AU687713B2 - Anti-vibration tap washer - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventors: Address for Service: CAMBRI PTY LTD 054 902 662) John Caleb Wells Biggers Henry George Brock Patricia Colburn Biggers CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

ANTI-VIBRATION TAP WASHER Ir: .a

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i Invention Title: Details of Associated Provisional Applications: Nos. PO7358 filed 17.06.97 P07257 filed 06.06.97

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The following statement is a full description of this invention, including the best method of performing it known to us BACKGROUND OF THE INVENTION This invention relates to tap washers for use in common domestic, agricultural and commercial water taps, which are designed to prevent water vibration, commonly referred to as water hammer. The invention is particularly concerned with tap washers of the type having a seal for seating against a valve seat of a tap and a stem which locates within a hollow spindle of the tap for aligning the seal with the seat. Closing the tap by rotating its handle causes the tap spindle to move towards the valve seat so as to bring the seal into engagement with the valve seat and thereby stop the flow of water through the tap body.

A common problem with existing tap washers of this type is that when the tap is partially turned on, or immediately before the tap is turned off, the washer vibrates and produces noises and vibrations in the pipes.

Research I have undertaken suggests that the washer vibrates because the stem loosely locates in the hollow spindle. Thus, by partially turning on the tap, the water pressure exerts an upward force upon the undersurface of the seal and partially lifts the seal from its seat.

Water escapes in fine jet streams alternating around 'he edge of the seat. The jet streams upon contacting the S•undersurface of the seal causing the washer to vigorously rock from side to side.

ee The stem of existing washers is deliberately 30 designed to be of a smaller diameter than the hollow tap spindle so that it can be accommodated in a wide range of spindles which have varying hole diameters. It has therefore not been previously recognised that this difference in diameters and hence loose fitting is what has given rise to water vibration.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide a tap washer of the aforementioned type but which can snugly fit within the hollow spindles of the range of taps which are commonly available, thereby addressing the problem of water vibration.

SUMMARY OF THE INVENTION According to the present invention there is provided a tap washer having a seal for sealing against a valve seat of a tap and a stem which locates within a hollow spindle of the tap for aligning the seal with the seat, wherein the stem is characterised by resiliently deformable elements which retain the stem snugly within the spindle.

DESCRIPTION OF THE INVENTION By including resiliently deformable elements, the stem of the tap washer can be compressed to enable *insertion within the hollow spindle of the tap so that it does not matter what diameter the hole in the spindle is, 20 there will always be a snug fit.

a Ideally, the tap washer is designed to also enable unhindered rotation within the tap body and to this end the resiliently deformable elements should be such 25 that they do not fit tightly within the hollow spindle.

i' Such a design can be achieved by adopting any one of a large number of variously shaped rtsiliently deformable elements. In one form, the stem Itself can comprise the resiliently deformable elements such as, for instance, by 30 being split longitudinally so that it comprises several pieces having a common point of c:,;rnection at the seal, and which pieces can be urged together at their other free ends against their natural tendency co be splayed apart. A specific instance of such a design is a stem comprising two legs which are sprung apart as in a cotter pin.

In another form, the resiliently deformable elements can be formed as separate integers to the stem itself. In this instance, the separate integers are preferably formed integrally with the stem (although they could be added as banded elements or the like, such as would be necessary when the stem is fabricated from a material which is not adapted to resiliert deformability).

Such integrally formed elements can be in the form of fins, that is, relatively thin or membrane-like protrusions extending outwardly from the surface of the stem. Preferably, such fins would project longitudinally from the stem, from equi-spaced positions at the base of the stem where they meet the seal, to locations adjacent to, but spaced from, the free end of the stem. Suitable dimensions for fins formed on a stem having a diameter of approximately 4.5mm would be between 0.4 and 0.6mm, most preferably 0.5mm, in width and depth. Ideally, there are between two and six fins per stem, most suitably three.

In still another form, the resiliently deformable elements comprise pieces which radiate outwardly from a common axis. An example of such an embodiment is a shape which, in cross-section, is starshaped.

Other shapes and configurations will be readily 25 apparent to the skilled addressee of this specification.

Suitable materials from which the tap washer can be fabricated are resiliently deformable non-toxic plastics and rubber materials, such as polypropylene, 30 nylon® and neoprene®. In some instances, metals can also be used.

water vibration in taps incorporating the aforementioned washers is substantially reduced or eliminated altogether. When in use, the snug fitting tap washer stem remains vertically aligned within the hollow spindle of the tap when subjected to extreme mains water pressure. The snug fitting stem is still able to freely rotate within the hollow spindle, but the washer is unable to rapidly vibrate within the body of the tap and there is consequently no water vibration noises set up in the pipes.

The tap washer according to the invention enhances performance and does not detract from normal tap operation.

