GB2391251A

GB2391251A - Retractable blind with an inclined edge

Info

Publication number: GB2391251A
Application number: GB0317340A
Authority: GB
Inventors: Andrew Ayling; Julian Leece; Nigel Campkin
Original assignee: Thomas Sanderson Ltd
Current assignee: Thomas Sanderson Ltd
Priority date: 2002-07-24
Filing date: 2003-07-24
Publication date: 2004-02-04
Anticipated expiration: 2023-07-24
Also published as: GB0317340D0; GB0217180D0; GB2391251B

Abstract

A retractable blind 1 which may be a pleated blind has an inclined edge 18a which forms part or all of one side, to allow it to fit a non-rectangular window. A cord-like retaining element 19 extends along substantially the whole length of the inclined edge, and the cord is attached to a resilient tensioning member 23, preferably a coil spring, to maintain sufficient tension to support the edge. The retaining element may be in the form of a loop. Support wires 13 may be provided, which may use the same holes as the tensioned cord 19. Alternatively the cord may be passed through rings (20, fig 7) attached adjacent to the edge.

Description

1 2391251

A Blind Assembly Background to the Invention

The present invention relates to a blind assembly, and in particular to a blind assembly comprising a retractable blind. Primarily the inventor relates to a pleated blind though it could be applied to Roman or festoon blinds.

Retractable pleated blinds are well-known. In such blinds, a plurality of support wires (or even rods) pass substantially vertically through the fabric of the blind in a longitudinal direction so as to support the fabric of the blind. The wires are generally parallel to one another. When such blinds are extended, i.e. covering a window or panel, the pleats of the blinds are expanded. However, when the blind is retracted, the pleats are folded on top of one another so that each pleat lies flat against its adjacent pleat and the window or panel is exposed. The reduced height of the blind is generally constant across the width of the blind. The support wires do not move as the blind is retracted. Such blinds can be retracted and extended manually or by means of a motor.

The retraction of a rectangular pleated blind is usually straightforward due to the generally uniform dimensions of the blind across its width. However, rectangular blinds are not suitable for all applications. In conservatories, some windows have unusual shapes, particularly in the area of the roof. Blinds containing at least one inclined edge do not have a uniform height across their width. When such blinds are

retracted, the pleats are folded on top of one another as in the case of rectangular blinds.

However, the difference in height of the blinds across their width results in a non-

constant folded height of the blinds. If the retracted position of the blinds is at an uppermost end of the window/panel to be covered, a downward unsightly sagging of the folded blinds occurs when such blinds are retracted, i.e. the longer and heavier sections of the blind sag below the remaining sections. Similarly, if the retracted position of the blinds is at a lowermost end of the windowtpanel to be covered, the unconstrained fabric of the blind tends to fan upwards due to the fabric's memory characteristics. In extreme cases, this sagging or fanning can obscure the window or panel which is covered by such blinds, which is disadvantageous.

It has been suggested that such sagging or fanning could be minimised by including a reinforcing transom bar across the blind where the shape of the blind changes from a generally rectangular shape to a generally triangular shape. However, such reinforcing bars complicate manufacture of the blinds and add to the overall weight of the blinds, which is undesirable.

It has been proposed to punch special holes along the inclined edge portion and thread a retaining element through the holes so that the retaining element controls the edge portion; if such special holes are punched, they normally do not register with other holes in the blind, for instance for support elements or tension elements, and separate punching operations are required.

An object of the present invention is to provide a blind assembly in which the above disadvantages are overcome.

The Invention The broadest concept of the invention is a blind assembly comprising a retractable blind having an inclined edge and a cord-like retaining element arranged along the inclined edge so as to support the inclined edge, wherein the retaining element is connectable to a resilient member to take up slack in the retaining element during retraction and/or extension of the blind. Another broad concept is a blind assembly having a blind which is extensible and retractable and has an edge portion which is inclined to the direction of extension and retraction and which forms part of or the whole of one lateral side of the blind, a cord-like retaining element being provided to support the inclined edge portion and for this purpose making a sliding engagement with the edge portion or with a part secured thereto at at least one location intermediate the ends of the edge portion and at the ends of the end portion, and a resilient member being provided to maintain tension in the retaining element both when the blind is extended and when the blind is retracted, the resilient member taking up the apparent lengthening of the retaining element during movement of the blind.

