AU2005202425B2 - A valve - Google Patents

Description

Regulation 3.2 Revised 2/98 AUSTRALIA Patents Act, 1990 ORIGINAL COMPLETE SPECIFICATION TO BE COMPLETED BY THE APPLICANT NAME OF APPLICANTS: FIX-A-TAP AustraliaPty Ltd (ACN 001 011 534) and United Cold Forming Pty Ltd (ACN 097 203 300) ACTUAL INVENTOR: Michael Norman Rutkowski ADDRESS FOR SERVICE: Peter Maxwell & Associates Level 6 60 Pitt Street SYDNEY NSW 2000 INVENTION TITLE: A VALVE DETAILS OF ASSOCIATED APPLICATION NO(S) Nil The following statement is a full description of this invention including the best method of performing it known to us: m:\docs\20051026\079418.doc 2 The present invention relates to a tap valve, and, in particular, to a valve which reduces the flow rate of liquid therethrough. Taps have been used in both domestic and industrial applications for many years. In more modern times these taps have included valves which 5 open and close to start and stop the flow of liquid. A standard tap valve comprises a valve body and valve seat. The valve seat is located at the opening to the liquid supply pipe. The valve body has a shaft and a base. The shaft attaches to the tap spindle. The spindle, which is turned by the user, can be turned in one direction to force the base of the valve body into contact with 10 the valve seat, forming a seal and turning off the tap. When the spindle is turned in the other direction, the valve body is no longer forced into contact with the valve seat, the seal is broken and liquid flows through the valve. These standard tap valves are still used at the present day. In the past ten years, and especially in Australia, there has been an 15 increasing focus on water conservation. As part of this focus on water conservation, new taps, showers and other sanitary ware have been developed which use less water. However, in some cases it is not possible for old taps to be replaced. For example, in older homes old plumbing may not be compatible with new 20 taps. Further, in homes with low water pressure, some new water saving taps may not function properly, something which may not be apparent until the taps are installed. In such cases it may be preferable to retain the existing taps but replace the standard valves with water saving valves. There are however very few water saving valves on the market which can be fitted to existing taps. 25 All of the water saving valves on the market require the valve body and valve seat to be replaced. Most then require a new valve body and valve seat, of different design, to be installed in addition to other components, such as a 3 spring located above the valve body or a flow reducing disc fitted to the bottom of the valve seat. The additional components make these water saving valves more difficult to install. In addition, the additional components add to the wear on the valve making it more likely to require replacement earlier. 5 There are some, very complicated, valves which reduce the rate of flow of liquid through the valve by changing the shape of the valve seat, for example by giving the seat external walls with small apertures therein. These valves are expensive as the valve seats are difficult and expensive to manufacture. In addition, valve seats are difficult to install. As such, few home 10 handypersons could install such a complicated valve seat correctly and they are usually installed only by tradespersons. Further, valve seats are extremely difficult to remove. Once the water saving valve seat was installed it would be a very difficult and time consuming process to replace the valve seat and could possibly damage the tap. As such, 15 these water saving valves are permanently installed. It is almost impossible to change the flow rate or return the tap to its normal flow rate once the valve is installed. It is impossible to change the flow rate or return the tap to its normal flow rate without undertaking the difficult task of replacing the tap seat, and possibly damaging the tap. 20 It is an object of the present invention to overcome or substantially ameliorate these problems by providing a valve which comprises only a valve seat and valve body and where the characteristics of the valve body reduce the rate of flow of liquid through the valve. It is another object of the present invention to provide a valve having a 25 reduced flow of liquid therethrough which is easy to install.

