GB2261194A

GB2261194A - Thermal barriers in refrigerated vehicles

Info

Publication number: GB2261194A
Application number: GB9222595A
Authority: GB
Inventors: Robert William Hewitt
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-10-28
Filing date: 1992-10-27
Publication date: 1993-05-12
Anticipated expiration: 2012-10-27
Also published as: GB2260951A; GB9122878D0; GB2261194B; GB9222595D0; GB2260951B

Abstract

The barrier system has two tracks 1, one arranged on either side of the interior of the compartment, adjacent the roof of the compartment. A cross beam 2 slidingly engages with each track 1. A locking device locks the cross beam 2 at various positions along the tracks. The cross beam 2 supports, on opposed sides thereof, two layers of overlapped flexible strips 3. The two layers 3 are separated by an insulating region of air. <IMAGE>

Description

Thermal Barriers The present invention relates to thermal barriers for use

in refrigerated vehicles and other refrigerated environments.

Refrigerated vehicles are well known for their usefulness in the transportation of both chilled and frozen foodstuffs. They are normally well insulated. When the doors are closed, temperatures can be accurately maintained using the on board refrigeration unit with temperatures ranging from for example, +CC to -24C.

Refrigerated vehicles are however, very much less efficient at maintaining accurate and economic temperature control whilst the doors are open or when travelling with only a partial load. Some vehicles are fitted with rigid partitions and interior doors to alleviate this problem, but they rely upon the driver to ensure that they are closed at all times. This is not always done.

A movable curtain is known for use in refrigerated vehicles from US-A-4, 639,031. This curtain comprises a layer of flexible sheet material strips which facilitate access through the curtain. The curtain can be moved along the length of the vehicle depending on the loading of the vehicle.

It is also known to use such multi-strip curtains in fixed installations, such as covering chiller cabinets in shops, where the curtains improve the efficiency of keeping e.g. food chilled whilst permitting easy access by customers.

According to one aspect of the present invention, there is provided a thermal barrier for use in a refrigerated environment comprising a first layer of flexible sheet material strips and a second layer of flexible sheet material strips arranged spaced apart from said first layer to thereby define an insulating air region between said first and second layers.

This thermal barrier has the advantage that it is more efficient at reducing the rate of heat loss.

In general, and in a manner known from single layer installation, each layer will comprise a plurality of parallel overlapping, relatively narrow strips. The strips may hang vertically under their own weight. In the case of a vehicle, for example, the layers may reach down to the floor of the load area. In the case of a chiller cabinet in a shop, the layers will cover the opening. The layers may be attached at their upper ends to a horizontal support member, which will hold the layers apart at the required spacing. The strips may be of any suitable flexible material, but preferably are of a plastics material such as PVC of a suitable low temperature grade. The strips are preferably transparent.

In the case of a refrigerated vehicle or other suitable environment such as a cold store warehouse, the barrier is preferably supported by track means so as to be movable in a horizontal direction. The support member for the strips will engage the track means.

Preferably the system is arranged in a refrigerated vehicle so as to span the width thereof. Thus, the vehicle can be divided by.the thermal barrier into two areas, one of which is isolated from the door. Products kept in the isolated area are able to avoid being subjected to a large heating effect when the doors of the vehicle are opened due to the efficient thermal insulation of the barrier. Advantageously the thermal barrier may provide a hygienic self-sealing barrier which can prevent or reduce the ingress of air-born dirt and traffic fumes when unloading. Furthermore interior icing in the isolated area is reduced as the quantity of moist air entering the isolated area is reduced.

The track means extend along at least part of the length of the vehicle so that the barrier is movable along at least part of the length of said vehicle. The position of the thermal barrier in the vehicle can thereby be selected depending on the amount of, for example, foodstuffs remaining in the vehicle. As products are off-loaded at various drop-off points, the thermal barrier can be moved down the truck to reduce the area isolated by the barrier. This may reduce the running costs as smaller demands are made on the refrigeration unit. For example, in experiments, it has been found that a thermal barrier embodying the present invention can maintain the temperature in the isolated area within 40C of the closed door temperature even when the rear doors are open for prolonged periods. of course more than one thermal barrier may be provided in a vehicle so as, for example, to separate areas of different temperatures.

The track means may comprise tracks arranged to be coupled to opposed side walls of the vehicle at locations adjacent the roof. Alternatively, in some embodiments, the tracks may be coupled directly to the roof of said vehicle. Of course, embodiments in which only a single track supports the support member are also contemplated within the scope of the invention. Furthermore, in some embodiments more than two tracks may be arranged so as to support the support member.

It is preferred that stop means be provided at each end of the track means so'as to retain the support member on or in the track means.

Preferably locking means are provided for locking the support member relative to said track means at various positions along the length of the track means. The desired position of the thermal barrier can therefore be selected and then fixed as required.

In a preferred embodiment, the two strip layers are attached to a cross beam which is slidably supported at either end on a track. There may be provided wheels or - 4 rollers to facilitate movement, or there may be a simple slide system. The components may be of metal or of low friction plastics to facilitate movement.

Viewed from another aspect, the present invention provides a thermal barrier system for a refrigerated vehicle compartment, comprising tracks on either side of the interior of the compartment, adjacent the roof of the compartment, a cross beam slidingly engaged with each track, means for locking the cross beam at various positions along the tracks, and two layers of overlapped flexible strips supported by and extending across the cross-beam, the layers being spaced apart by an insulating region of air and extending down to adjacent the floor of the compartment.

