GB2463154A

GB2463154A - A roller barrier

Info

Publication number: GB2463154A
Application number: GB0915453A
Authority: GB
Inventors: Michael Calderbank
Original assignee: BID GROUP Ltd
Current assignee: BID GROUP Ltd
Priority date: 2008-09-08
Filing date: 2009-09-04
Publication date: 2010-03-10
Also published as: GB0915453D0; GB0816369D0

Abstract

A roller barrier comprising a flexible barrier mounted to a train roller , the flexible barrier has a free edge serving as its leading edge as it is unwrapped, the flexible barrier comprises at least one central layer 14 of insulating material disposed between yet separate from first and second outer layers 16, 18 which are a continuous loop, and provide, at the leading edge, a bight in which an auxiliary roller 20 is mounted. A bottom rail 22 is suspended below the leading edge of the flexible barrier by attachment to the auxiliary roller 20 and at least one skirt 30 is connected to the bottom rail 22 to bridge the gap between the leading edge of the flexible barrier and the floor. A safety edge strip 32 may be connected below the bottom rail via at least one spring loaded suspension device 42. Preferably a skirt is attached to each side of the bottom rail and may be made from the same material as the central layer of the flexible barrier. The roller barrier is for use with a freezer or fridge door and the central layer may be an insulating layer.

Description

A ROLLER BARRIER DEVICE

The present invention concerns a roller barrier device and is particularly relevant to a roller door.

Roller doors of sheet material are widely used in commercial premises. Such a door comprises a flexible door curtain mounted to a roller, which is installed in or above the top of a door opening. The door curtain is typically made of single ply heavy duty polyvinyl chloride (PVC) or non-woven textile fabric. Such a curtain typically has a thickness of between 1 mm and 5 mm and it does not provide any thermal insulation. In order to provide thermal insulation, as required, for example, at the entrance to cooled or refrigerated storage areas, special insulated material is required, which is typically at least 9 mm thick. Such material has not hitherto been used for roller doors and has only been used in doorways in the form of hanging strips.

Insulating materials of superior thermal performance, which have insulation properties two to eight times better than previous conventional insulating materials, and are therefore provided in the form of relatively thin sheets, are available commercially, for example from Aspen Aerogels Inc. of USA under the trade names Cryogel and Pyrogel or from Cabot Corporation of USA or Cabot Nanogel GmbH of Germany under the trade name Nanogel. These materials comprise particles distributed within fibrous material.

Accordingly, they are usually encapsulated within a substantially nonporous outer membrane prior to supply to end users. These materials have been used successfully for pipe lagging and building insulation. These materials are not suitab'e for direct use as roller door curtains as even when encapsulated they do not have sufficient tensile strength to withstand repeated unrolling and rolling back up. Moreover, the material required for doors to refrigerated areas has a minimum thickness in the region of 10 mm, such thickness creating problems for smooth operation as the inner and outer surfaces travel different distances upon being rolled up.

To overcome this problem three layers of material are required for an insulated roller door curtain, a central layer of the insulating material of the type just described, which is between 1 and 40 mm thickness, and respective outer layers of standard door curtain material, each approximately 1 mm thickness, the outer layers being needed to provide the necessary tensile strength and wear resistance.

Bonding of the respective outer layers to the central layer is not appropriate and would lead to corrugations and damage because of the overall thickness and the different distances to be travelled by the three layers when rolling and unrolling.

US 4,408,650, US 4,313,484, US 4,453,584, and EP-A-0,065,876 all disclose roller barrier devices, such as a roller door or a roller for a window opening, comprising a main roller for mounting the device and a flexible barrier mounted to the main roller in a manner enabling it to be wrapped around the main roller and having a free edge serving as its leading edge as it is unwrapped from the roller to an extended condition, in which the flexible barrier comprises at least one central layer disposed between, yet separate from, first and second outer layers, and in which the outer layers are continuous with each other around the leading edge of the barrier and provide, at the leading edge, a bight in which an auxiliary roller is mounted.

A further problem in relation to providing an insulated roller door, particularly for a refrigerated area or enclosure, is the requirement to provide adequate insulation at the foot of the door opening. In this respect it is desirable to minimise the possibility of a gap in the insulation at the foot of the door opening which would lead to unacceptable heat gain in this area.

