REFRIGERATOR

Abstract

The present invention provides a refrigerator comprising at least one compartment capable of evacuation, said compartment being provided with evacuation means, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means provided on said drawer and/or said compartment for maintaining the drawer in sealing engagement with the compartment, means for activating the evacuation means when the drawer is, or is not, in sealing engagement with the compartment, and means for releasing the vacuum in said compartment as well compartment therefor. The invention also provides a box-like compartment suitable for insertion into a refrigerator which comprises evacuation means, means for connecting the evacuation means to an electrical source, an orifice located in at least one wall of the compartment, a lid capable of sealably engaging with said orifice, means provided on said orifice and/or said lid for maintaining the lid in sealing engagement with the orifice, means for activating the evacuation means and means for releasing the vacuum in said compartment.

Description

FIELD OF THE INVENTION

This invention relates to refrigerators and the like.

DESCRIPTION OF THE RELATED ART

It is well known that, when maintained cool in a refrigerator, perishable food keeps longer. It is also well known that perishable food can be preserved if it is kept under vacuum, as in vacuum packaging. Attempts have been made to combine these two effects by proposing a refrigerator with one or more zones where a reduced pressure can be achieved. Unfortunately the arrangements devised to date are unsatisfactory for one or more reasons. In one arrangement the food to be preserved is placed in a flexible container such as a bag. This is, though, restricting in that it is desirable to have in a refrigerator a compartment which can be placed under vacuum without having to place the food in a special container. Added to this there are difficulties in ensuring a seal between the evacuating pump and the flexible container. Attempts have been made to overcome these difficulties but only by involving more complicated arrangements which make the system less economic and, in some cases, completely unworkable.

In another arrangement a drawer of the refrigerator is subjected to a partial vacuum but, again, the problem of providing a gas-tight drawer remains. Thus if the drawer is not placed in exactly the correct position, i.e. fully in and centered in the compartment, a vacuum will not be produced. Further, manual pressure is needed for there to be any chance of a seal being provided and this is obviously inconvenient; the user does not want to keep pushing at the drawer until a sufficient vacuum has built up—particularly as this can take several minutes. This latter difficulty can be reduced by providing a protrusion on the inside of the refrigerator door which engages with the drawer forcing it forward but when the door is shut the user has no opportunity to check whether a vacuum is proceeding. Added to this there is a danger that the vacuum will be released any time the door is opened, particularly if it is opened before a sufficient vacuum has been created. Finally there has been proposal to provide a vacuum to the compartment rather than to the drawer within it; while this overcomes some of the difficulties others such as the door protrusion remain.

BRIEF SUMMARY OF THE INVENTION

There is therefore a need to provide a simple solution to this problem, a solution which has so far evaded research workers in this field. This has now been achieved, according to the present invention, by providing a refrigerator with a compartment having a drawer which can be sealed to it without the need for any interaction with the refrigerator door. According to the present invention there is provided a refrigerator comprising at least one compartment capable of evacuation, said compartment being provided with evacuation means, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means provided on said drawer and/or said compartment for maintaining the drawer in sealing engagement with the compartment, means for activating the evacuation means when the drawer is, or is not, in sealing engagement with the compartment, and means for releasing the vacuum in said compartment.

The present invention is applicable not only to domestic refrigeration but also to commercial refrigerators, wherever there is a need to preserve perishable goods. Typically a household refrigerator has two or more shelves. Generally the bottom level or shelf is occupied by one or more, for example two, drawers, typically denoted as crisper drawers; these are intended, in particular, for vegetables. It is this, or one of these, drawers which will typically be replaced by the vacuum compartment and drawer which forms an essential part of the present invention. However, it is to be understood that the vacuum drawer can be at some different location in the refrigerator e.g. at the top, and there can be more than one compartment. Indeed the whole of the interior of the refrigerator can be subjected to a vacuum but this is not normally desired. Of course the refrigerator may possess one or more additional compartments or sections such as a freezer section. The present invention has no direct effect on such sections any or all of which can be present in the refrigerator.