4 It is a further object of the present invention to provide a valve where the rate of flow of liquid through the valve can be easily changed after the valve has been installed. It is another object of the present invention to provide a valve where the 5 rate of flow of liquid through the valve can be easily retuned to normal after the valve has been installed. It is another, but merely preferred, object of the present invention to provide a valve which reduces the flow of liquid therethrough also comprising an improved seal between the valve body and valve seat, thereby reducing or 10 preventing leaks and further improving the liquid saving capabilities of the valve. According to one aspect of the invention there is provided a valve comprising: (a) a valve seat having a passage formed therein and an upper 15 surface having a non-planar contour, and (b) a valve body comprising a lower shaft adapted to be received within the passage, an upper shaft, and a middle portion intermediate the upper shaft and lower shaft, a lower surface of the middle portion having a non-planar contour, 20 wherein, when the valve is open, at least part of the lower shaft is located within the passage, and wherein, in use, the lower shaft partially obstructs the passage reducing the area through which liquid can flow, thereby reducing the flow rate, and wherein, when the valve is closed, the mateable engagement of the non 25 planar contours forms a watertight seal, characterised in that the seal is initially formed by frictional abutment between a tapered inner surface of the upper surface of the valve seat and a 5 tapered inner surface of the lower surface of the middle portion of the valve body. Preferably, the upper surface of the valve seat further comprises a tapered outer surface, and the lower surface of the middle portion of the valve 5 body further comprises a tapered outer surface, wherein, after the seal is formed by the frictional abutment between the tapered inner surfaces, there is further contact between the tapered outer surfaces. In a preferred form, the upper surface of the valve seat further comprises a flat uppermost surface between the tapered inner and outer 10 surfaces thereof. It is preferred that the lower shaft is cylindrical. The valve body can preferably be replaced by a valve body of increased or decreased diameter to alter the flow rate, without removing or altering the valve seat. 15 Alternatively, the valve body may, without removing or altering the valve seat, be replaced by a standard valve body which does not comprise a lower shaft adapted to be received within a passage in the valve seat, thereby producing a normal flow rate. In order that the invention may be readily understood and put into 20 practical effect, reference will now be made to the accompanying drawings, in which: Fig 1 is a perspective view of a valve body according to a preferred embodiment of the invention, Fig 2 is a sectional side view of the valve body of Fig 1, 25 Fig 3 is a perspective view of the valve seat according to a preferred embodiment of the invention, Fig 4 is a sectional side view of the valve seat of Fig 3, 5a Fig 5 is a sectional side view of a valve according to a preferred embodiment of the invention, showing the valve body of Fig 1 and valve seat of Fig 3, in normal use, fitted within a tap and also showing the other tap components, 5 Fig 6 is a sectional side view of the valve of Fig 5, showing the seal between the valve body and valve seat.