The present invention overcomes the problems just outlined by providing a roller barrier device of the type just described which is characterised in that a bottom rail is suspended below the leading edge of the flexible barrier by attachment to the auxiliary roller and a skirt is connected to the bottom rail to bridge the gap between the leading edge of the flexible barrier and a substrate there below in the extended condition of the barrier.

Preferably the skirt hangs down below the bottom rail and also extends upwards from the bottom rail in order to overlap an edge margin of the flexible barrier at its leading edge.

In preferred embodiments a safety edge strip is connected below the bottom rail by means of at least one spring-loaded suspension device.

For best effect, a respective skirt is preferably connected to each side of the bottom rail and in an advantageous development the safety edge strip is located between the respective skirts, between portions thereof which hang down below the bottom rail.

This skirt may be of the same material as the central layer of the roller barrier.

The reference to the central layer being "separate from" the first and second outer layers is intended here to mean that it is neither bonded nor otherwise connected, e.g. by stitching or stapling, to these outer layers. Such separation is required for independent rolling up of the layers onto the main roller to minimise problems of corrugation and other deformation of material as would be the case with a thicker multilayer material being wound onto the main roller, which in turn could damage the material and/or impede smooth operation of the roller barrier, which is often designed to operate at relatively high speed.

As the barrier material is raised by being rolled onto the roller, the three layers roll up at different rates. The outer layer which is radially furthest from the axis of the main roller travels furthest and moves upwards relative to the leading edge. The other outer layer which is radially closest to the axis of the main roller travels the least distance. Owing to the continuity between the respective outer layers and the presence of the auxiliary roller, this other outer layer actually moves downwards relative to the leading edge, and moves around the auxiliary roller to compensate for the upward movement of the first mentioned outer layer.

The auxiliary roller may be suspended in the bight to tension the barrier material by gravity alone. Alternatively, the auxiliary roller may be mounted at each end into suitable slots in adjacent door side members.

Although the invention has been made in the context of providing a heat insulated roller door, it should be understood that the central layer of the barrier could be of any type of material as the invention is applicable to any roller barrier where a multilayer barrier is required or desirable. Thus, low temperature insulating material, such as Cryogel, Nanogel or others, may be used as the central layer for a roller door for a refrigerated enclosure. High temperature insulating material, such as Pyrogel, Nanogel or others, may be used as the central layer for a roller door or roller blind which is required to have fire resistant or heat resistant and insulating properties. Other types of insulating materials may be used as the central layer for roller doors or roller blinds required to have thermal or acoustic insulating properties or fire resistance. Other materials having other properties required of doors or window blinds or other roller barriers may also be used as the central layer in a device in accordance with the invention.

Moreover, of course, more than one central layer may be provided between the respective outer layers and such central layers may be of different materials, different thicknesses and may also be separate from each other and the outer layers in the sense of not being bonded or otherwise connected thereto.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side/sectional view of a practical embodiment of a roller door in accordance with the present invention; Figure 2 is an enlarged fragmentary perspective view sketch showing the bottom roller and rail of the door of figure 1; Figure 3 is also a fragmentary perspective view showing a lower region of a roller door similar to that shown in figure 1; Figure 4 is a fragmentary perspective view of part of the bearing assembly inside the bottom roller shown in figure 3; Figure 5 is a partial side view showing a bottom region of a preferred practical embodiment of the roller door of the invention in its lowered position, in greater detail than figure 1; Figure 6 is a similar view of the same embodiment of roller door as figure 5, but in its raised condition; Figure 7 is a partial perspective view from below and one side, generally corresponding to figure 5 in showing a bottom region of the same embodiment in its lowered position; Figure 8 is a comparable view to figure 7 but with one of the bottom rail skirts removed in order to show the parts behind; and Figure 9 is an enlarged detail of a safety edge suspension unit as used for mounting the safety edge strip to the bottom rail in the embodiment of figures 5 to 8.

