GB2398369A - Framed enclosure with electric heating elements in a cover - Google Patents

Abstract

A heated enclosure has a frame 1 defining a volume and a cover or tent 2 supported on the frame, the cover 2 being of sheet material and having portions 5a,5b capable of being heated to effect heating of the volume. The sheet material may be breathable non-woven fabric and/or have vents, and the portions 5a,5b may comprise electric heating elements located inside an outer insulation layer 9. The heating elements may comprise carbon on a film substrate, a chemically etched foil or spirally wound wire. Frame 1 may have hinges (23,24 fig 3) to allow it to collapse, while the cover may have a releasably fastened flap 8. The enclosure may contain a clothes maiden 4 or shelves for use as a plant propagator.

Description

HEATED ENCLOSING ASSEMBLY

The invention relates to a heated enclosing assembly to provide a temperature-controlled environment, especially to such an assembly adapted 1-or construction on a temporary or semi-permanent basis. The invention for example relates to drying chambers such as but not limited to clothes dryers and airers, but also relates to other chambers requiring thermally controlled environments for other reasons, for example plant propagators and the like. 1()

It is well known to provide clothes dryers or airers in which the clothes are mounted upon a suitable drying or airing reek and a heat source is provided to generate heat in the vicinity of the rack. This has the effect of warming the air in the vicinity of the clothes to be dried or aired and assisting in the drying or airing process.

I Cited Kingdom Patent Nos. 860208 and 1017631 and US Patent No. 24454()3 are examples of such structures. US 2445403 in particular is notable in that it describes an open space-frame structure which provides not only a hanging rack for the clothes to be dried or aired but also a supporting reek over which a cover maybe draped. This cover has the effect of controlling airflow around the clothes, and creating an at least partially enclosed environment therearound. This environment may then be heated by electrical heating elements located at the base of the frame.

Such a design provides for a collapsible assembly that can be deployed as an enclosing, tented structure adapted for local heating of the clothes once assembled to facilitate the drying or airing process. However, it suffers from a number of drawbacks. In particular, the use of direct heating at the bottom of 3() the assembly is likely to raise safety issues. Heating is also likely to be uneven, with a tendency to create hot spots. The problem also arises of how moisture is to be removed as the clothes within the enclosure dry. The only practical way suggested in the prior art to address these last two problems requires the setting up of a circulating air current, for examp]c by a fan impcllcr, to cqualise temperature and to create an airflow whereby heated moist air can be partially vented. This can significantly reduce the efficiency of the drying process.

1 t is an object of the present invention to provide a heated enclosing assembly, for example deployable as a temporary or semi-permanent structure, adapted to create a heated environment in particular for clothes drying but also for other applications such as plant propagation which mitigates some or all of the above disadvantages.

It is a particular object of the present invention to provide a heated enclosing assembly which heats efficiently and reasonably consistently throughout a v-'lumc enclosed.

It is a particular object of the present invention to provide a heated enclosing 2() assembly which facilitates the removal of moisture from the controlled c nvironment of the volume enclosed therein without excessive loss of heat.

rl lotus, in accordance with the present invention in its broadest aspect, a heated enclosing assembly, especially for deployment as a temporary of semi pennancnt structure, comprises a support frame defining a volume to be heated, and a cover of sheet material adapted to be supported thereon, wherein the sheet material comprises or includes thermal material itself capable of being heated to effect heating of the said volume in use.

The support frame structure defines and determines the shape of the volume to be heated. The sheet material comprises a cover, which may be made up of one or more individual sheet portions, which hangs supportedly thereupon to define and at least partially enclose the said volume in the manner of a tented structure. The enclosed volume forms a controlled environment into which can be heated by the thermal material for drying or other purposes.

In particular, in use the sheet material completes a substantial or full enclosure of the said volume. The sheet material may itself comprise such a substantial 1() or full enclosure. More likely in practice, the frame is mounted on a floor and/or against a wall and/or on a suitable base and/or against any other surface(s), and the sheet material can be mounted in use co- operably with such surface(s) to effect such full or substantial enclosure of the volume defined thereby. For example the frame stands upon the floor or other base, and the sheet material hangs thereupon to enclose the said volume in the manner of a scat.

The assembly in accordance with the invention offers particular advantages over prior art systems where separate heater and cover are provided. The system is likely to be simpler and safer. Moreover, it provides the potential tor more even distribution of heating, eliminating hot spots etc. In particular this is the case when, in accordance with the preferred embodiment, the sheet material comprises or includes the said thermal material across a sufficiently major part of its surface area enclosing the said volume to ensure relatively even heating of the said volume. For example the said thermal material extends across a major part, and in particular substantially all, of the extent of the sheet comprising in use at least two generally opposite faces of the tented structure enclosing the said volume. More efficient heating is enabled by use ill accordance with the invention of a sheet material itself inherently adapted to generate 1leat and to apply such heat into the enclosed volume.

