NZ573411A

NZ573411A - Cistern with two tipping buckets mounted for rotation together and rotatable in different directions for respective full and reduced flush

Info

Publication number: NZ573411A
Application number: NZ573411A
Authority: NZ
Inventors: Sam Robertson England
Original assignee: Caroma Ind Ltd
Priority date: 2006-08-11
Filing date: 2007-08-09
Publication date: 2012-01-12
Also published as: NZ597121A; WO2008017114A1; AU2007283451B2; AU2007283451A1

Abstract

The dual flush cistern or flush tank (1) is disclosed having first (11) and second tipping buckets (12) each of which is pivotally mounted on a common axis of rotation (14). Each bucket is substantially a hollow half cylinder but the first bucket has a cover (19) typically as a half-cylinder, and the second bucket has an open top. Turning both buckets in one direction empties the second bucket but retains the water in the first bucket within the cover to create a reduced flush. However, turning both buckets in the opposite direction empties the second bucket and also empties the second bucket via an off centre exit aperture (21). The bucket preferably empty into a water director (6). A transfer aperture 22 allows water to be delivered to one bucket and overflow to the other with the inlet valve sensing the water level in the other bucket. Thus both buckets are filled via a single water inlet arrangement with an inlet (not shown) typically provided through hollow stub shaft 10. The cistern has a housing (not shown) shaped to be wall mounted to the rear of a lavatory pan upon which the user sits. The housing has front and rear, and left and right axes defined by a sitting user and the bucket axis of rotation is substantially parallel to the front and rear axis.

Description

TIPPING BUCKET CISTERN. MECHANISM & METHOD 7 5 Field of the Invention The present invention relates to cisterns (or flush tanks as the devices are 5 known in the United States of America).

Background Art One category of cisterns are those which incorporate a tipping bucket or buckets. Examples of such cisterns are disclosed in US Patent No. 4,646,369 (NRDC) 10 and US Patents 5,887,293 and 6,611,967 (both to Hennessy).

Such tipping bucket cisterns suffer from a number of disadvantages including that the axis of rotation of the bucket is aligned with the longitudinal axis of the cistern thereby generally resulting in a lever actuator which is used to initiate the 15 tipping action being located to one side of the cistern. Generally this is the right side as viewed by a user about to flush the cistern, however, this disadvantages left handed users. This is to be contrasted with the. category of cisterns which utilise an underwater valve and utilise push button operation. Such push buttons are normally centrally located on the top of the cistern and thus the arrangement is equally 20 convenient for both left and right-handed users.

Genesis of the Invention The genesis of the present invention is a desire to improve the operation of tipping bucket cisterns.

Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a dual flush cistern mechanism comprising first and second tipping buckets mounted for rotation together, said first bucket including a water retentive cover having an exit 30 aperture therein located to one side of the axis of rotation of said first bucket and having a volume generally equivalent to that of said first bucket, said second bucket having a substantially open top, and an inlet means arranged to fill both buckets to a similar extent, wherein rotating said buckets towards said one side simultaneously drains said second bucket via said open top and drains said first bucket via said exit RECEIVED at IPONZ on 16 December 2011 2 aperture to constitute a full flush, and wherein rotating said buckets away from said one side drains said second bucket via said open top but retains the water in said first bucket within said cover to constitute a reduced flush.

In accordance with a second aspect of the present invention there is disclosed a method of generating a dual flush in a cistern having first and second tipping buckets, said method comprising the steps of: (i) mounting said buckets for rotation together; (ii) providing said first bucket with a water retentive cover having a volume generally equivalent to that of said first bucket. (iii) providing an exit aperture in said cover to one side of the axis of rotation of said first bucket; (iv) providing said second bucket with a substantially open top; (v) filling both buckets to a similar extent; (vi) rotating said buckets towards said one side to simultaneously drain said second bucket via said open top and drain said first bucket via said exit aperture to constitute a full flush; and (vii) rotating said buckets away from said one side to drain said second bucket via said open top but retain the water in said first bucket within said cover to constitute a reduced flush.