The invention primarily also provides a blind assembly as claimed in Claim 1 or 13.

The remaining claims set forth preferred or optional features.

The retaining element only has an effect when the blind is fully bunched, when by engaging the end face of the blind, it holds the blind fully flat along the top of the bunched fabric. It is found that if the blind retracts upwards, the retaining element can prevent unsightly sagging of the folded blind, and that if the blind retracts downwards,

( the retaining element can prevent the fabric of the blind tending to fan upwards.

Another advantage of the invention is that there is no need to punch special holes for the retaining element and all the holes for any one support element or tension element can register and be punched in one operation on the folded blind, with no necessity for further punching.

The tend cord-like element is used herein. In the art, cords are normally used for the tension elements and drive cables (if motorised) and wires (or even rods) are used for the support elements. However, in function cords and wires are very similar and the retaining and tension elements could be wires and the support elements and drive cables cords. Preferred Embodiments The invention will be described in more detail with reference to the following drawings, in which: Figure 1 is a front view of a blind assembly for a standard rectangular pleated blind; Figure 2 is a side view of the blind assembly of Figure 1; Figure 3 is a section along the line III-III in Figure I for a motorised version of the blind assembly of Figure 1;

Figure 4a is a diagram of the path of a first arrangement of a tension cord in the blind assembly of Figures 1 and 2; Figure 4b is a diagram of the path of a second arrangement of a tension cord in the blind assembly of Figures 1 and 2; Figure 4c is a diagram of the path of a third arrangement of a tension cord in the blind assembly of Figures 1 and 2; Figure 4d is a diagram of the path of a fourth arrangement of a tension cord in the blind assembly of Figures 1 and 2; Figure 5 is a front view of a first embodiment of a blind assembly of the present invention, the retaining cord being shown schematically; Figure 6 is an enlarged rear view of part of the assembly of Figure 5; Figure 7 is a detail of the right-hand side of Figure 5; Figure 8 is a schematic rear view, showing the path of the retaining cord in a motorised assembly having the blind of Figure 5; Figure 9 is a third angle projection from in front and the left-hand side, showing the lower part of the assembly of Figure 5, with the blind retracted;

Figures 10 to IS are front views of second to seventh embodiments of the invention, showing just the blind; and Figure 16 is a schematic rear view, showing the path of the retaining cord in a manual assembly having the blind of Figure 15.

All of the Figures could if desired be the other way up, in Figures} to 4d depending on where it is desired to have the bunching of the blind (above or below) and in Figures 5 to 1 S. depending on the shape of the window or panel to be covered.

Figures 1 to 4d In Figures I and 2, a standard blind assembly l has a rectangular blind 2 comprising a plurality of pleats 3. The blind 2 is attached at its bottom end to a fixed rail (commonly called a bunch rail) 4 and at its top end to a travelling rail (commonly called a float rail) S which travels with the free top of the blind 2. An additional fixed rail 6 is arranged generally parallel to the fixed rail 4 at the top of the blind assembly 1. When the blind 2 is retracted, it lies against the rail 4 and the pleats 3 lie flat on top of one another.

The fixed rail 4 and its mounting with respect to a window or panel frame member 7, are shown in more detail in Figure 2. In Figure 2, the fixed rail 4 is designed for use with a manual blind and has a rear window or panel side 8 and a front non-window or non-panel side 9, the sides 8, 9 being connected to one another by means of a cross panel 10. The sides 8, 9 of the fixed rail 4, together with the cross panel 10, enclose a

hollow area 11. A panel 12 is connected to the window or panel frame member 7 and extends across and below the fixed rail 4.

The fixed rail 4 of Figure 3 is designed for use with a motorised blind. The hollow area 11 is, therefore, somewhat larger than that of the fixed rail 4 of Figure 2, so as to provide adequate space for housing a motor (not shown).

