Most babies in the developed world now enjoy the comfort of disposable nappies; this has made parenting easier, but is a cause of pollution in the home and beyond it. Disposable nappies are considered environmentally unfriendly because they generally end up in landfill sites and can thereby pollute ground water (see Dr Spock ISBN 0-671-71126-1 page 77).

Since the contents of nappies belong in the sewerage system, it would be preferable to shred the complete nappy so that it can be flushed away.

Such disposal is preferable to putting out soiled nappies with domestic waste where it may be accidentally opened.

Waste disposal units are known that shred waste such that it can be disposed of in the sewerage system. Typically, they are permanent installations that are built into locations in large institutions (e. g. hospitals). They are not generally found in domestic locations. They are relatively rare in public places where they may be of use-such as, for example, airports.

Preferred embodiments of the present invention aim to provide waste disposal units that are generally improved in this respect.

According to one aspect of the present invention, there is provided a portable waste disposal unit comprising:

a. a body adapted to be disposed in the bowl of a flushable toilet, in the path of flushing water of the toilet; b. a cavity provided within said body to receive solid waste; c. closing means for closing said cavity; d. shredding means within said body; e. activating means for activating said shredding means to shred solid waste within said cavity and output the shredded waste; and f. directing means for directing into said cavity flushing water of a flushable toilet when said body is fitted in the bowl of the toilet: the arrangement being such that, in use, flushing water directed into said cavity carries away the shredded waste into the toilet.

Preferably, said body is provided with projecting parts to engage a toilet bowl, thereby to position said body in said bowl.

Preferably, said cavity is of such a size as to accommodate at least one disposable nappy.

Preferably, said closing means comprises a lid to close an aperture in an upper surface of said body.

Preferably, said activating means comprises a resiliently biased plunger.

Preferably, a waste disposal unit as above further comprises electrical drive means for said shredding means.

Such a waste disposal unit preferably further comprises electrical interlock means for preventing operation of said electrical drive means when said closing means is not in a cavity-closing condition.

Preferably, a waste disposal unit as above comprises batteries mounted in said body, for powering said electrical drive means.

Preferably, said directing means comprises one aperture or more provided in an upper portion of said body.

Preferably, said directing means comprises one aperture or more provided in an upper surface and/or a side surface of said body.

The invention extends to a waste disposal system comprising a waste disposal unit according to any of the preceding aspects of the invention, in combination with a storage bucket adapted to store said waste disposal unit.

Preferably, said storage bucket is provided with a carrying handle.

Preferably, said bucket is adapted to hold a disinfectant liquid such that at least a lower portion of the waste disposal unit is in contact with said liquid when the waste disposal unit is stored in the bucket.

Preferably, said waste disposal unit is provided with an electrical charging unit for charging batteries in the waste disposal unit.

Preferably, said storage bucket is provided with a closing means which is adapted to open and close together with said closing means of said waste disposal unit.

According to another aspect of the present invention, there is provided a method of disposing of solid waste in a flushable toilet, comprising the steps of a. disposing a portable body in the bowl of the toilet, in the path of flushing water of the toilet; b. placing solid waste within a cavity provided within said body; c. closing said cavity; d. activating shredding means within said body to shred the solid waste within said cavity and output the shredded waste; and e. directing into said cavity flushing water of the flushable toilet to carry away the shredded waste into the toilet.

The invention extends to a flushable toilet which is provided with a waste disposal unit or system according to any of the preceding aspects of the invention.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Figure 1 shows in outline, in three projections, an example of a portable disposal unit;

Figure 2 shows the disposal unit in schematic cross-section; Figure 3 shows in outline a storage bucket; Figure 4 shows the storage bucket in schematic cross-section; Figure 5 shows in schematic cross-section the storage bucket with the disposal unit stowed inside it ready for charging; and Figure 6 illustrates three stages of the disposal unit in use in a flushable toilet bowl.

Referring firstly to Figure 6, in step A, the disposal unit 1 is placed within the bowl 30 of a flushable toilet. To this end, the outside dimensions of the disposal unit are compatible with the inside dimensions of most toilet bowls. A disposable nappy 35 is placed into a cavity 15 of the disposal unit 1.

In step B, the cavity 15 of the disposal unit 1 is closed by a lid 12, and a user presses down on a spring-loaded plunger 11 of the disposal unit 1, to activate a shredder within the disposal unit 1. The disposal unit lid 12 incorporates or cooperates with a safety switch to disable the shredder except when the lid is closed. The plunger 11 presses the waste products onto the shredder.

In step C, the toilet is flushed and water entering the toilet bowl 30 is directed over the disposal unit 1. The water enters the disposal unit 1

through openings 10, and carries away the shredded nappy into the toilet bowl 30 and thence into the sewerage system.

The disposal unit 1 and its associated components will now be described in further detail.

