GB2623488A

GB2623488A - Rollable blind

Info

Publication number: GB2623488A
Application number: GB2214055.2A
Authority: GB
Inventors: Thijs Kuperus Koop
Original assignee: Hunter Douglas Industries BV
Current assignee: Hunter Douglas Industries BV
Priority date: 2022-09-27
Filing date: 2022-09-27
Publication date: 2024-04-24
Also published as: GB202214055D0

Abstract

A roller blind 2 includes an inner layer 4 and an outer layer 6 arranged in parallel, each layer including an array of cutout flaps 8, 18, which may be used to create different lighting effects. The flaps of the inner and outer layers extend towards each other. Material of the inner layer between the inner openings 12 includes strips 30 extending continuously straight in the direction of extension of the blind. Material of the outer layer between the outer openings 22 includes undulating paths 40 extending in the direction of extension of the blind, without any strips extending continuously straight. When the blind is rolled up, the outer layer is elongated by straightening the said undulating paths of material, thus allowing the outer layer to stretch as the blind is rolled up.

Description

ROLLABLE BLIND

The present invention relates to a rollable blind, for example for an architectural opening and a roller blind assembly including such a rollable blind.

Roliable blinds are well known, for example for extending over and retraction from an architectural opening.

It is also known to provide a rollable blind with two layers which are connected together, for example via vanes. The two layers may have different respective material properties and/or apertures therein. By moving the layers laterally with respect to one another, the patterns and/or openings may be moved relative to one another so as to create different lighting effects.

US 7,686,060 describes a retractable covering which may be wrapped around a roller and unwrapped from the roller. A plurality of cut-out vanes are formed in one sheet having a free edge thereof secured to the other sheet. When the sheets are in the closed contiguous relationship, the vanes which are integral with one sheet become coplanar therewith, but when the sheets are separated, the vanes pivot to open a passage through the sheet from which they were cut to permit the passage of vision and light.

US 2,140,049 describes a sheet similarly having two layers. According to this teaching, both layers have their own arrays of ventilating openings. However, the two respective arrays are different (in particular having different numbers of ventilating openings along each row), such that the ventilating openings of the two layers never line up.

A problem with a two-layer rollable blind is that wrinkling may occur as a result of one of the layers being wound (along a longer path) around the outside of the other layer.

US 2,140,049 addresses this problem of buckling by having a longer sheet on one layer and also by increasing the spacing of the ventilating openings in the long sheet in relation to those on the short sheet.

It is an object of the present invention to provide an improved rollable blind, in particular allowing rolling of the blind whilst reducing the disadvantages of buckling and wrinkling of the blind layers.

According to the present invention, there is provided a rollable blind which extends laterally in a first direction, extends from one end to another end longitudinally in a second direction perpendicular to the first direction, and is rollable longitudinally in the second direction about an axis extending in the first direction. The blind includes an inner layer and an outer layer parallel with the inner layer. The inner layer includes an array of a plurality of cut-out inner flaps, each respectively hinged from the inner layer and extending to the outer layer, and each respectively leaving a respective inner opening. The outer layer includes an array of a plurality of cut-out outer flaps, each respectively hinged from the outer layer and extending to the inner layer, and each respectively leaving a respective outer opening. Material of the inner layer between the inner openings includes strips having respective widths in the first direction and extending continuously straight in the second direction from said one end to said another end. Material of the outer layer between the outer openings includes undulating paths extending in the second direction from said one end to said another end and undulating side-to-side in the first direction without any strips extending continuously straight in the second direction from said one end to said another end, so that, when the blind is rolled longitudinally, the outer layer is elongated by straightening the undulating paths along the second direction.

In this way, the strips of material between the inner openings form load bearing columns in the inner layer between the top and the bottom of the rollable blind. Because they extend continuously in the second direction between the top and the bottom, it is not possible for the inner layer to deform so as to elongate in the second direction. In contrast, the outer layer is formed without such strips or columns. The only paths existing between the top and bottom of the rollable blind in the outer layer undulate from side-to-side around the outer openings. The paths zig zag from side-to-side. There are no strips of material in the outer layer which extend directly/straight in the second direction. There can be defined a respective centre line between each respective pair of adjacent array of outer openings extending (as columns) in the second direction. The outer openings of such a pair on either side of a path all cross the respective centre line between those outer openings. The centre line may be midway between the respective lines joining the centres of the outer openings in the respective adjacent arrays. However, the centre line may alternatively be off-centre provided that the outer openings on either side cross the centre line. As a result, when forces are applied to the outer layer so as to extend it along the second direction, the material of the outer layer forming the undulating paths between the outer openings is able to straighten, thereby extending the length of the outer layer in the second direction. Thus, when the two-layer rollable blind is rolled longitudinally in the second direction about the first direction axis with the outer layer wound outside the inner layer, it is possible for the outer layer to extend in the second direction such that wrinkling of the rollable blind is avoided.