The blind 2 is supported by several support elements in the form of wires 13, which run substantially vertically up the blind and pass through holes 14 in the fabric of the blind 2. The support wires 13 are fixed at one end to the fixed rail 4 and at another end to the additional fixed rail 6 or to fixings 15 (see Figure 5) in a wall (not shown) on which the window or panel is mounted. The wires 13 are made of PVC-covered stainless steel, or any other suitable material, and serve to support the fabric of the blind 2.

In use, the blind 2 covers the window or other panel when it is extended, i.e. when the pleats 3 are unfolded. In the manually-operated version, the retraction and/or extension of the blind is controlled manually by means of a handle (not shown) on the front of the travelling rail S. In order to retract the blind 2, the travailing rail 5 is pushed towards the fixed rail 4 so that the pleats 3 are folded one on top of another, exposing the window or other panel behind the blind 2. The travelling rail 5 will remain at either end of its travel or indeed at any position by means of friction provided by a tension element in the form of a cord 16. Various arrangements of the tension cord 16 are shown in Figures 4a to 4d. The function of tension cords in blinds is well-known and will not be fully described here. A resilient member 17, which is in the form of a helical spring, is attached to the cord 16 to maintain tension in the cord, so that the necessary friction is

achieved. In the motorised version, the cord 16 is replaced by a drive cable which is engaged by one or two capstans (not shown) on the motor (not shown), to move the travelling rail 5.

The rails 4, 5 and 6 are usually made of aluminium and usually have end caps.

Figures 5 to 9 On its right-hand side, the blind 2 of Figure 5 has an upper inclined edge 18a and a lower vertical edge 1 8b, but the inclined edge 1 8a is not supported by the travelling rail 5. The principle of operation of the blind 2 of Figure S is essentially the same as that for the blind 2 of Figures 1 to 4d. However, in addition to the support wires 13, a retaining element in the form of a cord 19 is provided to retain the inclined edge 18a when the blind 3 is retracted, and the cord 19 runs generally parallel to the inclined edge 18a.

The cord 19 is shown schematically at the right-hand end of the inclined edge 18a.

Adjacent the vertical edge lab, the cord 19 passes through the same holes 14 in the fabric as the right-hand support wire 13. This avoids making additional holes 14 in the fabric to accommodate the cord 19. The righthand support wire 13 is located close to the vertical edge l 8b so that bunching of the fabric can be avoided as the cord 19 passes across the fabric along the inclined edge 1 8a. As shown in Figure 7, stainless steel rings 20 are arranged on at least some of the support wires 13 in the region of the edge 18a of the blind 3; the cord 19 is also threaded through the rings 20, so that the rings 20 serve to retain the cord 19 along the inclined edge 1 8a.

Possible paths of the cord 19 are shown in Figures 5 and 8; the path of the cord 19 can be different depending on whether the blind 3 is manually driven (see Figure 5) or whether the blind 3 is driven by means of a motor (see Figure 8) or any other non-

manual means.

In Figure 5, a first end of the cord 19 is held by a shrink bush 21 which engages an end cap 22 of the fixed rail 4 (for clarity, the bush 21 is shown spaced from the end cap 22) and then passes through an eye at the end of a resilient member in the form of a helical tension spring 23, which is in turn attached to the back of the fixed rail 4. The cord 19 then passes up over the side 8 of the fixed rail 4 (here the cord 19 is shown schematically) to enter the hollow area 11 and exits through a hole in the closure panel 10, about which it is fumed through approximately 90 so that the cord 19 runs vertically up through the holes 14 together with the right-hand side support wire 13, then through an eyelet 24 (see Figure 7) and turns to run along the inclined edge 1 8a until it reaches the travelling rail 5. Just before the travailing rail 5, the cord 19 passes through an eye 25 formed in the end of a guide member 26 projecting from the end of the travailing rail 5 adjacent the inclined edge 1 8a. The guide member 26 is shown as a piece of shaped wire but could for instance be made of plastics material. Its effective length can be adjusted by pulling the guide member 26 further out from the rail 5 or pushing it further in. The cord 19 then enters the interior of the travelling rail 5 and passes generally horizontally through the travelling rail 5 to a hole in the opposite or left-hand end cap of the travelling rail 5. The cord 19 turns through the hole and travels substantially vertically towards a corresponding hole in the left-hand end cap of the fixed rail 6. On the inside of the latter hole, the end of the cord 19 is held by a shrink bush 25 (schematically represented). The eyelet 24 (see Figure 7) is arranged in the last

hole 14 in the fabric before the inclined edge 18a, so as to prevent the cord 19 from cutting through the fabric when it turns to run along the inclined edge 18a at approximately the same angle as the inclined edge 18a. The eyelet 24 also acts as an anti-wear guide for the cord 19.

