The invention relates to open display refrigerators, and to cooling units (refrigerators or freezers) which have doors comprising transparent windows. The invention also relates to methods of modifying such open display refrigerators and cooling units.

Open display refrigerators are commonly used in retail environments, such as supermarkets, to store and display products, such as meat and dairy products, which must be kept at lower than ambient temperatures. The open front of such a refrigerator makes it easy for customers to view the products being displayed and to retrieve products they wish to purchase from the refrigerator.

This type of refrigerator has an air curtain, which is established by blowing cold air across the front of the refrigerator. The air curtain issues from an air outlet at the top of the refrigerator towards an air inlet at the bottom of the refrigerator. The air inlet recovers air from the air curtain and recirculates it to the air outlet via a cooling heat exchanger and fan.

Generally, it is intended that the air curtain follows a broadly linear path from the air outlet to the air inlet thereby preventing cold air in the refrigerator from mixing with warm air exterior to the refrigerator. However, such an air curtain is rather inefficient, in particular because the air curtain tends to spill out from the bottom of the refrigerator and warm air from the exterior becomes entrained into the air curtain. To ameliorate this problem of inefficiency, air guides fixed on the front edge of shelves in the refrigerator can be used to help constrain the air curtain within a desired region.

Some refrigerators include sloped shelves in order to better display the top surface of produce on the shelf, for example packets of meat. Where sloped shelves are used, it is common to use transparent risers with the shelves to prevent the displayed produce from sliding off the shelf. If the risers extend from an angled shelf such that a 90° angle is formed between the base of the riser and the shelf, the risers can extend into the air curtain, disrupting the flow of air. A known solution to this problem is to form the risers with an angled profile, such that an acute angle is formed between the base of the riser and the shelf and the risers extend vertically upwards.

This prevents the riser from extending into the air curtain and disrupting the flow of air within the air curtain.

To work effectively, the air guides need to be in reasonably good alignment with an outer edge of the air curtain. Historically, this has been achieved by attaching the air guide to the edge of the shelf. However, where the shelves are sloped, such an arrangement can prevent shoppers from viewing produce on a shelf sited below the air guide.

In accordance with a first aspect of the invention, there is provided an open display refrigerator comprising: a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the open display refrigerator by an air curtain established by a fan which blows air towards an air outlet, air in the air curtain being recovered by an air inlet which recirculates the air from the air curtain into an air duct coupled to the air outlet; at least one shelf having a riser attached to the shelf; and an air curtain guide coupled to the riser, the air curtain guide for guiding the flow of air within the air curtain.

In accordance with a second aspect of the invention, there is provided a cooling unit comprising: an interior space, the interior space comprising (i) a refrigerated storage space and (ii) an access space, wherein air in the refrigerated storage space is separated from air in the access space by an air curtain established by a fan which blows air towards an air outlet, air in the air curtain being recovered by an air inlet which recirculates the air from the air curtain into an air duct coupled to the air outlet; a door, the door comprising a transparent window and which separates the interior space from air external to the cooling unit; at least one shelf having a riser attached to the shelf; and an air curtain guide coupled to the riser, the air curtain guide for guiding the flow of air within the air curtain.

Establishing the air curtain by a fan which blows air towards an air outlet and which recovers air in the air curtain via an air inlet for recirculation to the air outlet may also include recirculating the air via a cooling heat exchanger.

By raising the air guide from the edge of the shelf and onto the riser, when viewed at an angle from above, the line-of-sight of a user is less impeded by the air guide or is not impeded at all.

By moving the air guide onto the riser, it is easier for a user to view produce on a shelf sited below the air guide, due to the increase in space between the lower edge of the air guide and the upper surface of the shelf below the air guide.

Unless specifically mentioned otherwise, the optional features described in the following paragraphs may relate to open display refrigerators or cooling units according to either of the first or second aspects of the invention.

In some embodiments, the at least one shelf has a first edge which is parallel to the air curtain and proximate the air exterior to the open display refrigerator. In some embodiments, the at least one shelf is at an angle, such that the first edge of the shelf is lower than an opposite second edge of the shelf when the open display refrigerator is in use. This angle can be one of 10°, 15° or 20°.

