GB2414065A

GB2414065A - Vacuum storage compartment construction in cooling apparatus

Info

Publication number: GB2414065A
Application number: GB0410718A
Authority: GB
Inventors: Simon James Naylor; Sameer Shirgaonkar; James Beeching Neave; Max William Middleton
Original assignee: Cambridge Consultants Ltd
Current assignee: Cambridge Consultants Ltd
Priority date: 2004-05-13
Filing date: 2004-05-13
Publication date: 2005-11-16
Anticipated expiration: 2024-05-13
Also published as: GB2414065B; CN100533012C; EP1747414B1; WO2005114071A1; EP1747414A1; CN1950650A; GB0410718D0

Abstract

Cooling apparatus, for example, a refrigerator (10), is provided with an evacuatable storage compartment defined by a separately constructed, i.e. self-contained, box unit (16) mounted in a housing of the apparatus and basically composed of a robust integral structure (18) which forms two side walls (19), a top wall (20), a bottom wall (21) and a back wall (22) and bounds an aperture (24) serving as an access opening of the compartment. The unit is completed by a door (26) sealably closing the aperture. The back wall (22) of the integral structure (18) includes two connections (31) for vacuum pipes, hoses or other conduits for extraction of air from the compartment an an evacuation phase. Each of the walls of the structure is preferably curved to increase resistance to collapse or deformation under load. The structure may comprise a plastics material moulding.

Description

24 1 4065

VACUUM STORAGE COMPARTMENT CONSTRUCTION IN COOLING APPARATUS

The present invention relates to cooling apparatus and has particular reference to vacuum storage compartment construction in cooling apparatus.

It has been proposed to include in cooling apparatus, particularly domestic refrigerators, freezers and refrigerator/freezer combinations, vacuum storage compartments for storage of foodstuffs in a vacuum environment. Such an environment offers the possibility of retarding deterioration of the stored products by, amongst other factors, reducing aerobic bacterial growth and photosynthesis. Compartments of that kind should preferably be evacuated automatically when products are placed in storage and returned to atmospheric pressure to allow removal of products via a closable access opening of the compartment.

Accordingly, the compartments should be simple to evacuate and repressurize, capable of withstanding subatmospheric pressure levels in the order of 200 millibars absolute for lengthy periods of time and with repeated cycling, and relatively easy to keep hygienic and to clean. The requirement of sustained maintenance of an internal underpressure should be met in part by a minimum number of potential points of leakage. In wider terms, such compartments should be simple and economic to produce, light in weight and, if possible, capable of universal use in cooling apparatus of different designs, specifically a compartment construction usable without modification or significant modification in different apparatus configurations.

The principal object of the invention is therefore to provide cooling apparatus having a storage compartment which may be capable of universal use and which is of robust yet simple construction to withstand differential pressure without undue susceptibility to leakage.

Subsidiary objects of the invention include low-cost construction with a relatively small number of parts so as to facilitate mass production and assembly. Further objects and advantages are evident from the following description.

According to the present invention there is provided cooling apparatus provided with an evacuatable storage compartment defined by a separately constructed box unit comprising an integral structure, which forms two side walls, a top wall, a bottom wall and a back wall of the unit and bounds a front access opening, and an openable door sealably closing the access opening.

A storage compartment in the form of a separately constructed box unit represents a self- contained module with a capability of use in different types or variations of cooling apparatus, including refrigerators, freezers and refrigerator/freezer combinations. This is of particular advantage in the case of product ranges containing models which may have different sizes and fits of internal equipment, but the same fundamental features, such as refrigerating, freezing and vacuum storage compartments. The unit may then be able to be used with little or no modification in all products within the range, which represents a significant advantage with respect to manufacturing cost. This advantage is combined with the intrinsically strong and robust compartment construction achieved by an integral structure forming all of the walls of the box unit. This one-piece design eliminates all potential points of leakage otherwise present at wall junctions and provides a substantial reduction in the number of parts necessary for making up the unit, which is of benefit for low-cost manufacture and assembly. The integral structure can, at the time of production, be readily provided with integrated features associated with mounting of the door and supply of air to and extraction of air from the compartment.

