GB2288194A

GB2288194A - Dry toilet

Info

Publication number: GB2288194A
Application number: GB9405323A
Authority: GB
Inventors: Robert Douglas Hawkins; James Alan Hawkins
Original assignee: WATERSTATE Ltd
Current assignee: WATERSTATE Ltd
Priority date: 1994-03-18
Filing date: 1994-03-18
Publication date: 1995-10-11
Also published as: GB9405323D0; EP0814696A4; EP0814696A1; WO1995024853A1

Abstract

A dry toilet with a disposable lining material (17) comprises a roll (18) of continuous, folded sheet material lining and a toilet bowl (16) adapted to receive the folded sheet material lining through a side entrance aperture (21) and to remove the soiled sheet material lining together with the contained waste through a side exit aperture (23). A concealed conveyance apparatus deployed around the perimeter of the toilet bowl has means for holding, advancing, separating, rejoining and releasing the opposing edges of the folded sheet material and thereby draping the opened or unfolded sheet material to form a liner in the proximity of the inner surfaces of the toilet bowl while simultaneously removing the soiled liner material for disposal into a drain (26). <IMAGE>

Description

DRY TOILET This invention relates to improvements in dry toilets and particularly to dry toilets with disposable toilet bowl lining.

Dry toilets do not use water and are useful in localities where water supply is limited or where water should be conserved or where sewage facilities for handling toilet waste water are not available. Dry toilets are also useful as portable, mobile or temporary toilets where connection to the water supply or to the sewer mains is not practical. Dry toilets include chamber pots, privies, composting toilets, incinerator toilets and some chemical toilets.

Dry toilets have no water to convey waste away or to clean toilet surfaces and therefore various earlier patents describe bags or tubes to fit within a dry toilet to contain the waste or to convey the waste to a place of storage or disposaL Despite the need for this improvement there has been virtually no commercial acceptance of these various published ways of lining dry toilets. The requirements for low operating cost, low maintenance costs and user acceptance are not adequately satisfied by the ideas that have been proposed.

Low operating cost requires a low cost liner. Liners shown in earlier patents requireing special prefabrication or special materials are relatively expensive to dispose of each time a toilet is used.

Low maintenance cost depends on the need to store within the available space enough lining for a large number of use cycles ('flushes') and the need for simple, reliable operating mechanisms that cannot malfunction because of user carelessness.

User acceptance requires a conventional toilet appearance with a clean enclosed bowl, no visible waste accumulation, no upward splash while in use, an ability to empty ('flush') at any time and no special user rules or user training.

Generally, it is the objective of this invention to provide a waterless or dry toilet having the operating charactereristics that are normally associated with flushing toilets. These characteristics being the better aesthetic properties of a closed bowl, the ability to rapidly remove waste from the bowl and to convey that waste to an independent tank or drain and the ablility to provide a clean bowl after each use.

Specifically, one object of the present invention is to provide an improved dry toilet having a bowl area lined with a disposable layer of sheet material. This sheet material being deployed to contain the human waste and to prevent the soiling of the internal toilet surfaces.

Another object of the invention is provide relatively simple apparatus to automatically emplace the sheet material liner within the bowl area prior to use and to similarly remove the soiled liner after use together with the contained waste.

Another object of the invention is to provide toilet bowl liner material in the form of low cost, flat film supplied from a roll having enough material for a large number of use cycles. This liner material could, for example, be a thin plastic film.

Another object of the invention is to provide a toilet bowl liner sheet made with materials that are easily disposed of in conventional water flushed sewage drains or which are compatible with the biological action of composting processes.

According to a preferred aspect of the present invention there is provided a dry toilet comprising a supply of folded sheet material, an upright toilet bowl, the toilet bowl walls being adapted by means of a side entrance aperture and a side exit aperture for the passage through the bowl of the folded sheet material, a conveyance apparatus deployed around the rim of the bowl with means for holding, advancing, separating, rejoining and releasing the opposing edges of the folded sheet material and thereby draping the opened or unfolded sheet material to form a liner in the proximity of the inner surfaces of the bowl, a means of actuating the conveyance apparatus to advance the liner sheet material a distance that will cause the soiled liner sheet material to be removed from the bowl and be replaced with clean liner sheet material, an entranceway into an enclosure beyond the exit aperture through which the soiled sheet material passes for disposal or storage after being released by the conveyor apparatus, said entranceway may be equipped with an automatic closure to prevent the escape of odours when the sheet material is not in motion, a means for exhausting air from within the bowl beneath the liner material to assist the liner material to conform to the shape of the bowl, and a cover adapted to provide for a toilet seat and further adapted to enclose, protect or support, in cooperation with other structure, the aforesaid operating components.

