirable occurrence of water hammer frequently occurs as a result of conventional tap valves. 20 When plumbing a valve, it is known to provide a device for reducing or inhibiting backflow to the supply line. However, such known backflow device are commonly constructed in a manner which negatively impacts on energy and flow rate. It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. 25 -3 SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided a valve including: a housing having a supply port through which fluid can be charged into the housing and an exhaust port through which fluid can be discharged from the housing; and 5 a valve member movably arranged within the housing between an open position in which an open passageway is defined from the supply port to the exhaust port and a sealing position in which the passageway is closed, the valve member having a pressure relief formation arranged such that the passageway is gradually opened or closed in response to movement of the valve member. 10 Preferably, the valve member is rotatably arranged within the housing. The valve member is preferably a valve ball having a through bore, the bore having an inlet and an outlet. Preferably, the bore is L-shaped. Preferably, the supply port, the exhaust port and the bore of the valve member each have substantially the same cross-sectional open area. The valve member is preferably arranged such that the inlet of the bore is coaxially aligned 15 with the supply port such that rotation of the valve member moves the outlet of the bore into and out of alignment with the exhaust port, to bring the supply port and the exhaust port into and out of fluid communication. The supply port and exhaust port are preferably arranged transversely to each other. Preferably, the supply port defines a valve seat for the valve member. 20 Preferably, the valve member has a retaining formation for retaining alignment of the valve member relative to the housing. The retaining formation is preferably a flat portion of the valve ball, the flat portion bounding the inlet of the bore. Preferably, the housing includes at least one friction reducing element against which the valve member bears, the friction reducing element reducing friction during movement 25 of the valve member. The housing preferably includes two friction reducing elements.

-4 Each friction reducing element is preferably a disc having an abutment surface, the abutment surface having a complementary configuration to at least a portion of the outer surface of the valve member. The abutment surface may have a tapered section to facilitate abutment with the valve member. Preferably, the housing includes two friction 5 reducing elements, the friction reducing elements being located on opposite sides of the valve member. Preferably, the pressure relief formation includes an eccentric surface of the valve member. The eccentric surface preferably extends from the outlet of the bore to a point at least partly around the valve member. The pressure relief formation preferably includes a 10 recess formed in the eccentric surface of the valve member, the recess extending circumferentially from the outlet of the bore. The recess is preferably tapered, the widest part of the taper being adjacent the outlet of the bore. Preferably, the valve includes an actuating member for moving the valve member between the open position and the sealing position. The actuating member preferably is a 15 spindle operatively connected to the valve member. The valve member preferably has a receiving formation for receiving the distal end of the spindle. Preferably, the receiving formation is a groove. The proximal end of the spindle is preferably splined for receiving and engaging a handle. The actuating member is preferably rotatably mounted in the housing such that 20 rotation of the spindle causes a corresponding rotation of the valve member. The distal end of the spindle is preferably configured as a tongue which can be received in the groove. Preferably, the housing defines a spindle seat against which the distal end of the spindle abuts to position the spindle relative to the housing. Preferably, a washer is arranged between the distal end of the spindle and the spindle seat for reducing friction between the -5 spindle and the housing. The washer is preferably self-lubricating. In one embodiment, the washer is formed of Teflon, preferably GFPTE. The inlet port preferably defines a valve seat for the valve member. Preferably, the housing includes a backflow module associated with the supply port 5 for limiting fluid return to a supply line via the supply port. Preferably, the housing and the backflow module are integrally formed as a one-piece unit. Instead, the backflow module may be connectable to the housing, preferably threadedly engagable with the housing. The backflow module preferably includes a fluid chamber and an operative member 10 movable within the fluid chamber to open and close the fluid chamber, the operative member being operable in response to fluid flow. The operative member may also operate in response to a change in a pressure differential across the operative member. Preferably, the operative member is a backflow ball. The fluid chamber of the backflow module preferably includes a backflow seat against which the operative member sealingly engages 15 to close the fluid chamber. Preferably, the backflow seat is a circumferential ring. The circumferential ring preferably defines a sealing surface, the sealing surface having a complementary profile to that of the operative member to facilitate the sealing engagement between the operative member and the backflow seat. The friction reducing elements and the backflow seat are preferably self-lubricating. In one embodiment, the friction reducing 20 elements and the backflow seat are formed of Teflon, preferably GFPTE. Preferably, the chamber has guide means for guiding movement of the operative member within the chamber. The guide means preferably includes a plurality of fins extending radially inwardly from a wall of the chamber such that the fluid can flow around the backflow ball and through the inlet port of the housing. Preferably, the ends of the fins 25 adjacent the supply port are curved to help promote laminar flow.

