BACKGROUND ART Although the present invention will be described with particular reference to a septic system it will be appreciated that the device may be used with any toilet system in which it is desirable to close the outlet and no limitation is intended thereby.

In areas where commercial sewage treatment is unavailable, sewage may be treated in septic tanks or pits. Septic tanks and pits are typically watertight chambers in which bacterial decomposition of the sewage sludge takes place. Inlet and outlet vents are generally provided to allow a flow of air through the tank or pit.

The vents are typically covered with a fly proof mesh to prevent flies from entering the tank or pit. The bacterial decomposition generates unpleasant odors. In order to control the entry of the unpleasant odors into the room housing the toilet and the entry of flies into the tank or pit, the inlet and outlet vents are located external to the room. It is therefore important that the inlet and outlet vents are the only openings into the tank or pit. With toilets of the water closet type, the water in the toilet bowl provides an effective seal for the septic tank. Thus, odor and fly control of the septic tank is normally not a problem in these systems.

However, other types of toilet systems do not have a water seal and are sometimes referred to as "dry" toilets. Such toilets are normally used in arid or remote areas where there is an unreliable water supply.

Typically toilets of this type have a bowl which opens directly into the septic tank or pit.

It is therefore important for odor and fly control that the toilet lid remains closed when the toilet is not in use. This relies upon a person to reclose the lid immediately after use. However, people often neglect to close the lid and the present inventor has observed that this is particularly so in some communities who are unfamiliar with the operation of dry toilets. Extended exposure of the septic tank or pit contents to the atmosphere within the toilet room may also occur if the toilet lids and seats are broken and/or removed by vandals.

Toilets having means for closing an outlet are known. Such known closure devices may be vacuum operated or operated by compressed air. These mechanisms require a power source. Power operated closure devices are not viable in isolated areas where no power is available.

Also, these toilets require manual operation such as pulling a lever, pressing a button or are operated in response to raising and lifting of the toilet lid. It can be seen that these types of devices also suffer from the disadvantage that some degree of manual intervention is required. Further disadvantages of the known devices are that they are typically complicated to manufacture and operate and have a number of parts which require servicing and maintenance. They are therefore unsuitable for use in remote areas where regular servicing is not possible.

Mechanical devices which automatically open when a person sits on a toilet seat are also known. These devices typically have a pair of hinged doors which swing downwardly. Typically, the devices have an arm or pair of arms depending from the toilet seat. In the non-use position, the device is biased towards the closed position by a spring or springs. In the non-use position, the seat is generally raised above the level of the pan. The seat may then be lowered when a person sits on the seat. The present inventor has observed that a disadvantage of such devices is that the doors and/or

hinges are prone to obstruction, blockage or damage by rubbish and other debris being thrown into the toilet.

This may be a problem in remote areas where regularly cleaning of the toilet does not take place.

It is therefore an object of the present invention to provide a device for closing a toilet which may at least partially overcome the above disadvantages or provide the public with a useful choice.

SUMMARY OF THE INVENTION According to a broad form of the invention, there is provided a device for closing an outlet of a toilet, the device including a sliding member which is slidable between a closed and an open position and which is biased towards the closed position, an actuating means for sliding the sliding member between the closed and open positions and which is adapted to be actuated by the weight of a user, such that when the toilet is in use, the actuator slides the slide member to the open position and when the toilet is not in use, the slide member is returned to and maintained in the closed position.

The device of the present invention may be used with any type of "dry" toilet having an outlet. Such toilets include conventional toilets having a ceramic bowl, wooden bench type toilets, portable toilets or toilets for use in moving vehicles.

The actuating means may be any suitable type of actuator which is operated by the weight of a user. In one form the actuating means may include an arm and lever which is located such that it abuts the lower surface of a toilet seat. When a user sits on the seat, the arm or lever is depressed which actuates the sliding member to open. This can be accomplished by a suitable lever arrangement. Alternatively, the actuating means may include a pressure actuator located beneath the seat. The pressure actuator in turn controls a hydraulic or pneumatic ram which operates to move the sliding member to the open position. When the pressure is released, the rams return the sliding member to the closed position.

The sliding member of the toilet of the present invention may be of any suitable type. In the closed position, the sliding member should substantially restrict the entry of flies into and odor from the septic tank or pit. It is not necessary that an airtight seal be provided, although a substantially airtight seal is preferred. Preferably, the device has a pair of opposing semicircular slide members which slide away from and to each other so as to open and close the opening.

In a particularly preferred embodiment of the invention, the device is housed in a frame having an upper portion movable between an upper and a lower position relative to the frame. The upper frame portion is biased towards the upper position. The actuating means'is operatively associated with the frame member and the lower part of the toilet pan is adapted to rest on the frame member. When a person sits on the toilet seat or the upper part of the pan if there is no toilet seat, the upper portion of the frame is depressed to the lower position and the actuating means operates to open the slide. An advantage of this embodiment is that if a toilet seat is removed by vandals, the device will still operate so as to open and close the toilet.

According to a further embodiment of the present invention, there is provided a device for closing an outlet of a toilet, the device having a frame, a frame member movable between an upper and a lower position in response to weight being placed on a toilet pan, biasing means for biasing the frame member in the upper position and a closure means movable between a closed and an open position when the frame member is depressed and a closed position.