Further according to the preferred aspect of the present invention the said conveyance apparatus might, for example, comprise two separate but synchronised and horizontally supported belt drives, each belt transporting one edge of the folded sheet material and each belt traversing one half of the toilet bowl rim, a series of pulleys and guides to constrain the belts to follow the prescribed path, short pins projecting at intervals from the outer surface of the belts to penetrate and hold the edge of the sheet material , said pulleys and guides on the outer surface of the belt having grooves to clear the projecting pins while pressing the sheet material against the belt, a tensioning means to assist the accurate alignment of the edges of the sheet material when engaging with the belt drive, brackets to support the conveyance apparatus in alignment with the toilet bowl, other transmission, linkage and controls as might ordinarily be required to propel the conveyance apparatus by mechanical lever or electric motor and a fan or bellows as may be required to exhaust air from beneath the toilet bowl liner.

Sheet material in the form of plastic film can be made very thin, eg 10 microns thick, and still remain adequately strong and impervious to liquids. Under these circumstances, with a standard size toilet, a 150 mm diameter roll of centre folded, plasttic film would hold enough material for in excess of one thousand 'flushes'.

Further, as may be preferred for some applications of the present invention the liner sheet material could be composed of substances which are either biodegradable or are water soluble in order to aid their ultimate disposal. In this respect water soluble plastic films such as poly(ethylene oxide) have been used for some years to contain dry substances intended to be dissolved in water without the need to open the package. In a more recent development a water soluble film base has been combined with a thin layer that is nonstructural and impervious to water. This type of material could be used to contain and package moist toilet waste inside but would dissolve when the package was disposed of in the presence of water on the outside.

Alternatively, there are other materials that can be fabricated into water soluble films such as polyvinyl alcohol which according to the formulation can be made to dissolve in water only above a predetermined temperature. This type of sheet material might be employed with this invention in cooperation with a heated holding tank The invention will be further described by way of example only, with reference to the accompanying and purely diagrammatic drawings, in which:: Figure 1 is a simplified perspective view showing elements of the dry toilet which illustrate the principle of the invention; Figure 2 is a front section elevation through the toilet bowl; Figure 3 is a top view of the toilet with covers partly removed to show a liner conveyance apparatus; Figure 4 is a section detail of part of the liner conveyance apparatus, and Figure 5 is a section detail of another part of the liner conveyance apparatus.

The dry toilet shown in Figure 1 has the toilet seat 15 raised to reveal the bowl 16 which is lined with a sheet material 17 supplied from a roll 18. The sheet material 17 is folded in the middle. The fold 19 is lowermost and the edges 20 of the sheet material 17 are uppermost when entering the side of the toilet bowl 16 through an entrance channel 21. At the top of the entrance channel the sheet edges 20 are separated by a conveyance apparatus which is concealed beneath the rim 22 of the bowl 16. The separated edges 20 are each conveyed halfway around opposite sides of the rim 22 to an exit channel 23. In the middle of the bowl 16 the sheet edges 20 are widely separated which unfolds the sheet material 17 and allows it to cover the sides and the bottom of the bowl 16.At the top of the exit channel 23 the edges 20 of the sheet are brought close together again by the conveyance apparatus and then released. After release, the sheet material 17, assisted by gravity and possibly air flow, passses through an opening 24 into an enclosed space 25 and thence into a drain 26 leading to a container 27 where processing or removal of the waste together with the soiled liner material can be implemented.

To contain odours, the opening 24 can be kept closed by a door 28 except when the sheet material 17 is being moved to empty the bowl 16 of waste. The door 28 could have a soft sealing gasket around its perimeter which when pressed against the thin liner material 17 would effect an air tight closure. Alternatively the door 28 might not be necessary if the container 27 was equipped with exhaust fan ventilation to the outside air as is often done with dry toilets. Air would then be drawn through the opening 24 and into the enclosure 25 which would prevent odours from escaping. The passage of the liner sheet material 17 through the bowl 16 is further illustrated by reference to Figure 2 which shows a section through the middle of the bowl and along the axis of the entrance channel 21 and the exit channel 23.To aid the draining of liquid wastes both the entrance channel floor 29 and the exit channel floor 30 slope downwards in the direction of the drain 26. This drainage slope prevents liquid waste from accumulating in the bottom of the bowl where it might otherwise result in splashing or where it could contaminate clean liner material 17 residing within the entrance channel 21. The drainage slope also allows the bowls to be easily washed and rinsed in the unlikely event that a lining becomes damaged and leaks.

By referring to Figure 3, the positions of entrance channel floor 29 and the exit channel floor 30 can be seen within the bowl 16. The entrance channel floor 29 need only be wide enough to clear the passage of the thin sheet material 17 whereas the exit channel floor 30 must be wider in order to clear the passage of the soiled liner material containing solid waste. The door 28 is hinged on a shaft 31 which, as further illustrated in Figure 2, can project through the upper wall of the enclosure 25 and connect to a control arm 32. The control arm 32 can be linked to the toilet operating mechanism to open the door 28 when the toilet is being emptied.

