WO2004059116A1

WO2004059116A1 - Motorised blinds and shutters

Info

Publication number: WO2004059116A1
Application number: PCT/GB2003/005719
Authority: WO
Inventors: Brian Malcolm Wilkins
Original assignee: Brian Malcolm Wilkins
Priority date: 2002-12-28
Filing date: 2003-12-29
Publication date: 2004-07-15
Also published as: GB2396657A; GB0230241D0; AU2003296831A1

Abstract

A shutter or blind comprises a frame (1-3) adapted to fit an opening, a plurality of vanes (4) movably mounted relative to the frame, and drive means for moving the vanes to selectively cover/uncover the opening, the drive means comprising a screw-threaded rod (6) coupled to drive at least one of the vanes.

Description

MOTO ISED BLINDS AND SHUTTERS Field of the Invention

The present invention relates to window and door blinds and shutters adapted selectively to open and close a window or door opening. Background to the Invention

Roller blinds, Venetian blinds, shutters and the like are a convenient means of opening and closing an opening in a room or building, such as a door or window opening. They can have simply an aesthetic effect or can be a security measure or both.

Traditionally, such devices are manually operated. They rely on pulleys and cords to operate various types of mechanism to raise or lower, in the case of Venetian blinds, or to draw to one or both sides, in the case of horizontally movable shutters. Motorised devices are known in the case of larger installations, such as in garage or warehouse type structures, where the weight of the shutters is unreasonably high for manual operation. In smaller scale, for example domestic, installations motorised operation has only relatively recently become more available. In virtually every instance, this mechanisation has taken the form of a motor drive for the same type of pulley arrangements as previously found in manually operated installations.

Although these mechanisms are generally accepted, they still rely on old technology and suffer from the same problems of pulley wear, cord fraying, dirt contamination and often jamming of the cord/pulley mechanism.

The present invention is a complete departure form such known constructions and provides a more "positive" drive that is not prone to the same problems as the prior art.

Summary of the Invention The invention provides a shutter or blind comprising a frame adapted to fit an opening, a plurality of vanes moveably mounted relative to the frame, and drive means for moving the vanes to selectively cover/uncover the opening, the drive means comprising a screw-threaded rod coupled to drive at least one of the vanes.

An advantage of the driven vane being driven by a screw-threaded rod is that when the driven vane has reached a desired position and rotation of the rod is ceased, the vane is effectively locked in that position. Furthermore, by employing a screw drive mechanism, the problems of pulley wear, cord fraying, dirt contamination and jamming of the cord/pulley mechanism are avoided. The screw drive thus provides a robust, positive direct drive to at least one of the vanes.

Although more than one vane may be directly driven, in a preferred arrangement only the leading vane of the plurality of vanes or group of vanes is directly driven, movement of the remaining vanes being achieved by means of suitable links to the driven vane.

Just one screw-threaded drive rod may be utilised, but preferably two such rods are provided at opposite sides of the frame such that the driven vane is supported and driven at each of its ends.

The frame may fully surround the array of vanes. For example, in the case of a shutter or blind adapted to fit a rectangular window, the frame may be rigid and rectangular, comprising upper, lower, and side members. It will be appreciated, however, that such a frame configuration is not essential. In one form, the frame may consist of a single side or lateral member, which advantageously may house the screw-threaded rod.

In alternative embodiments, the frame may consist of a pair of opposing side members, or a pair of opposing upper and lower members.

Preferred embodiments of the invention aim to provide a blind which also acts as a security shutter. In such embodiments, it is preferable that each driven vane is driven at both ends by respective opposing screw-threaded rods.

Preferably, the vanes which are not directly driven by the screw-threaded rods

(which shall be referred to as the remaining vanes) are linked to the driven vanes. The linking means may comprise a series of flexible links, each link coupling a respective pair of adjacent vanes. Ends of the remaining vanes may be constrained by guide means provided in the frame to improve security and/or inhibit movement under the influence of any wind.