In some embodiments, the riser is substantially vertical, such that an acute angle is formed between the first edge of the shelf and the portion of the riser that extends vertically from the first edge of the shelf when the open display refrigerator is in use. This may be achieved by providing an angled riser comprising two parts, with the two parts joined at an angle.

Alternatively, a first end of the riser may be attached directly to surface of the shelf on which products are placed in use, this first end may be bevelled at the same angle as the shelf so that the riser is substantially vertical when attached to the shelf. The shelf may also comprise a slot for receiving a bevelled riser, with bottom of the slot comprising a sloped surface such that the bevelled riser is substantially vertical when received in the slot.

A technical advantage, in addition to the previously mentioned technical advantage, is that a simple bracket, with a rectangular longitudinal cross-section, can be used to attach the air guide to the angled riser, as the face of the riser facing the air guide and the face of the air guide facing the riser are parallel. This is in contrast to a riser that does not extend substantially vertically and hence extends towards the air curtain, where an additional bracket would be needed to ensure that an air guide attached to the riser is parallel to the air curtain.

In some embodiments, the air curtain guide is integral to the riser.

A technical advantage of making the air curtain guide integral to the riser is that it is easier for a user, such as a member of staff, to configure the refrigerator. The user does not need to add a riser to a shelf and then an air guide to the riser, thereby simplifying the process of configuring the refrigerator. This also prevents a user from forgetting to add air guides to a riser or from adding an incorrect air guide to a riser when configuring a refrigerator. The integrated air curtain guide and riser may also comprise a number of pre-set positions for positioning the air guide, for example in a vertical plane.

In some embodiments, the air guide is removably attached to the riser.

In some embodiments, the air guide is attached to the riser by one or more brackets. The bracket(s) may comprise a number of different locations to which the air guide can be attached, so that the distance between the air guide and the shelf can be adjusted and/or the angle of the air guide can be adjusted. A technical advantage of such an arrangement is that it makes it easier to configure the air guide to best guide the air curtain.

In some embodiments, the air curtain guide is an aerofoil.

An aerofoil is a type of air guide that guides air in a specific manner. An aerofoil works by being situated in the air curtain of the refrigerator, with a portion of the air curtain flowing either side of the aerofoil. The aerofoil imparts a shape into the airflow and guides the airflow in a desired direction. The specific shape of the aerofoil causes a change in the direction of flow of the air curtain as it flows over the aerofoil. A typical design of aerofoil that can be used is a cambered aerofoil. This will usually be oriented with the leading edge uppermost and the cambered surface facing away from the interior space. An aerofoil is a shape that gives rise to lower pressures on one side (on the suction surface) compared with the other side (on the pressure surface) when placed in the air curtain.

In some embodiments, the riser is attached to the first edge of the shelf.

In some embodiments, the shelf comprises a slot for receiving the riser.

In some embodiments, the riser comprises a transparent portion, which is optionally made of Perspex ^® .

A technical advantage of having a riser comprising a transparent portion is that it allows a user to more easily see produce on the shelf.

In accordance with a third aspect of the invention, there is provided a riser for use with an open display refrigerator or a cooling unit, wherein the riser comprises an integral air curtain guide.

In some embodiments, the riser comprises an acute angle.

In some embodiments, the air curtain guide is an aerofoil.

An aerofoil is type of air guide that guides air in a specific manner. An aerofoil works by being situated in the air curtain of the refrigerator, with a portion of the air curtain flowing either side of the aerofoil. The aerofoil imparts a shape into the airflow and guides the airflow in a desired direction. The specific shape of the aerofoil causes a change in the direction of flow of the air curtain as it flows over the aerofoil. A typical design of aerofoil that can be used is a cambered aerofoil. This will usually be oriented with the leading edge uppermost and the cambered surface facing away from the interior space. An aerofoil is a shape that gives rise to lower pressures on one side (on the suction surface) compared with the other side (on the pressure surface) when placed in the air curtain.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 shows a cross-section through an angled refrigerator shelf with an angled riser attached to the angled refrigerator shelf and an air guide attached to the angled riser.

