GB2336606A - Variable flush facility for a siphon-discharge W.C. cistern - Google Patents

Abstract

A siphon control system for a lavatory cistern including control means coupled to the crown of the siphon for adjusting the water level at which the siphon action is broken. The control means comprise a valve 31, 33, 35 which controllably couples a pair of downwardly extending pipes 37, 39 of different lengths attached thereto to the siphon crown via a pipe 41. When the lavatory is flushed, the siphon action will terminate when the water level reaches the lower end of the shortest pipe selected by the valve. The valve can be set by a control dial 21, 23 located on the outside of the cistern concentrically with the flushing handle 25.

Description

- 1 2336606 The present invention relates to water cistern apparatus, and

in particular to an improvement to the siphon discharge type water cistern.

In developed countries, it is still not unusual to regard clean water as a virtually free and limitless resource. Increasingly, however, the cost of providing this water is being recognized in terms of both the environment (the extraction of water from rivers for example) and the processing needed to ensure that the water is free from contaminants. There is now much interest in methods and devices which reduce domestic water consumption.

The modern system of disposal of human sewage in a hygienic fashion depends on the water closet lavatory. This has been dependent upon copious supplies of water, and for some time efforts have been directed towards making this system more efficient. One of the simplest methods for reduce the amount of water used in flushing a lavatory is the placing of a brick in the water cistern. This has the disadvantage that if the amount of water in the flush turns out to be insufficient, a second flush is necessary, thus wasting water instead of conserving it. It will be observed that the amount of water required for evacuating the lavatory pan will 'vary, and that being able to vary the amount of water used in a controlled fashion would increase the efficiency of the lavatory.

Whilst the amount of water used for each flush may easily be controlled using the simple valve-controlled water cistern, this is not possible with the siphon discharge water cistern, as once the siphon action has been initiated, the flush will only end when the cistern has emptied to the level that the siphon can no longer draw water.

A conventional siphon discharge system comprises a long vertical discharge leg beside a shorter leg, the two legs being connected at their tops by a crown. The long leg leads at its base to a pipe to the lavatory bowl. The short leg ends at its base with a widened section or barrel, which is fitted inside with a sealing disc. Depressing the lavatory's handle causes the disc to rise within the barrel, forcing water up the short leg, over the crown, and down the discharge leg. The falling of the water in the discharge leg causes a drop in pressure, so that the remaining water in the cistern is forced through the two legs by atmospheric pressure. The sealing disc contains one-way flaps to allow this process. When the level of water in the cistern falls below the barrel's inlet, the siphoning of the water stops.

In this fashion then, a regulated volume of water is released, but there is no means to vary this volume. A common modification of this system which allows the amount of the flush to be varied involves the inclusion of a hole upon the upper surface of the barrel, and a corresponding stopper upon the scaling disc. When the lavatory handle is depressed and the sealing disc is raised, the stopper on the disc plugs the hole in the barrel and the siphon operates in the conventional way. But upon raising the handle and allowing the disc to fall, the hole is opened, and should the water level be below the hole, the siphon will cease. The amount of water used thus depends on whether the handle is kept depressed or is released immediately. Unfortunately, many people are unwilling to learn to use this system, or misjudge when to release the handle. Other devices use apparatuses in the wall of the sipion leg, or valves within the siphon, similarly controlled by the length of time by which the handle is depressed.

It is therefore preferable to use a system whereby the amount of water discharged may be preset, and then the flushing initiated by a single depressing action of the handle.

One system (GB 2 275 697 A) includes a pipe coupled to the barrel of the short leg in such a manner that the pipe may be rotated between a vertical position and a horizontal one. The siphon action will cease when the level of water in the cistern drops to the opening of the pipe. Similarly, another system (GB 2 162 214 A) uses a pivoting pipe to vary the water level at which the siphon will cease. This system though either requires an additional hole in the cistern, or a modification of the cistern cover. Also, not all cisterns will have a suitable configuration to allow a pipe to describe an arc.