Alternatively, the remaining vanes may be coupled to the screw-threaded rods by guide blocks, each guide block having a bore forming a sliding fit over the bar such that rotation of the bar does not drive the guide block. Preferably the drive means is operable to move the vanes between a bunched arrangement and a spaced arrangement to selectively cover and uncover the opening. Where the blind comprises an array of vertical vanes, the links between the vanes and the leading, driven vane may be arranged such that as the leading vane moves towards the "closed" position the remaining vanes are successively drawn behind it. When the leading vane is driven in the reverse direction, to open the shutter, it may successively pick up the trailing vanes and drive them back into the bunched configuration.

In the case of a shutter with horizontally extending vanes, in the open position the vanes may be bunched together at the top of the frame, and may be linked such that as the leading vane is driven downwards the trailing vanes are allowed to fall into their respective "closed" positions under gravity. Preferably, the vanes are linked by flexible links, such that when the driven vane reaches its end, closed position, all of the links are taught so as to inhibit any movement of a particular vane relative to the other vanes and the frame.

Preferably, the or each driven vane is coupled to the or each screw-threaded rod by a respective drive block or blocks, the drive block having a screw-threaded bore engaging the rod. Thus, as the rod rotates, the drive block is driven axially along the rod so as to impart movement to the vane.

In one preferred arrangement, the plurality of vanes comprises a first group and a second group, each group including a driven vane coupled to be driven by the screw- threaded rod or rods, the or each rod comprising a first portion and a second portion, the first and second portions being screw-threaded in opposite senses, the driven vanes of the first and second groups being coupled respectively to the first and second portions of the rod, whereby rotation of the rod in one sense drives the groups together and rotation in the opposite sense drives the groups apart. This arrangement is particularly suited to shutters or blinds having vertically extending vanes. The opening may thus be closed by driving the leading vanes of two groups together, from their bunched positions on opposing sides of the opening, to the closed position where the leading vanes are next to one another, in the "centre" of the opening.

The first and second portions may be provided by separate rods, which may be connected together in a suitable fashion. Alternatively, the first and second portions may be formed by cutting opposing threads on a common rod. It will be appreciated that throughout the specification, the term "rod" is used in a broad sense, and is by no means limited to a continuous, solid bar.

Preferably, each vane is adapted so as to be rotatable about a respective longitudinal axis, and the shutter or blind comprises control means for simultaneously rotating the vanes so as to selectively open or close spaces between adjacent vanes to control the amount of light and/or ventilation between the vanes.

Preferably, at least one of the vanes comprises a rigid bar, extending along the length of the vane, and a blade coupled to the bar. The bar may be coupled to its respective drive block or blocks in such a manner to permit rotation of the bar about its axis.

Alternatively, the bar may comprise at least one threaded end screwed into a corresponding threaded receiving bore in a drive block. In such arrangements, the rigid bar is not free to rotate, but the blade is arranged to rotate about the bar.

Preferably, the blade is hollow and the bar passes through the blade. Advantageously, the blade may be formed by extrusion. Certain preferred embodiments of the invention utilise extruded aluminium blades, which are extremely rigid and provide an attractive yet secure shutter assembly.

Other materials may, of course, be used for the vanes.

Advantageously, the hollow blade may comprise bearing means arranged to engage the bar and permit rotation of the blade around the bar. This bearing means may be provided by suitable formations on the extruded cross section.

Each hollow blade may be provided with a respective pair of end caps, the end caps incorporating bearing means, such as collars, arranged to rotatably engage the bar. Each end cap may comprise a lug coupled to control means for rotating the blade about the bar. ^'

Conveniently, the drive means may comprise an electric motor. The shutter or blind may include a proximity detector and control means. Thus, when a person is detected in the vicinity of the shutter, the motor may be stopped.

In addition or as an alternative to the drive motor, the drive means may comprise a handle arranged to permit manual rotation of the screw-threaded rod or rods. Rotation of the handle may be communicated to the rods by means of a drive train comprising suitably arranged gears, shafts or the like.