Tle frame is conveniently a rigid, open space-frame structure. In particular, the frame is adapted for ready assembly and disassembly, for example being modular and/or comprising hinged or otherwise folding and/or telescoping components to allow for rapid deployment from a collapsed and/ or disassembled configuration for storage to an opened and/ or assembled configuration for use.

In a particular preferred embodiment the frame is provided as folding 1 () construction, for example comprising a framework of rigid struts at least some of which are hinged, to be deployable between a folded collapsed configuration for storage and an opened configuration for use. In particular, Else frame is provided as a single foldable construction for ease of deployment.

(conveniently, the frame comprises a pair of rigid face frames for a pair of generally planar faces intended to comprise generally parallel opposed faces when deployed, the rigid face frames being joined by a plurality of elongate cross-struts each hingedly mounted to the rigid face frames and having at least hinge intermediately along the length thereof (for example generally in the middle) to enable the frame to be collapsed flat when not in use. 2()

The flame is provided with a cover of sheet material adapted to be supported hereon. The cover may be placed upon the frame once it is deployed or assembled. Alternatively, the cover or part(s) thereof may be provided integral to the frame or part(s) thereof, for ease of assembly (i.e. such as to be in place automatically once the frame is deployed and/ or assembled. In particular, the frame is provided as a folding construction to be deployable between a folded collapsed configuration for storage and an opened configuration for use, with the cover provided attached thereto to be collapsible therewith for ease of storage and deployment.

Tle frame, or elements thereof making up the frame structure, is preferably adapted to be environmentally resistive to resist corrosion and other c'vironnental degradation in the warm moist atmosphere envisaged for use.

leer example, the frame or frame elements comprise plastics material and/or plastic or otherwise protectively coated metallic material.

The frame preferably includes means for stable engagement in a desired situation. For example, means may be incorporated into the frame to enable the assembled frame to seat or rest and/or hold it stably in position against a 1 () wall and/or floor when deployed. Additionally or alternatively a stand or base may be provided for use in conjunction with the frame.

The frame as above described defines the volume to be heated once the sheet material is applied in tent-like manner. Additional internal mounting structural members may be provided to be deployed within this heated volume to facilitate the easy location of objects within the volume. Such internal mounting structures will be selected dependent upon the envisaged application. For example racks, shelves, hooks and like mountings etc might To provided. Where the assembly is intended to be a clothes dryer, these mounting structures might include clothes drying racks.

Such mounting structures may be provided as part of the frame or for integral assembly with the frame. Alternatively, such mounting structures may be provided separately in conjunction with the frame and sheet for mounting upon the frame once assembled, for deploying within the space defined by the assembly in use non-integrally with the frame, or in any suitable convenient combination.

The sheet material is any suitable flexible material adapted to drape over the fame to form a tented structure and to define, and in particular substantially complete enclosure of, the volume that is to be heated in use. The sheet and/or frame may include releasable mounting or fixing means to stably mount or fix the sheet material in suitable position. Alternatively, the sheet material may be so constructed as to be retained stably in position upon the frame under its own weight.

I he sheet material may comprise a single sheet adapted to seat upon the frame to complete a tented structure in the manner above described, or may comprise a plurality of sheets adapted to be cooperably seated upon the frame to act together to complete a tented structure, for example being mounted in particular positions on the frame and/or connected together on assembly to complete the tented structure.

In a preferred embodiment, the sheet in position on the frame allows heated moist air to escape in controlled manner. For example, vents may be provided, optionally with user accessible closures, and preferably in the vicinity of the top of the tented structure in use. However, heat will also be lost through vents. In consequence it is desirable in a preferred embodiment if the sheet material is itself specifically adapted to allow escape of water vapour 2() fiom the moist heated air within the enclosed volume without allowing excessive loss of heat. Accordingly, in a particularly preferred embodiment, the sheet material comprises a vapour "breathable" fabric. This might limit or remove the need to vent the air to remove moisture during drying, and so reduce unnecessary loss of heat from the enclosed volume and enhance the efficiency of the process.

The sheet material may comprise any flexible sheet material, including polymeric, rubber, metallic films, woven or non-woven fabric sheets, fine nets or meshes or the like or combinations thereof. For many applications, woven 3() or non-woven fabric based materials will be particularly preferred. In particular, non-woven polymeric fabrics made by melt-spinning non- woven processes, such as spunbond processes or melt blowing processes, are likely to be particularly suitable.

Note that where used herein "meltblown" refers to a process in which a high velocity fluid, normally air blows molten thermoplastic resin from an extruder die tip onto a conveyor, or take-up screen, or substrate onto form a fine fire sclf-bondcd web. The thermoplastic resin can be any resin, including adhesives, which are fibrous forming, having relatively low viscosity as it l O exits the die. The thermoplastic resin (s) can be in solid form or in solution or slurry form.