In some arrangements it might be possible to use continuous layers rather than layers of strips, although this would create access problems. Thus according to a further invention disclosed herein there is provided a thermal barrier system for a refrigerated vehicle compartment, comprising tracks on either side of the interior of the compartment, adjacent the roof of the compartment, a cross-beam slidingly engaged with each track, and two layers of flexible sheet material supported by and extending across the cross-beam, the layers being spaced apart by an insulating region of air and extending down to adjAcent the floor of the compartment.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which:- Figure 1 shows in perspective, a portion of an assembly comprising track, cross beam and flexible strips in a section of a refrigerated vehicle with part of the roof and side wall cut away for clarity; Figure 2 shows in perspective a view of one end of the cross beam, slide, track and flexible strips; Figure 3 shows a plan view of one end of the cross X beam and a slide track section with a portion removed for clarity and the flexible strips; and Figure 4 shows an end elevation of the cross beam and flexible strips and a side elevation of the slide and track.

As shown in the figures the system comprises a track 1 fitted to opposed side walls of a vehicle fridge compartment 5 and adjacent to the roof. A cross beam 2 has slides 7 engaging each track. The slides may be made from metal section, provided with wheel or rollers (not shown). Alternatively the slides may be made of low friction plastic as illustrated in Figures 2, 3 and 4. The cross-beam is fitted with a suitable, locking means (not shown) attached to both ends. This is to enable the cross beam 2 to move easily along the tracks in the directions of arrows 4 and to be locked in various positions along the length of the tracks 1.

Suspended by attachments (not shown) from the cross beam 2 on both sides, are respective layers of overlapped flexible strips 3 of transparent polar grade PVC, the layers being kept a specific distance apart by the section of the beam. Thus an air layer of predetermined size is trapped between the two flexible strip layers.

The thermal barrier, comprising the insulating air layer defined by the width of the beam 2 and delimited by the layers of overlapped flexible strips 3, can be moved along the tracks as the cargo volume in the vehicle increases or decreases. The refrigerated area can therefore be made as large or as small as required by the cargo in transit. The empty space created by the discharge of cargo during deliveries would be between the rear of the thermal barrier system and the rear doors of the vehicle 5 and would no longer be directly refrigerated.

As a consequence of their own weight the overlapped flexible strips are self sealing i.e. there are no gaps - 6 or spaces between adjacent flexible strips of each of the layers. The insulating air layer formed by the flexible strips 3 and the movable beam 2 will be reestablished each time it is disturbed by, for example, such Actions as loading and unloading.

Whilst this embodiment is concerned with a movable thermal barrier for use in a refrigerated vehicle, it will be appreciated that such a barrier need not be movable and can be fixed in place at all times. Furthermore such a barrier can be suitably modified so as to be used in a fixed installation such as a cold store room or the like.

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Claims

1. A thermal barrier for use in a refrigerated environment comprising a first layer of flexible sheet material strips and a second layer of flexible sheet material strips arranged spaced apart from said first layer to thereby define an insulating air region between said first and second layers.

2. A thermal barrier as claimed in claim 1, wherein each layer comprises a plurality of parallel overlapping, relatively narrow strips.

3. A thermal barrier as claimed in claim 1 or claim 2, wherein the layers are attached at their upper end regions to a horizontal support member which holds the layers apart at the required spacing.

4. A thermal barrier as claimed in claim 3, wherein said horizontal support member is supported by track means so as to be movable in a horizontal direction.

5. A thermal barrier as claimed in claim 4, wherein said horizontal support member is provided with slide means so as to allow said support member to slide relative to the track means.

6. A thermal barrier as claimed in claim 5, wherein said slide means comprise wheel members.

7. A thermal barrier as claimed in claim 5, wherein said slide means are shaped so as to be received a corresponding shaped section of said track means.

8. A thermal barrier as claimed in any of claims 5 to 7, wherein said slide means are of low friction plastics.

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9. A thermal barrier as claimed in any of claims 5 to 7, wherein said slide means are of metal.

10. A thermal barrier as claimed in any of claims 4 to 9, wherein locking means are provided for locking said support member relative to said track means at various positions along the length of said track means.

11. A thermal barrier as claimed in any preceding claim, wherein said system is arrangeable in a refrigerated vehicle to span a width thereof.

12. A thermal barrier as claimed in claim 11 when appended to any of claims 4 to 10, wherein said track means is arrangeable to extend along at least part of the length of said vehicle whereby said support member is movable along at least part of the length of said vehicle.

13. A thermal barrier as claimed in claim 12, wherein said track means comprises two tracks arranged to be coupled to respective side walls of said vehicle at locations adjacent the roof.

14. A thermal barrier as claimed in claim 12, wherein said track means comprise.s at least one track arranged to be coupled to the roof of said vehicle.

15. A thermal barrier system for a refrigerated vehicle compartment, comprising tracks on either side of the interior of the compartment, adjacent the roof of the compartment, a cross beam slidingly engaged with each track, means for locking the cross beam at various positions along the tracks, and two layers of overlapped flexible strips supported by and extending across the cross-beam, the layers being spaced apart by an insulating region of air and extending down to adjacent - 9 the floor of the compartment.

16. A thermal barrier system for a refrigerated vehicle compartment, comprising tracks on either side of the interior of the compartment, adjacent the roof of the compartment, a cross-beam slidingly engaged with each track, and two layers of flexible sheet material supported by and extending across the cross-beam, the layers being spaced apart by an insulating region of air and extending down to adjacent the floor of the compartment.

17. A thermal barrier substantially as hereinbefore described with reference to the accompanying drawings.