EP0913344A1

EP0913344A1 - Waste bin and method of treating waste

Info

Publication number: EP0913344A1
Application number: EP97305840A
Authority: EP
Inventors: designation of the inventor has not yet been filed The
Original assignee: Rentokil Ltd
Current assignee: Rentokil Ltd
Priority date: 1997-08-01
Filing date: 1997-08-01
Publication date: 1999-05-06

Abstract

A method of treating waste, preferably waste comprising material contaminated with body fluid, wherein a waste-treating particulate material is introduced, by a dispensing means (1), into a waste bin, preferably a sanitary bin (10), from a reservoir (14) for the waste-treating particulate material.

Description

The present invention relates to a waste bin, in particular, a waste bin, usually known as a sanitary bin, for material contaminated with body fluid, for example, sanitary towels and tampons, medical dressings, and nappies.
Sanitary bins are provided in public toilets, primarily for the disposal of sanitary towels and tampons, although they may also be used for the disposal of other material contaminated with body fluid. The bins are emptied periodically, and so act as temporary stores for the waste material. The storage of such waste can cause odour problems. Accordingly, an anti-microbial liquid is usually used to treat the waste stored in sanitary bins.
EP-A-0 324 602 describes a waste bin where waste-treating liquid is sprayed onto the waste before the waste is deposited in the bin. Waste is deposited in the bin via a rotary inlet valve operated by a foot pedal. Depressing the foot pedal causes the inlet valve to rotate to a position in which the inlet is open, and a plate on which waste can be deposited is positioned adjacent to the inlet. Depressing the foot pedal also primes a pump with treating liquid. Releasing the foot pedal causes the pump to spray the waste with liquid, and also causes the inlet valve to rotate back to its original position so that the treated waste is deposited in the bin.
The applicants have found that in some circumstances the use of an anti-microbial liquid is disadvantageous. There is thus a need for a waste bin which permits storage of material contaminated with body fluid, but which does not rely on the use of an anti-microbial liquid.
The present invention provides a waste bin having associated therewith a reservoir for particulate material, and dispensing means for introducing particulate material from the reservoir into the bin. The reservoir will normally itself be in the bin (although this is not essential), and in this case particulate material from the reservoir passes out of the reservoir so that it is free to treat material in the bin.
In some embodiments of the invention, the reservoir may be remote from the dispensing means. Usually, however, the reservoir and the dispensing means will be closely associated, in which case, for convenience, the reservoir and the dispensing means together will be referred to hereinafter as "a dispenser".
Usually, the reservoir is distinct from the dispensing means. However, the wall(s) that define(s) the reservoir may also be the dispensing means. For example, the reservoir may comprise an outer shell enclosing waste-treating particles which breaks when waste being deposited in the bin falls on it, or breaks down by chemical or physical reaction over time.
For the dispensers described above, it is difficult to control the timing of the introduction of particulate material into the bin from the reservoir. Accordingly, advantageously, the bin has associated therewith actuating means which, in use, causes or allows the dispensing means to introduce material to the bin. For example, for the dispenser comprising a frangible reservoir, actuating means may be provided to break the reservoir when desired.
A dispenser where the wall which defines the reservoir is also the dispensing means may only be used once, and thus is not readily able to treat waste subsequently deposited in the bin. Accordingly, preferably, the dispensing means comprises an outlet for the reservoir through which, in use, particulate material is introduced, directly or indirectly, into the bin. It is then not necessary to break the reservoir to introduce material into the bin, thus allowing for re-use of the dispenser, and treatment of waste throughout the bin.
In one embodiment of the invention, the actuating means, in operation, moves the reservoir between a first position in which no material passes through the outlet, and a second position in which material passes through the outlet.
In another embodiment of the invention, not at present preferred, the dispensing means comprises a closure means for the outlet, and the actuating means, in operation, moves the closure means between a first position in which the outlet is closed, and a second position in which the outlet is open and material passes through the outlet. The closure means may be, for example, a pivotally mounted rod, one end of which is able to block the outlet (or some other device which is able to move into and out of blocking contact with the outlet), or an outer sleeve for the reservoir which may be moved so as to cover and uncover the outlet (or some other sliding cover for the outlet).
In both of the above-mentioned embodiments, the amount of particulate material introduced to the bin cannot readily be controlled. Accordingly, preferably, the dispensing means comprises a dosing means which, in use, introduces a measured portion of material into the bin. This means that, providing the dosing means is recharged after each use, the amount of material introduced into the bin can be controlled. (It will be understood that a precise degree of control is not required when treating waste, and that accordingly some variation from dose to dose is acceptable.)