Referring again to Figure 2, indentions 33 have been provided in the inner surface of the bowl 16 leading to exhaust holes 34 connecting through the wall of the bowl to a duct 35 wherein air pressure can be lowered by the action of a bellows or fan to cause the liner sheet material 17 to be sucked against the surface of the bowl 16. Such vacuum suction need only to be applied momentarily and would normally be relieved when the liner material is being conveyed through the bowl.

Also, in Figure 2 the seat 15 is shown lowered and resting on the rim 22 which has been made integral with the cover 36 to conceal the conveyance apparatus 37 as well as other working components of the toilet.

A conveyance apparatus which could transport the sheet material 17 around the perimeter of the bowl 16 will be described with reference to Figures 3,4 and 5. Two synchronised timing belts 38 each forming a return loop are guided and driven along the perimeter of the bowl by timing belt pulleys 39. The belts are further guided on their outside surfaces by pulleys 40 with a radial groove 41 to provide clearance for the pins 42 which project from the outside surface of the belts 38 to pierce and hold the edges 20 of the sheet material 17. Two other similarly grooved pulleys 43 located at the top of the entrance channel 29 press the incoming edges 20 of the sheet material onto the projecting belt pins 42.To help maintain even tension of the liner material 17 as it is being fed into the pulleys 43 a roller 49 is positioned so as to maintain alignment of the sheet material edges 20 along the central axis. To control the supply tension of the sheet material 17 a friction device or other mechanical braking device could be adapted to the supply roll 18 or its spindle. After being conveyed along the bowl perimeter the sheet material is forced off the pins 42 by the constraint of the exit channel walls 44.

Along portions of the belts 38 where there are no grooved pulleys 40 it may be desirable to provide slotted guide surfaces 45, as shown in section in Figure 4, to prevent the sheet material edges 20 from being pulled off the belt pins 42. Alternatively, instead of guide surfaces additional grooved pulleys could be provided. Guide surfaces 45 and pulleys 39, 40 and 43 are supported on mounting brackets 46 which in turn are fastened to the top edge of the bowl by studs 47. The rim 22 combined with cover 36 rests on pads 48 on the upper surface of the mounting brackets 46 thus shielding the conveyance apparatus 36 from user interference and contamination.

The two belts 38 can be synchronised, for example, by linking their respective timing belt pulleys 39 located at the entrance door 21 with matching spur gears. The spur gears could be located beneath the entrance channel floor 29 and connected by shafts to the belt pulleys 39 above. By similar additional mechanical linking the conveyance apparatus, the drain area door and the air exhaust means could be made to operate automatically with the force of a foot pedal or the power of a small electric motor.

Claims

1. A dry toilet mechanism which uses a length of sheet material to contain and remove waste from a toilet waste receptacle, the length of sheet material extending from within a storage space through the toilet waste receptacle and into a disposal space, a portion of the sheet material being shaped to form an open container within the toilet waste receptacle assisted by means for guiding and spacing the two opposed edges of the sheet material, and with a means for intermittently moving the length of sheet material in a direction leading from the storage space into the disposal space.

2. A dry toilet mechanism for the containment and removal of waste comprising: a supply of sheet material, a conveyance apparatus to be arranged around the perimeter of the toilet waste receptacle, the conveyance apparatus having means for holding, advancing, separating, bringing together and releasing two opposite edges of the sheet material and thereby draping the sheet material to form an open container within the toilet wase receptacle, guide surfaces adjacent to the sheet material to assist the formation of the container shape and a means of actuating the conveyance apparatus to advance the sheet material a distance that will cause the soiled sheet material to be removed from the toilet waste receptacle into a disposal space and to be replaced with clean sheet material from the supply.

3. A dry toilet comprising: a toilet bowl with walls adapted by means of a side entrance aperture and a side exit aperture for the passage through the bowl of sheet material, a supply of sheet material, a conveyance apparatus arranged around the rim of the bowl with means for holding, advancing, separating, bringing together and releasing two opposite edges of the sheet material and thereby draping the sheet material to form a liner in the proximity of the inner surfaces of the bowl and a means of actuating the conveyance apparatus to advance the sheet material a distance that will cause the soiled sheet material to be removed from the bowl into a disposal space and to be replaced with clean sheet material from the supply.