In an especially preferred embodiment, the device further includes an additional actuating means adapted to locate on the floor or ground directly in front of the toilet. Thus the closure may also be activated to open when a user is standing in front of the toilet bowl.

DETAILED DESCRIPTION OF THE INVENTION By way of example only, the present invention will be described with reference to the accompanying drawings in which: Figure. 1 is a side view of a toilet having a preferred device of the present invention installed therein, the device is in the closed position, Figure 2 is a schematic side view of the toilet of Figure 1 in the open position and Figure 3 is a plan view of the toilet of Figure 1.

Figure 1 illustrates a device 11 having a frame 12. A pan 10 of a toilet rests on frame 12 and the frame is supported by legs 9. An outlet conduit 13 is housed within the frame 12. Sewage passes into the tank or pit through conduit 13. A pair of semicircular slide members 14, 15 are located in conduit 13 and are illustrated in the closed position. The slide members are slidable between open and closed positions and pass through slots 16, 17 located on conduit 13. A drip tray 18 extends about conduit 13 and below slide members 16, 17.

The frame 12 has a rectangular upper frame member 20. The frame member is movable between upper and lower positions in response to weight placed on pan 10.

The frame member 20 is biased in the upper position by springs 21. It will be appreciated that any type of resilient material may be used to bias the position of the upper frame member 20 such as a portion of an elastomeric plastic material such as rubber. A vertical rod 22 is attached at its upper end to the upper frame member 20. Rod 22 is pivotally attached at its lower end to one end 23, 24 of a pair of arm members 25, 26. Each arm member 25, 26 has a further arm 27, 28 extending normal thereto. To these arms 27, 27 are pivotally attached opposing ends of a pneumatic cylinder 29.

The lower ends 30, 31 of the arm members 25, 26 have an elongate aperture 32, 33 located therein. Through each aperture 32, 33 extends a linkage 34, 35 which is attached at one end to a respective slide member 14, 15.

The opposing side of the device has identical features.

In use, a person sits on the upper portion of the pan 10 which may be provided with a toilet seat (not illustrated) . The weight on the pan depresses the upper frame -member 20 against the bias of springs 21. Such movement also depresses arm 22 which causes arm members 25, 26 pivot away from each other. This in turn moves links 34, 35 to move away from each other so as to move slide members 14, 15 away from each other, through slots 16, 17. In this position, conduit 13 is open so as to allow sewerage to pass therethrough. Figure 2 illustrates the device in the open position.

When the person stands up and the weight is lifted from the pan 10, the springs 21 return the upper frame member 20 to the original position. When this occurs arm members 25, 26 and slide members 14, 15 return to their original position as illustrated in Figure 1.

Figure 3 is a plan view of the device of figure 1. The slide members are illustrated in the closed 14a, 15a position and in the open 14b, 15b position.

In an alternate embodiment of the invention, the rod 22 may extend further along the toilet pan and abut the lower face of a toilet seat. Weight on the seat actuates the device in the manner as described above.

An advantage of having the device in a frame beneath the pan as illustrated in the Figures, is that the whole device may be enclosed and cannot be tampered with or vandalized. Further, the device will also function if the seat has been removed or damaged.

The device may also be operated by a foot pedal, not illustrated. The pedal may be pivotally connected at one end to the floor. A spring or other biasing means may be located at the other end of the pedal so as to lift the pedal slightly above floor level.

The pedal is attached via a lever to rod 22. In use, when the pedal is depressed the slide members are caused to open in the manner as described above. When not in use, the spring returns the pedal and slide members to

the closed position.

The springs or other biasing means as used in the present invention are preferably selected so that the device will only be actuated to open when the weight on the pan, toilet seat or pedal exceeds about 9kg. This weight corresponds to the average weight of a child who is beginning to use a toilet. Thus the seal cannot be activated during cleaning of the toilet or by smaller children who may be crawling on the toilet. It can be seen that this provides an additional advantage in that objects which may be inadvertently dropped in the toilet will be caught by the slide members and will not fall into the septic tank or pit.

The foot pedal may also be connected to a water cistern. Water nozzles may be located on opposing edges of the inner surface of the upper part of the bowl. When the pedal is activated, any water in the cistern may be released to wash out the bowl. It will be appreciated that in arid areas, fresh water may not always be available for washing the bowl. In these circumstances the water cisterns may be adapted to collect gray water.

It can be seen that the device of the present invention effectively seals a septic tank or pit irrespective of the position of the toilet lid. The device automatically opens when the toilet is being used and subsequently closes when the toilet ceases to be used. The device also does not rely on external power sources such as compressed air, solar power or mains electricity. Further, the device has a minimal number of moving parts and is particularly suited for installation in remote areas where regular servicing or maintenance is not possible. Finally, the outlet is closed automatically and no manual control is required.

In, the preferred embodiment of the invention, the device may also be fully enclosed and no moving parts are exposed. This means that the device may at. least partially protected from vandalism. Further, the device does not require the presence of a toilet seat for operation.

It should be appreciated that various other changes and modifications can be made to the embodiment described, without departing from the spirit and scope of the invention as claimed.