Typically the drawer will be made of a plastics material, generally transparent, which can be the same as that of existing “crisper drawers”. However if desired part or all of the drawer or compartment can be made of another material such as glass but, as will be seen below, glass is not the material of choice in certain embodiments due to manufacturing difficulties.

In the case of a drawer, typically at the base of the refrigerator, extending the full width of the interior of the refrigerator, the underside of the shelf above it together with the interior sides and base of the refrigerator define a compartment, as this word is used in this specification. Usually the shelves or parts of them in a refrigerator are removable. It will be appreciated that the shelf which is to form the top or ceiling of the compartment with which this invention is concerned is desirably made integral with the walls and floor of the compartment in order to facilitate vacuum formation in the compartment. Thus this shelf will preferably be moulded to the sides and rear wall. If desired there can be two or more drawers which together extend the full width of the interior of the refrigerator. Alternatively it is possible for there to be a single drawer which does not extend the full width of the interior of the refrigerator. In this case a partition wall extending from the base to the shelf above is needed to define the compartment.

In accordance with the present invention the compartment is provided with evacuation means, normally a pump, for evacuating it. Typically an orifice is located in the rear wall of the compartment and the pump is connected via a hose to this orifice so that when the pump is turned on, the compartment can be evacuated. Thus the pump will typically be located either behind the rear interior wall of the refrigerator or under the internal floor of the refrigerator, in the same space which normally accommodates the compressor. Desirably the orifice is provided with a grid or mesh so as to prevent any food material from entering the pump; desirably also the orifice is equipped with a one way valve so that air cannot enter the evacuated compartment. The seal can be assisted by surrounding the orifice with a deformable cone thereby enhancing the seal within the compartment.

It will be appreciated that the pump will usually take several minutes to evacuate the compartment. While this is not normally a disadvantage because the user is unlikely to want to reopen the compartment during this time and, in any event, no damage occurs to the produce in the compartment, nevertheless, if desired, a substantially instantaneous evacuation can be achieved, according to another embodiment of this invention. According to this embodiment, the pump does not evacuate the compartment directly. Rather the pump evacuates a container or storage tank which is connected to the compartment, typically via the orifice in the wall of the compartment via a valve. In use, after releasing the vacuum, the drawer is moved out of sealing engagement with the compartment, as by releasing the clips (see below), and this causes a switch to close the valve between the container and the compartment and to turn on the pump. As a result the container is evacuated. When the drawer is reinserted and placed in seating engagement, this switch causes the valve to open, with the result that air in the compartment escapes substantially instantaneously into the evacuated container thus resulting in a vacuum in the compartment. In this instance, therefore, the switch or other device for activating the pump is activated when the drawer is not in sealing engagement with the container. In an alternative embodiment, the orifice in the rear wall of the compartment is replaced by a release valve, typically spring loaded. With such an arrangement, when the drawer is pushed to its furthermost position the spring is depressed and the valve is automatically opened. Since the vacuum is created substantially instantaneously in the compartment there is no need for any other means such as clips to maintain the drawer in sealing engagement with the container. In a sense, therefore, the release valve coupled with the evacuated storage tank acts as the means for maintaining the drawer in sealing engagement with the compartment. The release valve can be constructed such that once the vacuum in the tank has equilibrated with the pressure in the compartment it closes and the pump is automatically turned on so as to evacuate the storage tank ready for the next re-insertion of the drawer. Alternatively a separate switch can be located in the rear wall as discussed above. Accordingly the present invention also provides a refrigerator comprising at least one compartment capable of evacuation, said compartment being provided with evacuation means, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means for activating the evacuation means when the drawer is in sealing engagement with the compartment, said means comprising a valve operable when the drawer is positioned in sealing engagement with the compartment, connected to an evacuatable storage tank, said evacuation means being connected to said compartment via said storage tank and valve.