As a further improvement, the edges of the outer layer may be formed as similar undulating paths extending in the second direction from said one end to said another end and undulating side-to-side in the first direction so that those two edges do not form strips extending continuously straight in the second direction from said one end to said another end. Thus, in the same way as for the paths between the outer flaps of the outer layer, when forces are applied to the outer layer so as to expand it along the second direction, the material of the outer layer forming the undulating paths at the two edges of the outer layer is able to straighten, thereby extending the length of the outer layer in the second direction. When the two-layer rollable blind is rolled longitudinally in the second direction about the first direction axis with the outer layer wound outside the inner layer, the outer layer better extends in the second direction and better avoids wrinkling of the roller blind.

Each respective inner flap may be secured to a respective outer flap so as to form a respective bridge between the inner layer and the outer layer. In this way, the flaps themselves connect the layers to one another. Also, in this way, relative movement of the layers in the second direction itself pivots the flaps. The inner and outer flaps may be secured to each other in any known or convenient manner. For example using adhesive and/or welding, such as ultrasonic welding.

Rather than using adhesives or welding, the inner and outer flaps may be secured to each other by means of a mechanical interconnection. One advantage of this is the resulting mono-material which is easily recyclable.

An example of mechanical interconnection which is particularly effective and advantageous uses at least one hinged tongue cut out of each respective inner and outer flap. In particular, an inner tongue is formed in each respective inner flap and an outer tongue is formed in each respective outer flap. The respective tongues may hinge or deflect relative to their respective flaps. The tongues face the hinges of the respective flaps. For example, each tongue extends from its respective hinge towards the hinge of its respective flap. In this way, a double hook arrangement is formed whereby the inner tongue of an inner flap passes through the space left by the outer tongue of a respective outer flap and the outer tongue of that respective outer flap passes through the space left by the inner tongue of the respective inner flap. The respective inner and outer tongues overlie the opposite surfaces of the outer flap and inner flap respectively. The respective inner and outer flaps become interlocked accordingly.

Each respective inner flap may overlap the respective outer flap. In this way the inner and outer flaps operate together.

Each respective inner flap may be concentric with the respective outer flap With respect to the second direction, at a first side of each respective inner opening, the respective inner flap may be hinged to the inner layer. Similarly, with respect to the second direction, at a second side opposite the first side of each respective opening, the respective outer flap may be hinged to the outer layer. In other words, for a rollable blind which extends from top to bottom, the inner flaps may be hinged at the top of the inner openings with the outer flaps hinged to the bottom of the outer openings or, alternatively, the inner flaps may be hinged to the bottom of the inner openings with the outer flaps hinged to the top of the outer openings.

Each respective inner flap may be smaller than the respective outer flap. This may be a convenient way of providing the undulating paths in the outer layer. Also, the difference in size may improve the quality of room-darkening, with the slightly larger outer flaps acting as lids on the slightly smaller inner openings.

Each respective inner flap may be the same shape as the respective outer flap.

Alternatively, it is possible to provide the inner flaps and inner openings with a different shape to the outer flaps and outer openings.

In one embodiment, each respective inner flap and each respective outer flap are disc shaped.

Each respective inner flap may be integrally connected with the inner layer by a respective hinge portion by which the respective inner flap is hinged to the inner layer. Similarly, each respective outer flap may be integrally connected with the outer layer by a respective hinge portion by which the respective outer flap is hinged to the outer layer. This simplifies production and may reduce costs. The hinge portions for at least the smaller inner flaps may have an extent between the inner layer and the periphery of the respective inner flaps. The extent may be substantially equal to or greater than the additional extent of the corresponding outer flap. In this way, the corresponding outer flaps do not interfere with hinging of the inner flaps relative to the inner layer.

The present invention may also provide a roller blind assembly including the rollable blind as defined above together with a roller. One end of the rollable blind in the second direction, for example the top end, may be secured to the roller. The roller may be configured to retract the rollable blind by rolling the rollable blind longitudinally around the roller with the outer layer outside the inner layer.

