GB2419609A

GB2419609A - Dual flush facility for siphon-discharge flushing cistern

Info

Publication number: GB2419609A
Application number: GB0422994A
Authority: GB
Inventors: Neil Tromans; Adrian Mark Hinkley
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-10-16
Filing date: 2004-10-16
Publication date: 2006-05-03
Also published as: GB0422994D0

Abstract

A siphonic dual flush toilet flushing system operated by two operating handles which may be pressed together or independently to initiate the flush system. Operation of one handle delivers a part flush or two handles together delivers a full flush.

Description

1 2419609

SIPHONIC DUAL FLUSH SYSTEM

The present invention is a device which can be fitted to a new or existing cistern of a siphonic toilet flushing system in order to enable the user to select the volume of water discharged to the pan from the cistern with the object of reducing the overall water consumption.

There are generally two types of toilet cistern in use today and they can be described as directly draining systems or siphonic systems. None of these systems have been developed to introduce water saving to address today's urgent need to save water and the costs involved vary considerably between these systems.

In a typical directly drained system the operating lever is connected to a chain which passes down through the water in the cistern and engages the top of a flush valve. When the lever is operated the flush valve is raised and the water is free to pass through the valve and down into the discharge tube which connects the cistern to the toilet. These systems can be complex because they need to incorporate either a float system or other mechanical means in order to keep the flush valve open until the cistern is empty because the user would normally release the handle immediately after operating it and without the float system the water flow would be stopped.

In order to introduce water saving techniques into these directly drained designs, improvements were made to the directly drained flush system by introducing a dual flush system and an example of said dual flush can be found in US Patent 1,960,864. This art is an example of a system where one operating lever can operate one or both of two different outlet flush valves which are set at different levels in the cistern. The higher level valve discharges a lesser volume of water.

Said directly drained systems are expensive because of the mechanism required to ensure the continuance of water flow after release of the handle and the addition of the much needed dual flush system further increased the costs even further, making the cistern less desirable. In order to overcome the high cost of production further systems were devised to simplify the mechanism and an example of such an improvement can be found in US patent number 4,881,279, in which a two handle system was introduced which required only one flush valve. A float was used to ensure the continuance of the flow of water after the handles had been released. This went a long way to reducing the cost of a direct discharge dual flush system however the mechanism to ensure the flow of water after release of the handle is still required.

A much simpler and more cost effective method of flushing a toilet cistern is to be found in a siphonic system.

A typical siphon has a bell shaped inlet portion alongside a vertical discharge tube. Said tube being connected to the bell shaped inlet portion by means of a connecting tube at the top of the assembly. A plunger extends through the top of the bell shaped inlet portion and is connected to a round frame conforming to the inside shape of the bell shaped inlet portion which is slideably mounted for vertical displacement in order to initiate the siphonic flushing action which discharges water into the toilet bowl. Said frame also containing a flexible diaphragm, of, for example, rubber or plastic material acting as a one way valve. The plunger, which extends through the top of the bell shaped inlet portion is connected to the operating handle by means of a connecting link.

Operation of the handle causes the link to lift the plunger inside the bell shaped portion. This propels water above the frame into the discharge tube and also draws up water from below the diaphragm which passes through the diaphragm valve and continues to flow into the discharge tube and onwards into the toilet bowl until the water in the cistern reaches the level of the bottom of the belt shaped inlet portion. When the water reaches said level air is introduced into the system and this breaks the siphonic action.

Various dual flush devices have been previously designed for siphonic systems, however they are either very expensive or are not truly dual flush in the sense of a person selecting one option or another.

British patent number GB 2 270 528 is an example of a dual flush system where the dual flush is achieved by varying the entry point for air into the system. Entry of said air breaks the siphonic action and stops the flow of water into the toilet. In this example of the art, the position of the air vent has to be set in on of several pre set positions, when installing the siphon unit and it cannot be varied afterwards unless the toilet is dismantled and an adjustment is made to the position of the air vent.

British patent number 2 329 398 is an example of a siphon system which has incorporated a user controlled dual flush system. A conventional siphon is vented at a point higher than the bottom of the bell shaped inlet portion and control of the air to that additional vent is achieved by the position of the actuating lever. The default condition is the long flush for which the lever has to be pressed and quickly released then there is a short flush available which requires the user to hold down the operating lever. This method suffers from the disadvantage that the user may not necessarily know how to use the unit or cannot be bothered to wait and take the extra time required to operate the unit for the short flush system.

All of the systems currently designed require the person operating the unit to initiate the siphon and then to operate the unit again to introduce the water saving element. Recent studies show that users of these systems which require two separate actions are failing to operate the water saving elements of the system.

It is the object of the present invention to overcome the previously stated difficulties by providing a dual flush system with two operating handles with easily understood functionality, both for full flush and one for partial flush which can be fitted to a new or existing cistern. Said system to be capable of delivering, either a full or part flush, with one single initiating action and in the event of a failure in any part of the system, to default to full flush.