It will be appreciated that the vacuum produced in the compartment by this arrangement will be dependent on the volume of the tank, assuming the same pump or degree of vacuum; the larger the tank the greater the vacuum which can be produced in the compartment. Thus if the tank has roughly the same volume as that of the compartment, the final level of vacuum will be about half the value of that obtained by direct evacuation by that pump.

In some instances the rear part or base of the refrigerator which usually houses the refrigerator pump or compressor can accommodate the container but, generally, it is better if the tank or container forms a separate unit outside the refrigerator so that it can be made as large as desirable. Thus the container and pump will typically be placed, e.g. in at the rear of, a kitchen unit adjacent the refrigerator with a hose leading from the container to the orifice in the rear wall of the refrigerator which accommodates the release valve. Desirably the hose is made to carry the electrical wire to the pump and the valve.

By evacuating the compartment incorporating the drawer rather than the drawer by itself it is possible to reduce the number of places where the vacuum seal can break down. Effectively the only place where a seal is needed in the case of a moulded compartment is at the interface between the drawer and the front edge of the compartment. In a preferred embodiment this seal is provided by a centreless O-ring on the drawer and/or the compartment but preferably on the latter since it is static. The O-ring can be made of a usual rubbery or synthetic rubber material. Such materials which can be used include olefin non-conjugated diene polymers. Typical olefins include ethylene and propylene. Typical non-conjugated dienes which can be used include ethylidene norbornene (ENB) and dicyclopentadiene (DCPD). Thus typical synthetic rubbers which can be used include EPDM rubbers such as a terpolymer of ethylene, propylene and ENB or DCPD. The seal is typically in the form of an endless pipe. This can be recessed in a face, typically a flange which extends along or above the upper wall of the compartment, down the side walls of the compartment, which desirably possess a flat open (or outward facing) end, and along the base of the compartment which again should desirably possess a flat open end. The recess should be less than the thickness e.g. the diameter of the O-ring material, so that the O-ring protrudes beyond the edge of the compartment; for example if the O-ring is ¼ inch diameter the recess is perhaps ⅛ inch deep. Thus when the drawer is in its furthest, or fully pushed in, position in the compartment the O-ring is depressed or squashed so that or a seal can be made between the two. Clearly this is assisted by having the surfaces which abut the compartment flat. This can readily be achieved by providing the drawer with a flange around the outer wall of the handle end with the inner or forward facing walls of the flange being generally flat. If desired a corresponding O-ring can be located in the front face of the walls of the handle end of the drawer.

It will be appreciated that if the pump is turned on a vacuum is unlikely to result in the compartment unless the abutting faces of the drawer and compartment are held together; the slightest gap between them will prevent a seal, and, in consequence, a vacuum being formed. Accordingly it is an essential feature of this invention that the drawer and/or the compartment is/are provided with means to ensure that they remain in sealing engagement when the drawer is pushed fully home into the compartment. In a preferred embodiment the drawer is provided on its handle end, generally at the top of its front wall, with one or more, generally two or more, for example two, or three, clips, preferably positioned at opposite ends of the drawer. These clips, preferably spring clips, are positioned so that they extend over the edge of the handle wall of the drawer, for example on the left and right sides of the drawer, and can be clipped, when pressure is applied, over the front edge of the compartment, thus maintaining the top edge of the wall of the handle wall of the drawer in tight engagement with the front edge of the compartment. Typically the clips are constructed such that the application of pressure in the direction of closure of the drawer i.e. towards the rear of the refrigerator causes them to be clipped over the front edge of the compartment and fixed tight to it while the application of pressure towards the front of the refrigerator enables it/them to be released from this locked position. When, as is preferred, two or more clips are used, they are desirably connected to one another by, for example, a bar so that the user can secure all the clips with one hand. To assist the user, a handle can be placed near the clips.