In an extended state of the roller blind, the inner layer and the outer layer of the roller blind may be configured to extend in parallel from the roller. The roller may be configured to translate the inner layer and the outer layer with respect to each other in the second direction between at least a closed position and a see-through position. In some arrangements, there may be provided a privacy position between the closed and see-through positions. In the closed position, the inner flaps fit in their respective inner openings and the outer flaps fit in their respective outer openings and each inner opening is opposite a respective outer opening in a third direction perpendicular to the first and second directions. In this position in the embodiments described below, the inner layer and outer layer have substantially no space between each other in the third direction and hence are directly adjacent one another. In the privacy position, the inner flaps and the outer flaps extend in the third direction and each respective inner opening is not opposite a respective outer opening in the third direction such that a line of sight through the inner openings and the outer openings in the third direction is obstructed, in particular by the material of the inner and outer layers between the respective openings. In this position in the two stage embodiment described below, the inner layer and outer layer are still parallel with one another but are spaced apart in the third direction. In the see-through position, the inner flaps and the outer flaps are angled with respect to the inner layer and the outer layer such that each respective inner opening is opposite a different respective outer opening so as to allow line of sight directly through the inner openings and the different respective outer openings. In this position in the two stage embodiment described below, the inner layer and outer layer are still parallel with one another but are spaced apart in the third direction. In this position in the three stage embodiment described below, the inner layer and outer layer are spaced close to one another in the third direction, separated by the folded flaps which maybe close to parallel with the inner and outer layers. The inner layer and the outer layer may be secured to the roller at different radial positions of the roller. According to the present invention, there may also be provided a method of enabling a blind to be rolled. The blind extends laterally in a first direction, extends from one end to another end longitudinally in a second direction perpendicular to the first direction and includes an inner layer and an outer layer parallel with the inner layer. The inner layer includes an array of a plurality of cut-out inner flaps, each respectively hinged from the inner layer and extending to the outer layer and each respectively leaving a respective inner opening. The outer layer includes an array of a plurality of cut-out outer flaps, each respectively hinged from the outer layer and extending to the inner layer and each respectively leaving a respective outer opening. The method includes arranging the array of the plurality of cut-out inner flaps so as to provide material of the inner layer between the inner openings including strips having respective widths in the first direction and extending continuously straight in the second direction from said one end to said another end. The method also includes arranging the array of the plurality of cut-out outer flaps so as to provide material of the outer layer between the outer openings including undulating paths extending in the second direction from said one end to said another end and undulating side-to-side in the first direction without any strips extending continuously straight in the second direction from said one end to said another end, so that when the blind is rolled longitudinally, the outer layer is elongated by straightening the undulating paths along the second direction.

The invention will be more clearly understood from the following description, given by way of example only, with reference to the accompany drawings, in which: Fig. I illustrates schematically a roller blind assembly including a rollable blind embodying the present invention; Figs. 2(a) and (b) illustrate schematically a roller blind in alternative orientations with respect to the interior and exterior of a building; Figs. 3(a) and (b) illustrate schematically opposite perspective views of a portion of inner and outer layers of the rollable blind; Figs. 4(a), (b) and (c) illustrate interlocking of an inner flap and an outer flap with a double hook method; Figs. 5(a) and (b) illustrate a portion of a two stage roller blind in two different respective positions; Figs. 6(a) and (b) illustrate corresponding perspective views of the portion of the two stage roller blind in the two different respective positions; Figs. 7(a), (b) and (c) illustrate a portion of a three stage roller blind in three different respective positions; Figs. 8(a), (b) and (c) illustrate corresponding perspective views of the portion of the three stage roller blind in the three different respective positions; Fig. 9 illustrates schematically an inner flap attached to an outer flap; Figs. 10(a) and (b) illustrate schematically the inner layer and the outer layer of a two stage rollable blind; Figs. 11(a) and (b) illustrate schematically the inner layer and the outer layer of a three stage rollable blind; Fig. 12 illustrates schematically rolling of the rollable blind; Fig. 13(a) and (b) illustrate schematically stretching of an outer layer of a rollable blind; Fig. 14 illustrates an alternative arrangement in which the two opposite edges of the outer layer undulate side-to-side; and Fig. 15 illustrates an arrangement with the undulating edges of fig 14 together with the double hook arrangement of fig. 4.

Rollable blinds as such are known in the art.

Fig. 1 illustrates a roller blind assembly 1 including a rollable blind 2 embodying the present invention.

Fig. 2(a) and fig. 2(b) illustrate schematically a rollable blind embodying the present invention in an intermediate state of being rolled.

As illustrated in fig. 2(a), the rollable blind 2 may be orientated with its outer surface facing towards the exterior, for instance facing an architectural opening. Alternatively, as illustrated in fig. 2(b), the inner surface of the rollable blind 2 may face the exterior.

The rollable blind 2 is made up of two layers, namely an inner layer 4 and an outer layer 6. The rollable blind 2 and, hence, both layers 4 and 6, extend laterally in a first direction and extend longitudinally in a second direction perpendicular to the first direction. The two layers 4 and 6 overlay one another and, hence, are separated in a third direction perpendicular to the first and second directions. As illustrated, the rollable blind 2 and, hence, both layers 4 and 6, are rollable longitudinally about an axis X extending in the first direction.