However, these systems require the user to set the pipe's position by manipulation inside the cistern. While they permit presetting of the amount of the flush, they do not allow adjustment of the amount of flush in use.

3 Another system (GB 2 241 717 A) provides a flexible pipe, linked to the crown of the siphon, which can be raised and lowered. Again, the siphon action will cease when the level of water in the cistern reaches the pipe's opening. In this system the means for controlling the amount of water used are located outside the cistern, so that the user may vary the flush before each operation. However, this system is impractical to install, requiring modification of the cistern cover.

The object of the present invention is to provide an improved apparatus for controlling the amount of water used during the flushing of a lavatory.

According to the invention there is provided a siphon control system for a lavatory cistern including control means coupled to the crown of the siphon for adjusting the water level at which the siphon action is broken, wherein the control means comprise a valve which controllably couples a downwardly extending pipe attached thereto to the siphon crown. Preferably the valve-has a plurality of pipes of different lengths attached to it. When the lavatory is flushed, the siphon action will therefore be terminated when the water level reaches the lower end of the shortest pipe selected by the valve. The valve can preferably be set by a control dial located on the outside of the cistern concentrically with the flushing handle. The invention also provides a valve for such a system, and a cistern including such a system.

The present system can be provided as original equipment for a cistern which is being newly installed, or retro-fitted to an existing cistern.

A water cistern apparatus embodying the invention and various modifications thereof will now be described, by way of illustrative example and with reference to the drawings, In which:

Fig. 1 is an exploded perspective view of the system; Fig. 2 shows the location of the valve block in the cistern and the arrangement of tubing; Fig. 3 shows a section of the valve block and valve cylinder; Fig. 4 shows a fitment for the siphon crown; Fig. 5 shows a lifting arm; and Fig. 6 shows the components of a modified valve assembly.

Referring to Fig. 1, the system comprises a selection valve means, tubing associated with the selection valve, and a control means. The control means includes a control dial, here shown in two parts 21 and 23, which incorporates a conventional handle 25 consisting of a lever 24 and a shaft 26, a control dial surround 27, and a control dial support 29. The selection valve means comprises valve block 31, valve cylinder 33, and back plate 35, the valve block having having pipes 37 and 39 and tubing 41 leading off from three ports. The valve block is located in the cistern as shown in Fig. 2. All major components (apart from the handle 25, which will usually be metal) can conveniently be made by injection moulding of plastics material.

The end of the tubing 41 has to be attached to the crown of the siphon as shown. This may require drilling a hole in the crown (which will normally be constructed of plastics material). To achieve a quick and easy connection, a rubber adaptor 44 may be used as shown in Fig. 4. This adaptor is pushed into the hole in the siphon crown 45, and then has the end of the tubing 41 pushed into it, The tubing 41 may end in an angle adaptor: as shown.

The construction and use of the apparatus will be described in detail below, but it may be useful to note at this point that the structure consists broadly of three groups of components. The first group consists of the control dial surround 27, the control dial support 29, the valve block 31, and the valve back plate 35; these components are all immovably attached together to the cistern. The second group consists of the control dial (parts 21 and 23) and the valve cylinder 33, which are attached together and are rotatable inside the control dial surround 27, the control dial support 29, and the valve block 31. The third group is formed by the handle 25 alone; the shaft 26 of this handle passes through the first two groups and is freely rotatable inside those first two groups.

Referring back to Figure 1, the valve block 31 has two cylindrical cavities. One cavity is threaded, and allows the valve block to be screwed onto the threaded shaft of the control dial surround; the other cavity is on the opposite side to accommodate the valve cylinder (only the threaded cavity is visible in Fig. 1). The control dial support 29 has a hollow threaded shaft 30 which is passed from the outside of the water cistern through an aperture usually present in a conventional cistern to accept a handle. It is then screwed onto the valve block 31 until both components are tightly secured to the cistern.