Of course alternative arrangements are possible including rubber straps which can be made to stretch between the drawer and compartment edges. For example rubber straps can be used possessing a hole near each end; when stretched such straps can be secured to protrusions on the drawer and compartment via the holes in them; of course one end of the strap can be permanently attached to either the drawer or compartment. Again a seal can be provided magnetically by placing magnetic strips or other magnetic devices on the flange of the drawer which cooperate with corresponding strips on the compartment. In one embodiment, these are placed inside the O-ring seal which facilitates their positioning.

When the drawer has been secured in the compartment it is necessary for the pump to be turned on to start evacuation (or where a separate container has been evacuated the valve opened). This can be achieved by pressing a switch positioned in the wall of the refrigerator (the switch being electrically connected to the pump or valve as appropriate), typically near the open or door end of the refrigerator cabinet. However this requires special action by the user. Accordingly it is preferred that a switch is activated automatically when the drawer is secured in position i.e. is in sealing engagement with the compartment. In one embodiment a switch is located in the rear wall of the refrigerator, positioned such that it is depressed by the fully located drawer; thus it is preferably a plunger-type switch. In another embodiment a switch, for example a microswitch, is provided on the rear facing edge of the compartment flange, positioned so that when a clip is pressed into its locking position over the compartment flange, it simultaneously depresses the switch. In this embodiment there is, of course, a need for electrical wires to be located in a side wall of the compartment, connecting the switch with the pump. It will be appreciated that when reference is made to electrical wires this is intended to include other types of electrical connection e.g. printed circuits.

Once the pressure inside the compartment has been reduced sufficiently, the pump should be turned off. This can be achieved by locating a gas pressure switch at a convenient location, for example in the back wall of the compartment; this can be preset so that it causes the pump to stop evacuating when the pressure has reduced to preset level. Typically the pump will be switched off when the pressure in the compartment has reduced to 550 to 650, especially 575 to 625, for example about 600 to 610, mm Hg, i.e. a partial vacuum prevails. It will be appreciated that the word ‘vacuum’ as used herein strictly means partial vacuum since a complete vacuum is neither desired nor can be obtained. It will be realized that the power of the pump will be dependent on the volume of the compartment. The power should be such that the desired reduced pressure can be achieved within a few minutes, as one of skill in the art can readily adjust.

It will be realized that if the switch is located at the front of the container, and is typically activated by the clip(s), electrical wiring is needed from it to the pump (directly or indirectly. It is generally simpler to bury this wiring in plastics components of the compartments rather than attach it to a glass surface, hence the advantage of using plastics.

Alternatively the time required for the pump to reduce the pressure to the desired level can be determined and the pump turned off by a preset time switch. This dispenses with the need for a gas pressure switch.

When the user wishes to extract something from the compartment, the reduced pressure will usually make it difficult to pull out the drawer. Desirably therefore the drawer/compartment is provided with pressure-releasing means, generally a release valve which the user can operate thereby restoring atmospheric pressure to the compartment. Typically the pressure-releasing means are located in the free, outer or handle end of the drawer and are thus readily accessible to the user. The nature of the pressure-releasing means is not critical. While the means can take the form of a spring-loaded valve this has the disadvantage that the vacuum may be released suddenly. It is therefore preferred that the valve is of the threaded type such that unscrewing the valve enables the vacuum to be released progressively. Such a valve typically takes the form of a threaded insert, typically of plastic, which possesses an O-ring around a central shaft. A head on the insert enables it to be fixed into the drawer wall; a groove is present axially down this insert such that as the cap is turned anticlockwise, air enters the drawer/compartment down the groove. Such a valve is easy to make and easy to install. If desired a washer, for example of a silicone, circles the central shaft. The use of such a washer can make the groove unnecessary since as the valve is turned anticlockwise it first allows the washer to slowly expand before allowing the gradual ingress of air. Once the user has operated the release valve and allowed the air to re-enter the compartment, the valve will need to be re-activated prior to re-vacuuming the compartment by screwing it fully clockwise.