With the rollable blind 2 fully extended (unrolled), it becomes possible to translate the inner layer 4 and the outer layer 6 relative to one another in the second (longitudinal) direction. Although not illustrated in fig. 2(a) and 2(b), the inner layer 4 is provided with a plurality of through holes, named herein as inner openings 12. Similarly, the outer layer 6 is provided with a plurality of through holes, named herein as outer openings 22. The positions and sizes of the inner openings 12 and the positions and sizes of the outer openings 22 are such that relative translation of the inner layer 4 against the outer layer 6 cause the rollable blind 2 to provide different lighting effects. For example, different respective relative positions of the inner layer 4 and outer layer 6 may obscure substantially all light through the rollable blind 2, or allow line-of-sight through the rollable blind 2 in a see-through manner. In some arrangements, an intermediate relative position allows indirect transmission of light through the rollable blind 2.

The inner layer 4 and outer layer 6 are also provided with cut-out flaps 8, 18 in the respective openings 12, 22.

Fig. 3(a) and 3(b) illustrate a small section of an inner layer 4 and an outer layer 6.

The inner layer 4 includes an array of a plurality of cut-out inner flaps 8. The inner flaps 8 are hinged to and pivot with respect to the rest of the inner layer 4 via a respective hinge 10. The pivoting part of the hinge may take the form of a fold line in the material of the respective layer 4, 6. In the illustrated embodiment, thus, the inner flaps 8 are integral with the inner layer 4.

Each inner flap 8 is able to hinge or pivot away from the inner layer 4 towards the outer layer 6 via its respective hinge 10. Each inner flap 8 thus leaves a respective inner opening 12 in the inner layer 4.

As illustrated, similarly, the outer layer 6 includes an array of a plurality of cut-out outer flaps 18 which are hinged to and pivot with respect to the rest of the of the outer layer 6 via respective hinges 20. The outer flaps 18 hinge or pivot towards the inner layer 4 and, thus, leave respective outer openings 22 in the outer layer 6.

As illustrated, with respect to the first direction, namely top to bottom as illustrated, the inner flaps 8 are hinged to one side (the bottom) and the outer flaps 18 are hinged to the other side (top). In any convenient manner, such as with adhesive or by welding (for example ultrasonic welding), each respective inner flap 8 is secured to a respective outer flap 18. In this way, as the inner layer 4 and outer layer 6 are translated relative to one another in the second direction (up and down), the inner flaps 8 and their corresponding respective outer flaps 18 open and close together simultaneously.

Rather than securing each respective inner flap 8 to a respective outer flap 18 with adhesive or by welding, it is possible to provide a mechanical interconnection. One example of this is the double hook method illustrated in figs. 4(a), (b) and (c).

As illustrated in fig. 4(a), each inner flap 8 of the inner layer 4 includes a through passage or division such as a cut 8a which extends so as to define an inner tongue 8c which may pivot, bend or hinge about a hinge portion 8b formed naturally between the two ends of the cut 8a.

Similarly, as illustrated in fig. 4(b), each outer flap 18 of the outer layer 6 includes a through passage or division such as a cut 18a which extends so as to define an outer tongue 18c which may pivot, bend or hinge about a hinge portion 18b formed naturally between the two ends of the cut 18a.

The inner tongue 8c faces in an opposite direction to the outer tongue 18c. In particular, the inner tongue 8c faces towards the hinge 10 of the inner flap 8 and the outer tongue 18e faces towards the hinge 20 of the outer flap 18. In this way, when the respective inner and outer tongues 8c, 18c are interlocked, they resist separation of the inner and outer layers 4, 6.

In the example illustrated in figs. 4(a), (b) and (c), so as to interlock the inner and outer flaps 8, 18, the inner tongue 8c is deflected or bent slightly downwards so as to leave a space defined by the cut 8a and the outer tongue 18c is bent or deflected slightly upwards so as to leave a space defined by the outer cut 18a. The inner tongue 8c is then inserted into and moved down through the space defined by the cut 18a in the outer flap 18. Simultaneously, the outer tongue 18c is moved upwardly into and through the space defined by the cut 8a in the inner flap 8. Thus, in the interlocked state, as illustrated in fig.4(c) the outer tongue 18c lies against the upper surface (as illustrated) of the inner flap 8. Because the inner tongue 8c has been deflected downwardly (as illustrated) and lies against the lower surface (not illustrated) of the outer flap 18, what can be seen in fig. 4(c) is the space left in the inner flap 8 defined by the cut 8a) and the top surface of the outer flap 18 is visible within that space.

As will be apparent from fig. 4(c), if the inner flap 8 is pulled by means of its hinge 10 away from the outer flap 18 by its hinge 20, the interlocking tongue arrangement inhibits movement of respective flaps, with the outer tongue 18c) abutting at its hinge 18b the inner flap 8c at its hinge 8b.