Figure 2 shows two angled refrigerator shelves with angled risers attached to the angled refrigerator shelves and air guides attached to the angled risers.

Figure 3 shows an open air refrigerator with angled refrigerator shelves with angled risers attached to the angled refrigerator shelves and air guides attached to the angled risers.

Figure 4 shows the impact of an embodiment of the present invention on the field of view of a user using a refrigerator.

Figure 1 shows a cross-section through an angled refrigerator shelf la. The shelf la has an angled riser 2a attached to an edge of the shelf la. An air guide 3a is attached to the angled riser 2a by a bracket 4a. An acute angle is formed between the riser 2a and the edge of the shelf la, causing the riser 2a to extend substantially vertically with respect to the ground. In use, the riser 2a prevents products from sliding off of the edge of the angled shelf la. The bracket 4a may be formed separately to the air guide 3a and the shelf la, with the air guide 3a being attached to a first end of the bracket 4a and the second end of the bracket 4a being attached to the riser 2a. The air guide 3a may be configured to be mounted on the riser 2a. For example, the air guide 3a may be removably attached to the riser 2a via the bracket 4a. Alternatively the air guide 3a may be fixedly attached to the riser 2a via the bracket 4a. In a different alternative, the riser 2a, the bracket 4a and the air guide 3a may be integrally formed, such that they are formed from the same piece of material. The riser 2a is usually made of a transparent material, such as Perspex ^® , but can be made of any metallic, plastic-based or any other suitable material (or a mix of materials). Likewise, the bracket 4a and the air guide 3a may be made of any metallic, plastic- based or any other suitable material (or a mix of materials).

Figure 2 shows an arrangement of two angled refrigerator shelves la, lb, with angled risers 2a, 2b attached to the angled refrigerator shelves la, la and air guides 3a, 3b attached to the angled risers 2a, 2b, as discussed with respect to Figure 1, but with the addition of an optional ticket strip 5a, 5b extending downwards from the edge of each of the shelves la, lb. Figure 3 shows a cross-section through an open display refrigerator 6. The refrigerator 6 has a storage space that is maintained at a lower than ambient temperature. Within the storage space, there are four angled storage shelves la (only one of which is labelled) as discussed with respect to Figure 2. Different embodiments may have one, two, three, five or any number of storage shelves. A typical angle of incline for the angled storage shelves is 20°. Other angles include 10° and 15°; however, shelves at other angles may be used as long as the product does not slide off of the shelves. In use, the refrigerator 6 establishes an air curtain (not shown) by a fan which blows cold air towards an air outlet 7, out of the air outlet 7 and towards an air inlet 8. Air inlet 8 recovers air from the air curtain and a fan within the refrigerator recirculates the air to the air outlet 7. A cooling unit or heat exchanger within the refrigerator 6 maintains the recirculated air (and hence the air blown through the air outlet 7 to form the air curtain at a desired temperature. The desired temperature may be chosen to be lower than the ambient temperature and acts to prevent cold air in the storage space from mixing with warm air exterior to the refrigerator. As before, the angled shelves la have angled risers 2a attached to the angled refrigerator shelves la and air guides 3a attached to the angled risers 2a as discussed with respect to Figure 1. The shelves la also have an optional ticket strip 5a extending downwards from the edge of each of the shelves la.

Figure 4 shows a solution, as provided by the present invention, to the problem associated with attaching air guides to the edges of angled shelves in a refrigerator. As discussed with respect to Figure 3, a cross-section through an open display refrigerator 6 is shown. As before, the refrigerator 6 has four angled shelves la (only one of which is labelled) with angled risers 2a attached to the angled refrigerator shelves la and air guides 3a attached to the angled risers 2a. A user of the refrigerator 6 is shown, with their line-of-sight shown by area 9. As can be seen, by raising the air guide 3a from the edge of the shelf and onto the riser 2a, it is easier for a user to view products on the angled shelf la below an air guide 3a due to the increase in space between the lower edge of the air guide 3a and the top surface of the shelf la below the air guide 3a. If the air guide 3a was attached to the edge of the shelf la, then the line-of-sight of a user would be impeded.