- The control dial consists of two parts, the control dial knob 23 and the control dial intermediate member 21. Member 21 has splines which pass through the hollow shaft 30 of the control dial support 29, so that the face of te con- trol dial rests just proud of the outside of the cistern. The valve cylinder is inserted from inside the cistern into the cavity of the valve block not occupied by the threaded shaft of the counter support. A hole between the two cavities allows the splines of the valve cylinder 33 and the splines of the control dial 21 to engage. The valve cylinder will now turn with the control dial. An annular ring 35 secures the valve cylinder 33 in the valve block 31. The ring 35 is shown with two screws for securing it to the valve block, but may be attached by ultrasonic welding.

In an alternative embodiment, the valve block 31 has a single cylindrical cavity, the location of whose opening is indicated by the dotted line 34, and on the opposite side of the valve block there is present only a hole large enough to allow the shaft 26 of the handle 25 through. The valve cylinder 33 is inserted into the valve block, whereupon a tubular element is placed after the valve cylinder to secure it, this element being secured itself to the valve block by means of screws. The tubular element bears a screw thread upon its inner surface, which engages with the shaft 30 of the control support 29. In this embodiment, the element 35 is of course not used.

The control dial 23 features a raised rib across its diameter. When engaged correctly, this rib should be aligned with the central depression of three depressions present on the valve cylinder. If desired, the splines could be made dissimilar so that the two sets of splines will only engage when the control dial 21-23 and the valve cylinder 33 are correctly orientated to each other.

Both sets of splines of the control dial 21 and the valve cylinder 33 are hollow, so that the shaft 26 of the handle 25 may pass through the valve selection means and out the other side, and may be attached in a conventional manner within the cistern to the means for raising the siphon's scaling disc. Thus the lever 24 of the handle, which during rest is approximately horizontal, will be capable of a clockwise rotation about its shaft 26 of 60 to initiate the emptying of the cistern in the conventional way.

The control dial 23 is attached to portion 21 by a projection 22 which spaces it from portion 21 sufficiently to accommodate the lever 24 of the handle - 6 and extends around only a part of the circumference of the dial 23, to allow adequate movement of the handle 25. The attachment of the dial 23 and portion 21 may be by means of p set of pins projecting from eg the knob 23 pnd enggiing in p corresponding set of hollow pegs projecting from portion 21. These pins pnd pegs con conveniently be locpted inside the projection shown.

In most lpvptories, the hondle is on the right side of the cistern, isnd extends to the right. The projection 22 con therefore extend jaround p substpntipl port of the circumference of the dipl 23. If, however, it is desired thpt the system should be uspble on p lpvotory hpving Fa hpndle on the left side of the cistern os opposed to the more usuffi right side, or with the lever of the hondle extending to the left, the size of the projection on the dipl 23 becomes restricted. This con be overcome to some extent by mpking the two ends of the rib on this diMI identicpl, so thpt the dipl clan be fitted in either of two positions 180 pport, depending on which wpy the handle 25 extends. The number of splines on the control diMI portion 21 pnd the volve cylinder 33 should be eyen (eg 2, or 4 ps shown), so that the system may be fitted to either 51de of the cistern, and still operote.

When the pppprotus is being supplied ps originpl equipment, it is desirpble to include p lifting prm which couples the shpft 26 of the hpndle to the sepling disc in the siphon. A conventionpl prm con be used, but it is preferred to use on prm 47 of the form shown in Fig. 5. This has in row of apertures 48 into pny of which the link to the sepling disc con be inserted, depending on the distonce between the link pnd the shpft of the hondle 25. It plso hps two squpre apertures 49, set pt slightly different ongles (typicplly 25 pnd 35) through either of which the shgft 26 con be ppssed.