In the illustrated arrangement, it will be seen that one of the tongues, namely the inner tongue 8c in this particular example, is wider than the other tongue. In other words, it has a larger extent in the direction of its bendable or hinge portion 8b. Nevertheless, in order for the respective inner and outer tongues 8c and 18c to interlock as required, the respective hinge portions 8b and 186 should be the same length. Thus, for the wider tongue, the cut 8a extends at its ends inwardly towards the two opposite ends of the hinge portion 8b. Advantageously, as illustrated, the wider tongue, namely the inner tongue 8c of this example, is formed from a cut 8a having, at each end, portions 8d which loop around on the opposite side of the hinge portion 8b from the rest of the cut 8a and the majority of the tongue Sc.

By having one of the tongues, the inner tongue Sc as illustrated, wider than the other tongue, it becomes necessary to deform the tongue Sc slightly in the width direction (that of the hinge portion 8b) in order to insert it through the space formed by the cut 18a for the other tongue 18c. With the interlocked double hook arrangement of fig. 4(c), decoupling is thus resisted. This is further enhanced by the form/shape of the inner tongue 8c which, by virtue of the looped portions 8d extends back either side of the space formed by the cut 18a for the opposite outer tongue 18c.

The positions of the through holes in the inner layer 4 and the outer layer 6, the sizes of the through holes, their shapes and the resulting patterns may be chosen to achieve different respective effects. In particular, the relative distances between adjacent through holes within one layer and with respect to the pattern of through holes in the other layer will create different respective effects as inner and outer layers 4, 6 are moved relative to one another. Depending upon the positions/patterns of the through holes in the inner layer 4 and the outer layer 6, rollable blinds may be arranged either as a two-stage blind movable between a closed position and an open position or as a three-stage blind movable between a closed position, a privacy position and a see-through position.

A two-stage rollable blind 2 is illustrated in fig. 5(a) and (b).

In fig. 5(a), the inner layer 4 lies adjacent the outer layer 6 in the third direction and the inner flaps 8 all close their respective inner openings 12. The respective outer flaps 18 of the outer layer 6 are secured to respective inner flaps 8. Although not illustrated in fig. 5(a), it will be understood that, therefore, similarly, the outer flaps 18 all fit within their respective outer openings 22. The rollable blind 2 thus takes the closed position.

By translating the outer layer 6 downwardly with respect to the inner layer 4 (or the inner layer 4 upwardly with respect to the outer layer 6) as illustrated in fig. 5(b), all of the inner flaps 8 pivot downwardly about their respective hinges 10 whilst, at the same time, the respective outer flaps 18 pivot upwardly with respect to their respective hinges 20. Fig. 6(a) and fig. 6(b) show corresponding perspective views of the closed and open positions illustrated in fig. 5(a) and fig. 5(b) respectively. It can be seen that, in the closed position, the inner layer 4 and outer layer 6 have substantially no space between each other in the third direction and hence are directly adjacent one another. In the open position, the inner layer 4 and outer layer 6 are still parallel with one another but are spaced apart in the third direction, with the flaps 8, 18 extending substantially in the third direction perpendicular to the inner and outer layers 4, 6.

In the state illustrated in fig. 5(b) and 6(b), the inner flaps 8 and outer flaps 18 have pivoted by just over 90 degrees to an orientation substantially perpendicular to the second direction and extend mostly in the third direction between the inner layer 4 and outer layer 6.

With the illustrated interlaced or angled arrays of inner and outer openings 12, 22, the relative positions of the openings 12, 22 in the open position illustrated in fig. 5(b) and 6(b) result in the inner openings 12 being in alignment and facing the outer openings 22. Hence, direct line of sight is possible through the inner layer 4 and the outer layer 6, in particular through inner openings 12 and different respective outer openings 22.

A three-stage rollable blind 2 is illustrated in fig. 7(a), (b) and (c).

In fig. 7(a), the inner layer 4 lies adjacent the outer layer 6 (in the third direction) and the inner flaps 8 all close their respective inner openings 12. The respective outer flaps 18 of the outer layer 6 are secured to respective inner flaps 8. Although not illustrated in fig. 7(a), it will be understood that, therefore, similarly, the outer flaps 18 all fit within their respective outer openings 22. The rollable blind 2 thus takes the closed position.

By translating the outer layer 6 downwardly with respect to the inner layer 4 (or the inner layer 4 upwardly with respect to the outer layer 6) as illustrated in fig. 7(b), all of the inner flaps 8 pivot downwardly about their respective hinges 10 whilst, at the same time, the respective outer flaps 18 pivot upwardly with respect to their respective hinges 20.

In the intermediate state illustrated in fig. 7(b), the inner flaps 8 and outer flaps 18 have pivoted by approximately or substantially 90 degrees to an orientation substantially perpendicular to the second direction and extend substantially in the third direction between the inner layer 4 and outer layer 6. In this three stage arrangement, this intermediate state results in what will be called a privacy position.