The present invention thus provides a simple way of equipping a refrigerator with a vacuum compartment which is effective and easy to use. In particular the vacuum is completely unaffected by opening the refrigerator door. In other words the user can access material in other parts of the refrigerator without disturbing the vacuumed compartment(s). Of course there is no reason why, if desired, the whole of the refrigerator should not be equipped with one or more vacuumable compartments; in this instance releasing the vacuum in one compartment need not affect the vacuum in the other(s).

In another embodiment of the present invention rather than providing a novel refrigerator comprising a vacuum compartment, a unit with a vacuumable compartment is provided which can be installed in an existing refrigerator. In other words a self-contained unit is provided. Accordingly the present invention also provides a compartment suitable for insertion into a refrigerator which comprises evacuation means, means for connecting the evacuation means to an electrical source, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means provided on said drawer and/or said compartment for maintaining the drawer in sealing engagement with the compartment, means for activating the evacuation means when the drawer is, or is not, in sealing engagement with the compartment, and means for releasing the vacuum in said compartment.

The compartment will typically be in the form of a generally rectangular box with a free end in which the drawer is located. Usually the compartment will be of a size such that it will fit on a shelf in a refrigerator or, for example, replace an existing crisper drawer, and generally extend across half or, alternatively, the whole width of a typical refrigerator shelf. Typically the compartment will have a depth comparable to or, rather, slightly less than, that of a typical refrigerator shelf. For example the compartment is typically 8 to 15, e.g. 10 to 12, inches deep, 10 to 30 e.g. 10 to 15 or 24 to 30 inches wide and 4 to 8 e.g. 5 to 7, inches high. If the box is square its side is typically 12 to 15 inches. The evacuating means, generally a pump, will generally be positioned in a separate rear enclosure beyond the drawer. In other words the box possesses a substantially vertical partition, the rear portion of the box thus formed housing the pump, the latter usually being connected to an orifice via a hose which penetrates the partition. Desirably the orifice is equipped with a one way valve. If desired this rear portion possesses a vent hole to allow the extracted air to escape. The nature of the drawer, the sealing engagement thereof with the compartment, the pump and its action and the vacuum release can all be the same as described above. The electrical power source for the pump is most conveniently provided via the light socket which is present in a typical refrigerator. To achieve this the light bulb is removed from its socket and an electrical cable or wire attached to the pump is passed to it, typically up the rear wall of the refrigerator, the wire terminating in a plug which can be inserted into the light bulb socket. If desired a two-way adaptor can first be inserted into the socket so that the light bulb can be re-connected by insertion into the second socket of the adaptor (the first being occupied by the pump plug). It will be appreciated that in the usual situation, the power to the light is switched off when the door is closed because closing the door causes a pressure sensitive switch on the refrigerator frame to be in the open position. For the purposes of the present invention this switch should be in the closed position so that power to the light socket is maintained when the door is closed. In the case of a switch with an extending probe which is pushed down by the closing door, this can be achieved by removing the probe or securing it in the depressed position. This does, of course, mean that if a light bulb is inserted in the two way switch, it remains illuminated at all times. This is not normally a problem as the electricity used is insignificant, with insignificant heating of the refrigerator interior. If desired, though, a fluorescent light bulb can be used to reduce the effects of this. Again, the light socket can incorporate a light sensor which completes an electrical circuit to the bulb. The sensor activates to complete the circuit when the door is opened and the sensor receives light through the opened door. Alternatively, the power can be provided via a power socket external to the refrigerator i.e. the pump is equipped with an electrical connection e.g. a plug which terminates in a conventional wall socket. In this instance a cable typically passes from the pump through the refrigerator door to the external socket. Particularly if the cable is bilobal rather than cylindrical in cross section, it can readily pass through the perimeter seal of the door without adversely affecting the seal. Again the pump can be powered by one or more, e.g. 4 to 6, batteries, for example 1.5 volt batteries, which can be rechargeable in which case a connector is located in the rear wall of the compartment, which is in electrical contact with the rechargeable battery(ies).