4. A dry toilet comprising: a toilet seat, a supply of sheet material, a conveyance apparatus positioned beneath the toilet seat, the conveyance apparatus having means for holding, advancing, separating, bringing together and releasing two opposite edges of the sheet material and thereby draping the sheet material to form an open container beneath the toilet seat, guide surfaces adjacent to the sheet material to assist the formation of the container shape and a means of actuating the conveyance apparatus to advance the sheet material a distance that will cause the soiled sheet material to be removed from the area beneath the seat into a disposal space and to be replaced with clean sheet material from the supply.

5. A dry toilet or a dry toilet mechanism according to claim 2,3 or 4, wherein the conveyance apparatus includes one or more guided belts having projecting points along the belt face which in cooperation with opposing slotted surfaces pierce and hold the edges of the sheet material.

6. A dry toilet or a dry toilet mechanism according to any of the preceding claims, with closure means across the entrance way into the disposal space to restrict the escape of odours when the sheet material is not being transported.

7 A dry toilet or a dry toilet mechanism according to claim 6, wherein the closure is implemented at least in part by apparatus which firmly presses against a cross section of the sheet material at the entrance way into the disposal space.

8. A dry toilet or a dry toilet mechanism according to claim 6 or 7, wherein air is exhausted from at least part of the space below the sheet material to assist the sheet material to form a functional shape.

9. A dry toilet with disposable liner according to claims 1, 2, 3 or 4, wherein the material content of the sheet assists its decomposition after disposal.

9. A dry toilet or a dry toilet mechanism according to any of the preceding claims, wherein the sheet material is supplied on a roll.

10. A dry toilet or a dry toilet mechanism according to any of the preceding claims, wherein the sheet material is supplied folded.

11. A dry toilet or a dry toilet mechanism according to any of the preceding claims, wherein the material content of the sheet material assists its decomposition after disposal.

Amendments to the claims have been filed as follows 1. A dry toilet with disposable lining comprising; lining material in the form of a substantially continuous length of sheet, the sheet extending from a storage space, transversely through the toilet waste receptacle and into a disposal space, a portion of the sheet being shaped to form an open container within the toilet waste receptacle assisted by means for guiding and spacing the two opposed edges of the sheet , and with a means for intermittently moving the sheet in a horizontal direction leading from the storage space into the disposal space.

2. A dry toilet with disposable lining comprising; lining material in the form of a substantially continuous length of sheet, a conveyance apparatus arranged around the upper perimeter of the toilet waste receptacle, the conveyance apparatus having means for holding, advancing, separating, bringing together and releasing two opposite edges of the sheet and thereby draping the sheet to form an open container within the toilet waste receptacle, guide surfaces adjacent to the sheet to assist the formation of the container shape and a means of actuating the conveyance apparatus to advance the sheet a horizontal distance that will cause the soiled portion of the sheet to be removed from the toilet waste receptacle into a disposal space and to be replaced with a clean portion of sheet from a storage space.

3. A dry toilet with disposable lining comprising; a toilet bowl with walls adapted by means of a side entrance aperture and a side exit aperture for the transverse passage through the bowl of liner material in the form a substantially continuous length of sheet, a conveyance apparatus arranged around the upper rim of the bowl with means for holding, advancing, separating, bringing together and releasing two opposite edges of the sheet and thereby draping the sheet material to form a liner in the proximity of the inner surfaces of the bowl and a means of actuating the conveyance apparatus to advance the sheet a distance that will cause the soiled portion of the sheet to be removed sideways from the bowl into a disposal space and to be replaced with a clean portion of sheet from a storage space.

4. A dry toilet with disposable lining comprising; lining material in the form of a substantially continuous length of sheet, a toilet seat, a conveyance apparatus positioned in a horizontal plane beneath the toilet seat, the conveyance apparatus having means for holding, advancing, separating, bringing together and releasing two opposite edges of the sheet and thereby draping the sheet to form an open container beneath the toilet seat, guide surfaces adjacent to the sheet material to assist the formation of the container shape and a means of actuating the conveyance apparatus to horizontally advance the sheet a distance that will cause the soiled portion of the sheet to be removed from the area beneath the seat into a disposal space and to be replaced with a clean portion of sheet from a storage space.

5. A dry toilet with disposable liner according to claim 2, 3 or 4, wherein the conveyance apparatus includes one or more guided belts having projecting points along the belt face which in cooperation with opposing slotted surfaces pierce and hold the edges of the sheet.

6. A dry toilet with disposable liner according to claims 1, 2, 3 or 4, with closure means across the entrance into the disposal space to restrict the escape of odours when the sheet is not being transported, 7. A dry toilet with disposable liner according to claims 1, 2, 3 or 4, wherein air is exhausted from at least part of the space below the sheet material to assist the sheet to form a functional shape.

8. A dry toilet with disposable liner according to claims 1, 2, 3 or 4, wherein the sheet is supplied in a substantially continuous length rolled up in a cylindrical form.