The control dipl surround 27 is pttpched to the hepd 28 of the control digil support 29 by snpp locking type splines (not here visible). This must of course be cprried out during the pssembly of the ppporotus before the hpndle 25 or control diol 21-23 is inserted into the control digl support. Since different cisterns hove different thicknesses, it is not possible to predict the orientption thpt the control dial support will finish in to achieve pdequpte securing of the pppprptus (the vplve block 31 should be orientpted so thpt the two pipes 37 ond 39 ore pointing downwiards from the vplve block). For this repson, the control diial surround, which hpe the legends MAX, MED, pnd MIN (for Miaximum, Medium, iand Minimum) imprinted on it, must be pttisched to the control dijal support 29 7 - after the control dial support has been screwed onto the valve cylinder, with the legend MED uppermost.

Referring to Fig. 3, the valve block has three ports, two on its underside, connected to the short pipe 37 and the long pipe 39, and one port on its side, which is connected by tubing 41 to the crown of a conventional siphon discharge system. A small hole must be made in the crown of the siphon for this purpose, and the tube connected er. shown in Fig. 2 so that the system is substantially airtight. A further port 43 is located on the valve block so that the same apparatus may be fitted to a lavatory having a handle on the left side of the cistern as opposed to the more usual right side, but the redundant port should be plugged shut. The pipes 37 and 39 and the tubing 41 may be simple press fits in their ports.

The control dial surround 27 (Fig. 1) has the legends MAX, MED, and MIN (for Maximum, Medium, and Minimum) imprinted on it so that if the legend MED is uppermost, the legends MAX and MIN will be located approximately 45 anticlockwise and clockwise respectively. Aligning the control dial rib with MAX, MED, or MIN and depressing the lever 24 of the handle will cause a full emptying, a partial emptying or a lesser emptying still of the cistern respectively. As the dial must be capable of turning through approximately 90 and the handle through approximately 60', it will be seen that the section by which the two portions of the control dial are' attached together must occupy no more then the remaining 210 section of the control dial.

Referring to Figure 3, the valve cylinder has a channel cut into its cylindrical surface in such a way as to offer connection between the three ports. The channel extends round approximately 300 of the circumference of the valve cylinder. In this way, the short pipe 37 port, the long pipe 39 port and the tubing 41 port are so positioned in the valve block that the valve offers three modes, corresponding to the MAX, MED, and MIN positions of the control dial.

Other arrangements and types of valve may of course be used to achieve a similar effect, such as slide valves or flap valves. In particular, the channel here shown cut intothe curved surface of the cylinder could equally be cut into either of the flat circular faces of the valve cylinder, with the ports being suitably adapted.

8 - In the MAX position, the channel does not connect the crown port 41 to either of the other ports; upon flushing, the siphon discharge system acts in a conventional manner and the siphon action only ceases when the water level of the cistern reaches the bottom of the barrel of the short leg. In the MED position, the channel connects the crown port with the long pipe 39 port; upon flushing, the siphon action will cease when the level of water in the cistern drops below the end of the long pipe, as at this point the pressure difference between the crown and the atmosphere is destroyed. In the MIN position, the crown port is connected to both the long pipe port and the short pipe port 37; upon flushing, the siphon action ceases when the water level in the cistern drops below that of the end of the short pipe.

It will be seen that the actual volume of water released during a flush in the MIED and MIN modes is dependent upon vertical depth of the pipes in the cistern. A convenient subdivision might be to have the pipes extend so that the long pipe ends at a level at which the cistern is one third ful-1, and the short pipe ends at a level at which the cistern is two thirds full. The two pipes, the channel and ports in the valve, and the tube should be of sufficient diameter to ensure a speedy equalizing of pressure between the crown and the atmosphere to achieve consistent flushes.

The selection valve includes a sprung ball bearing (not shown) in the body 31, which may rest in one of three depressions on the valve cylinder, corresponding to the three modes of the apparatus, so that the dial will rest with a click when turned to the correct orientation. This effect may be achieved by other well known methods.