When the travelling rail 5 moves to retract the blind, the portion 19a of the cord 19 which extends along the inclined edge 18a is shortened because the portion 19a is moving towards the horizontal. Simultaneously, the vertical portion 19b of the cord 19 extending between the travelling beam 5 and the fixed beam 6 will lengthen and the vertical portion l9c of the cord 19 between the eyelet 24 and the fixed beam 4 will shorten. As a result, the cord 19 tends to shorten and this is compensated by extension of the spring 23, ensuring that the cord 19 remains in tension.

The opposite effect occurs when the blind 3 is extended. The cord 19 tends to lengthen and the spring 23 shortens.

When the blind 2 is fully extended, the spring 23 is relaxed. As the blind 2 is retracted, the spring 23 typically extends by 10% to 300% of its relaxed length, thus compensating for movement and also ensuring that there is sufficient tension in the cord 19 for it to overcome friction and move properly.

The spring 23 is located behind the fixed rail 4 in order to save space in the fixed rail 4, particularly, as may be required in motorised blinds, if the fixed rail 4 is required to carry a motor (not shown). Saving space avoids having to enlarge the fixed rail 4 and thus obscure a larger area of the window or panel, and avoids increased manufacturing

costs. Furthermore, locating the spring 23 behind the fixed rail 4 facilitates installation as well as replacement and repair, should replacement or repair be necessary.

Nonetheless, it is possible to locate the spring 23 within the hollow area 11, should this be desirable, with consequent minor alteration of the runs of the cord 19.

Figure 8 illustrates an assembly in which the blind of Figure 5 is motorised. A first end of the retaining cord 19 is attached to a resilient member 31 in the form of a helical tension spring, which is in turn attached to the fixed rail 4. The cord 19 then passes substantially horizontally across the rear side 8 of the fixed rail 4 and through a hole 32 at the right-hand end of the fixed rail 4. The cord 19 then travels substantially vertically inside the rail 4 and then exits through a hole 33 in the cross panel 10 of the rail 4, where it exits. The cord 19 continues to travel substantially vertically through the holes 14 in the fabric until it reaches the inclined edge 18a. The cord 19 travels along the inclined edge 18a until it enters the travelling rail 5 through a hole in the right-hand end cap. The cord 19 travels horizontally to the left-hand end of the rail 5, where it exits through a hole in the top of the left-hand end cap, travels vertically to enter a hole in the lefthand end cap of the fixed rail 6, travels horizontally to a hole in the right-hand end cap of the rail 6 and then vertically, down through the right-end cap of the rail 5 to a turning point in the form of a rivet 34 projecting from the front of the fixed rail 4. The cord 19 then travels substantially horizontally across the fixed rail 4. A second end of the cord 19 is then attached to a second resilient member in the form of a helical tension spring 35 which is attached to the fixed rail 4.

Two springs 31, 35 are desirable to compensate for the motorised movement of the travelling rail 5. In the manual version of the blind assembly, the user will tend to move

the travelling rail 5 at a non-constant and relatively low speed. As a result, a single spring 23 adequately prevents slackening of the cord 19. In the motorised version of the blind assembly, the travelling rail 5 moves relatively quickly at a substantially constant speed. It has been found that a single spring does not adequately prevent slackening of the cord 19 and that the addition of a second spring achieves improved cord control because each end of the cord 19 is controlled independently.

When the triangular portion of the blind 2 retracts, the spring 35 continues to extend, whilst the spring 31 starts to extend. The extension rates are not equal; the spring 35 will typically extend at twice the rate of the spring 31. The extension of the springs 31, 35 continues until the blind 3 is fully retracted, at which time spring 35 is extended typically by 1.5 times the length of the spring 31.

