WASTE CONTAINER

This invention relates to waste containers .

According to the present invention there is provided a waste container having a lid for closing the container and wherein closing of the lid effects an airtight seal that serves to seal the interior of the container from the ambient atmosphere, and wherein provision is made for withdrawing air from the sealed interior.

The waste container of the invention is of application especially as a receptacle for short- or long-term accumulation of waste, and in particular of kitchen or other food waste, where unpleasant odour and infestation, especially by flies and their larvae, can easily arise before the container is emptied. The sealing of the interior of the container from the ambient atmosphere reduces considerably the likelihood of odour and infestation.

The airtight sealing effected when the lid is closed may be such as to establish negative pressure within the container. In this regard the sealing may be effected by closing the lid onto and compressing a resilient element, for _N example as a rim peripheral to the lid or body of the container. The lid may be closed under hand- or other externally-applied pressure. The compression of the resilient element, which may be of diaphragm or bellows form, may cause release of air from the interior of the container, such that on withdrawal of the externally-applied pressure with the lid closed, the seal relaxes resiliently to reduce air pressure within the interior of the container.

As an alternative or in addition, air may be exhausted from the interior of the container by means of a pump or bellows. Where

a pump is involved, it may be operated manually, for example by actuation of a lever on the container, or may be driven by an electric motor which is energised (for example from a battery) via a switching unit that is responsive to closing, or the action of closing, of the lid, to maintain drive to the pump until a pre-set level of part-vacuum is created, or for a preset interval of time, after the lid is closed. However, the pump may as an alternative be driven from the action of closing the lid, and in this respect may be driven from an energy- storage mechanism that is coupled to the lid to store energy as the lid is closed and/or as the lid is opened. For example, the opening and/or closing of the lid may be used to wind up a spring that is released to operate the pump for a short period in response to lid closure; the release may for example be triggered by engagement of a catch or clip that holds the lid closed. Instead of using the mechanical energy stored to drive the pump directly, it may be converted into electrical energy for energising electrical-motor drive to the pump.

The pump may involve one or more pistons for reciprocating sliding movement in individual cylinders. More especially, the pump may comprise a plurality of pistons that are each actuated in one stroke to draw in air from the interior of the container and to exhaust that air into the ambient atmosphere on the other stroke. In these circumstances, one or more of the pistons may be drawing air in while one or more is exhausting air to the atmosphere .

Where a bellows is used to exhaust air from the container, it may be mounted on top of the lid to the container between this lid and a hinged member so as to be worked by pivotal movement of the hinged member up and down. The lid in these circumstances may carry a flap or other one-way valve that opens when the bellows are being expanded so as to draw off air from the interior of the container. The hinged member may also carry a flap or other one-way valve which in this case opens to expel

the drawn-off air into the ambient atmosphere when the bellows are closed, so that by pivoting the hinged member up and down, air is exhausted from the interior of the container to establish a low pressure within the interior and thereby reduce significantly both infestation and leakage of odour from the container.

In circumstances where the interior of the container is left at a significantly-low pressure after the lid has been closed, it may be necessary or desirable for the container to include a valve that is operable for releasing partial-vacuum so as to facilitate opening of the lid.

Waste containers in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawing, in which:

Figure 1 is perspective view of a first form of waste container according to the invention, with its lid open;

Figure 2 is illustrative of detail of an example of a peripheral vacuum seal that may be used with the waste container of Figure 1;

Figures 3 and 4 are, respectively, a side elevation and a front view of another waste container according to the invention, with bellows that form part of the waste container in this case, shown expanded;

Figure 5 is illustrative schematically of a further form of waste container according to the invention; and

Figures 6 and 7 are, respectively, a side elevation and a part- sectional plan that are illustrative of part of a still further form of waste container according to the invention.

Referring to Figure 1, the waste container 1 in this example has a container-body 2 with an open top 3 that is closed by means of a lid 4 hinged to the body 2. The body 2 and lid 4 are conveniently, but not necessarily, of plastics, and a plastics or rubber seal 5 extends round the open top 3 to provide airtight sealing of the interior of the container 1 when the lid 4 is closed.

A vacuum-pump unit 6 is mounted on the inside of the lid 4 and includes a pump (not shown) for withdrawing air from the interior of the container 1 and exhausting it through the lid 4, when the lid 4 is closed. The creation in this way of a slightly negative pressure as compared with the ambient atmosphere, reduces the likelihood of odour from waste within the container 1 leaking out, and furthermore reduces the likelihood of infestation by flies and the activity in it of larvae and other undesirable agents .

The pump unit 6 also includes an electric motor for driving the pump and a battery for powering the motor. A switch within the unit 6 closes for a short period of time when the lid 4 closes, so as to energise the motor from the battery and drive the pump. In this regard the switch may exhibit a transitory response to change of orientation of the lid 4 by which it closes initially when the lid 4 closes but opens again after a short period while the lid 4 continues to remain closed. Alternatively the switch may be mounted separately from the unit 6, for example near the hinge of the lid 4, so as to be closed when the lid 4 is closed. In these latter circumstances, the limited-time operation of the pump can be achieved by connecting a delay circuit in series with the switch, the battery and the motor. Furthermore, where the switch is mounted separately from the unit 6, it may be associated with a clip 7 that is used for engagement with the lid 4 in holding the lid 4 closed, and in these circumstances the switch may be actuated by engagement of the clip 7 with the closed lid 4.

