AU2010101326A4

AU2010101326A4 - Ceramic disc tap spindle assembly

Info

Publication number: AU2010101326A4
Application number: AU2010101326A
Authority: AU
Inventors: Tao Zhang
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-11-26
Filing date: 2010-11-26
Publication date: 2010-12-23
Anticipated expiration: 2018-11-26

Description

Title CERAMIC DISC TAP SPINDLE ASSEMBLY 5 Field The present invention relates to taps, in particular to the conversion of screw-down type taps into ceramic disc taps. 10 Background to the Invention Conventional screw-down taps commonly used for garden and household applications have several known limitations. 15 Specifically, the jumper valve which bears down on the tap seat wears rapidly, requiring regular replacement and commonly resulting in a damaged tap seat when the tap is used with a jumper washer in worn condition. In addition, the screw-down action sometimes requires significant 20 strength to operate. Taps with ceramic disc valves that operate by relative rotation of two juxtaposed ceramic discs, overcome these problems as they rarely require maintenance and do not 25 require a screw-down action to effect a seal. Existing screw-down taps can be converted to ceramic disc taps by replacing the spindle assembly and jumper washer with a spindle assembly adapted to containing a ceramic disc valve. Currently known conversion assemblies include an 30 annular washer adapted to seal between the tap seat and the ceramic disk cartridge to prevent leaks. A substantial problem with these known conversion assemblies is that the seal at the tap seat can be hard to perfect, due to a damaged or tilted tap seat, and successful installation 35 can be tricky, particularly for the home handyman. Conversion of screw-down taps to ceramic disc taps is uncommonly performed, as a result.

- 2 There is therefore a need to provide an improved ceramic disk tap spindle assembly. 5 Summary of the Invention According to a broad aspect of the invention there is provided a water tap spindle assembly for converting a 10 screw-down tap into a ceramic disk tap, comprising: a tap stem for attachment of a handle; a spindle housing holding the tap stem in rotatable engagement and adapted to screw into a tap body having a tap inlet hole, a tap seat disposed around an opening of 15 the tap inlet hole and a tap outlet; a ceramic disc valve installed in the spindle housing and engaging with the tap stem so as to be operated between an open and a closed position by rotation of the tap stem; and 20 a washer adapted to seal between an inner surface of the tap inlet hole and the ceramic disc valve so as to prevent water from the inlet leaking around the ceramic disc valve. 25 In one embodiment, the washer comprises a washer inlet seal surface shaped to engage with and seal against the inner surface of the tap inlet hole around a circumference thereof. 30 In one embodiment, the washer comprises a washer valve seal surface shaped to engage with and seal against an inlet rim of the ceramic disc valve around a circumference thereof. 35 In one embodiment, the washer comprises an outward facing washer flange adapted to engage with a base of the housing to maintain a desired spacing between the tap seat and the base.