Advantageously, the actuating means, in operation, moves the dosing means between a first position in which material passes into the dosing means, and a second position in which material is introduced into the bin from the dosing means.
Preferably, the dosing means comprises an intermediate support, spaced apart from the outlet, and located such that material passing through the outlet can fall onto the support.
We believe that the size of the outlet, and the distance between the outlet and the intermediate support, should preferably be such that particulate material which has fallen on the support is able to bridge with material passing through the outlet. When bridging occurs, that is, when the particles form a bridge between the plate and the outlet, no further material is able to pass through the outlet. For any given particulate material, a set amount of material determined by the size of the outlet, and the distance between the outlet and the intermediate support, will then be held between the outlet and the intermediate support. Thus, provided the dosing means remains in the first position for sufficient time to allow bridging to occur and remains in the second position for sufficient time to allow all the material on the plate to fall into the bin, approximately the same amount of particulate material will be introduced to the bin each time the dispenser is used.
We believe that the bridging is stronger, the larger the particles compared to the distance between the outlet and the intermediate support, and the rougher the surface of the intermediate support. Accordingly, preferably, the distance between the outlet and the intermediate support, the particle size and the texture of the surface of the intermediate support should be selected so that a bridge is formed which is sufficiently stable when the dosing means is in the first position, but which can be broken so that the particulate material readily falls off the intermediate support when the dosing means is in the second position. (It will be appreciated that the invention is not to be limited by any theory as to how part of the apparatus operates).
Preferably, the intermediate support is substantially horizontal when the dosing means is in the first position, and substantially vertical (such that the particulate material on it can fall off) when the dosing means is in the second position.
Preferably, the support comprises a plate.
Advantageously, the dosing means and the reservoir are movable together, as a single unit, between the first position and the second position.
Preferably, the reservoir is detachable from the dosing means. This allows the reservoir to be re-filled once empty, or replaced by a full reservoir, so that the dispenser may be re-used indefinitely.
Advantageously, the dispensing means comprises means, preferably a baffle, to disperse the material on being introduced by the dispensing means into the bin. This means that treatment will not be confined to waste located directly below the dispensing means.
Advantageously, the actuating means operates intermittently. This means that treatment may occur as fresh waste is deposited in the bin. Preferably, the bin comprises a lid, and the actuating means comprises the lid. Preferably, the lid rotates the reservoir and/or dispensing means through approximately 90° when the lid is opened and/or closed. Particulate material will then be introduced to the bin each time an item of waste is deposited in the bin. The reservoir and/or dispensing means may, for example, be mounted on the lid, or on part of the bin that moves with the lid, for example, a tray for receiving waste. In another embodiment, the reservoir and/or dispensing means may be mounted on the bin, and connected to the lid by a mechanical linkage.
Alternatively, the actuating means may comprise a motor, which is preferably operated in response to a signal. The signal may be generated in response to the opening and/or closing of the lid, for example, in response to a counter that counts the number of times the lid of the bin is opened, or it may be generated independently of the lid, for example, in response to an internal electronic clock, or a photo cell which operates once per day when the lights are switched on.
Preferably, the bin is a sanitary bin.
Preferably, the particulate material is a waste-treating material. Advantageously, the mean particle size of the particulate material is in the range of 1 to 1000µm, preferably 1 to 500µm, especially 50 to 250µm.
The present invention further provides a method of treating waste, wherein a waste-treating particulate material is introduced, by a dispensing means, into a waste bin according to the invention, from a reservoir for the waste-treating particulate material.
Preferably, the waste comprises material contaminated with body fluid.
The present invention permits the use of particulate waste-treating materials when storing material contaminated with body fluid, thus removing the need for anti-microbial liquids. The dispenser may be of simple construction. In preferred embodiments of the invention, a measured portion of material is introduced into the bin each time an item of waste is deposited in the bin, without the dispenser having any moving parts.
A number of embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Fig. 1 shows a side view of a first embodiment of a dispensing means in accordance with the invention;
Fig. 2 shows a section along line A-A of Fig. 1;
Fig. 3 shows a plan view of the dispensing means of Fig. 1;
Fig. 4 shows a section along line B-B of Fig. 3;
Fig. 5 shows a section through a waste bin according to the invention, the waste bin having attached thereto a particle dispenser which includes the dispensing means of Figs. 1 to 4;