The capability of the box unit to resist the load induced by evacuation of the interior and by maintenance of an appropriate level of underpressure may be enhanced if at least one of the walls, preferably each of the side, top and bottom walls, formed by the integral structure is curved so as to be convex at the outside of the unit. The structure then has a construction, at least in part, simulating a pressure vessel with walls bowed outwardly to prevent collapse or buckling due to underpressure at the concave faces. The strength of the structure may be further increased if one or more of the junctions of the walls is radiussed so as to eliminate abrupt transitions; this feature also assists maintenance of hygiene by reducing food traps and eases the task of cleaning.

The door can be mounted on the integral structure in any desired manner, but, in one particularly advantageous embodiment, mounting is on a drawer movable in the unit, for example slidable on guides formed on inner surfaces of the side walls. Opening of the door thus permits convenient removal of products deposited in the drawer. The guides, for example in the form of runners, can be integral parts of the side walls.

The unit preferably comprises sealing means for sealing the door relative to a surround which is formed by the integral structure and encircles the access opening. The sealing means can, for example, be incorporated in a recess which is provided in the surround and in which the door engages when closing the access opening.

The door itself can be transparent at least in part, for example made partly or entirely of glass, to permit inspection of the contents of the compartment. The integral structure, however, is preferably a plastics material moulding, which can be readily produced by co- operating male and female moulds of simple form without undercuts or movable parts. At least one of the walls preferably includes at least one integral stiffening rib to further promote resistance of the wall to deformation under differential pressure loading.

An additional feature of the unit can be connections provided in the back wall of the structure for the supply of air to and removal of air from the compartment. The connections can consist of, for example, pipe or hose coupling elements mounted in apertures in the back wall or formed integrally with that wall.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a schematic sectional side view of a refrigerator incorporating a vacuum storage compartment, in an embodiment of the invention; and Fig. 2 is an exploded schematic perspective view, to enlarged scale, of a box unit defining the storage compartment.

Referring now to the drawings there is shown in Fig. 1, in highly schematic form, a refrigerator 10 comprising a thermally insulating housing 11 enclosing a cooled storage space 12 for storage of items at atmospheric pressure. The space 12 is closed by a door 13. The housing 11 additionally contains a vacuum storage compartment 14 accessible at the housing exterior by way of a door 15. The compartment 14 is defined by a separately constructed, i.e. entirely self-contained, box unit 16 which is mounted in the housing 11 and is described in more detail further below, the unit being closed by a respective door.

Located below the compartment 14 is a space 17 accommodating conventional components of an evaporating and condensing circuit of the refrigerator as well as a vacuum pump and associated ducts and control elements for the vacuum storage compartment 14.

Fig. 2 shows the box unit 16, which defines the storage compartment 14, separately and to enlarged scale. In addition, the unit is shown in exploded illustration to assist understanding of the unit construction. The basic component of the unit is an integral structure 18 which consists of a one-piece moulded part of plastics material and which forms two mutually opposite side walls 19, a top wall 20, a bottom wall 21, a back wall 22 and a front surround 23 encircling an aperture 24 which serves as an access opening to the interior of the unit 16. Each of the side walls 19, top wall 20 and bottom wall 21, as well as optionally the back wall 22, is curved so as to be convex at its outer face and thereby impart to the unit increased resistance to collapse or deformation under load, in particular an internal underpressure. In addition, one or more of the walls can incorporate an integral stiffening rib 25 or rib pattern - shown by way of example at the top wall 20 - to further increase resistance to distortion under load. The junctions of the various walls are radiussed so as to optimise the strength of the structure 18 by removing bend locations.

Radiussed junctions at the inside of the unit also assist cleaning and eliminate traps for food residues.