Referring to Figure 1, the disposal unit 1 comprises a body 5 which contains the above-mentioned openings 10 at one side, designed to duct the flushing water of a conventional toilet over the moving parts of the shredder. The central spring-loaded plunger 11 (biased upwardly in use) is operated by a user to press any contents in the cavity of the disposal unit 1 onto the shredder, and also activates an electrical driving motor for the shredder. The disposal unit lid 12 can be removed completely and is secured to the body 5 of the disposal unit 1 by means of a lip (not shown) at one side of the lid 12 and a swivel latch 13 at an opposite side.

Referring to Figure 2, integral rechargeable batteries 14 are housed in sealed, waterproof compartments of the body 5 of disposal unit 1. The disposal unit cavity 15 is large enough to accept a single large, wet folded nappy. The shredder 16 (or shredders) is immediately below the disposal unit cavity 15. Control mechanisms and switches 17 are housed at a side opposite to that at which the flushing water ducts 10 are located.

Referring to Figures 3,4 and 5, the disposal unit 1 may be stored and carried in a special storage bucket 2, which protects, stores and charges the disposal unit. The base of the storage bucket 2 contains a mains charger and cable store-part of the cable is illustrated at 18. The storage bucket 2 has a lid 19 which has a twist mechanism and seal 22 to provide positive, air-

tight and water-tight closure. It is possible to open both the storage bucket 2 and the disposal unit lids 19 and 12 simultaneously, so as to put a soiled nappy in the disposal unit 1 prior to transfer to a toilet.

The storage bucket 2 has a convenient, strong carrying handle 20.

The complete and combined disposal system, comprising disposal unit 1 and storage bucket 2, could be made strong enough to pass through airport baggage handling unharmed.

The storage bucket 2 may be part filled with disinfectant fluid 23.

The lower part of the storage bucket 2 contains a sealed mains charging unit 25 over a cable reel and plug store 24. The weight of the charging unit 25 gives the storage bucket 2 a low centre of gravity, so as to render it stable even if knocked.

The disposal unit 1 mates with the storage bucket 2 with the sides of the disposal unit 1 locating on lugs 21 provided, so that the integral batteries of the disposal unit 1 are connected to charge whenever the mains charger of the storage bucket 2 is powered, the storage bucket lid 19 is secure, and the batteries require charging.

One or more indicator light 26 is provided on the storage bucket 2 to show that there is mains connected and also to indicate the state of charge of the disposal unit internal batteries. An overnight charge should suffice for use of the disposal unit 1 on at least five occasions during the subsequent day. The charger is switchable between 120V a. c. and 240V a. c., or may be auto-ranging over a range of input voltages. A shaver socket adapter may be provided.

The disposal unit 1 may be supplied with folding or telescopic arms to suspend it properly within the toilet bowl.

The disposal unit controls include a shredder reverse operation mode to unjam blockages. A shredder overload switch is incorporated in the disposal unit electronic control system.

A filter to catch any solid particles or particles above a certain size may be included on the output side of the disposal unit 1.

All components are modular and demountable for cleaning or replacement.

Variants may be produced to suit other styles of toilet (such as Asian versions), and the term"bowl"is to be construed accordingly, to include all such other styles of toilet.

Variants may be produced with Ultra Violet lamps included as an extra-this treatment may degrade the plastic elements of waste before or after it is shredded. Strong Ultra Violet light also kills bacteria.

In another variant, the capacity of the storage bucket 2 is increased so that a day's worth of nappies may be shredded and held under the disposal unit 1. The storage bucket 2 can then be emptied at a convenient time and place.

Another variant includes a solar charging option for remote use.

In another variant, the disposal unit 1 is flush-initiated so that the shredder is turned on when toilet water passes over the disposal unit 1.

A variant could also be made to carry a reserve of fresh water/disinfectant to make the equipment useable independent of toilet availability.

A further variant could offer some analysis of the baby's health, by analysing the contents of the nappy.

Nappies (and their associated wipes) are not the only unpleasant sanitary waste material. The disposal unit 1 may be made sturdy enough to shred paper, cotton buds, condoms, sanitary towels, incontinence pads and medical dressings. It could become a standard household accessory.

There may thus be provided a hygienic, portable, sanitary waste disposal system. A particular advantage of the illustrated waste disposal system is its portability, enabling it to be used in many different locations, and readily carried about from one location to another.

In this specification, terms of absolute orientation are used conveniently to denote the usual orientation of items in normal use and/or as shown in the accompanying drawings. However, such items could be disposed in other orientations, and in the context of this specification, terms of absolute orientation, such as"top","bottom","left","right","vertical"or "horizontal", etc. are to be construed accordingly, to include such alternative orientations.

In this specification, the verb"comprise"has its normal dictionary meaning, to denote non-exclusive inclusion. That is, use of the word "comprise" (or any of its derivatives) to include one feature or more, does not exclude the possibility of also including further features.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and 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 embodiment (s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.