NZ328798A - A tap handle and spindle assembly having a torque clutch with first and second parts - Google Patents

Description

New Zealand No. International No. 328798 PCT/ TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates: 19.09.1996; Complete Specification Filed: 19.09.1997 Classification^) F16K5/08; F16K31/60 Publication date: 26 June 1998 Journal No.: 1429 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: An adjustable plumbing joint Name, address and nationality of applicants) as in international application form: CAROMA INDUSTRIES LIMITED, an Australian company of GWA House, 13th Floor, 10 Market Street, Brisbane, Queensland 4000, Australia % 3287 0 V; lIzTPftfENT OFFKJE 6 OCT 1997 hpc&vcB.

PATENTS FORM 5 Number PATENTS ACT 1953 Dated COMPLETE SPECIFICATION A TAP HANDLE AND SPINDLE ASSEMBLY We, CAROMA INDUSTRIES LIMITED, an Australian company, of GWA House, 13th Floor, 10 Market Street, Brisbane, Queensland 4000, Australia, do hereby declare the invention for which we pray that a patent may be granted to us, and the 25 method by which it is to be performed, to be particularly described in and by the 4 following statement.

GW387223B9.001 - 1 - 328798 A TAP HANDLE AND SPINDLE ASSEMBLY The present invention relates to a tap handle and spindle assembly and, in particular, to a torque clutch arrangement for the assembly.

Tap spindles are traditionally made from brass in order to provide adequate anti-corrosion properties over a long period of time. WMlst brass tap spindles have gained universal market acceptance, they suffer from a number of disadvantages, particularly in public places where vandalism is prevalent.

The first difficulty with brass tap spindles is that they shear or break at a torque of the order of 20 newton-metres. This is a torque which is capable of being administered by a vandal in certain circumstances and the result is that the spindle shears and the tap is rendered inoperable.

It is the object of the present invention to overcome this difficulty by the provision of a torque clutch arrangement for the tap spindle by means of which low torque loads are transmitted between the tap handle and the tap spindle but a torque in excess of a predetermined torque causes the clutch to slip and thereby prevents the spindle being overloaded.

In accordance with the present invention there is disclosed a tap handW and spindle assembly comprising a tap spindle adapted to receive a tap washer at one end and a handle mountable on the other end, the assembly characterised in that it includes a torque clutch arrangement comprising a first clutch part on the handle end of the spindle and a second clutch part engageable with the first clutch on the handle to thereby limit the torque able to be transmitted from the handle to the spindle, wherein one of said clutch parts comprises an annulus having a plurality of inwardly facing teeth; the other of said clutch parts comprising a plurality of outwardly facing teeth; and at least some of said plurality of teeth being resiliency biased whereby rotation of said handle rotates said tap spindle by inter-engagement of said teeth except on a predetermined rotational torque being exceeded whereby said mnYfi fit INTELLECTUAL PROPERTY OFFICE 0FN.Z 3 0 APR 1998 Recreweb 328798 -predeterminetLrotatienal torque being exceeded whereby said resilient teeth move at least partially out of engagement to permit said clutch parts to slip relative to each other.

Preferably at least some of the resilient teeth include a distal lip which provides a snap engagement mechanism between said first and second clutch parts.

Preferably the annular clutch part is carried by the handle and the other clutch part is carried by the spindle.

Preferably the resilient teeth are carried by the spindle.

The spindle, handle and both the clutch parts are desirably manufactured from a plastics material such as, for example, PBT (polybutylene teraphthalate).

One embodiment of the present invention will now be described with reference to the drawings in which: Fig. 1 is an exploded perspective view illustrating the tap handle, tap spindle, and tap body, Fig. 2 is a perspective view of the clutch ring, Fig. 3 is a plan view of the clutch ring of Fig. 2, Fig. 4 is a cross-sectional view through the clutch annulus along the line IV-IV of Fig. 3, Fig. 5 is a perspective view of the clutch fingers, Fig. 6 is a plan view of the upper end of the tap spindle, and Fig. 7 is a longitudinal cross-section through the tap spindle showing the handle inter-engaged with the spindle.