With reference to figures 1 to 3 of the drawings, an exemplary roller door in accordance with the invention comprises a main supporting roller 10, which in use is mounted above the top of a door opening, to which a three layer door curtain, indicated generally at 12, is mounted. The central layer 14 is a relatively thick sheet of insulating material, such as encapsulated material of the type sold under the trade name Cryogel, which may be approximately 10 mm thick, and may be supplied in sheets of up to 4 m in width. The respective outer layers 16, 18 are provided as a continuous sheet of conventional roller door material, such as 1 mm thick PVC, which extends as a loop around the bottom, i.e. 1 5 leading edge of the insulating sheet 14. An auxiliary roller 20 is seated in the bight provided by that loop.

The connection between the upper ends of the layers 14, 16, 18 and the roller 10 may be made in any conventional manner. It is important to note, however, that these three layers 14, 16, 18 are separate from each other, that is to say they are not bonded or otherwise connected to each other, but hang separately from the main roller 10. The lower end of the central layer 14 may be at a short spacing from the auxiliary roller 20, as shown in figure 1, or may virtually touch that roller 20, as shown in figure 3.

The auxiliary roller 20 is connected to a bottom rail 22 which hangs below the bight connecting the respective outer layers 16, 18. As shown in figure 2, this connection may be accomplished by a shaft 24 on which the roller 20 is rotatably mounted having bearings in upstanding end flanges 26 of the rail 22.

In use, the door curtain 12 may be raised and lowered at a relatively high speed of between 1 and 2 m per second. Owing to the relatively large overall thickness of the door curtain 12 the three layers 14, 16, 18 roll up at different rates as the curtain is raised and rolled onto the roller 1 0. The outer layer 18, which is radially furthest from the axis of the main roller 10, travels furthest and moves upwards relative to the leading edge of the curtain 12. The other outer layer 16, which is radially closest to the axis of the main roller 10 travels the least distance. Owing to the continuity between the respective outer layers 16, 18 and the presence of the bottom roller 20, the outer layer 16 actually moves downwards relative to the leading edge of the curtain 12, and moves around the auxiliary roller 20 to compensate for the upward movement of the outer layer 18, as shown by the arrows in figure 1.

A pair of skirts 30 of the same material as the central layer 14 of the door curtain are provided at the leading end of the curtain 12 to provide reliable insulation at the foot of the door opening, or at least minimise the possibility of a gap in the insulation leading to heat loss at the foot of the door opening. As shown in figure 1, these skirts 30 comprise respective short lengths of the aforesaid flexible material which are fastened to opposing sides of the bottom rail 22 and extend upwards to overlap a leading edge margin of the respective outer layers 14, 16 of the curtain 12, but additionally hang down below the bottom rail 22 to contact the ground when the curtain 12 is fully lowered, as shown in figure 1.

Figure 4 shows a bearing assembly comprising a cylindrical bearing block 28, a connection sleeve 27 and a locking nut 29 by means of which the bottom roller 20 can be rotatably mounted on its axial shaft 24. A trace heating element (not shown) may optionally be provided, extending through the hollow shaft 24 in order to provide sufficient heating at the base of the curtain 12 to prevent adhesion by ice when the curtain 12 remains lowered for a period of time. However, with the provision of a skirt 30 of highly efficient insulating material, such heating means may not be necessary or appropriate.

Figures 5 to 8 illustrate a bottom region only of a preferred practical embodiment in which a safety edge strip 32 is suspended below the bottom rail 22, between the respective skirts 30. The same reference numerals are used in these figures as in figures 1 to 3 to denote corresponding parts of the assembly and avoid unnecessary

repetition of description.

The respective skirts 30 are fastened to the opposing sides of the bottom rail 22 by means of respective continuous plates 34 of substantially same width as the curtain 12, these plates 34 being secured to the rail 22 by self tapping screws 36 which are applied through the material of the respective skirts 30. Compared to the version shown in figure 2, respective brackets 38, as shown in figure 8, are provided at each end of the bottom rail and provide upstanding flanges 39 for mounting upon the shaft 24 of the auxiliary roller 20.

The safety edge strip 32 may be of known form. It serves to stop the rotation of the main roller, thereby stopping lowering of the curtain 12, in the event of impact with any obstruction during lowering of the curtain 12. It may also trigger a mechanism to raise the curtain again in that situation.

