The present invention relates to a flexible door, particularly, but not exclusively, a flexible door which is intended to isolate regularly accessed areas within a building, such as cold stores, storage areas etc. from other areas within or outside of the building.

In many buildings it is desirable to be able to isolate certain areas of the building from other areas. Examples of when such isolation is desirable include the isolation of areas from public access and to prevent the flow of air from one area to another. A specific example of when the isolation of air flow may be required is in a supermarket or distribution depot where the cold store area is to be closed off from other areas in the building in order to maintain the temperature and atmospheric conditions of the cold store within certain parameters. Further examples of where this may be beneficial include, but are not limited to internal divisions, temperature controlled areas, wash-down areas, refrigerated areas, food processing and preparation areas, catering and commercial kitchens, supermarkets and retail outlets, hospitals and healthcare etc.

Such divisions can be achieved by way of standard rigid doors; however, since a high volume of traffic (and bulky loads such as staff with trolleys etc.) typically passes through the door, rather than rigid doors, partitioning is often achieved by suspending curtains of plastic or similar material from a door sub frame. This provides a barrier to the flow of air between one side of the door and the other side and also helps to provide a visual separation between public and private areas. However, one problem with such plastic curtains is that the user often has to duck under the curtains when passing through the door which tends to hinder ease of passage therethrough. In addition, where such doors comprise rigid sub-frames and flexible plastic curtains, a certain amount of clearance is required on either side of the door in order to allow the door to open and close unimpeded. According to a first aspect of the present invention there is provided a flexible door comprising a main door structure, a fixing arrangement for securing the main door structure to a door frame; and a hinge arrangement adapted to allow hinged movement of the main door structure on the door frame between a closed configuration and an at least partially opened configuration and wherein the main door structure comprises at least a resilient support member adapted to allow the door to bend through a bend radius when an opening force is imparted on the door wherein the resilience provided by the resilient support member is arranged such that, when an opening force up to a threshold opening force is imparted on the door, the resilient support member and hence the main door structure will bend under the action of such force substantially without any hinged movement occurring at the hinge arrangement and, when an opening force above said threshold opening force is imparted on the door, in addition to the resilient support member and hence the main door structure bending under the action of such force, hinged movement of the door will occur at the hinge arrangement.

Further features and advantages of the present invention will become apparent from the claims and the following description.

Embodiments of the present invention will now be described by way of example only, with reference to the following diagrams, in which:-

• Fig. 1 is a cross sectional plan view of a flexible door according to the present invention;
• Fig. 2 is a schematic illustration of a sub frame of the flexible door illustrated in Fig. 1;
• Fig. 3 is front facing illustration of a pair of adjacent flexible doors according to the present invention in a closed configuration;
• Fig. 4 is a more detailed view of a hinge arrangement provided on the flexible door of Fig. 3;
• Fig. 5 is a more detailed view of a hinged arrangement of the flexible door of Fig. 3;
• Fig. 6 is a schematic plan view illustration of a single flexible door according to the present invention where the flexible door is illustrated in a closed configuration;
• Fig. 7 is a schematic plan view illustration of the door of Fig. 6 during bending in a flexed configuration where no hinged movement of the door occurs;
• Fig. 8 is a schematic plan view illustration of the door of Fig. 7 during bending in a flexed configuration and where the door has been pushed with a force greater than a threshold force such that it is also hinged toward an open configuration;
• Fig. 9 is a schematic layout illustrating a narrow corridor and entrance provided with a pair of flexible doors according to the present invention and where one flexible door is illustrated in a neutral configuration and the other flexible door is illustrated in a flexed configuration;
• Fig. 10 is an illustration of the flexible door of the present invention in a flexed and hinged open configuration;
• Fig. 11 is a schematic diagram illustrating the range of movement of the flexible door of the present invention in both directions between a first and second range of bend radii; and
• Figs. 12 and 13 are schematic diagrams illustrating alternative embodiments of the flexible door having varying degrees of flexural rigidity and hence varying maximum degrees of bend radii.