AH21 (5824683_1 ):MAH RECEIVED at IPONZ on 16 December 2011 3 Brief Description of the Drawings Two preferred embodiments of the present invention will now be described with reference to the drawings in which: Fig. 1 is a perspective view of the cistern of the preferred embodiment; the inlet 5 control float being omitted so as not to overburden the drawings; Fig. 2 is a vertical cross-sectional view of the cistern of Fig. 1 with the housing being shown in cross-section and the cistern mechanism being illustrated in front elevation; Fig. 3 is a perspective view of the cistern mechanism of Figs. 1 and 2; AH21(5824683_1);MAH WO 2008/017114 PCT/AU2007/001113 4 Fig. 4 is an exploded perspective view of the cistern mechanism of Fig. 3, Figs. 5-10 are front elevational views of the cistern mechanism illustrating the sequence of events in relation to a reduced flush, Figs. 11-16 are front elevational views of the cistern mechanism illustrating 5 the sequence of events in a full flush, Figs. 17-20 are equivalent to Figs. 1-4 but illustrating one embodiment of the water supply arrangements for an inlet mechanism, Figs. 21-26 are equivalent to Figs. 5-10 but illustrates a float arm positioned within the second bucket, and 10 Figs. 27-32 are equivalent to Figs. 11-16 but again illustrating a float arm positioned in the second bucket.

Detailed Description As seen in Figs. 1-4, the cistern 1 of the first embodiment has a cistern housing 15 2 which takes the form of a body 3 and a top 4. Located within the body 3 is a water director 6 which constitutes a hollow half cylinder and which is directly connected to the flush pipe 7 of the cistern 1. - In addition, as best seen in Fig. 4, the water director 6 includes two U-shaped 20 bearings 8 which support a combination bucket 9 having a pair of stub axles 10 (only one of which is visible in the drawings).

The combination bucket 9 takes the form of a first bucket ll and a second bucket 12 which have a common axis of rotation 14 defined by the stub axles 10. The 25 first and second buckets 11, 12 are preferably of the same size and have a common wall 16. The first and second buckets are each half cylinders with the axis of the cylinders being the axis of rotation 14. The second bucket 12 has an open top 18 whilst the first bucket has a cover 19 which is also substantially half-cylindrical. As a consequence, the first bucket 11 and its cover 19 together constitute a substantially 30 hollow cylinder.

In the circumferential wall of the cover 19 is located an exit aperture 21 through which water in the first bucket 11 can exit. In addition, in the common wall 16 is a transfer aperture 22 which enables water to transfer between the buckets. As WO 2008/017114 PCT/AU2007/001113 will be explained hereafter, the preferred inlet arrangement is for water to be delivered into the first bucket 11, to transfer via the transfer aperture 22 into the second bucket 12 and for the level of water in both buckets to be controlled by the level of water in the second bucket 12.

Preferably the combination bucket 9 is provided with two lips 24, 25 which extend in opposite directions and over which water pours as will be described in relation to Figs. 5-16. The combination bucket 9 is preferably also weighted by a slight mis-alignment of its centre of gravity and the axis of rotation 14 so that the 10 empty combination bucket 9 returns to the upright position illustrated in Figs. 1-4 under the influence of gravity.

Turning now to Figs. 5-10, the sequence of events in creating a reduced flush (typically three litres) will now be described. Fig. 5 illustrates the rest position of the 15 combination bucket 9 with both buckets full of water. The combination bucket 9 is rotated by any convenient mechanism clockwise as seen in Fig. 6. As a consequence, the water within the second bucket 12 pours over the lip 25 as a result of the-open top 18 of the second bucket 12. This pouring action reinforces the initial impetus given to the combination bucket 9 which therefore continues to rotate approximately 90° into 20 the position illustrated in Fig. 7. As a consequence, the second bucket 12 is substantially entirely drained of water which enters the flush pipe 7.

However, only water from the second bucket 12 enters the flush pipe 7 because the water in the first bucket 11 is retained within the first bucket 11 by means 25 of the cover 19. In particular, the exit aperture 21 of the cover 19 is uppermost and therefore no water exits the first bucket 11 via the exit aperture 21. A similar situation applies in relation to the transfer aperture 22.