- 3 In one embodiment, the washer is composed of rubber. 5 Brief Description of Drawings Figure 1 is a view through a vertical cross-section of a water tap spindle assembly according to an embodiment of 10 the current invention, installed in a tap; Figure 2 is a perspective view of a washer component of the embodiment of Figure 1; 15 Figure 3 shows the external appearance of the embodiment of Figure 1. Detailed Description of embodiments 20 An embodiment of the current invention will now be described. Referring first to Figure 1, water tap spindle assembly 25 comprises tap stem 10, spindle housing 12, ceramic disc valve 20 and washer 40. Tap stem 10 attaches to handle 11, held in rotatable engagement with spindle housing 12, and incorporates o-ring seals 13 to prevent water leaking out between the housing 12 and stem 10 when the tap is turned 30 on. Spindle housing 12 has a screw thread adapted to screw into tap body 30 of a conventional screw-down tap arrangement. Tap body 30 has a tap inlet hole 31, a tap seat 33 disposed around an opening of the tap inlet hole 31 that normally (before conversion)is sealed by a jumper 35 washer, and tap outlet 32. Ceramic disc valve 20 is installed in a recess of spindle housing 20 and engages with tap stem 10 so as to be - 4 operated between an open and closed position by rotation of the tap stem. Away from the closed position, apertures in each of two juxtaposed discs overlap to allow water to pass from the tap inlet hole 31, through the overlapped 5 apertures and out through housing apertures 16 and tap outlet 32 in the direction of the black arrows. Body washer 14 prevents water leaking out between spindle housing 12 and tap body 30. 10 Washer 40 is moulded from natural rubber and is designed according to the invention to provide a sealing function even when tap seat 33 is damaged. Since the ceramic valve 20 now provides the flow regulation, tap seat 33 is now redundant and does not have to be a sealing surface. 15 Washer 40 is adapted to seal between a circumferential inner surface 34 of the tap inlet hole with washer inlet surface 41 that acts as a plug. The diameter of washer inlet surface 41 is moulded to be slightly larger than the diameter of the inner surface 34 of the tap inlet hole, to 20 allow a tight sealing fit. Washer 40 also comprises an annular washer valve seal surface 42 shaped to engage with and seal against an inlet rim of the ceramic disc valve around its circumference. 25 Referring to Figure 2, washer 40 is shown in perspective view, with washer inlet surface 41 and washer valve seal surface 42, surrounding washer hole 44 for passage of water. Washer 40 also comprises a flange 43 adapted to engage with a base 15 of the housing to maintain a desired 30 spacing between the tap seat 33 and the base 15. A set of washers 40 with flanges 43 of different heights may be provided to allow fitting in the circumstances that tap seat 33 or the seat of body washer 44 has been 35 refaced, whereby the desired spacing between the tap seat 33 and the base 15 is different from a designed spacing. Referring now to Figure 3, the external appearance of the - 5 embodiment of Figure 1 is shown, with spindle housing 12, housing aperture 16, housing base 17 and washer 40. Persons skilled in the art will also appreciate that many 5 variations may be made to the invention without departing from the scope of the invention. For example, washer 40 may have many different shapes within the scope of the invention while maintaining its 10 seal between the inner surface of the tap inlet hole and the ceramic disc valve, and may be composed of any suitable material. In the claims which follow and in the preceding 15 description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but 20 not to preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute 25 an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims

1. A water tap spindle assembly for converting a 5 screw-down tap into a ceramic disk tap, comprising: a tap stem for attachment of a handle; a spindle housing holding the tap stem in rotatable engagement and adapted to screw into a tap body having a tap inlet hole, a tap seat disposed around an opening of 10 the tap inlet hole and a tap outlet; a ceramic disc valve installed in the spindle housing and engaging with the tap stem so as to be operated between an open and a closed position by rotation of the tap stem; and 15 a washer adapted to seal between an inner surface of the tap inlet hole and the ceramic disc valve so as to prevent water from the inlet leaking around the ceramic disc valve. 20

2. A water tap spindle assembly for converting a screw-down tap into a ceramic disk tap as claimed in claim 1, wherein the washer comprises a washer inlet seal surface shaped to engage with and seal against the inner surface of the tap inlet hole around a circumference 25 thereof.

3. A water tap spindle assembly for converting a screw-down tap into a ceramic disk tap as claimed in claim 1, wherein the washer comprises a washer valve seal 30 surface shaped to engage with and seal against an inlet rim of the ceramic disc valve around a circumference thereof.

4. A water tap spindle assembly for converting a 35 screw-down tap into a ceramic disk tap as claimed in claim 1, wherein the washer comprises an outward facing washer flange adapted to engage with a base of the housing to maintain a desired spacing between the tap seat and the -7 base.

5. A water tap spindle assembly for converting a 5 screw-down tap into a ceramic disk tap as claimed in any one of claims 1 to 4, wherein the washer is composed of rubber.