The partial-vacuum within the container opposes opening of the lid 4, so that it is necessary or desirable to release this before a user attempts to open the lid 4. To this end, a hand- operated vacuum-release valve 8 accessible by the user from outside the container 1, is provided for operation in bringing the pressure within the container 1 to that of the ambient atmosphere .

The seal 5 may be of a resilient form which is compressed under the pressure of the user's hand closing the lid 4, and which under its resilience returns to its normal uncompressed state when the hand pressure is released. Air is exhausted from the interior of the container when the seal 5 is compressed but cannot return when the seal 5 returns to its uncompressed state, leaving the interior of the container 1 at a negative pressure. The functioning of the seal 5 in this way may be achieved using foam-rubber strip or other compliant medium for the seal 5, but a diaphragm or bellows-type configuration of the seal may be used instead.

In the latter respect, a bellows-type seal 20 between the lid of 21 and open top 22 of a waste container 23 is illustrated in Figure 2.

The action of the seal 5 or 20 as described above in reducing air pressure within the container may be found in some circumstances adequate in itself without the need for provision of a pump such as that of the pump unit 6 of Figure 1. Nonetheless, it may still be found necessary for ease of opening of the lid to retain the use of a vacuum-release valve such as the valve 8 of Figure 1.

A another form of waste container according to the present invention will now be described with reference to Figures 3 and 4.

Referring to Figures 3 and 4, this form of waste container 31 includes a bellows 32 mounted on top of its hinged lid 33. The lid 33 closes over the open top of the container-body 34 and in this compresses a flexible sealing-ring (not shown) so as to establish an airtight seal between the lid 33 and body 34 when a resilient retaining-clip 35 mounted on the body 34 is engaged over the edge of the lid 33 (as shown) .

The bellows 32 is mounted on the lid 33 under a second lid 36 that is mounted to pivot on the same hinge 37 as the lid 33 so as to be moveable up and down (as indicated by arrows) in working the bellows 32. In this respect, the lid 33 carries a one-way valve 38 that opens when the bellows 32 are being expanded, drawing off air from within the container-body 34, whereas the lid 36 carries a one-way valve 39 that opens to expel the drawn-off air into the ambient atmosphere when the bellows 32 are closed. Accordingly, by pivoting the lid 36 up and down, air is exhausted from inside the container-body 34, and the valves 38 and 39 block the passage of air in the reverse direction so as to maintain a low pressure within the body 34 and thereby reduce significantly both infestation and leakage of odour from the container 31.

The valves 38 and 39 may be simple flap valves, and a clip (not shown) may be provided to hold the second lid 36 down with the bellows in the closed condition. This latter clip may be provided on the clip 35.

A further form of waste container will now be described with reference to Figure 5.

Referring to Figure 5, the container 50 in, this case incorporates a pump 51 that is operated from energy stored in a coiled spring 52. The spring 52 is coupled via a mechanical connection 53 to the hinged lid 54 of the container 50 to be

wound up by opening movement of the lid 54; as an alternative, or in addition, the spring 52 may be wound up by closing movement of the lid 54. When the lid 54 is closed to seal the container 50, the energy stored in the wound-up spring 52 is released to drive the pump 51 and exhaust air from inside the container 50 via a one-way valve 55. The valve 55 may be operable from outside the closed container 50 for release of the partial vacuum.

A yet further form of waste container, which is illustrated by

Figures 6 and 7, and which includes a hand-operated pump mounted externally on the top of the lid of the container, will now be described.

Referring to Figures 6 and 7, the hand-operated pump 60, which is for drawing air from within the container through an aperture 61 in the lid 62, is operated by reciprocating movement of a lever-handle 63. The handle 63 is mounted on the pump-casing 64 in a pivot 65 and is coupled through the casing 64 to a bar 66 so that reciprocating movement of the handle 63 causes the bar 66 to slide laterally to and fro within the casing 64.

A bank of six pistons 67 that slide within respective cylinders 68 are located on either side of the bar 66. Each of the twelve pistons 67 of the two banks is coupled via an individual rod 69 to the bar 66 so as to move back and forth within its respective cylinder 68 as the bar 66 slides to and fro under movement of the handle 63. The six pistons 67 of each bank move together in phase with one another, each drawing air in via the aperture 61 from the interior of the container in one stroke and exhausting it through a one-way valve 70 of its cylinder 68 in the other stroke. While the pistons 67 of one bank are drawing air in, air is being exhausted by the pistons 67 of the other bank and •vice versa in synchronism with the reciprocating movement of the handle 63, thus creating a partial vacuum in the container. A

vacuum-release valve (not shown) is provided to facilitate opening of the lid 62.