The sheet material may comprise a single or multiple layer of material. In particular, the sheet material comprises at least an outer layer having thermally insulating properties, and carrying on the inside thereof at least one thermal layer comprising or including the said thermal material. This structure ensures that the majority of the heat generated by the thermal material is directed inwardly in USE into the volume to be heated and is not lost.

The insulating layer is preferably a non-woven polymeric fabric, for example being a spunbond or melt blown polypropylene or polyester nonwoven, or some combination, and in particular multi-layered combination thereof.

Optionally further layers may be provided, for example at least an inner layer whereby a thermal layer incorporating thermal material is sandwiched between at least one inner and one outer layer. Additional layers may be provided for example to give desired structural properties, to give desired thermal properties, to facilitate the wicking of moisture from the internal volume to the outside without excessive loss of heat etc. 3() The thermal material comprises material able to be heated, which is formed as a sheet layer, as a part thereof, or mounted on or between sheet layer(s).

Preferably, this comprises a resistance heated material, for example comprising linear or planar resistance heating elements suitably arrayed within the sheet material to effect heating of the enclosed volume in use, and in particular arrayed across the extent of the sheet to ensure that at least a substantial part thereof effects such heating. The heating elements may be disposed for example as part of a thermal layer additionally comprising support material, and/ or be mounted upon or sandwiched between layer(s) of 1() facet material.

In a particular preferred construction of sheet material, the sheet material will c omprise at least the following layers: an inner sandwich layer and an outer sandwich layer with resistance heating elements sandwiched therebetween, arid an outermost insulation layer. The sandwich layers are preferably non- woven polymeric fabrics. The outer insulation layer may be of any suitable material as above described. In particular the layers comprise moisture- breathable fabric.

2() The thermal material is preferably heated from an electrical power source. For most applications it is envisaged that a mains power source will be used, but other suitable power sources might include rechargeable or non-rechargeable battery power sources, and environmentally derived power sources such as solar power sources and the like. Conveniently, the sheet material incorporates a power supply means and in particular a power supply lead adapted for engagement to such a power source, and in particular to a mains power source. Where connection to the mains is envisaged the power supply means may incorporate a step-down transformer to transform mains to a more suitable operating voltage. 3()

(control means are preferably incorporated in association with the power supply means to control operation of the system. These might include an on- off switch and/or a timer switch, thermal cut-out safety system to cut power to the thermal material if the temperature in the enclosed volume exceeds a predetermined safe level, a user-gettable thermostat to control the power supply and maintain a predetermined target level temperature within the enclosed volume. Other control features will readily suggest themselves.

Al he invention will now be described by way of example only with reference to I () 1- igures I to 3 of the accompanying drawings wherein: Figure 1 is an illustration of an assembled enclosing structure in accordance with the invention adapted for use as a clothes dryer; leisure 2 is an illustration of the enclosing structure of figure 1 giving greater detail about thermal properties; Figure 3a to figure 3c show the collapsibly deployable arrangement of the enclosi ng structure of figure 1.

Rcterring first to figure 1, an example assembly in accordance with the invention is shown. The assembly is shown full assembled with cover in place, with externally visible features denoted by solid lines and internal detail illustrated where covered by the sheet by lighter and/or broken lines.

Ihc assembly comprises a frame (1) which is foldable out from a collapsed configuration to the deployed configuration shown (see figure 3 for detail).

I he frame comprises plastic coated metal rods for rigidity, durability, environmental protection and manageable weight.

()n the Irame is mounted a sheet tent (2) of breathable fabric (for example material described in detail with reference to figure 2). This encloses the volume (3) to be heated in which can be placed suitable drying support structures such as a clothes maiden (4) if the assembly is to be a clothes dryer, shelves for seedlings if the assembly is to be a plant propagator.

The construction of the tent (2) is such that there is a heated element set of two elements which are sandwiched within the fabric wall to the left and right sides of the tent, and whose position is shown by the broken line outlines (5a, 5b) on those walls. Electrical power is supplied by the flex (6) and plug (7) and the elements protected by auto reset thermal eut-outs.

l () The front of the tent has a lift up flap (8) to allow access to the clothes maiden (4). This is releasably fastened shut by means of releasable closures (11) which in the illustrated embodiment comprise complementary resilient hook and felt pads, but could clearly comprise alternatives such as ties, zips, hooks etc. The roof and the back of the tent are stitched to the two side-walls to complete the structure.

An insulation layer (9) on the outer side of the sheets containing the heated elements is provided in order to restrict heat loss and direct as much heat as I'ossible into the volume (3) enclosed by the tent. In the embodiment, the I'abric ol' the tent is selected to be breathable and no venting is required, but vents could be incorporated, for example in the roof.