With particular reference to Figs. 1 and 2, a door panel 10 of a main door structure comprises a resilient support member which, in the present embodiment, comprises a polycarbonate support arm 12, and a flexible insulated door sheet 14 suspended therefrom. A flexible upper air seal 16 is also provided along the top edge of the door 10. The inner edge of the door sheet 14 is provided with a fixing arrangement in the form of a longitudinal anchoring profile 18 which corresponds with a longitudinal mounting profile 20 provided on a two-way hinge 22 in order to allow the door panel 10 to be fixed to a door frame and to hinge in either direction. As shown in Fig. 1, the hinge 22 also comprises a flexible hinge guard 24 which has a pair of flexible flaps that cover the gap between the root of the door panel 10 and the hinge 22 in order to prevent trapping of fingers etc. therebetween. Intermediate cover strips 21, 23 are provided between the anchoring profile 18 and the material of each door sheet 14. The longitudinal edges of the cover strips 21, 23 are attached to the door sheet 14 by releasable attachment means which, in the present embodiment, comprise vertical strips of hook and loop material 26, 28 (best illustrated in Fig. 10). Each door sheet 14 also has a plastic viewing window 15 provided therethrough; this may comprise transparent rigid or flexible panels.

As shown in Fig. 3, a pair of flexible door panels 10 are typically provided adjacent one another; however, a single flexible door panel 10 could alternatively be provided in isolation, or several flexible door panels 10 could be provided alongside one another or in series (one after the other) depending upon the required functionality. Toward the outer edge of each door sheet 14 a vertical sealing edge 29 is provided in order to provide an air seal between the two door sheets 14 of each adjacent door panel. Furthermore, a lower door seal flap 31 is also provided toward the bottom of each door sheet 14 to help provide an air seal between the bottom edge of the door sheet 14 and the floor surface there below. A door frame 11 and wall 13 surrounds the pair of flexible doors 10.

In use, when a door panel 10 is pushed by a user (by hand, via a trolley, or other means) with an opening force up to a predetermined threshold opening force the resilient support arm 12, and hence the door sheet 14, will bend from its neutral configuration illustrated in Fig. 6 to a curved / flexed configuration illustrated in Fig. 7 without any movement of the hinge 22.

If the door panel 10 is pushed further with a force that is greater than the predetermined threshold opening force, rather than continuing to bend the door panel 10 and associated door sheet 14 further, the continued pushing force causes the hinge 22 to open as illustrated in Fig. 8. As illustrated in Fig. 9, this is particularly useful when the door 10 is provided in a narrow corridor 30 having a nearby wall 32 since this maximises accessibility for the user (and trolleys etc.) in this confined space by not only allowing hinged opening of the door but also ensuring that the opened door is tucked toward the wall 13. In this example, cold store walls 13 are provided with an additional sliding door 33 which allows the aperture behind the doors 10 to be more securely sealed e.g. at night or during other periods of low traffic through the doors 10.

As best illustrated in Fig. 10 as the door panel 12 bends, the hook and loop strips 28 provided on the intermediate cover strip 23 on either side of the door panel 10 disengage to accommodate the relative stretch of the door sheet 14 on one side of the door and compression on the other side of the door.

The resilience of the support arm 12 can be altered during manufacture to provide a range of doors with varying degrees of flexibility. This determines the predetermined threshold opening force required to begin opening of the hinge as opposed to further bending of the support arm 12 and also determines the degree of bend radius of the door for a given pushing force. In this regard, as shown in Fig. 11, a very thin support arm 12 may be flexed away from the neutral position (indicated by dashed line A) in either direction by, for example, a 3200mm bend radius illustrated at position B and a 100mm bend radius illustrated as position C. This therefore allows the door to flex through approximately 180 degrees in either direction from the neutral position A.

In an alternative embodiment, as shown in Fig. 12, where a thicker and or more rigid support arm 12 is provided, the bend radius may be restricted to for example 1200mm and, in another embodiment, where a narrower and or less rigid support arm 12 is provided, the bend radius may be restricted to for example 300mm.

The flexible door described above therefore has the advantage of bending with, or without, hinged movement when desired. An advantage of this is that it allows the user to pass more easily through the door. Furthermore, the bending ability coupled with the hinging movement of the flexible door results in a door which requires a minimum amount of clearance when actuated between the open and closed configurations.

Although particular embodiments of the invention have been disclosed herein in detail, this has been done by way of example and for the purposes of illustration only. The aforementioned embodiments are not intended to be limiting with respect to the scope of the appended claims.

It is contemplated by the inventors that various substitutions, alterations, and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims, for example:-

The hinge 22 and flexible hinge guard 24 of the hinge arrangement are provided toward the top of the door in the presently described embodiment; however, several such hinge arrangements could be provided along the height of the door, or alternatively a single hinge arrangement running along the length of the door could be provided. Furthermore, a much shorter hinge arrangement could be provided where desired.

Furthermore, although in the previously described embodiment the support arm 12 has a relatively narrow dimension, in an alternative embodiment, the support arm may comprise a resilient panel which extends substantially the full height of the door. In addition, rather than comprising polycarbonate, the resilient support arm or resilient support panel may comprise any plastics or other material having suitable resilience properties.