It is envisaged that this compartment will be inserted into the refrigerator on a shelf immediately above the usual crisper drawer(s) but of course, it can be located in any position within the refrigerator.

In a further embodiment, the compartment does not include a drawer. Rather the compartment takes the form of a box with an orifice, generally having an upstanding flange, on, preferably one, or more faces allowing the insertion or removal of food from the compartment. The orifice(s) is/are provided with a lid which can sealably engage it. Typically a seal of a deformable material, for example a silicone, such as an O-ring seal, is located in the rim of the lid and/or the rim of the orifice, preferably in the lid. If desired the lid can be hinged to the box along one edge. Generally the orifice will extend substantially over one face of the box. Desirably the box and the lid are made of a rigid plastics material, for example an acrylics material. While if the box and the lid are sufficiently rigid and small, nothing further is required to form a vacuum, usually means are needed on the compartment and/or the lid to maintain the compartment and the lid in sealing engagement when the pump is turned on. This can take the form of one or more, preferably at least two, for example four, clips which thereby keep the lid and box in gas tight contact. It will be appreciated that the box will generally have similar dimensions to those of the compartment of the previous embodiment. As with the previous embodiment, the compartment comprises a pump, preferably a battery powered pump, situated as with the previous embodiment. Thus this embodiment provides a complete self-contained unit although, if desired, the pump can be connected to the mains. The box will be equipped with a vacuum release mechanism as discussed above. In a further arrangement, the pump is such that it can be charged either by one or more batteries or by the mains via a suitable transformer desirably located in the rear compartment. For example, if the batteries are low, the box is connected to the mains to be evacuated. Once evacuated, the box can be disconnected from the mains and inserted in a refrigerator. In this embodiment, the pump is activated by the user, generally by operating a switch or button located on the outside of the box but which is electrically connected through the box wall to the pump; the pump can be turned off automatically as discussed above. Alternatively the switch can be equipped with a pressure monitor so that the user can turn the switch off when the desired reduced pressure has been reached. Desirably the lid and base are shaped so that one compartment can be stacked on another.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will now be illustrated, merely by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic representation of a refrigerator according to one embodiment of the present invention,

FIG. 2 is a diagrammatic representation of a refrigerator compartment according to the present invention positioned in a refrigerator,

FIG. 3 is a diagrammatic representation of a refrigerator with storage tank according to the present invention,

FIG. 4 is a diagrammatic representation of one form of pressure release valve which can be used in the present invention,

FIG. 5 is a diagrammatic representation of a side view of a box and lid according to the present invention, and

FIG. 6 is a rear view of a box of the present invention (without the lid).

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the lower portion of a refrigerator is shown in section at 1. It comprises a crisper drawer, 11, which possesses drawer slides, 2, which enable the drawer to slide in a compartment which is defined by ceiling, 17, back wall, 18, and base, 19. Drawer, 11 is equipped with locking clips, 8 on either side of it, together with O-ring seals, 6, which form a seal between the drawer handle end, 20, with flanges 20A and 20B and the front edge of the compartment shown at 21. The end 20 is also provided with a vacuum release valve, 7. The compartment base 19, is equipped with an activator switch, 12 which is depressed when the drawer is pushed fully home. The compartment also possesses an orifice, 22, which is connected via pipe, 23 to a vacuum pump, 3 located in the base of the refrigerator.