According to the invention in addition to the normally expected siphon components there are provided two operating lever handles connected to an inner and an outer drive shaft which extend through the side of the cistern and pass through a valve body to connect with a co-acting cam and a rota respectively. The rota operates a slide which is slideably mounted within the valve body. Said slide co-acts with the shuttle and controls the flow of air through the valve body to the siphon via a suction pipe.

The invention will now be more particularly describe with reference to the following drawings, in which: - Figure 1 Is a drawing of the invention fitted into a typical cistern Figure 2 Is an assembly drawing of the invention showing how it is fitted to a typical cistern.

Figure 3 Shown how all of the individual components of the invention are assembled.

Figure 4 shows to porting arrangements for control by the shuttle within the valve body.

Figure 5 Is a three dimensional drawing of the valve body showing the porting which was illustrated in diagrammatic form in figure 4.

Figure 6 Is the same as figure 5 with the shuttle in a different position.

Figure 7 Shows both handles in use to produce a full discharge.

Referring now to figure 1 this shows two handles in tandem providing a combination of positive visual and tactile indication to a person using the invention of the options for flushing. The invention also does not require a second action by a person operating the toilet to pre-select an option or interrupt the discharge when the invention is used. The inventions ability to deliver the entire cistern content, partial cistern content and the remaining cistern content if required provides a true dual flush and water saving device with minimal risk of misuse.

The invention can take the form as in Figure 2 as a device retrofitted to an existing system where the cistern (1.1), the siphon (1.2), the connecting rod (1.3), the bush (1.4) and crank arm (1.5) remain and the device as in Figure 3 is added consisting of an outer handle (1), an inner handle (2), a cover (3), a delivery pipe (4), a shuttle lift (5), shuttle valve (6), a valve body (7), a suction pipe (8), a rota (9), a slide (10), a cam (11) .

The outer handle (1) has a square section shaft which slides into a tubular shaft of the inner handle (2). The square section acts as a positive drive for the cam (11) and siphon crank (1.5). The tubular shaft of the inner handle (2) is splined to provide a positive drive for the rota (9).

Both handles extend through an existing plastic bush (1.4). This is secured to the cistern (1.1). The outer handle (1) extends to the crank arm of the toilet siphon (1.2) while the inner handle shaft protrudes through the cistern plastic bush (1.4) sufficiently to accept the rota (9) .

The slide (10) is position in a grove in the rota (9) and has the shaft of the outer handle (1) pass through a slot in the slide (10). The cam (11) is positioned onto the shaft of the outer handle (1) and positioned to engage the slide (10). The existing siphon crank arm (1.5) is then secured to the shaft of the outer handle (1).

The delivery pipe (4) extends from the cover (3) to the desired level of partial discharge in the cistern (1.1). The suction pipe (8) extends from the valve body (7) to a pre formed hole in the siphon (1.2) to form a sealed connection.

The shuttle lift (5) is held in a cavity formed by the valve body (7) and cover (3) directly below the shuttle (6). A round section of the shuttle lift (5) connects to the shuttle (6) through a circular orifice in the cavity, where the linear motion of the shuttle lift (5) is communicated to the shuttle (6). The shuttle lift (5) can translate in a linear motion governed by the motion of the slide (10).

The shuttle lift (5) is prevented from rotating by a perpendicular circular section of the shuttle lift (5) extending through a slot in the valve body (7) to form a connection to the slide (10).

The shuttle (6) is located in a chamber created by a cavity in the valve body (7) and sealed from the atmosphere with the cover (3). In Figure 4 a number of ports can be seen connected to the chamber, from the siphon connection (A) the vacuum enters a plenum chamber (B) where the pressure is diverted into the upper port (C) and into a restricted lower port (D).

The upper port (C) will always be covered by the shuttle (6) in any operation of the invention. Its static position is covering both ports as can be seen in Figure 5 providing the default full flush.

A connection is made to the cistern water when the lower port (0) is exposed by the absence of the shuttle (6). This allows the low pressure to enter the shuttle cavity (E) and port (F) where once the water level drops below the delivery pipe (4) air can be drawn into the siphon (1.2).

The shuttle (6) is designed with a recessed face to provide the maximum surface area and minimum contact area between the shuttle (6) and valve body (7). With the restriction of the lower port (D) a pressure differential occurs between the inner and outer surfaces of the shuttle (6). This pressure differential causes the shuttle (6) to remain in the upper position due to a greater force being applied to the recessed surface of the shuttle (6).

When the siphon (1.2) is actuated by rotating the crank arm (1.5) a positive pressure wave is communicated to the invention, this may also include quantity water injected into the plenum chamber (B). As the crank (1.5) reaches its zenith the siphonic draw begins producing a low level vacuum drawing water from the cistern and producing a vacuum in the invention.

The various pressures produced in the invention from the siphon are utilised in a number of ways, firstly the positive pressure is used to ensure that the shuttle (6) is not adhered to the surlace of the valve body (7). The vacuum is utilised to hold the shuttle (6) in place, in both lower and upper position.