Fig. 6 shows a schematic section through a second embodiment of a particle dispenser in accordance with the invention;
Fig. 7 shows a schematic section through a third embodiment of a particle dispenser in accordance with the invention, the dispensing means being so orientated that particles are not introduced to the bin;
Fig. 8 shows the dispenser of Fig. 7, the dispensing means being so orientated that particles are introduced to the bin;
Fig. 9 shows a schematic section through a fourth embodiment of a particle dispenser in accordance with the invention, the reservoir being so orientated that particles are not introduced to the bin;
Fig. 10 shows the dispenser of Fig. 9, the reservoir being so orientated that particles are introduced to the bin;
Fig. 11 shows a schematic section through a fifth embodiment of a particle dispenser in accordance with the invention, the dispenser having closure means being so positioned that particles are not introduced to the bin; and
Fig. 12 shows the dispenser of Fig. 11, the closure means being so positioned that particles are introduced to the bin.
Fig. 13 shows a schematic section through a sixth embodiment of a particle dispenser in accordance with the invention.
Fig. 14 shows a schematic section through a seventh embodiment of a particle dispenser in accordance with the invention.
Referring to Figs. 1 to 4, the dispensing means, indicated generally by the reference numeral 1, comprises a tube 2 of circular cross-section having an open upper end 99 and a half-closed lower end 98. The tube 2 has a spike 3 at its upper end 99. The tube 2 is supported centrally above a plate 4 by four supports 5. When the size of the particles used is in the preferred range (50 to 250µm), the distance between the lower end 98 of the tube 2 and the plate 4 is typically of the order of 1 to 2mm. The dispensing means 1 further comprises a clip 6 at one edge of the plate 4, and a baffle 7 at another edge of the plate 4, opposite the clip 6. The clip 6 includes a groove 8 on its inner face, extending in a direction perpendicular to the axis of the tube 2. The baffle 7 also includes a groove 9 on its inner face, opposite the groove 8 in the clip 6. (In some circumstances it may be advantageous for the tube to be completely open at both ends, and/or to include slots to aid flow of particles into the tube, especially if the tube is longer than shown in Figs. 1 to 4.)
Referring now to Fig. 5, the waste bin indicated generally by the reference numeral 10 comprises a waste receptacle 11, and a pivotally mounted lid 12 formed integrally with a tray 13 for receiving waste. The lid 12 is shown (in broken lines) in the open position in which the tray 13 is positioned to receive waste, and to hide the interior of the receptacle 11 from view, and is also shown (in bold lines) in the closed position in which the tray 13 is positioned to deposit waste in the bin 10.
A reservoir 14 containing waste-treating particles is attached to the dispensing means shown in Figs. 1 to 4. The reservoir 14 comprises an open-ended container 15 containing waste-treating particles (not shown), the open end of the container 15 being surrounded by a rim 16 and covered by a sheet material (not shown), typically a plastics/aluminium foil or plastics/paper laminate. The reservoir 14 is attached to the dispensing means 1 by piercing the sheet with the spike 3 on the tube 2, and pushing the reservoir 14 down onto the spike 3 until the rim 16 of the reservoir 14 is almost level with the lower end of the tube 2, at which point the rim 16 of the reservoir 14 engages with and is held by the grooves 8,9 in the baffle 7 and the clip 6 of the dispensing means 1. The tube 2 of the dispensing means 1 now forms an outlet for the reservoir 14.
The reservoir 14 and the dispensing means 1 together form a dispenser indicated generally by the reference numeral 17. The dispenser 17 is attached to the tray 13 of the lid 12 by the clip 6. (For clarity, the dispenser 17 is shown attached to the tray 13 of the lid 12 in the closed position only.) When the dispenser 17 is in the position shown in bold lines in Fig. 5, that is, when the lid 12 is in the closed position, particles pass from the reservoir 14, through the tube 2, and fall onto the plate 4 until particles bridge the space between the lower end 98 of the tube 2 and the plate 4, and no further particles are able to pass out of the tube 2. When the lid 12 is opened, the dispenser 17 is tilted on its side, and the particles located between the lower end 98 of the tube 2 and the plate 4 fall down towards the baffle 7, which disperses the particles as they drop into the waste receptacle 11. Closing the lid 12 again, returns the dispenser 17 to the position shown in Fig. 5 so that particles again fall onto the plate 4, thus re-charging the dispensing means 1.
Referring to Fig. 6, the dispenser indicated generally by the reference numeral 18 comprises a reservoir 19 and a dispensing means 20. The dispenser 18 comprises a container 21 having two end walls 22 and one or more side walls 23. A plate 24 is located inside the container 21 near one end wall 22. The plate 24 extends across most but not all of the cross-section of the container 21, to form two communicating chambers 25,26 within the container. The larger of the two chambers 25 is the reservoir 19, and the smaller of the two chambers 26 is the dispensing means 20. The dispensing means 20 includes an opening 27 in the side wall 23.
In use, when the dispenser 18 is in the position shown in Fig. 6, treatment particles pass from the reservoir 19 into the dispensing means 20. When the dispenser 18 is rotated clockwise through approximately 90°, those particles which are located in the dispensing means 20, rather than in the reservoir 19, fall through the opening 27 in the side wall 23. The dispenser 18 may be rotated by, for example, attaching it to the tray of a waste bin lid as shown in Fig. 5.