After adding some food to the drawer, 11, the user pushes the latter as far as it will go into the compartment which causes the switch, 12 to be depressed completing an electrical circuit (not shown) with the pump causing the latter to switch on. The user then secures the clips 8 around the front edge of the compartment thus creating a seal enabling the pump to suck air out of the compartment including the drawer. The pump will continue to operate until the desired vacuum has been produced. Typically this will be pre-set by operating the pump for a pre-set time whereupon it switches off. When the user wishes to extract food from the drawer, 11, the vacuum release valve, 7 is unscrewed causing air gradually to enter the compartment. Once atmospheric pressure has been re-established in it, the drawer can readily be pulled out.

The portable refrigerator compartment shown in FIG. 2 generally comprises the same features as the compartment and drawer shown in FIG. 1. In FIG. 2 the drawer is denoted by 4 while the container is denoted by 5. The vacuum activator switch which in this embodiment is placed to the rear of the drawer is denoted by 10. The compartment does, of course, have to accommodate a pump, 3. As shown, the pump, 3 is positioned on the floor of the compartment with the base of the drawer moulded to accommodate it i.e. the rear portion is shallower. Of course it would also be possible to make the drawer with a flat floor corresponding to the level of the shallower end portion. There is an electrical connection (not shown) between the pump, 3 and activator switch, 10 and also between them and the light socket of the refrigerator (not shown). If desired the base of the compartment can be provided with rubber suction cups or Velcro type feet, 9 with reciprocal rubber suction cups or Velcro strips positioned on the floor of the refrigerator to keep the compartment from moving.

In use, the portable compartment shown in FIG. 2 operates in the same way as the drawer and compartment of the refrigerator shown in FIG. 1.

As indicated, FIG. 3 illustrates a refrigerator according to the present invention incorporating a storage tank, 13 to which pump, 3 is connected, in a kitchen cabinet, 16. The features are otherwise the same as for FIG. 1 except that orifice, 22 is replaced by spring loaded vacuum release valve, 14 with an activator pin, 15. In use, when drawer, 11 is pushed to its furthermost position, activator pin, 15 is depressed. This has two effects. First, depression of pin, 15 causes the release valve, 14 to open. In consequence, air in the compartment escapes into the previously evacuated storage tank, 13, causing the pressure in the compartment to be reduced. Second, though, depression of the pin, 15 completes an electrical circuit (not shown) to the pump, 3 so that the latter is turned on. Almost instantaneously the pressures in the compartment and tank are equalized. When this happens the spring in valve, 14 causes the valve to close thus enabling the tank, 13 to be evacuated. In the same way as the embodiment shown in FIG. 1, once the desired reduced pressure has been reached in the tank, 13 the pump turns off. The system is now ready for a fresh evacuation of the compartment. Of course when the drawer is withdrawn the activator pin, 15 protrudes once again into the compartment.

The vacuum release valve, 7 shown in FIG. 4 comprises a head, 23 and a shaft, 24. An O-ring seal, 32 surrounds the shaft, 24 where it abuts the head, 23. Shaft, 24 comprises threads, 33 and a groove, 34. To maintain reduced pressure, the release valve, 7 is screwed tight into the handle end of the drawer so that the O-ring, 32 is squashed. When it is desired to increase the pressure to atmospheric the valve, 7 is unscrewed slightly. This enables air to enter the compartment via the groove, 34 in the valve. The rate at which air enters can be controlled by the amount of unscrewing of the valve, 7. Of course before the compartment can be re-vacuumed the valve, 7 has to be screwed back tight into the handle end of the drawer.

A box arrangement of the present invention is illustrated in FIGS. 5 and 6. A box or container, 101, is provided with a sealable edge, 102, which can engage with an inside edge, 106, possessing a seal, 104, on a lid, 105. Locking clips, 107, can be forced under pressure over catches, 108, on the container, 101, thereby forming a gastight seal between the container, 101, and the lid, 106. A vacuum pump, 111, is located in the rear portion of the container, 101, in a partition, 120. A switch, not shown, is operated by the user to turn on the pump, 111 (unless the clips when located over the catches complete an electrical circuit causing the pump to turn on), which then evacuates the main body of the container via a one way valve, 113. A vacuum sensor, 112, determines when the pressure has reduced to the desired level and then, via wires not shown, switches off the pump. Alternatively, the sensor possesses a readable gauge so that the user can switch off the pump when the desired pressure has been reached. The pump can be powered by removable batteries, 114 (six are shown in end view FIG. 6). If, as is preferred, the batteries, 114, are rechargeable, a battery charger, not shown, is housed behind them and this can be electrically connected via an outlet, 109, to a power source. In addition an outlet, 110, electrically connected to the pump via a 110 volt converter can be connected to the mains so that the pump can be operated by the mains. A pressure release valve, 103, is located in a wall of the container, 101.