Many lavatory cisterns have a pair of apertures, one on each side, so that the handle can be located on either side; the aperture on the other side is normally blanked off by a blanking plate. The present apparatus can if desired be located on the side opposite the handle, by removing the blanking plate. This avoids having to remove the existing handle if the system is being retrofitted to an existing cistern. If desired, the control dial knob 23 may be made to fit flush against the control dial surround or a filler element used to fill in the space through which the handle 25 would normally pass.

In many lavatories, the cistern is exposed. A significant number, however, have the cistern concealed inside a casing which generally forms a flat back wall to the lavatory (usually of limited height and so providing a shelf behind the lavatory pan).

The apparatus shown in Fig. 1 is intended for attachment direct to an exposed cistern. With a concealed cistern, the spacing between the head 28 of the control dial support 29 and the valve block 31 will be larger. To accommodate such larger spacing, the control dial support must be modified by having its threaded portion extended. (Of course, the modified control dial support can be used for an exposed cistern by cutting off the end of the threaded portion.) The above description sets out the principles of the present apparatus. In practice, however, it may be desirable to make a number of modifications of the details.

The control dial surround 27 is shown as having a relatively flat face upon which the legends (MIN, MED, and MAX) are carried. It can however be made closer to a cylindrical shape, with the legends on the'cylindrical surface.

Second, the attachment of the selection valve and the control dial support may be modified. For this, the threaded portion of the control dial support is passed through the aperture (not shown) in the cistern as before, but a threaded nut (not shown) is used to secure the control dial support to the cistern. The control dial support is extended beyond the end of the threaded portion by a set of short splines, which engage with a similar set of splines on the corresponding face of the valve block 31; the splines can conveniently be quadrants. Further, to retain the valve body (valve block 31 and back plate 35) in position, the shaft of the handle 25 is grooved where it emerges from the valve body and a square circlip (not shown) is clipped into this groove'.

This arrangement allows the control dial support to be firmly attached to the cistern with a desired angular orientation'. The valve body can then be attached to it, taking up the same orientation'.

For a concealed cistern, an extended control dial support can again be used, as discussed above. However, a control dial support of standard size can be used, together with an extension piece in the form of a cylinder with splines at both ends'. It will also be necessary to adjust the position of the circlip on the shaft 26 of the handle 25. The shaft can be made with a plurality of grooves along it; if desired, a resilient washer can be inserted between the circlip and the valve to hold the valve firmly in place'.

To use this modified form of control dial support and selection valve on the opposite side of the cistern to the handle, it is necessary to provide means for fixing it is place'. This can be done by providing a dummy handle (eg with a small knob at its end instead of the usual lever 24), or by modifying the control dial support 29 to extend through the valve so that a circlip can be attached to its end'.

This modified form of control dial support and selection valve allows the control dial support 29 and the control dial surround 27 to be made as a single integral unit'.

It may be desirable for the control dial surround 27 to be partially cut back around part of its circumference, to allow the lever of the handle 25 to effectively be partially recessed in the dial surroun& The cut-back should extend around 60 (the angle through which the handle is rotated to operate the flush mechanism). Providing such a cut-back allows the depth (in the axial direction) of the projection on the control dial knob 13, attaching it to the intermediate member 21, to be reduced'.

It will be realized that if the control dial surround is cut back in this way, the apparatus will be specialized to one particular side of the cistern'. However, by appropriate positioning of the cut-back, and possibly by extending cut-back to somewhat more than 60% the same design of control dial surround can be used for both positions of the cistern, subject only to changing of the positioning of the legends thereon'.

Instead of the valve block 31 being provided with two outlets, one on each side, a single outlet may be provided. located centrally, and preferably pointing parallel into the cistern rather then vertically upwards'. The tube 41 may be coupled to this outlet by means of a 90 elbow element which has a press fit engagement with the valve outlet and can be turned to point in either direction, depending on which side of the cistern the apparatus is located on'.