In the embodiments of the dispenser shown in Figs. 1 to 4, and Fig. 6, the dispenser may be operated by attaching it to the tray of a waste bin lid. In the following embodiment, not at present preferred, this is not the case, the dispenser operating automatically after a period of time has elapsed.
Referring to Figs. 7 and 8, the dispenser indicated generally by the reference numeral 28 comprises a reservoir 29 and a dispensing means 30. The dispensing means 30 comprises an outlet 31 for the reservoir 29, and a container 32 mounted on a helical spring 33. The outlet 31 is located such that particles passing through the outlet 31 are deposited predominantly in one side of the container 32. The spring 33 is attached to the container 32 at a point below the centre of gravity of the container 32 when full of particles. Particles pass from the reservoir 29 into the container 32 until the point shown in Fig. 8 is reached where the container 32 tips over so that the particles fall out of the container 32. The spring 33 and a guide mechanism (not shown) return the container 32 to the position shown in Fig. 7. The outlet 31 is closed by a closure means (not shown) when the container 32 tips over. The container 32 opens the outlet 31 by striking the closure means on returning to the position shown in Fig. 7.
In the embodiments of the dispenser shown in Figs. 1 to 4, 6, and 7 and 8, provided sufficient time is allowed to re-charge the dispensing means after use, a set amount of particulate material is introduced into the bin, the amount being determined by the physical properties and geometry of the dispenser, and the particulate material. In the following embodiments, not at present preferred, this is not necessarily the case.
Referring to Figs. 9 and 10, the dispenser indicated generally by the reference numeral 34 comprises a reservoir 35 and a dispensing means 36. The reservoir 35 comprises a cylindrical container 37 with a hemi-spherical lid 38. The dispensing means 36 comprises a number of small outlets 39 in the hemi-spherical lid 38. The reservoir 35 further comprises a counter-weight 40 at the end of the reservoir 35 opposite the hemi-spherical lid 38, and is pivotally mounted about an axis parallel to the ends of the container 37.
When the reservoir 35 is in the position shown in Fig. 9, the particles rest at the end of the reservoir 35 opposite the hemi-spherical lid 38. When the reservoir 35 is rotated to the position shown in Fig. 10, particles fall through the outlets 39.
The reservoir 35 may be rotated to the correct position by, for example, attaching it to the tray of a waste bin lid as shown in Fig. 5. Opening the lid will rotate the reservoir by approximately 90°, and the reservoir will then continue to rotate under the influence of the counter-weight 40 so that it passes through the position shown in Fig. 10 and back to the position shown in Fig. 9. Closing the lid will rotate the reservoir back in the other direction.
Referring to Figs. 11 and 12, the dispenser indicated generally by the reference numeral 41 comprises a reservoir 42 and a dispensing means 43. The dispensing means comprises an outlet 44 for the reservoir 42, and a closure means 45. The closure means 45 comprises a pivotally mounted rod 46, biassed towards a position in which the outlet 44 is closed by a block 47 on one end of the rod 46.
The outlet 44 is opened by rotating the rod 46 about its pivot 48. The rod 46 may be rotated by, for example, striking the free end of the rod 46. The rod 46 may be struck by, for example, the tray of a waste bin such as that shown in Fig. 5 on opening the lid. The biassed rod 46 will then return to the position in which the outlet 44 is closed.
Alternatively, in another embodiment of a particle dispenser (not shown), the closure means comprises an outer sleeve for the reservoir. The sleeve may be moved between a position in which it covers the reservoir outlet, and a position in which it does not cover the reservoir outlet. Or, in another embodiment of a particle dispenser (not shown), the closure means comprises a sliding cover for the outlet. The cover slides between a position in which it covers the reservoir outlet, and a position in which it does not cover the reservoir outlet. In another embodiment of a particle dispenser (not shown), the closure means comprises a plug for the outlet biased toward a position in which it blocks the outlet and a reciprocable rod. The rod moves between a position in which it pushes the plug out of the outlet, and a position in which it allows the plug to block the outlet again.
Referring to Fig. 13, the dispenser indicated generally by the reference numeral 48 comprises a reservoir 49 and a dispensing means 50. The dispensing means 50 comprises a frangible outer shell 51 for the reservoir 49 of particulate material. Particulate material is released by breaking the shell 51 of the reservoir 49. The shell 51 may be broken by, for example, being hit by waste being deposited in a bin.
Referring to Fig. 14, the dispenser indicated generally by the reference numeral 52 comprises a reservoir 53 and a dispensing means 54. The reservoir 53 comprises a container 55. The dispensing means 54 comprises an outlet 56 for the reservoir 53, and bellows 57 having an outlet 58 directed into the particulate material in the reservoir 53. Depressing the bellows 57 causes particles to be blown out of the reservoir 53 through the reservoir outlet 56. The bellows 57 may be depressed by, for example, being struck by the tray of a waste bin such as that shown in Fig. 5 on opening the lid.