It will be appreciated that in certain preferred embodiments, where at least one vane is directly driven (e.g. by means of a drive bock attached to its end and in screw- thread engagement with the drive rod) the remaining vanes are preferably linked to the said at least one vane so as to be driven therewith. The link may be a succession of pockets in a tape, as in conventional Venetian blinds, or may comprise a series of flexible links. This construction permits the said at least one vane to draw the remaining vanes behind it, in the case where the vanes are vertically disposed, or enables the vanes of a Venetian blind-type of shutter to follow behind under gravity as it is lowered to close the opening. Of course, the reverse occurs when the said at least one vane is moved in the opposite direction.

The vanes may be simply for aesthetic effect and/or they may be strengthened to act as security shutters. In the latter case, the vanes may consist of a rigid bar extending along the length of the vane and a blade fixed to the bar.

In order to open and close the opening completely, to obscure light and/or for security, the said at least one vane is preferably rotatably mounted about its longitudinal axis. This may be achieved by providing journals in blocks moveable along the screw- threaded rod, the vanes being rotatably mounted in the journals. Where the vanes are of security type with a central or off-centre rigid bar, the ends of the bars may be rotatably mounted in the journals.

The journal block for the said one vane is internally threaded for driving engagement by the screw-threaded rod. If blocks are provided for any of the remaining vanes they may be a loose fit on the rod to enable the vanes to "stack" independently of the movement or position of the said vane. The advantage in this construction is that the vanes will be constrained and less likely to blow about in the wind if the opening is not otherwise closed with a door or window. As a further alternative, the ends of the vanes may be guided within the corresponding frame member.

The said one vane (i.e. the driven vane) is preferably the leading vane of the shutter or blind, i.e. the one that moves first when the mechanism is operated. Only the leading vane need be driven by the screw-threaded rod. The remaining vanes may simply be free to rise and fall, in the case of a Venetian blind with horizontal vanes or to be drawn along with the driven vane and the flexible links. Brief Description of the Drawings

The invention will now be described with reference to the drawings, which illustrate exemplary embodiments of the invention, and in which:

Figure 1 is schematic perspective view of an opening provided with a blind according to the invention;

Figure 2 is a partial elevation of the blind in Figure 1 , showing a preferred drive mechanism; Figure 3 is an exploded diagram showing the components of a security blind embodying the invention;

Figure 4 is a perspective view of the embodiment of Figure 3, shown in the partially closed position;

Figure 5 is a perspective view of part of the embodiment of Figures 3 and 4, shown in the open position;

Figure 6 is a schematic diagram of a further embodiment; and

Figure 7 is a schematic view of yet another embodiment. Detailed Description of the Illustrated Embodiments

Referring to Figure 1 , a window or door opening is provided with a frame, consisting of an upper member 1 , two side frame members 2 and a bottom frame member 3. In certain installations, the bottom frame member 3 may be omitted, its role being taken by a windowsill or door threshold, for example.

The blind consists of a plurality of horizontally disposed vanes 4. They are shown in a partially open position for the sake of explanation. The vanes rest on the lowermost vane 4a of the blind, as indicated by the arrow 4 in Figure 2. When the blind is lowered, the leading vane 4a descends first and the stack 4, resting on this vane 4a, is lowered until flexible links 5 reach the limit of their travel and the respective vanes stop one by one. Conventionally, the links 5 are formed by a tape with front and back strands and cross members supporting respective vanes. However, any form of link, such as a linked ball/chain or any other construction, may be used. The sole purpose is to guide the non- driven vanes 4 as the driven vane 4a is moved. The present invention departs from the usual cord and pulley arrangement by providing a screw-threaded rod 6 in one or both side frames 2. The lower end of the rod is rotatably mounted in a journal block 8. The upper end is similarly mounted in a "gear box" 7 in the upper frame member 1. The gear box 7 is coupled to a bar 8 which in turn is coupled to an electric motor 9 also mounted in the upper frame 1. When the motor is driven it causes rotation of the bar which is converted into rotation of the screw-threaded rod 6 through a worm drive or similar gearing in the gear box 7.