As seen in Fig. 1, the tap spindle 1 which is formed from plastics material carries a sealing O-ring 2 and receives a jumper washer 3. The spindle 1 is rotatably mounted within a plastics tap body 4.

, At the upper end of the tap spindle 1 are located a plurality of clutch fingers 6 which are engaged with a plastics clutch annulus or ring 7. In the embodiment shown, the fingers 6 are integrally moulded with the tap spindle 1. The clutch ring 7 is IN:\Uboo|00822:VXF 32 b 798 positioned within a tap handle 8 and is drivingly connected thereto by means of a shear pin 9. The handle is completed by means of an indicia button 10 which indicates either hot or cold water.

As best seen in Figs. 2-4, the clutch ring 7 is provided with ten inwardly facing teeth 12 whilst as best seen in Figs. 1 and 5, the four clutch fingers 6 are each provided with a pair of outwardly facing teeth 13. As is best apparent from Fig. 5, two of the clutch fingers 6 are each provided with a corresponding stiffening rib 15 and a securing lip 16 having a lead-in ramp 17 and a flat undercut 18 (Fig. 7). The upper ends of the finger teeth 13 not including the securing lips 16 are also provided with a lead-in bevel 19.

It will be apparent from Fig. 7 that the clutch ring 7 is secured within the handle 8 by means of the shear pin 9 which forms a frictional fit with both components. With the clutch ring 7 so mounted, the handle 8 can be passed over the top of the tap spindle 1 and the lead-in ramps 17 and lead-in bevels 19 inwardly deflect the clutch fingers 6 so as to pass same through the centre of the clutch ring 7. Once the securing lip 18 is past the clutch ring 7, it then moves outwardly into the position illustrated in Fig. 7 with the flat undercut 18 in engagement with the upper surface of the clutch ring 7. The clutch fingers 6 also carry a part annular flange 21 so that the clutch ring 7 is securely held between the flange 21 and flat undercut 18. Inserting the indicia button 10 into the handle maintains this relationship by means of frictional engagement between the stem 2.0 of the indicia button 10 and the stiffening ribs 15. With the clutch fingers 6 and clutch ring 7 so engaged, the ring teeth 12 are meshed with the finger teeth 13.

In order to dis-assemble the handle 9 from the tap spindle 1, the reverse procedure is applied. That is, the indicia button 10 is removed, the clutch fingers 6 are « manually (or by means of a tool) moved radially inwardly so as to permit the securing lip 16 to clear the ring teeth 12. Then the handle 8 with its clutch ring 7 is then able to be lifted clear of the clutch fingers 6.

[N:\Uboo]00822:VXF 328798 In the assembled condition illustrated in Fig. 7, rotation of the tap handle 8 is transmitted to the tap spindle 1 by means of inter-engagement of the ring teeth 12 with the finger teeth 13.

As the torque applied to the handle 8 increases, the two clutch fingers 6 not having the stiffening ribs 15 move inwardly as a result of the force exerted by the ring teeth 12 on the finger teeth 13. This partial disengagement of the teeth 12 and 13 is sufficient to cause the clutch ring 7 to slip relative to the clutch fingers 6 thereby relieving the excess torque being applied to the tap spindle 1. As soon as the applied torque is reduced the resilient clutch fingers 6 return to their original position with the ring teeth 12 and finger teeth 13 fully engaged.

The foregoing arrangement provides a number of substantial advantages. Firstly, the tap spindle 1 is not liable to be broken as a result of excess torque applied by the tap handle 8. Secondly, because the tap spindle cannot be overtightened, the tap washer 3 does not take on a compression set. As a consequence, the tap washers last longer. Thirdly, some members of a household, for example the father, cannot overtighten the tap so mucu that other members, for example a daughter, cannot undo the tap in order to turn it on. This is a common problem with taps where the washer has deteriorated to the point where normal tightening results in a dripping tap but overtightening results in the drip stopping. Further, the overall clutch arrangement facilitates the fabrication of the tap spindle from lightweight and inexpensive plastics material.