If desired, a ratchet mechanism can be included so that the apparatus automatically resets itself to the MAX setting when the handle is operated to flush the lavatory.

The valve mechanism is also preferably modified, as shown in Fig. 6, to consists of a valve front 31', a valve back 35', and a valve plate 3Y; these correspond roughly to the valve body 31, back plate 35, and valve cylinder 33. These elements are assembled in the sequence shown by the sectional drawings of the top part of Fig. 6; the bottom part of Fig. 6 shows corresponding face views. Thus the valve front 31' and valve back 35' are attached to each other, eg by ultrasonic welding, gripping the valve plate 33' between them.

The valve plate 33' comprises an annulus 50 with an aperture 51 and a pip 52. Thus annulus is carried on a boss 53 which in turn carries a locating stub 54 with splines 55 around it. The plate 33' has a central passage through which the handle shaft 26 can pass. The stub 54 locates in the--endof the axial portion of the control dial intermediate member 21,_ and the splines 55 engage with the splines on the end of that member.

The valve front 31' comprises an annular chamber 58 which has an extension 59 at one point around it. The inner edge 60 of the valve front bears against the inner region of the valve plate annulus 50.

The valve back 35' has an annular surface 63 which bears against the valve plate annulus 50. There are two inlets 64 and 65 which terminate in circular apertures in this annular surface. The valve plate annulus can be turned to 3 distinct positions, in which its aperture 51 is aligned with inlet 64, inlet 65, or neither inlet. Thus one, the other, or neither inlet is put into communication with the chamber 58 of the valve front 3V. The valve back 35' has a passage 66 which communicates with the extension 59 of this chamber, and the tubing 41 is connected to this passage, eg by means of an angle adaptor like that shown in Fig. 4.

The annular surface 63 of the valve back 35' has a U-shaped projection 61 on its surface which engages with the pip 52 on the surface of the valve plate annulus 50 to limit the extent to which the valve plate can be turned. if desired, a second U-shaped projection can be provided to limit its movement in the other direction. Also, depressions can be provided in the annular surface 12 - into which the pip 60 can engage to give position location of one or more of its positions.

Many other variations will present themselves to one skilled in the art. For instance, the attachment of the components may be achieved by many different methods having no effect on the operation of the apparatus. The valve selection means in particular may be subject to variation in order to achieve different effects, such as using only a single pipe, or adding more than two pipes so that the volume of water may be further subdivided. Further, the order in which the options are presented on the control dial may be varied, by varying the positions of the ports and the shape of the channel in the valve cylinder. The tube running to the crown may if desired be located at any height along the short leg, although the crown is the optimum position.

The apparatus may be combined with features present in the prior art, such as only having a predeterminable valve position inside the cistern, or combining the apparatus with a method for allowing the volume of water to be released to be varied with the holding down of the handle, in which cas this could be achieved by connecting the tube from the selection valve to an aperture present in the short leg's barrel which is plugged by a stopper on the sealing disc whilst the handle is depressed.

C-- 1 ea:L m M3 1 A siphon control system for a lavatory cistern including control means coupled to the crown of the siphon for adjusting the water level at which the siphon action is broken, wherein the control means comprise a valve which controllably couples a downwardly extending pipe attached thereto to the siphon crown.

2 A system according to claim 1 wherein the valve has a plurality of pipes of different lengths attached to it.

3 A system according to either previous claim wherein the valve can be set by a control dial located on the outside of the cistern.

4 A system according to claim 3 wherein the control dial and valve are concentric with the flushing handle.

A siphon control system substantially as herein described and illustrated.

6 The valve of any previous claim.

7 5. A cistern including a siphon control system according to any of claims 1

to 8 Any novel and inventive feature or combination of features specifically disclosed herein within the meaning of Article 4H of the International Convention (Paris Convention).