At least the leading vane 5 is rotatably mounted at its ends by means of a short spindle 11 itself rotatably supported in a block 10. The block 10 has an internal thread matching the thread of the rod 6. When the rod 6 is rotated, the block is driven along the rod, thereby taking the vane with it and drawing along the remaining vanes, as previously described.

The spindle 11 also permits the driven vane to rotate about its longitudinal axis to enable the vane to be oriented between open and closed positions, as with conventional blinds. The links 5 translate this rotational movement to the remaining vanes 4. If desired, further blocks, such as 10a may be located at spaced intervals along the rod 6. As previously mentioned, this can be to strengthen the blind, if used for security, or simply to prevent the blind moving excessively, e.g. in windy conditions, if the blind is the only cover for the opening or if the window or door of the opening is also open. If this construction is used, the blocks 10a will need to be a sliding fit on the rod rather than being screwed onto the thread since, otherwise, the vanes would be kept a certain distance apart at all times and would not stack.

As a further alternative, the ends of the vanes may extend between the edges of the side members 2. The side members will then be of U-shaped section and/or will be provided with guides for the ends of the vanes.

The vanes may be slender, aesthetically pleasing or may be security vanes, comprising a central bar, e.g. of steel, and blades of material resistant to attack or, in extreme conditions, bullet-proof. In the latter case, the reinforcing rod may be used as the spindle 1 1 for the leading and any other vane 10, 10a. The vanes may be hollow so as to enable insertion of a strip containing decorative material or conveying a message, advertising sign or a warning. The opposed faces of the side frame members 2 are preferably provided with a cover plate (not shown) with only a narrow opening for the spindle 1 1 of the driven vane, thereby concealing the screw-threaded rod. If the ends of the vanes are guided within the side frame members, the cover plate can be recessed so that the edges of the side frame members act as the guides.

The motor 7 is preferably operated by a simple "open/close" switch (not shown) situated locally to, or distant from, the blind or shutter. The switch may be operated by remote control. Where the shutter is of such a size that it could potentially cause injury to a person in its path, it is preferable to provide one or more sensors to stop operation of the motor. An infrared PIR detector would be suitable for larger installations. Alternatively, a proximity detector, such as a capacitance-based detector, may be sufficient in a domestic installation.

Although it is more likely that a screw-threaded rod will be provided at each side or at both top and bottom of the opening, it is envisaged that only one may need to be provided.

Referring now to Figure 3, a shutter assembly embodying the invention comprises a frame formed from an upper member 1 , opposing side members 2, and a lower member 3. Each side member 2 houses a corresponding threaded rod or bar 6. A lower end of each threaded bar 6 is connected to a respective bevel gear 93 which in turn is arranged to mesh with a further bevel gear 93 arranged to rotate about a horizontal axis, rotationally supported by a bearing block 92. The meshing bevelled gears are then coupled by means of drive shafts 94 to a central arrangement of 4 bevelled gears 93, again supported by respective bearing blocks 92. The central arrangement of 4 bevelled gears is arranged so as to be manually driven by a handle 91. Drive shaft support blocks 95 are provided at intermediate positions between the central array of bevelled gears and the ends adjacent to the threaded bars 6. Although not shown in Figure 3, when assembled the drive train is completely housed within the lower frame member 3 and the side members 2.

The blind further comprises a top support bar 1 1 which has threaded ends 1 1 1 and is housed within the upper frame member 1. The blind also comprises 4 vane assemblies, each of which includes a hollow blade 41 , a rigid bar 42 passing through the blade, a first end cap 43 capping a first end of the blade 41 , and a second end cap 44 capping a second end of the blade. The second end cap 44 comprises a lug 45 for attachment to control means for rotating the hollow blades 41 about their respective central strengthening bars 42. The lowest vane of the assembly is the leading vane, comprising hollow blade 41 a and strengthening bar 42a. The ends of each rigid bar 42 have threaded portions 421. For the leading vane, these threaded ends 421 are screwed into respective drive blocks 10. These drive blocks, in addition to their lateral bores for receiving the ends of the strengthening bars 42, also have internally threaded drive bores 101 which engage with the screw threads on the drive rods 6. Thus, the leading vane is driven at both ends when the drive rods 6 are rotated. The leading vane is thus directly driven, in contrast, the top three vanes are not directly coupled to the screw-threaded drive bars 6. They are linked together and to the support bar 1 and leading vane by means of flexible loops 51. Nuts 46 engage with the threaded ends 1 and 421 of the support bar 1 1 and strengthening bars 42, and constrain the flexible loops 51 and end caps 43 and 44 in their respective positions.