Fig. 8(a) and 8(b) illustrate corresponding perspective views of the rollable blind of fig. 7(a) and 7(b) respectively. Similarly, fig 8(c) illustrates the corresponding perspective view of the rollable blind of fig. 7(c) to be discussed below.

With the illustrated (checker board) arrays of inner and outer openings 12, 22, the relative positions of the openings 12, 22 in the privacy position illustrated in fig. 7(b) and fig. 8(b) result in the inner openings 12 facing the outer layer 6 between outer openings 22, and the outer openings 22 facing the inner layer 4 between the inner openings 12. Hence, although the inner openings 12 and outer openings 22 are open and, hence, allow transmission of light, there is no direct line of sight in the third direction through the inner layer 4 and outer layer 6.

As illustrated in fig. 7(c) and corresponding fig. 8(c), by translating the outer layer 6 still further downwardly relative to the inner layer 4, the outer openings 22 will come into alignment with other inner openings 12. The inner flaps 8 and outer flaps 18 have pivoted by approaching or substantially 180 degrees to an orientation substantially in the second direction and extend substantially parallel with the inner layer 4 and outer layer 6. In this state, a direct line of sight is possible through the inner layer 4 and outer layer 6, in particular through inner openings 12 and different respective outer openings 22. This state of the rollable blind is described as the open or see-through position. As illustrated in fig. 8(c), the inner layer 4 lies adjacent the outer layer 6 (in the third direction), separated only by the folded-open flaps 8, 18.

In the illustrated arrangements, the inner and outer flaps 8 and 18 have overlapping centre points C. This is illustrated schematically in fig. 9.

In the illustrated arrangements, the diameter of the outer flaps 18 (and, hence, also the outer openings 22) is slightly larger than the inner flaps 8 (and corresponding inner openings 12). The slightly larger outer flap 18 acts as a lid on the slightly smaller diameter inner opening 12 so as to improve the quality of the room-darkening when in the closed position.

Because the outer flaps 18 are slightly larger than the inner flaps 8, in the illustrated arrangement, the hinges 10 of the inner flaps 8 are correspondingly longer. For the circular openings and flaps of the illustrated arrangement, the hinges 10 of the inner flaps 8 will be longer by at least the additional radius of the larger outer flap 18. In this way, when the inner flaps 8 pivot relative to the inner layer 4 and the outer flaps 18 pivot relative to the outer layer 6, the edge/periphery of the larger outer flaps 18 do not interfere with pivoting of the smaller inner flaps 8. In particular, pivoting at the base of the hinges 10 occurs outside the perimeter of the larger outer flaps 18.

It will be appreciated that the openings need not be circular. Similar advantages can be provided with openings of other shapes. Also, similarly, such other shapes may have overlapping centre points (or centres of gravity) and may similarly use outer flaps and openings of slightly larger size.

With the arrangement as described above, the inner layer 4 is attached to the outer layer 6. It will be appreciated that this could cause difficulty when rolling the rollable blind 2 longitudinally about the axis X (extending in the first or lateral direction of the blind), because the outer layer 6 will take a longer path relative to the inner layer 4. Hence, there could be the issue of wrinkling of the layers.

The illustrated arrangement is intended to address this issue by arranging the array of flaps 8, 18 and openings 12, 22 and the sizes of the outer openings 22 such that the outer openings 22 of one array or column extending in the second direction slightly overlap (in the first direction) the adjacent array or column of outer openings 22 extending in the second direction. As a result, there only exists an undulating path (moving side-to-side in the first direction) between one end (one of the top and bottom) of the rollable blind 2 and the other end (the other of the top and bottom) in the second direction (top-to-bottom). There can be defined a respective centre line L (to be discussed below) between each respective pair of adjacent array or column of outer openings 22 extending in the second direction. The outer openings 22 of such a pair on either side of a path all cross the respective centre line L between those outer openings 22. The centre line L may be midway between the respective lines joining the centres of the outer openings 22 in the respective adjacent arrays. However, the centre line may alternatively be off-centre provided that the outer openings 22 on either side cross the centre line L. Fig. 10(a) and (b) illustrate respectively the inner layer 4 and the outer layer 6 of a two-stage roller blind 2.

As illustrated, for the inner layer 4, the array of flaps 8 and openings 12 are such that, between adjacent columns (in the second direction) of flaps 8 and openings 12, there is left in the inner layer 4 virtual strips 30 having non-zero widths in the first direction. The strips 30 extend continuously straight in the second direction from one end to the other end of the inner layer 4, in other words top-to-bottom as illustrated.

If a force is applied so as to stretch the inner layer 4 between the two ends in the first direction, the strips 30 act to resist any such stretching.