Claims

A waste bin having associated therewith a reservoir for particulate material, and dispensing means for introducing into the bin particulate material from the reservoir.
A bin as claimed in claim 1, wherein the bin has associated therewith actuating means, which preferably operates intermittently, and which, in use, causes or allows the dispensing means to introduce particulate material to the bin.
A bin as claimed in claim 2, wherein the dispensing means comprises an outlet for the reservoir through which, in use, particulate material is introduced, directly or indirectly, into the bin.
A bin as claimed in claim 3, wherein the actuating means, in operation, moves the reservoir between a first position in which no particulate material passes through the outlet, and a second position in which particulate material passes through the outlet.
A bin as claimed in claim 4, wherein the dispensing means comprises a closure means for the outlet, and the actuating means, in operation, moves the closure means between a first position in which the outlet is closed, and a second position in which the outlet is open and material passes through the outlet.
A bin as claimed in any previous claim, wherein the dispensing means comprises a dosing means which, in use, introduces a measured portion of material into the bin.
A bin as claimed in claim 6, when dependent on any one of claims 3 to 5, wherein the actuating means is able to move the dosing means between a first position in which material passes into the dosing means, and a second position in which material is introduced into the bin from the dosing means, the dosing means and the reservoir preferably being movable together, as a single unit, between the first position and the second position.
A bin as claimed in claim 7, wherein the dosing means comprises an intermediate support, preferably a plate, spaced apart from the outlet, and located such that particulate material passing through the outlet can fall on to the support.
A bin as claimed in claim 2, or any one of claims 3 to 8 so far as they are dependent on claim 2, wherein the bin, which is preferably a sanitary bin, comprises a lid, and the actuating means comprises the lid.
A method of treating waste, preferably waste comprising material contaminated with body fluid, wherein a waste-treating particulate material is introduced, by a dispensing means, into a waste bin, preferably a sanitary bin, from a reservoir for the waste-treating particulate material, the waste bin being as specified in any previous claim.