-6 Preferably, the cross-sectional open area of the fluid chamber around the operative member is substantially the same as the cross-sectional area of the exhaust port of the housing such that the fluid flow through the housing is laminar. Preferably, the housing and the backflow module are formed by an injection 5 moulding process. The housing and the backflow module are preferably formed of a thermo-plastic material. Preferably, the thermoplastic material has glass fibre reinforcement. More preferably, the thermoplastic material has approximately 33% glass fibre reinforcement. In one embodiment, the thermoplastic material is Zytel. According to a second aspect of the invention, there is provided a backflow module 10 for a valve, the backflow module including: a fluid chamber for providing fluid communication between a supply line and an supply port of the valve; an operative member movable within the fluid chamber to open and close the fluid chamber, the operative member being operable in response to fluid flow from the supply 15 line for limiting fluid return to the supply line via the supply port; and guide means arranged within the fluid chamber for guiding movement of the operative member within the chamber. BRIEF DESCRIPTION OF THE DRAWINGS 20 A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a partially cut-away view of a valve, according to the invention, fitted to a hand basin; Figure 2 is rear view of the valve of Figure 1; 25 Figure 3 is a cut-away view of the valve; -7 Figure 4 is rear view of the valve; Figure 5 is a cut-away view of the valve; Figure 6 is perspective view of the valve member; Figure 7 is side view of the valve member; 5 Figure 8 is top view of the valve member; Figure 9 is an enlarged cut-away section showing the valve member in the sealing position; Figure 10 is an enlarged cut-away section showing the valve member in an intermediate position between the sealing position and the open position; 10 Figure 11 is an enlarged cut-away section showing the valve member in the open position; Figure 12 is an enlarged cut-away view of the backflow module, according to the invention, with the operative out of sealing engagement with the backflow seat; Figure 13 is an enlarged cut-away view of the backflow module of Figure 12 15 showing the operative member in sealing engagement with the backflow seat, inhibiting return flow to the supply line; Figure 14 is an enlarged cut-away view of the backflow from a different view-point to that of Figures 12 and 13; Figure 15 is a similar view to Figure 14, highlighting the relationship between the 20 guide means and the operative member; Figure 16 is a similar view to Figures 13 and 14 with the operative member removed; Figure 17 is schematic view of the fluid flow path from the supply port to the exhaust port; Figure 18 shows a representation of the flow path through the valve; and 25 Figure 19 shows the changes in pressure through the valve during fluid flow.

-8 PREFERRED EMBODIMENT OF THE INVENTION Referring to the drawings, the valve 1 is shown in use as a tap valve connected to a hand basin. The tap valve 1 includes a housing 2 having a supply port 3 through which 5 fluid in the form of water 4 can be charged into the housing 2 and an exhaust port 5 through which the water 4 can be discharged from the housing 2. The supply port 3 and exhaust port 5 are arranged transversely to each other. A valve member in the form of a valve ball 6 is rotatably arranged within the housing 2 between an open position as shown in Figure 11 and a sealing position as shown in 10 Figure 9. The valve ball 6 has an L-shaped through bore 7 having an inlet 8 and an outlet 9. The bore 7, in combination with the supply port 3 and the exhaust port 5, defines an open passageway 10 through the housing when the valve ball 6 is in the open position. The passageway 10 is closed when the valve ball 6 is in the sealing position. The bore 7 has a cross-sectional open area substantially the same as the supply port 3 and the exhaust 15 port 5. The base of the valve ball 6 has a flat surface which bounds the inlet of the bore to retain the alignment of the valve ball relative to the longitudinal axis of the housing. The valve ball is rotatable about this longitudinal axis and is arranged such that the inlet 8 of the bore 7 is coaxially aligned with the supply port 3 such that rotation of the valve 6 20 moves the outlet 9 of the bore 7 into and out of alignment with the exhaust port, thus bringing the supply port and the exhaust port into and out of fluid communication. The housing 2 includes two friction reducing elements in the form of ring-like discs 11 between which the valve ball 6 is arranged. Each disc 11 has a conically-shaped abutment surface 12 which complements at least a portion of the outer surface of the valve 25 ball such that the valve ball 6 can rotate relative to the discs 11.