The box unit 16 is completed by the afore-mentioned respective door, which is referenced 26 and which closes the aperture 24. When closed, the door 26 nests in a recess 27 in the surround 23 and sealingly co-operates with a resilient seal 28 mounted in the recess, so that the interior of the storage compartment is then hermetically sealed from the atmospheric pressure otherwise prevailing within the refrigerator housing 11. The door 26 can comprise a panel of transparent material, for example glass, to afford the user a view of items stored in the compartment 14. The door 26 is carried by a drawer 29 which is guided on runners 30 integrally formed at the inner surfaces of the two side walls 19 of the unit 16. On opening of the door 26, for example by means of a handgrip (not shown), the drawer 29 slides out to provide easy access to products stored in the compartment.

The back wall 22 of the integral structure 18 includes two connections 31 for vacuum pipes, hoses or other conduits for extraction of air from the compartment in an evacuation phase, as well as maintenance of an evacuated state in a storage phase, and feed of air to the compartment to restore atmospheric pressure so that the door can be opened for removal and insertion of products.

Use of the vacuum storage compartment 14 in operation of the refrigerator 10 is self- evident from the foregoing description. Access to the compartment is gained by opening the external door 15 after which, and following pressurization of the compartment, the internal door 26 can be opened. After closure of the door 26, the compartment can be evacuated again. Pressurisation and evacuation can be carried out automatically by detectors responsive to operation of the door 26 and/or door 15 and to the pressure level.

The detectors can be, for example, mechanical switches and pressure switches. Manually actuated switches can also be provided for control exclusively by a user and/or for overriding automatic operation.

The refrigerator of the embodiment hereinbefore described incorporates a vacuum storage compartment of a construction that readily withstands the level of underpressure encountered in use and, subject to maintenance of effective door sealing, offers effective and long-term vacuum tightness. The basic part of the box unit 16, i.e. the integral structure 18, is inexpensive and simple to make, thus compatible with large-scale production, and can be easily provided with integrated features, such as the drawer runners, stiffening ribs and duct couplings, in the moulding phase. The compartment constitutes a self-contained module of a kind potentially capable of universal use for different models of refrigerator without requiring modification. In the event of modification, however, this may be able to be achieved by redesign and replacement of a single mould tool.

Claims

1. Cooling apparatus provided with an evacuatable storage compartment defined by a separately constructed box unit comprising an integral structure, which forms two side walls, a top wall, a bottom wall and a back wall of the unit and bounds a front access opening, and an openable door sealably closing the access opening.

2. Apparatus as claimed in claim 1, wherein at least one of the walls is curved so as to be convex at the outside of the unit.

3. Apparatus as claimed in claim 2, wherein the side, top and bottom walls are each curved so as to be convex at the outside of the unit.

4. Apparatus as claimed in any one of the preceding claims, wherein at least one of the junctions of the walls is radiussed.

5. Apparatus as claimed in any one of the preceding claims, wherein the door is mounted on a drawer movable in the unit.

6. Apparatus as claimed in claim 5, wherein the drawer is slidable on guides formed on inner surfaces of the side walls.

7. Apparatus as claimed in any one of the preceding claims, wherein the unit comprises sealing means for sealing the door relative to a surround which is formed by the integral structure and encircles the access opening.

8. Apparatus as claimed in claim 7, wherein the door when closed engages in a recess in the surround.

9. Apparatus as claimed in any one of the preceding claims, wherein the door is transparent at least in part.

10. Apparatus as claimed in any one of the preceding claims, wherein the integral structure comprises a plastics material moulding.

11. Apparatus as claimed in any one of the preceding claims, wherein at least one of the walls includes at least one integral stiffening rib.

12. Apparatus as claimed in any one of the preceding claims, wherein the back wall of the structure is provided with connections for the supply of air to and removal of air from the compartment.

13. Apparatus as claimed in any one of the preceding claims, wherein the apparatus is a refrigerator, a freezer or a refrigerator/freezer.