When the second bucket 12 has drained, the reduced volume flush is 30 completed and the combination bucket rotates in an anti-clockwise direction as seen in Fig. 8 back towards the rest position which is illustrated in Figs. 9 and 10. As the transfer aperture 22 approaches the rest position, so the level of water within the first bucket 11 reaches the lower edge of the transfer aperture 22 thereby resulting in water overflowing from the first bucket 11 to the second bucket 12. In addition, the inlet WO 2008/017114 PCT/AU2007/001113 6 mechanism (to be described hereafter) being controlled by the level of water in the second bucket 12 turns on thereby delivering water to the first bucket 11. Water is continually transferred from the first bucket 11 to the second bucket 12 until both buckets reach the same level at which the level of the second bucket 12 controls the 5 inlet mechanism and stops the delivery of water to the first bucket 11.

The sequence of events constituting a full flush (typically six litres) is illustrated in Figs. 11-16. From the rest position illustrated in Fig. 11, the combination bucket 9 is rotated in an anti-clockwise direction by any convenient 10 means as illustrated in Fig. 12. As a consequence, water pours over the lip 24 from both the first bucket 11 via the exit aperture 21 and from the second bucket 12 via the open top 18. The water flowing over the lip 24 reinforces the initial rotary impetus and thus the combination bucket 9 continues to rotate through approximately 90° as illustrated in Fig. 13. Both buckets 11,12 drain simultaneously into the flush pipe 7.

When both buckets 11, 12 are empty, the combination bucket 9 returns in a clockwise direction as illustrated in Fig. 14 back towards the rest position illustrated in Figs. 15 and 16. Again the inlet mechanism controlled by the level of water in the second bucket 12 delivers water to the first bucket 11 which as it fills reaches a water 20 level coincident with the lower edge of the transfer aperture 22. This therefore results in water transferring from the first bucket 11 into the second bucket 12. Eventually the position is reached as illustrated in Fig. 16 where both buckets are full and the water level within the second bucket 12 causes water flowing into the first bucket 11 to cease flowing.

Turning now to Figs. 17-20, a second embodiment of the present invention is illustrated in which details of the flush actuator 30 and inlet supply 40 are illustrated. The flush actuator 30 is centrally located on the top 4 and constitutes an inverted Y-shaped body 31 which is pivoted at 32. The circumferential wall of the cover 19 is 30 provided with a lug 33 which, in the rest position of the combination bucket 9, is positioned between the arms of the Y-shaped body 31. As a consequence, movement of the stem of the Y-shaped body 31 to either the right or the left induced by the hand of a user, initiates rotation of the combination bucket 9 in either an anti-clockwise direction or a clockwise direction respectively. 7 As best seen in Fig. 20, the inlet supply 40 includes an elbow 41 having a pair of sealing O-rings 43 positioned on a spout 44 which extends through the stub axle 10 and opens into the first bucket 11, A flexible hose 45 as seen in Figs. 17 and 18 5 interconnects a mains supply 47 with the elbow 41.

As seen in Figs. 21-32, a float arm 50 is provided above the second bucket 22 and senses the level of water within the second bucket. When the water level drops the float arm 50 opens a valve (not illustrated) contained within the spout 44 to 10 thereby permit water to flow from the main supply 47 into the first bucket 11. Conversely, when the water level within the second bucket 12 reaches its maximum desired level, the float arm 50 rotates so as to close the valve within the spout 44 and cease that water delivery.

The foregoing describes only two embodiments 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. For example, the buckets 11, 12 need not be cylindrical since a generally rectangular shape will achieve the same ends. However, the cylindrical shape illustrated has the advantage of less turbulent water 20 delivery. In addition, it is similarly not essential for the first and second buckets to have the same axis of rotation, nor is it essential for the first and second buckets to be fabricated in a single piece to form the combination bucket 9. Similarly, clearly a single flush cistern can be created using just a second bucket 12.

The above described arrangements have a number of advantages. Firstly, the flush actuator 30 is able to be positioned centrally on the top 4 in such a way to be entirely neutral as to whether the person operating the cistern is left or right handed. This is to be contrasted with the arrangements illustrated in the abovementioned prior art where a rocker arm is located to one side of the cistern and therefore at least some 30 users will be disadvantaged depending upon whether they are right or left-handed.