Fig. 10(b) illustrates the corresponding outer layer 6 of the two-stage roller blind 2. In the illustrated arrangement, the outer flaps 18 and openings 22 are concentric with (have the centres at the same position) the inner flaps 8 and openings 12 of the inner layer 4 Also, in this arrangement, the outer flaps 18 and openings 22 are slightly larger than the inner flaps 8 and openings 12 of the inner layer 4. In particular, in the illustrated arrangement, the outer flaps 18 and openings 22 are sufficiently large that, in contrast to the arrangement for the inner layer 4, there are no strips extending continuously straight in the second direction from one end to the other end of the outer layer 6. Virtual centre lines L may be imagined extending in the second direction between adjacent columns of flaps 18 and openings 22. As illustrated, the peripheries of the flaps 18 and openings 22 in the first direction at least meet with and preferably cross these virtual centre lines L so that there does not exist any strips extending continuously straight in the second direction from one end to the other of the outer layer 6. Instead, the flaps 18 and openings 22 leave, in the outer layer 6, virtual undulating paths 40 which extend in the second direction from one end to the other of the outer layer 6 only by undulating side-to-side in the first direction around adjacent openings 22.

Fig. 11(a) and 11(b) illustrate respectively the inner layer 4 and outer layer 6 for a three-stage rollable blind 2.

As illustrated in fig. 11(a), like the arrangement illustrated in fig. 10(a), in the inner layer 4, the flaps 8 and openings 12 leave between them virtual strips 30 which have non-zero widths in the first direction and extend continuously straight in the second direction from one end of the inner layer 4 to the other end. Hence, when a force is exerted on the inner layer 4 for stretching it from one end to the other, the strips 30 resist such stretching.

As illustrated in fig. 11(b), as with the arrangement of fig. 10(b), the flaps 18 and openings 22 are larger and cross the virtual centre line L between adjacent columns of flaps 18 and openings 22. Hence, similarly, there are no strips extending continuously straight in the second direction from one end to the other of the outer layer 6. Instead, the flaps 18 and openings 22 leave in the outer layer 6 the virtual undulating paths 40 which extend in the second direction from one end to the other of the outer layer 6 but undulate side-to-side in the first direction between and around the adjacent flaps 18 and openings 22.

When a force is applied to the outer layer 6 of either the two-stage rollable blind 2 illustrated in fig. 10(b) or the three-stage rollable blind 2 illustrated in fig. 11(b), there does not exist any strips to resist stretching of the outer layer 6 in the second direction between the two ends (top and bottom as illustrated). Instead, such a force will cause the paths 40 to straighten and allow the outer layer 6 to elongate in the second direction.

When the described and illustrated arrangement is rolled with the outer layer 6 around the inner layer 4, the outer layer 6 may elongate as a result of the undulating paths 40 straightening In this way, buckling and wrinkling of the blind layers may be reduced when rolling.

Fig. 12 illustrates schematically a three-stage rollable blind 2 in which the outer layer 6 elongates as the undulating paths 40 between the two ends straighten. As illustrated, the outer openings 22 will elongate in the second direction whilst their respective outer flaps 18 may retain their relaxed form (size and shape).

As noted above, the openings and flaps need not be circular. In order for the outer layer to be rolled effectively around the inner layer, it is enough for the inner openings and flaps to leave the continuous straight strips and the outer openings and flaps to cross the virtual centre lines and provide undulating paths, rather than continuously straight strips.

Fig. 13(a) and (b) illustrate respectively diamond shaped outer openings and flaps in a relaxed state with edges/peripheries crossing the virtual centre lines L and in a stretched state with the undulating paths straightened.

In order to better accommodate rolling of the outer layer around the inner layer, it is possible to modify the two opposite edges of the outer layer.

The arrangement illustrated in fig 14 is intended to address how to accommodate for the diameter difference along the edges of the blind in the second direction.

It is desirable that the edges of the outer layer elongate in relation to the inner layer at the same rate as all the areas (undulating paths) between those edges. To achieve this, the illustrated example does not use edges which extend in a continuous straight line.

For the inner layer 4, each edge 4a, 4b on opposite sides in the first direction extend continuously in the second direction between the two ends (top and bottom). As a result, as described above for the inner layer as a whole, the edges 4a and 4b resist elongation of the inner layer in the second direction. On the other hand, for the outer layer 6, the two edges 6a, 6b at the two opposite sides in the first direction extend along respective undulating paths which move side-to-side in the first direction. In other words, the edges 6a, 6b are formed such that there is no straight line from one end to the other (top to bottom). As a result, not even the edges 6a, 6b resist stretching of the outer layer 6 in the second direction between the two ends (top and bottom as illustrated). Instead, such a force cause not only the paths 40 discussed above to straighten, but also the edges 6a, 6b to straighten, thus allowing the outer layer 6 to elongate in the second direction.

Fig. 15 illustrates the same arrangement but incorporating the mechanical interlocking flaps 8c and 18c discussed above with reference to figs. 4(a), (b), and (c).