I-'igure 2 gives greater detail of the thermal layer structure for the heated side- walls of figure 1, shown partially cut away. The upper (15a) back (15b) and openable front (not shown) surfaces comprise a layer of suitable breathable fabric. 'I'he structure of the heated side-walls is shown, and comprises a heating element layer (17) and an insulating layer (19) immediately external thereto to direct heat back into the internal cavity (3), the whole sandwiched between inner (1 5e) and outer (15d) breathable fabric layers.

The insulating layer (15) is a multilayer of non-woven fabric material. In the embodiment this consists of a spunbond layer + meltblown layer + spunbond layer. All of these layers are made from polypropylene resins in a (j()g+4()g+6()g combination in the illustrated example but other layer combinations employing all types of spunbond and SMS polypropylene and polyester nonwovens might be considered.

The element sleeve layers comprise spunbond layers made from polyester r csin in the example. Again, spunbond and SMS polypropylene nonwovens might be considered The Element is in the example a carbon based electrically conductive heating element on either glass cloth or polymeric film substrate. Any other flexible resistance heated element would be suitable, other specific examples including l 5 a glass core spirally wound resistant wire insulated in silicone rubber insulation and laid out to a predetermined specification in a snake like pattern and then laminated to adhesive foil or ultra conically/bonded between cloth or a chemically etched foil element based on printed circuit technology.

Figure 3 shows the collapsible construction. In figure 3a the frame is shown fully open. Rigid rectangular side-wall frames (21a, 21b) are joined by cross- struts (22). The cross struts are hinged to the side-wall frames by means of hinges (23) and also hinged at a mid-point of their length (24). As a result the structure is collapsible as shown in the sequence of figures 3a to c. The cover is not shown, but in practice will conveniently be attached to and collapsible co-operably with the frame for ease of deployment.

Claims (15)

1. A heated enclosing assembly comprising a support frame defining a volume to be heated, and a cover of sheet material adapted to be supported thereon, wherein the sheet material includes thermal material itself capable of being heated to effect heating of the said volume in use.

2. A heated enclosing assembly in accordance with Claim 1 wherein the sheet material is so adapted that in use it completes a substantial or full enclosure of the said volume.

3. A heated enclosing assembly in accordance with Claim 1 or Claim 2 wherein the sheet material itself comprises a substantial or full 1 5 enclosure.

4. A heated enclosing assembly in accordance with Claim 1 or Claim 2 wherein the frame is adapted to be mounted on a floor and/or against a wall and/or on a suitable base and/or against other surface(s), and the sheet material is adapted to be mounted in use to act co-operably with such surface(s) to effect such full or substantial enclosure of the volume defined thereby.

5. A heated enclosing assembly in accordance with any preceding claim wherein the said thermal material extends across a major part of the extent of the sheet comprising in use at least two generally opposite faces of the enclosing structure formed thereby.

6. A heated enclosing assembly in accordance with any preceding claim wherein the frame is a rigid, open space-frame structure, being adapted for ready assembly and disassembly and for deployment as a temporary or semi-permanent structure.

7. A heated enclosing assembly in accordance with Claim 6 wherein the open space-frame structure is modular and/or comprises hinged or otherwise folded and/or telescoping components to allow for rapid deployment from a collapsed or disassembled configuration for storage to an opened or assembled configuration for use.

8. A heated enclosing assembly in accordance with Claim 7 wherein the frame comprises a pair or rigid face frames for a pair of generally planar faces intended to comprise generally parallel opposed faces when deployed, the rigid face frames being joined by a plurality of elongate cross-skuts each hingcdly mounted to the rigid face frames and having at least one hinge intermediately along the length thereof, for example generally in the middle, to enable the frame to be collapsed flat when not in use.

). A heated enclosing assembly in accordance with any preceding claim wherein the sheet comprises vents so located as to act when in position on the frame to allow heated moist air to escape in controlled manner.

10. A heated enclosure in accordance with any preceding claim wherein the sheet comprises polymeric fabric made by melt-spinning non-woven processes.

11. A heated enclosing assembly in accordance with any preceding claim wherein the sheet material comprises multiple layers of material including at least an outer layer having thermally insulating properties and carrying on the inside thereof at least one thermal layer comprising or including the said thermal material.

12. A heated enclosing assembly in accordance with Claim 11 further comprising at least one further inner layer whereby a thermal layer incorporating thermal material is sandwiched between at least one inner and one outer layer.

13. A heated enclosing assembly in accordance with any preceding claim wherein the thermal material comprises a resistance heated material.

14. A heated enclosing assembly in accordance with any preceding claim wherein the thermal material comprises linear or planar resistance heating elements suitably arrayed within a suitable support material, together comprising a thermal layer.

15. A heated enclosing assembly substantially as hereinbefore described with reference to the accompanying drawings.