Furthermore, the housing 2 is shaped to be wall mounted to the rear of a lavatory pan upon which a user sits. The housing 2 has a front to rear (transverse) axis and a left to right (longitudinal) axis both defined by the intended orientation of WO 2008/017114 PCT/AU2007/001113 8 the user whilst sitting on the pan. The cistern tipping bucket or buckets is/are pivotally mounted within the housing 2 so that the axis of rotation (eg. 14) of the or each tipping bucket is substantially parallel to the front to rear axis. That is the axis of rotation 14 is transverse to the longitudinal axis of the cistern housing 2. Thus the 5 entire arrangement is able to be fabricated in a much more compact manner than in the abovementioned prior art. This leads to a cistern housing 2 of conventional dimensions which therefore has increased market appeal.

The term "comprising" (and its grammatical variations) as used herein is used 10 in the inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of'.

WO 2008/017114 PCT/AU2007/001113 9

Claims

1. A dual flush cistern mechanism comprising first and second tipping buckets mounted for rotation together, said first bucket including a water retentive cover having an exit aperture therein located to one side of the axis of rotation of said first bucket and having a volume generally equivalent to that of said first bucket, said second bucket having a substantially open top, and an inlet means arranged to fill both buckets to a similar extent, wherein rotating said buckets towards said one side simultaneously drains said second bucket via said open top and drains said first bucket via said exit aperture to constitute a full flush, and wherein rotating said buckets away from said one side drains said second bucket via said open top but retains the water in said first bucket within said cover to constitute a reduced flush.

2. The mechanism as claimed in claim 1 wherein said first and second buckets rotate about a common axis of rotation.

3. The mechanism as claimed in claim 2 wherein said first bucket and cover constitute a hollow body of substantially cylindrical shape.

4. The mechanism as claimed in claim 3 wherein said second bucket comprises a hollow body of substantially half-cylindrical shape.

5. The mechanism as claimed in claim 4 wherein said first and second buckets are joined together by a common wall.

6. The mechanism as claimed in claim 5 wherein said inlet means includes a transfer aperture in said common wall.

7. The mechanism as claimed in claim 6 wherein said inlet mechanism includes a spout which opens into said first bucket and is controlled by the level of water in said second bucket

8. The mechanism as claimed in claim 7 wherein said inlet mechanism includes a float arm positioned adjacent the open top of said second bucket.

9. The mechanism as claimed in any one of claims 1-8 wherein said buckets rotate within a water director connected to a flush pipe of the cistern.

10. The mechanism as claimed in claim 9 wherein said water director comprises a hollow substantially half-cylindrical body.

11. The mechanism as claimed in claim 10 wherein said water director is positioned within a cistern housing. RECEIVED at IPONZ on 16 December 2011 10

12. The mechanism as claimed in any of claims 1-11 and located within a cistern housing having a body and a top, said mechanism including an actuator to impart rotary motion to said buckets in either one of two opposite directions.

13. The mechanism as claimed in claim 12 wherein said actuator is substantially centrally located on said top.

14. A method of generating a dual flush in a cistern having first and second tipping buckets, said method comprising the steps of: (i) mounting said buckets for rotation together; (ii) providing said first bucket with a water retentive cover having a volume generally equivalent to that of said first bucket; (iii) providing an exit aperture in said cover to one side of the axis of rotation of said first bucket; (iv) providing said second bucket with a substantially open top; (v) filling both buckets to a similar extend; (vi) rotating said buckets towards said one side to simultaneously drain said second bucket via said open top and drain said first bucket via said exit aperture to constitute a full flush; and (vii) rotating said buckets away from said one side to drain said second bucket via said open top but retain the water in said first bucket within said cover to constitute a reduce flush.

15. The method as claimed in claim 14 including the further steps of: (viii) filling said first bucket from an inlet controlled by the level of water in said second bucket, and (ix) providing a transfer aperture between said first and second buckets.

16. A dual flush cistern mechanism, the mechanism substantially as hereinbefore described with reference to the accompanying drawings.

17. A method of generating a dual flush in a cistern having first and second tipping buckets, said method substantially as hereinbefore described with reference to the accompanying drawings. Caroma Industries Limited By the Attorneys for the Applicant SPRUSON & FERGUSON AH21(5824683_1):MAH