-9 The valve ball 6 has a pressure relief formation in the form of a tapered recess 13 arranged such that the passageway 10 is gradually opened or closed in response to rotation of the valve ball 6, as described in greater detail below. As most clearly shown in Figure 8, the pressure relief formation includes a flat 5 portion 15 corresponding to the outlet of the bore and an eccentric surface 14. The eccentric surface 14 extends from the outlet 9 of the bore to a point 16 partly around the valve ball 6. The tapered recess 13 formed in the eccentric surface 14 extends from the outlet of the bore and converges to the point 16. The widest part of the tapered recess 13 corresponds to the size of the outlet of the bore. 10 The valve 1 includes an actuating member in the form of a spindle 18 operatively connected to the valve ball 6 for selectively moving the valve ball between the open position and the sealing position. The valve ball 6 has a receiving formation in the form of groove 19 for receiving a tongue 20 arranged at the distal end of the spindle. The proximal end 21 of the spindle 18 is splined for receiving and engaging a handle 22. 15 The housing 2 includes a backflow module 23 which operates as a check valve to limit water returning to a supply line via the supply port in the event that the pressure in the supply line is reduced. The backflow module 23 is integrally formed with the housing 2 as a one-piece unit about the supply port 3 of the housing. The backflow module 23 includes a fluid chamber 24 and an operative member in 20 the form of a backflow ball 25 which is movable within the fluid chamber 24 to open and close the fluid chamber 24. The backflow ball 25 moves in response to fluid flowing into the supply port from the supply line to open the backflow module 23. The fluid chamber 24 of the backflow module 23 includes a backflow seat 26 against which the backflow ball 25 sealingly engages to close the fluid chamber 24.

- 10 The fluid chamber 24 has guide means in the form of a plurality of fins 27for guiding movement of the backflow ball 25 within the chamber. Each fin 27 extends radially inwardly from an inner wall 28 of the fluid chamber such that the movement of the backflow ball 25 is constrained by the fins 27. As the fins 27 project inwardly, fluid can 5 flow around the ball and towards the inlet port when the backflow ball 25 is not in sealing engagement with the backflow seat 26. Advantageously, the cross-sectional open area of the fluid chamber defined by the area around the backflow ball 25 is substantially the same as the cross-sectional area of the exhaust port of the housing to promote substantially laminar flow through the passageway. 10 This is particularly advantageous where only a low pressure water supply is available. Furthermore, it is also advantageous that the water has only a single change in direction in low pressure applications. In use, the tap valve 1 is installed to, for example, a hand basin as shown in Figure 1. The backflow module 23 is connected to the water supply line. The water from the supply 15 line is under pressure and charged through the fluid chamber of the backflow module to the supply port of the valve housing. The water then passes through the bore of the valve ball and then along the tapered recess. In the closed position, shown in Figure 9 the exhaust port is closed such that water is not discharged through the exhaust port. As the handle is turned, the valve ball makes a corresponding rotation. As shown in 20 Figure 10, due to the tapered recess, a relatively small opening is initially provided such that water begins to bleed through the exhaust port at a reduced flow rate. By continuing to turn the handle, a greater opening through which the water is discharged to the exhaust port is gradually and progressively provided. It will be appreciated that this gradual opening of the passageway provides an initial pressure relief as the valve is opened such 25 that the occurrence and effect of water hammer is reduced.

- 11 Accordingly, it is an advantage of at least a preferred embodiment of the invention to provide a valve which enables water pressure to be bled on and off gradually such that the occurrence and effect of water hammer is reduced. It is another advantage of at least a preferred embodiment of the invention to provide 5 a valve which is formed of a thermoplastic material by an injection moulding process such that the valve has increased resistance to one or more of thermal stress, mechanical stress, hydrolysis, corrosion and mineral build-up. It is yet another advantage of at least a preferred embodiment of the invention to provide a valve having a backflow module with curved fins to promote laminar flow 10 through the valve. Although the invention has been described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

1. A valve including: a housing having a supply port through which fluid can be charged into the housing and an exhaust port through which fluid can be discharged from the housing; and 5 a valve member movably arranged within the housing between an open position in which an open passageway is defined from the supply port to the exhaust port and a sealing position in which the passageway is closed, the valve member having a pressure relief formation arranged such that the passageway is gradually opened or closed in response to movement of the valve member. 10

2. A valve according to claim I wherein the pressure relief formation includes an eccentric surface of the valve member, the eccentric surface extending from the outlet of the bore to a point at least partly around the valve member.

3. A valve according to claim 2 wherein the pressure relief formation includes a recess formed in the eccentric surface of the valve member, the recess extending 15 circumferentially from the outlet of the bore.

4. A valve according to claim 3 wherein the recess is tapered, the widest part of the taper being adjacent the outlet of the bore.

5. A valve according to any one of the preceding claims wherein the housing includes a backflow module associated with the supply port for limiting fluid return to a supply line 20 via the supply port.

6. A valve substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. - 13

7. A backflow module for a valve substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.