A novel feature of the present invention is the mounting of this safety edge strip 32 to the bottom rail 22 by means of at least one spring-loaded suspension unit 40, an example of which is shown separately in figure 9. This feature may be applied separately in respect of other types of roller barrier mechanisms, that is to say independently of the other features hitherto described in respect of this invention, particularly the feature of the continuous outer layers mounting the auxiliary roller in a bight at the leading edge of the curtain and the bottom rail skirt or skirts mounted to the bottom rail which is suspended from this auxiliary roller.

In the illustrated and preferred embodiment, several units 40 are fastened below the bottom rail 22 at intervals of approximately 250 millimetres. As shown in figures 5, 6 and 9, each unit 40 comprises a cylindrical mount 42 which fits through a corresponding aperture formed in the lower wall of the bottom rail 22, which is typically a hollow box section beam. The cylindrical mount 42 is itself mounted onto a plate 44 which may additionally be secured to the bottom rail, for example by bolts. A shaft 46 extends slidably through the cylindrical mount 44 and is held in place by a washer, lock nut and bolt 47, 48, 49 which are fastened onto the shaft inside the hollow rail 22. A helical spring 50 is mounted on the shaft between the plate 44 and a washer 52 which is held on a lower end of the shaft 46. A C-section retainer 54 is fixed, e.g. welded, onto the bottom of the shaft 46 and serves to engage an elongate T-formation 33 along the top of the safety edge strip 32.

These spring-loaded units 40 allow soft closing ground level impact for the skirts 30 when the curtain 1 2 is lowered to the position shown in figure 5, which minimises any likelihood of a gap remaining along the bottom of the lowered curtain. As shown, the suspension units 40 hold the safety edge strip 32 in a position projecting below the skirts 30 when the curtain 12 is above ground level and is being lowered, or opened, as shown in figure 6. But upon the safety edge strip 32 touching the ground, the shaft 46 slides through the cylindrical mount 42 and compresses the spring 50 until the condition shown in figure 5, where the skirts 30 are firmly in contact with the ground.

The foregoing are just particular specific examples and the inventions could be applied more widely to any roller barrier, not just a door, and in respect of any type of material as the central layer and the respective outer layers of the barrier material. Although the outer layers need to be continuous with each other around the leading edge of the barrier in order to loop around and provide a bight for the auxiliary roller, it is not essential that they are made of the same material or made as one continuous piece of material. The outer layers at each surface of the barrier may simply be connected together for continuity and may be of different materials, different thicknesses.

Throughout the description and claims of this specification, the words "comprise", "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other components.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires.

Features described in conjunction with a particular embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Claims

CLAIMS1. A roller barrier device comprising a main roller for mounting the device and a flexible barrier mounted to the main roller in a manner to enable it to be wrapped around the main roller in a retracted condition, the flexible barrier having a free edge serving as its leading edge as it is unwrapped from the roller to an extended condition and comprising at least one central layer of insulating material disposed between yet separate from first and second outer layers, these outer layers being continuous with each other around the leading edge of the barrier and providing, at the leading edge, a bight in which an auxiliary roller is mounted, characterised in that a bottom rail is suspended below the leading edge of the flexible barrier by attachment to the auxiliary roller and a skirt is connected to the bottom rail to bridge the gap between the leading edge of the flexible barrier and a substrate there below in the extended condition of the barrier.
2. A device according to claim 1 wherein the skirt hangs down below the bottom rail and also extends upwards from the bottom rail in order to overlap an edge margin of the flexible barrier at its leading edge.
3. A device according to claim 1 or 2 wherein a safety edge strip is connected below the bottom rail by means of at least one spring-loaded suspension device.
4. A device according to any preceding claim wherein a respective skirt is connected to each side of the bottom rail.
5. A device according to claims 3 and 4 wherein the safety edge strip is located between the respective skirts, between portions thereof which hang down below the bottom rail.
6. A device according to any preceding claim wherein the skirt comprises the same material as the central layer of the flexible barrier.
7. A device according to any preceding claim wherein the central layer is of a thickness of over 5 mm.
8. A device according to any preceding claim further including heating means extending through the auxiliary roller.
9. A roller barrier device in the form of a roller door substantially as hereinbef ore described with reference to and is illustrated by any of the accompanying drawings.