As the blind 3 is extended from its fully retracted position, the triangular portion of the blind 3 extends first. Typically, the spring 35 fully relaxes during this part of the blind's travel, whilst the spring 31 reduces in length from its fully extended length by typically 15%-30%. When the triangular portion of the blind 3 is fully extended, the rectangular portion of the blind 3 starts to extend. At this point, the spring 35 is fully relaxed. In the remaining part of the blind's travel, the spring 31 relaxes until it is in its fully relaxed state.

The distance between the springs 31, 35 should be calculated such that the springs 31, 35 will work effectively relative to one another. The distance between the springs 31, 35 will depend on the type and dimensions of the blind used in the blind assembly.

Figure 9 shows how the retaining cord 19 lies along the top of a narrow top face 3a of the blind 3, which faces generally in the direction in which the blind 3 is extended and is formed of the very inclined edge portion of the blind 3. In general, the cord 19 can make a sliding engagement with the edge portion 1 8a or with a part secured thereto at at least one location intermediate the ends of the edge portion 1 8a and at the ends of the edge portion 1 8a, at least as the blind 2 approaches its Filly retracted position. The cord 19 extends along the whole length of the face 3a and, being in tension, thereby retains the edge portion 1 8a in position.

Figures 10 to 15 The principle of operation of the blind assembly 1 of each of Figures 10 to IS is essentially the same as in Figure 5 or Figure 8 and will not be described in detail. If the inclined edge 18a extends for nearly the whole of the respective side of the blind 2, the eyelet 24 can be omitted. However, in such circumstances it is desirable to provide a cord guide member 38 like the guide member 26 shown in Figure 5 but extending from the end cap of the fixed rail 4 to keep the cord 19 clear of the fabric of the blind 2 in this zone - see Figures 12 to 15. In general, it is not desirable to have the inclined edge 1 8a extending for the whole of the respective side but to have half a pleat with a vertical edge, as shown in Figures 12 to 14.

In Figure 10, the blind 2 effectively comprises two blinds arranged side by side. Each half of the blind 2 has a cord path corresponding to one of the cord paths described above in relation to Figure 5 or 8, i.e. the blind 2 has two substantially identical cord

paths. As before, the cord path will depend on whether the blind 2 is for manual or motorised use.

The blind 2 of Figure 11 is very similar to that of Figure 5.

Figure 12 shows a blind 2 having an inclined edge 18a, generally as in Figure 5 or 10, but only a very short vertical edge 1 8b (half a pleat high).

In Figure 13, the blind 2 effectively comprises two blinds as in Figure 12, arranged side by side. Each half of the blind 2 has a cord part corresponding to one of the cord paths described above in relation to Figure 5 or 8, i.e. the blind 2 has two substantially identical cord paths. As before, the cord path will depend on whether the blind 2 is for manual or motorised use.

In Figure 14, a blind 2 is shown which is effectively a composite blind comprising the blind of Figure 5 and the blind of Figure 12 arranged side by side. Therefore, each part of the blind 2 will have its own cord path, the cord path of each part corresponding to one of the cord paths for the blind to which it corresponds. As before, the cord path will depend on whether the blind 2 is for manual or motorised use.

In Figure 15, an obtuse blind 2 is shown, similar to the blind 2 of Figure 12 but comprising an additional triangle portion 2, so that there are two non-identical inclined edges 1 8a, 1 8a. The cord path for manual operation of the blind 2 is shown in Figure 16. When the blind 3 is retracted, only the upper triangular portion 2" moves, i.e. the remaining portion 2 of the blind 2 continues to cover the window or panel