The benefit of the snug fitting tap washer stem is not only in the elimination of water vibration but also Sin providing the end user with a very cheap solution to this age old problem. In addition, the ability for the tap washer to snugly fit within the tap spindle facilitates the replacement of the washer as in conventional arrangements, the washer, which has to be aligned and placed with the stem extending vertically into S• the spindle, would te- to fall out before the tap housing 20 could be tightened, leading to frustration and often repeated attempts before the washer was properly installed.

DETAILED DESCRIPTION OF THE DRAWINGS 25 Figure 1 is a top perspective view of a tap washer according to one aspect of the present invention, Figure 2 is a cross-sectional view of the tap washer depicted in Figure 1, e Figure 3 is a cross-sectional view of the stem of the tap washer depicted in Figures 1 and 2, Figure 4 is a cross-sectional view of a tap washer according to another aspect of the present invention, and Figure 5 is a cross-sectional view of a stem of a tap washer according to yet another aspect of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Preferred embodiments of the invention will now be described with reference to the accompanying drawings, Sin all of which like reference numerals refer to like parts.

Referring firstly to Figures 1 to 3, the tap washer comprises a stem, indicated generally at 10, and a seal, indicated generally at 11.

The seal 11 is of the type found on a standard tap washer, that is, it comprises a fibre or rubberised disc 12, held to a rigid plastic or metal base 13 by a nut 14 or other common means.

The stem 10 comprises a solid cylindrical member 15 projecting perpendicularly from the base 13 to which it is integrally connected. The cylindrical member is 16mm in length and has a diameter of 4.Erim.

Radiating outwardly from the stem 10 at equispaced intervals are three fins 16, 17, 18. Each fin is formed integrally with the stem and has a flat trapezoidal shape. The top end of each fin is tapered downwardly from ~where it meets the stem so as to facilitate placement of the stem within the spindle housing. The top end of each 30 fin is also located 3mm from the end of the stem for the .io same reason.

The fins are dimensioned so as to be only slightly deformed out of shape when the stem is inserted within the tap spindle. The illustrated version has fins dimensioned at 0.5mm in width and 0.5mm in depth.

In use, upon urging the tap washer into the hollow spindle of a tap handle, the fins are slightly deformed so that the stem is snugly retained in the spindle in vertical alignment therewith. The fitting is such as not to be so tight as to prevent rotation of the washer during operation of the tap.

Referring now to Figure 4, the tap washer comprises a stem 20 split into two longitudinal segments 21, 22, each having, in cross-section, a semi-circular shape. The stem is integrally connected to a seal 23 having substantiality the same construction as the seal 11 depicted in Figures 1 and 2. The top ends 24, 25 of the segmented stem are splayed outwardly from one another in their naturally untensioned state and must be urged toward one another upon insertion into the spindle housing. Once in the housing, the segments spring outwardly to make a snug contact with the housing wall, thereby maintaining the stem in the desired vertical alignment therewith.

20 The embodiment of Figure 5 shows a variation of the stem 20 depicted in Figure 4. In this variation, instead of the stem being split into two equal segments, it is split into three sections 26, 27, 28. Each section is equivalent to the other and is spaced at its outer end from an adjacent section by a gap 29. The use of a washer incorporating such a stem is similar to that shown and Sdescribed with relation to Figure 4.

Whilst the above has been given by way of illustrative example of the invention, many modifications and variation may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.

Claims (7)

1. A tap washer having a seal for sealing against a valve seat of a tap and a stem which locates within a hollow spindle of the tap for aligning the seal with the seat, wherein the stem is characterised by resiliently deformable elements which retain the stem snugly within the spindle.

2. A tap washer as claimed in claim 1 wherein the resiliently deformable elements comprise a plurality of fins which project outwardly from the stem.

3. A tap washer as claimed in claim 2, wherein the fins project longitudinally A the stem.

4. A tap washer as claimed in claim 3, wherein the fins project from a location adjacent to the base of the stem where it meets the seal to a position adjacent the 20 free end of the stem. Sbetween 0.4 and 0.6mm thick. A tap washer as claimed in any one of claims 2 Sto 5, wherein there are between two and six fins.

7. A tap washer as claimed in claim 6, wherein e 30 there are three fins.

8. A tap washer as claimed in any one of the preceding claims which is fabricated from resiliently deformable plastics material.

9. A tap washer substantially as herein described withe reference to Figures 1-3 of the accompanying drawings. A tap washer substantially as herein drescribed with reference to Figure 4 or Figure 5 of the accompanying drawings. DATED this day of CAMBRI PTY LTD By their Patent Attorneys CULLEN CO. 1997 *000** 0 0 0.0. 0 0 0* 00 0 ABSTRACT Fig. 1 A tap washer which prevents water vibration. The washer is of the type having a seal and a stem which locates within a hollow spindle of a tap housing. The :washer is characterised in that the stem (10) has resiliently deformable elements (16, 17, 18) which retain the st, n snugly within the spindle while still permitting the washer to rotate. e. t ;*o