Water injected into the invention from the positive pressure when the siphon (1.2) initial is activated is allowed to run back to the cistern via port (F) and the deliver pipe (4).

When the shuttle (6) is in the lifted position a temporary connection is made between the siphon and cistern when the end of the pipe in the cistern is uncovered by the water air is drawn into the siphon aerating the siphonic draw to such an extent that it stops the draw.

The level of vacuum increases in the siphon (1.2) in a linear manner as the water level drops during a flush. This is due to the increase in head pressure or the distance between the top of the siphon and water level.

The increase in the level of vacuum allows the accommodation of the air being drawn through the invention to break the siphonic draw, as the net force remains greater than the weight of the shuttle (6). However there is a lag between the uncovering of the pipe to atmosphere and the loss of suction.

When a partial discharge is required the outer handle (1) is rotated as in figure 6, two simultaneous acts occur. The first action is that the siphon (1.2) is actuated via the crank arm (1.5) and connecting rod (1.3). The second action is that the cam (II) is rotated engaging on an upper projection on the slide (10).

The continuing rotation of the outer handle (1) causes the slide (10) to lift via the increasing positional height of the cam (11). The lifting motion is translated to the shuttle (6) via the shuttle lift (5) which uncovers the lower port (D) as in Figure 6 producing a pathway for atmospheric air to be let into the siphon (1.2) when the water level drops below the end of the suction pipe (4).

When the outer handle (1) is released a force is applied to the shaft of the outer handle (1) from the siphon (1.2) in the form of a weight or spring. This force is communicated to the invention by the connecting rod (1.3) and crank arm (1.5) causing the outer handle (1) to rotate back to its start position. This counter rotation causes the cam (11) to engage on the lower projection of the slide (11) pushing the slide downwards. The motion is transferred to the shuttle lift (5) pushing to its start position.

The shuttle (6) is held in position by lower levels of vacuum from port C leaving port D open until the siphonic draw ceases and the net force applied to the shuttle (6) is removed. The shuttle (6) then drops back into its start position due to gravity as in figure 5.

When a full discharge is required both handles are used as in figure 7, three simultaneous acts occur. The first action is that the outer handle (1) and inner handle (2) are prevented from operating independently by a projection from the outer handle (1) engaging on the inner handle (2).

The second action is the initiation of the siphon (1.2). The third action is the rotation of the rota (9) which causes the slide (10) to maintain its position in relation to the cam (11). As the rotation of both inner handle (2) and outer handle (1) continues the slide (10) disengages from the shuttle lift (5).

This stops the shuttle (6) from uncovering port 0 and prevents a pathway for atmospheric air being to be let into the siphon (1.2). When the siphonic draw begins the shuttle (6) is held in place over ports C and D. When the outer handle (1) is released a force is applied to the shaft of the outer handle (1) from the siphon (1.2) in the form of a weight or spring. This force is communicated to the invention by the connecting rod (1.3) and crank arm (1.5) causing the outer handle (1) to rotate back to its start position.

The projection on the outer handle (1) communicates the counter rotation to the inner handle (2) rotating it back to the start position. This causes the rota (9) and slide (10) to rotate back to the start position re-engaging the slide (10) with the shuttle lift (5) as in figure 5.

Each feature disclosed in this specification including the drawings, may be replaced by alternative features serving the same, equivalent or similar purpose unless expressly stated otherwise. Thus, unless expressly stated otherwise each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiments, the invention extends to any novel one or any novel combination of the features disclosed in this specification including any accompanying claims and drawings.

Claims

A siphonic dual flush toilet flushing system comprising a water inlet, a water reservoir and a water siphon with associated handle which in use is depressed to initiate the siphonic action which empties the contents of the water reservoir into the toilet bowl, characterised by the provision of two operating handles which in use can be operated together or independently to deliver a full or part flush with one single initiating action of the handle or handles.
2. A siphonic dual flush toilet flushing system as claimed in claim 1 capable of defaulting to a full flush system in the event of failure of part of the system.
3. A siphonic dual flush toilet flushing system as claimed in claims 1 or 2 where the two operating lever handles are connected to inner and outer drive shafts respectively which shafts extend through the body of the water reservoir and connect to an internal mechanism.
4. A siphonic dual flush toilet flushing system as claimed in any previous claim where inner an outer shafts which are connected to two operating lever handles pass through the body of a water reservoir and then through a valve body and then connect to a cam and a rotor respectively.
5. A siphonic dual flush toilet flushing system as claimed in any previous claim where a rotor operates a slide which is slideably mounted within a valve body.
6. A siphonic dual flush toilet flushing system as claimed in any previous claim where a slide co-acts with a shuttle to control the flow of air through a valve body to the siphon.
7. A siphonic dual flush toilet flushing system as claimed in any previous claim where the flow of air through a valve body to the siphon is via a suction pipe.