6 The valve 10 consists of a valve body 12 and a valve seat 14. The seat 14 has an upper portion 16 and a lower portion 18. The lower portion 18 has an external surface 20 and a passage 22 having an inner surface 24. The upper portion 16 of the seat 14 has an upper surface 17 which is 5 non planar. In the preferred embodiment shown in Figures 3 and 4, the upper surface 17 comprises an outer surface 26 and an inner surface 28 which together form an inverted V shape. The valve body 12 comprises an upper shaft 30 attached to a metal base 32. A non metallic base 34 is abutingly located, in use, below the metallic 10 base 32. Together the metal base 32 and non metallic base 34 form the middle portion 33 of the valve body 12. The lower surface 36 of the non metallic base 34 is non planar. In the preferred embodiment shown in Figures 1 and 2, the lower surface 36 comprises a first surface 38 and a second surface 40 which together form an 15 inverted V shape. The shape of the lower surface 36 and upper surface 17 are such that when the valve body 12 and valve seat 14 are forced together the lower surface 36 and upper surface 17 are mateably engaged. It would be readily apparent to persons skilled in the art that other non planar mateable upper and lower surfaces are also within the scope of this 20 invention. A cylindrical lower shaft 42 extends from the non metallic base 34. The lower shaft 42 has an outer surface 44. The diameter of the shaft 42 is slightly less than the diameter of the passage 22 in the seat 14 so that, in use, the shaft 42 can be located within the passage 22 without contacting the inner 25 surface 24 of the passage 22. It is also within the scope of this invention for the lower shaft 42 to be other shapes, including ribbed or square, and for the lower shaft 42 to be partially in contact with the inner surface 24 of the passage 7 22. Where the lower shaft 42 is ribbed and partially in contact with the inner surface 24 liquid flows around the raised portions of the ribbing. It is preferable that the valve seat 14 be manufactured from metals such as stainless steel or brass, or plastics such as acetal. It is preferable that the 5 valve shaft 30 and metal base 32 be manufactured from metals such as stainless steel or brass, or plastics such as acetal. It is also preferable that the non metallic base 34 and the lower shaft 42 be manufactured from materials such as plastics or rubber and, in particular, from polypropylene co-polymers. The non-metallic base 34 and lower shaft 42 can be integrally formed or 10 separately formed. Alternatively, the lower shaft 42 can be manufactured of metal, and can be separately or integrally formed with the metallic base 32. Where the lower shaft 42 is manufactured from metal the non-metallic base 34 can be in the form of a separate sealing member, such as an o-ring or washer. To install, the seat 14 is fitted by pushing it into the opening in the liquid 15 supply pipe as shown in Fig 5. The valve body 12 is installed by placing it loosely on the valve seat 14 while inserting the shaft 42 into the passage 22. The upper shaft 30 is then attached to the spindle 46 of the tap. In use, to close the valve, the user turns the spindle 46 which, through the upper shaft 30, forces the valve body 12 towards the valve seat 14. The 20 lower surface 36 of the valve body 12 comes into contact with the upper surface 17 of the valve seat 14. The lower surface 36 and the upper surface 17 are contoured to be a perfect dimensional match. The surface 38 on the valve body 12 contacts the surface 26 on the valve seat 14. The surface 40 on the valve body 12 contacts the surface 28 on the valve seat 14. 25 As the lower surface 36 and upper surface 17 are a perfect dimensional match they become mateably engaged. The individual surfaces on the upper surface 17 and lower surface 36 fit together perfectly. The frictional abutment 8 between the surfaces forms a seal, preventing liquid leaking through the valve. The valve is closed and liquid stops flowing. To open the valve the spindle 46 is turned in the opposite direction. The valve body 12 is no longer being forced towards the valve seat 14. The lower 5 surface 36 and upper surface 17 separate, the seal is broken and the valve is forced open by liquid pressure. Liquid is then free to flow through the valve. When the valve is forced open by the liquid pressure the valve body 12 is located only slightly above the valve seat 14. The lower shaft 42 remains at least partially within the passage 22 in the valve seat 14. As the lower shaft 42 10 remains at least partially within the passage 22 it obstructs liquid flowing through the passage 22. In the preferred embodiment shown in Figures 5 and 6 the lower shaft 42 is cylindrical and is located in the centre of the passage 22. The diameter of the lower shaft 42 is slightly less than the diameter of the passage 22 so, as is 15 best seen in Figure 6, there is a small gap between the inner surface 24 of the passage 22 and the outer surface 44 of the lower shaft 42. When liquid enters the valve through the bottom of the passage 22, it can no longer flow through the entire passage 22 but can only flow through the gap between the inner surface 24 of the passage 22 and the outer surface 44 20 of the lower shaft 42. As the gap is very small, less liquid can flow through the valve 10 and the flow rate is reduced. The exact flow rate depends upon the diameter of the lower shaft 42 and thus the size of the gap between the inner surface 24 of the passage 22 and the outer surface 44 of the lower shaft 42. Increasing the diameter of the 25 lower shaft 42 decreases the flow rate, and decreasing the diameter of the lower shaft 42 increases the flow rate.

9 The present inventors have achieved flow rates of between 1 and 12 litres per minute using diameters of between 10mm and 10.9mm for the lower shaft 42. In particular, the inventors have achieved a flow rate of approximately 6 litres per minute using a lower shaft diameter of approximately 5 10.5mm, a flow rate of approximately 9 litres per minute using a lower shaft diameter of approximately 10.4mm and a flow rate of approximately 12 litres per minute using a lower shaft diameter of approximately 10.35mm. It is a preferred aspect to produce valve bodies 12 having lower shafts 42 of various diameters so that users can choose the appropriate flow rate. 10 These different sized valve bodies 12 are produced in different colours, such as blue for the 6 litre per minute valve body and green for the 9 litre per minute valve body, so that each flow rate is a particular colour, making it easier for users to select the appropriate valve body 12 for their desired flow rate. As the valve body 12 will be available with lower shafts 42 of different 15 diameter, users can choose a flow rate which is appropriate to their application. Users will also be able to easily replace one valve body 12 with another valve body, if the flow rate achieved by the initial valve body 12 is not appropriate. The valve body 12 is fitted by placing it loosely on the valve seat 14 as described above. The spindle 46 is then attached to the upper shaft 30 of the 20 valve body 12 and the upper part of the tap is assembled. To replace one valve body 12 with another, the user simply takes the upper part of the tap apart, removes the spindle 46, takes out the existing valve body 12 and inserts the new valve body. No special tools are required. The valve body 12 can be removed by the user with their fingers. The new valve body is again placed 25 loosely on the valve seat 14. There is no requirement for the valve body 12 to be properly aligned with the valve seat 14. The spindle 46 is then reattached and the upper part of the tap reassembled.