Claims

CLAIMS1. A rollable blind extending laterally in a first direction, extending from one end to another end longitudinally in a second direction perpendicular to the first direction, and rollable longitudinally in the second direction about an axis extending in the first direction, the blind including: an inner layer; and an outer layer parallel with the inner layer; wherein: the inner layer includes an array of a plurality of cut-out inner flaps, each respectively hinged from the inner layer and extending to the outer layer, and each respectively leaving a respective inner opening; the outer layer includes an array of a plurality of cut-out outer flaps, each respectively hinged from the outer layer and extending to the inner layer, and each respectively leaving a respective outer opening; material of the inner layer between the inner openings includes strips having respective widths in the first direction and extending continuously straight in the second direction from said one end to said another end; and material of the outer layer between the outer openings includes undulating paths extending in the second direction from said one end to said another end and undulating side-to-side in the first direction without any strips extending continuously straight in the second direction from said one end to said another end, so that, when the blind is rolled longitudinally, the outer layer is elongated by straightening the undulating paths along the second direction.
2. A rollable blind according to claim 1 wherein each respective inner flap is secured to a respective outer flap so as to form a respective bridge between the inner layer and the outer layer.
3 A rollable blind according to claim 2 wherein each respective inner flap overlaps the respective outer flap
4. A rollable blind according to claim 2 or 3 wherein each respective inner flap is concentric with the respective outer flap.
5. A rollable blind according to any preceding claim wherein, with respect to the second direction, at a first side of each respective inner opening, the respective inner flap is hinged to the inner layer and, with respect to the second direction, at a second side opposite the first side of each respective outer opening, the respective outer flap is hinged to the outer layer.
6. A rollable blind according to any preceding claim wherein each respective inner flap is smaller than the respective outer flap.
7. A rollable blind according to any preceding claim wherein each respective inner flap is the same shape as the respective outer flap.
8 A rollable blind according to claim 7 wherein each respective inner flap and each respective outer flap are disk shaped.
9. A rollable blind according to any preceding claim wherein each respective inner flap is integrally connected with the inner layer by a respective hinge portion by which the respective inner flap is hinged to the inner layer, and each respective outer flap is integrally connected with the outer layer by a respective hinge portion by which the respective outer flap is hinged to the outer layer.
10. A roller blind assembly including: a rollable blind according to any preceding claim; and a roller; wherein: one end of the rollable blind in the second direction is secured to the roller; and the roller is configured to retract the rollable blind by rolling the rollable blind longitudinally around the roller with the outer layer outside the inner layer.
11. A roller blind assembly according to claim 10 wherein, in an extended state of the roller blind, the inner layer and outer layer of the rollable blind are configured to extend in parallel from the roller and the roller is configured to translate the inner layer and the outer layer with respect to each other in the second direction between: a closed position in which the inner flaps fit in their respective inner openings and the outer flaps fit in their respective outer openings and each respective inner opening is opposite a respective outer opening in a third direction perpendicular to the first and second directions; and a see-through position in which the inner flaps and the outer flaps are angled with respect to the inner layer and the outer layer such that each respective inner opening is opposite a different respective outer opening so as to allow line of sight directly through the inner openings and the different respective outer openings.
12. A roller blind assembly according to claim 11 wherein the roller is configured to translate the inner layer and the outer layer with respect to each other in the second direction to a privacy position in which the inner flaps and the outer flaps extend in the third direction and each respective inner opening is not opposite a respective outer opening in the third direction such that a line of sight through the inner openings and the outer openings in the third direction is obstructed, the privacy position being intermediate the closed position and the see-through position
13. A roller blind assembly according to claim 11 or 12 wherein the inner layer and the outer layer are secured to the roller at different radial positions of the roller. 20
14. A method of enabling a blind to be rolled, the blind extending laterally in a first direction, extending from one end to another end longitudinally in a second direction perpendicular to the first direction and including an inner layer and an outer layer parallel with the inner layer, the inner layer including an array of a plurality of cut-out inner flaps, each respectively hinged from the inner layer and extending to the outer layer and each respectively leaving a respective inner opening, and the outer layer including an array of a plurality of cut-out outer flaps, each respectively hinged from the outer layer and extending to the inner layer and each respectively leaving a respective outer opening, the method comprising: arranging the array of the plurality of cut-out inner flaps so as to provide material of the inner layer between the inner openings including strips having respective widths in the first direction and extending continuously straight in the second direction from said one end to said another end; arid arranging the array of the plurality of cut-out outer flaps so as to provide material of the outer layer between the outer openings including undulating paths extending in the second direction from said one end to said another end and undulating side-to-side in the first direction without any strips extending continuously straight in the second direction from said one end to said another end, so that, when the blind is rolled longitudinally, the outer layer is elongated by straightening the undulating paths along the second direction.