Particularly to those taps able to be operated by the general public and therefore possibly subject to vandalism, the replaceable shear pin 9 provides an additional, but once only, "super torque" limiter. As a consequence, should the clutch mechanism not work as well as intended, or be subject to a large, quickly acting « torque, then the shear pin 9 will shear thereby causing the tap handle 8 to spin freely relative to the clutch ring 7. Although such a circumstance does require a call by service personnel in order that the shear pin 9 be replaced, the tap itself is not rendered |N:\Libool00822:VXF 32879 inoperative, only the handle is inoperative. Thus, for example, even if a replacement shear pin 9 is not immediately available, the tap spindle 1 can be rotated by fingers, long nose pliers or the like and the tap thereby operated so as to prevent the waste of water. This is to be contrasted with the situation where the prior art brass tap spindle is sheared with the tap in the fully open position. Under these circumstances not only is the tap rendered inoperative, but the tap is open and thereby substantial amounts of water can be wasted.

The above described embodiment is also relatively inexpensive to produce as the spindle, handle and both the clutch parts are moulded plastic components and simple to assemble in the "snap-engaging" fashion previously described.

Further, the plastic spindle is stronger than prior art brass spindles, notwithstanding it is produced from a weaker material, due primarily to the larger moment of inertia provided by the relatively large diameter hollow cylindrical spindle construction.

The foregoing describes only one embodiment of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.

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Claims (14)

- 6 - The claims defined in the invention are as follows: 328798

1. A tap handle and spindle assembly comprising a tap spindle adapted to receive a tap washer at one end and a handle mountable on the other end, the assembly characterised in that it includes a torque clutch arrangement comprising a first clutch 5 part on the handle end of the spindle and a second clutch part engageable with the first clutch on the handle to thereby limit the torque able to be transmitted from the handle to the spindle, wherein one of said clutch parts comprises an annulus having a plurality of inwardly facing teeth; the other of said clutch parts comprising a plurality of outwardly facing teeth; and at least some of said plurality of teeth being resiliently 10 biased whereby rotation of said handle rotates said tap spindle by inter-engagement of said teeth except on a predetermined rotational torque being exceeded whereby said resilient teeth move at least partially out of engagement to permit said clutch parts to slip relative to each other.

2. An assembly as claimed in claim 1, wherein at least some of the is resilient teeth include a distal lip which provides a snap engagement mechanism between said first and second clutch parts.

3. An assembly as claimed in preceding claim 1 or 2, wherein the resilient teeth include distal lead-in ramps to facilitate axial sliding of the annular clutch part over the resilient teeth into snap engagement therewith. 20

4. An assembly as claimed in claim 1, 2 or 3, wherein the annular clutch part is carried by the handle and the other clutch part is carried by the spindle.

5. An assembly as claimed in any one of the preceding claims, wherein the resilient teeth are carried by the spindle.

6. An assembly as claimed in any one of the preceding claims, wherein 25 the outwardly facing teeth are integrally moulded with the tap spindle.

7. An assembly as claimed in any one of the preceding claims, wherein the annular clutch part is positioned within the handle and drivingly connected thereto by a shear pin. INTELLECTUAL^PROPerty OFFICE 3 0 APR 1998 RECFfWTT8 329798

8. An assembly as claimed in claim 7, wherein the shear pin is adapted to frictionally engage the annular clutch part and the handle.

9. An assembly as claimed in any one of the preceding claims, wherein at least two of the outwardly facing teeth include an inwardly facing stiffening rib.

10. An assembly as claimed in claim 9, wherein the handle includes a hot or cold indicia button, the shaft of the button pausing through the handle into frictional engagement with the stiffening ribs.

11. An assembly as claimed in any one of the preceding claims, wherein the end of the spindle remote the handle includes an outer threaded portion adapted to threadably engage a tap body, a distal shaft portion having a groove for receiving and locating a sealing O-ring and a recess adapted to receive the stem of a jumper washer.

12. An assembly as claimed in any one of the preceding claims, wherein the tap spindle, the handle and both the clutch parts are formed from a plastics material.

13. An assembly as claimed in claim 11, when the plastics material is PBT (polybutylene teraphthalale).

14. A tap handle and spindle assembly, said assembly substantially as described herein with reference to the accompanying drawings. END OF CLAIMS