10 The process for replacing a valve body 12 is significantly easier than replacing the valve seat, as required by some of the prior art water saving valves, which requires specialised tools used with precision to ensure a watertight seal between the valve body and seat. Any user can replace the 5 valve body 12, a valve seat is usually only replaced by tradepersons. The valve body 12 can also be replaced by a standard valve body. A standard valve body has an upper shaft and a middle portion but does not have a lower shaft which can be located with the passage 22 in the valve seat 14. As such, it does not reduce the flow rate. As, unlike other water saving 10 valves available on the market, the valve seat 14 of the present invention is of similar design to valve seats presently available on the market, it is compatible with a standard valve body. Any user who wishes to convert their tap back to full flow can therefore easily replace the valve body 12 with a standard valve body using the method described above, without having to replace the valve 15 seat 14. It would be apparent to persons skilled in the art that the external surface 20 of the valve seat 14 could include a thread. If the surface 20 included such a thread it would be installed by either screwing the valve seat 14 into the opening using an existing thread or using a tool to create a thread 20 and fitting the valve seat 14 to the opening using that thread. In the inventors' opinion such installation would usually be performed by tradespersons. Various modifications may be made in details of design and construction without departing from the scope and ambit of the invention.

Claims (13)

1. A valve comprising: (a) a valve seat having a passage formed therein and an upper surface having a non-planar contour, and (b) a valve body comprising a lower shaft adapted to be received within the passage, an upper shaft and a middle portion intermediate the upper shaft and lower shaft, a lower surface of the middle portion having a non-planar contour , wherein, when the valve is open, at least part of the lower shaft is located within the passage, and wherein, in use, the lower shaft partially obstructs the passage reducing the area through which liquid can flow, thereby reducing the flow rate, and wherein, when the valve is closed, the mateable engagement of the non planar contours forms a watertight seal, characterised in that the seal is initially formed by frictional abutment between a tapered inner surface of the upper surface of the valve seat and a tapered inner surface of the lower surface of the middle portion of the valve body.

2. The valve of claim 1 wherein the upper surface of the valve seat further comprises a tapered outer surface, and the lower surface of the middle portion of the valve body further comprises a tapered outer surface, wherein, after the seal is formed by the frictional abutment between the tapered inner surfaces, there is further contact between the tapered outer surfaces.

3. The valve of claim 2 wherein the upper surface of the valve seat further comprises a flat uppermost surface between the tapered inner and outer surfaces thereof.

4. The valve of any one of the preceding claims wherein the lower shaft is cylindrical. 12

5. The valve of any one of the preceding claims wherein the diameter of the passage is approximately 11 mm and the diameter of the lower shaft is between 10mm and 10.9mm.

6. The valve of any one of the preceding claims wherein, without removing or altering the valve seat, the valve body is replaced by a valve body comprising a lower shaft of smaller diameter, thereby increasing the flow rate.

7. The valve of any one of claims 1 to 5 wherein, without removing or altering the valve seat, the valve body is replaced by a valve body comprising a lower shaft of larger diameter, thereby further reducing the flow rate.

8. The valve of claims 6 or 7 wherein each valve body with a lower shaft of different diameter is a different colour.

9. The valve of claims 4 or 5 wherein the lower shaft is located centrally of the passage and the liquid flows between an outer surface of the lower shaft and an inner surface of the passage.

10. The valve of any one of claims 1 to 3 wherein the outer surface of the lower shaft is ribbed.

11. The valve of any one of the preceding claims wherein the valve seat is stainless steel.

12. The valve of any one of claims 1 to 5 wherein, without removing or altering the valve seat, the valve body is replaced by a standard valve body which does not comprise a lower shaft adapted to be received within a passage in the valve seat, thereby producing a normal flow rate. 13

13. A valve substantially as hereinbefore described with reference to the accompanying drawings. Dated this 22 day of November 2010 FIX-A-TAP Australia Pty Limited and United Cold Forming Pty Limited Patent Attorneys for the Applicants PETER MAXWELL & ASSOCIATES