( In Figure 16, a first end of the cord 19 is attached to the spring 23 which is in turn attached to the fixed rail 4. The cord 19 then passes across the rear side of the fixed rail 4, towards a turning point 22 in the form of a projecting rivet, where it is turned through approximately 180 , so that the cord 19 travels across the same surface in an opposite direction, towards the spring 23. The cord 19 then crosses under the bottom of the rear side of the fixed rail 4 into the hollow area 11 and continues in the same direction (shown schematically). The cord 19 exits the fixed rail 4 through a hole 36 in the right-hand end cap of the fixed rail 4, after which it passes through the eye of the adjustable cord guide member 28 and continues in the direction of the first inclined edge 1 8a' towards a fixed turning point 37 (which can be a rivet projecting e. g. from the window or panel frame member 7), where it turns to travel along the inclined edge 1 8a at approximately the same angle as that of the inclined edge 1 8a. The cord 19 meets the travelling rail 5 at the end of the inclined edge 18a. The path of the cord 19 at the travelling rail 5 is the same as that described with reference to Figure 8. At the fixed rail 4, the cord 19 is turned at the fuming point 22, so that it travels generally parallel to the fixed rail 4. A second end of the cord 9 is then attached to the spring 23.

x x x General Many of the components described above can be replaced by suitable alternatives. For example, rings of any low-friction material could replace the stainless steel rings 20.

Thin rods, monofilaments or lengths of"Kevlar" might replace the PVCcovered

stainless steel support wires 13. The retaining cord 19 can be made of polyester, nylon, "Kevlar" id, or any other suitable material and could be in the form of a plastics or metal wire.

The present invention has been described above purely by way of example, and modifications can be made within the spirit of the invention.

Claims

l CLAIMS:

1. A blind assembly having: a blind which is extensible and retractable and has an edge portion which is inclined to the direction of extension and retraction and which forms part of or the whole of one lateral side of the blind, and which, when retracted, forms a narrow face facing generally in the direction in which the blind is extended; a cord-like retaining element extending along substantially the whole length of the inclined edge portion and arranged such that when the blind is filly retracted, the retaining element extends along substantially the whole of said narrow face and thereby retains the edge portion in position; and at least one resilient member maintaining tension in the retaining element both when the blind is extended and when the blind is retracted, the resilient member taking up the apparent lengthening of the retaining element during movement of the blind.

2. A blind assembly as claimed in Claim 1, wherein the blind is a pleated blind.

3. A blind assembly as claimed in Claim 1 or 2, wherein the retaining element is in the form of a loop.

4. A blind assembly as claimed in Claim 3, wherein the loop is attached to the resilient member.

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5. A blind assembly as claimed in Claim 1, 2 or 3, wherein two resilient members are provided to take up slack in the retaining element, one resilient member being attachable to each end of the retaining element.

6. A blind assembly as claimed in any of the preceding Claims, wherein the resilient member(s) is/are in the form of a tension spring(s).

7. A blind assembly as claimed in any one of the preceding Claims, wherein a support element is provided, extending parallel to the direction of extension and retraction and passing through holes in the blind, a part of the retaining element passing through Me same holes.

8. A blind assembly as claimed in any of the preceding Claims, wherein a support element is provided, extending parallel to the direction of extension and retraction, the retaining element where it extends along the inclined edge portion of the blind, being held adjacent the support element by a ring through which pass both the retaining element and the support element.

9. A blind assembly as claimed in any of the preceding Claims, wherein the resilient member(s) is/are arranged externally of a fixed rail.

10. A blind assembly as claimed in any of the preceding Claims, wherein the inclined edge of the blind terminates short of the end of a travelling beam but aligned with the travelling beam in the direction at right angles to the direction of extension and retraction, the retaining cord passing through a guide member adjacent the end of the

( inclined edge of the blind, which guide member is held by a member projecting from the end of the travelling beam.

11. A blind assembly as claimed in any of the preceding Claims, wherein the inclined edge of the blind terminates short of the end of a fixed beam but aligned with the fixed beam in the direction at right angles to the direction of extension and retraction, the retaining cord passing through a guide member adjacent the end of the inclined edge of the blind, which guide member is held by a member projecting from the end of the fixed beam.

12. A blind assembly as claimed in any of the preceding Claims, wherein the retaining element has a further part, spaced (in the direction at right angles to the direction of extension and retraction of the blind) from the inclined edge portion of the blind, which extends in the direction of extension and retraction of the blind.

13. A blind assembly, substantially as herein described with reference to any one of the embodiments of Figures 5 to 16 of the accompanying drawings.