Claims

1. A refrigerator comprising at least one compartment capable of evacuation, said compartment being provided with evacuation means, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means provided on one of said drawer and said compartment for maintaining the drawer in sealing engagement with the compartment, means for activating the evacuation means when the drawer is, or is not, in sealing engagement with the compartment, and means for releasing the vacuum in said compartment.

2. A refrigerator according to claim 1 wherein sealing engagement between the drawer and the compartment is provided by an O-ring seal located in the front face of the compartment.

3. A refrigerator according to claim 1 wherein the means for maintaining the drawer and the compartment in sealing engagement comprises one or more clips which, when the drawer is in its furthermost position in the compartment, extends over the top of the front face of the drawer to the back face of the front wall of the compartment.

4. A refrigerator according to claim 3 wherein the clips are pressure releasable.

5. A refrigerator according to claim 4 wherein the back face of the front of the compartment is provided with at least one microswitch which is positioned such that when the clip engages with said back face the microswitch is depressed causing the evacuation means to operate.

6. A refrigerator according to claim 4 wherein a switch is located in the rear wall of the compartment such that it is depressed when the drawer is in sealing engagement with the compartment.

7. A refrigerator according to claim 1 wherein the front wall of the drawer is provided with a screw threaded pressure-release valve.

8. A refrigerator according to claim 1 where in an orifice is located in the rear wall of the compartment and the evacuation means comprises a pump connected to said orifice.

9. A compartment suitable for insertion into a refrigerator, the compartment comprising evacuation means, means for connecting the evacuation means to an electrical source, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means provided on one of said drawer and said compartment for maintaining the drawer in sealing engagement with the compartment, means for activating the evacuation means when the drawer is, or is not, in sealing engagement with the compartment, and means for releasing the vacuum in said compartment.

10. A compartment according to claim 9 wherein the means for connecting the evacuation means to an electrical source comprises a cable equipped with a plug suitable for insertion into a light socket located in the interior of a refrigerator.

11. A compartment according to claim 9 wherein the means for connecting the evacuation means to an electrical source comprises a bilobal cable which terminates in a plug suitable for insertion into a socket.

12. A box-like compartment suitable for insertion into a refrigerator, the box-like compartment comprising evacuation means, means for connecting the evacuation means to an electrical source, an orifice located in at least one wall of the compartment, a lid capable of sealably engaging with said orifice, means provided on one of said orifice and said lid for maintaining the lid in sealing engagement with the orifice, means for activating the evacuation means and means for releasing the vacuum in said compartment.

13. A box-like compartment suitable for insertion into a refrigerator which comprises evacuation means, means for connecting the evacuation means to an electrical source, an orifice located in at least one wall of the compartment, a lid capable of sealably engaging with said orifice, means for activating the evacuation means and means for releasing the vacuum in said compartment.

14. A refrigerator comprising at least one compartment capable of evacuation, said compartment being provided with evacuation means, a drawer locatable in said compartment, the front wall of said drawer possessing a face capable of sealably engaging the front face of the compartment, means for activating the evacuation means when the drawer is in sealing engagement with the compartment, said means comprising a valve, operable when the drawer is positioned in sealing engagement with the compartment, connected to an evacuatable storage tank, said evacuation means being connected to said compartment via said storage tank and valve.