When the illustrated blind is assembled, the nuts 46 are accommodated within channels 21 in the side frame members 2. Thus, the ends of the non-driven vanes (i.e. the top three vanes) are guided by the side members 2 and movement of the vanes in a direction perpendicular to the general plane of the blind is inhibited. Referring now to figure 4, this shows the blind assembled, but with the frame members omitted so that the relative positions of the components in the assembly can be seen more clearly. The blind is shown in a partially closed position. Rotation of the handle 91 in the direction shown by arrow A causes corresponding rotation of the drive shafts 94 in the directions shown by arrows B. The bevel gear arrangements at the bottom corners of the assembly in turn translate this shaft rotation into rotation of the screw- threaded bars 6 in the same sense, shown by arrows D. The screw-thread engagement between the drive block 10 and the drive bars 6 then causes the drive blocks 10 and hence the leading blade 41 a to be driven downwards in the direction shown by arrows C. The top three vanes are not directly driven, but are able to fall under gravity as the leading vane is driven in the downward direction. The eventual positions of the top three vanes are thus determined by the flexible links 51 by which they are suspended, in series, from the top support bar 1 1. In this embodiment the links 51 are formed from substantially inelastic material. In the position shown in the Figure, the leading vane has been driven downwards sufficiently far for each of the linking loops 51 to be fully extended. In this position, when the drive rods are not rotating, the vertical position of the leading vane is fixed, and so are the vertical positions of the remaining vanes. Vertical movement of the remaining vanes is prevented by the extended loops 51 , each of which passes round the strengthening bars of adjacent vanes, or in the case of the top link, around the supporting bar 11 and the strengthening bar of the top vane. Horizontal movement of the non-driven vanes is inhibited by the guide channels in the side frame members 2 (not shown). In Figure 4, the vane blades 41 are shown in the inclined position. Simultaneous control of blade orientation is achieved by means of a control link 451 connecting the lugs 45 of the respective end caps 44.

Moving on to Figure 5, this shows the same embodiment as was illustrated in Figs 3 and 4. In Figure 4, the vanes were shown in the "closed" position, i.e. they were spaced apart so as to close the opening. In Figure 5, the vanes are shown bunched together, i.e. in the "open" position. Rotation of the handle 91 in the direction shown by arrow A (i.e. counter clockwise) results in the drive shafts 94 rotating in the opposite senses (see the arrows B) this is turn causes the drive rods 6 to rotate in the directions shown by arrows D which then drives the leading blade 41 a upwards (i.e. the direction shown by arrows C) as a result of the threaded coupling between drive blocks 10 and the drive rods 6 as the leading vane is driven upwards in this manner, the remaining vanes which were suspended via the flexible links 51 are successively picked up by the leading vane and moved towards the top of the frame. Thus, the non-driven vanes form a stack. In the bunched position shown in Figure 5, the linking loops 51 are flexed. Referring now to Figure 6, a further embodiment is in the form of a vertical blind, i.e. a blind comprising a plurality of vanes which extend in the vertical direction and are rotatable about their vertical, longitudinal axes. In this blind, the plurality of vanes are divided into two groups, a left group and a right group. Of these two groups, only the leading vanes are shown in the figure. The remaining vanes of the two groups are coupled to the respective leading vane by suitable links such that they may be drawn behind the leading vanes as they are closed. The blind assembly comprises upper and lower screw- threaded rods 6, each of which is arranged to rotate about a substantially horizontal axis. Each screw-threaded rod 6 comprises a first section 61 which is screw threaded in one sense, and a second section 62 which is screw-threaded in the opposite sense. The first and second section 61 , 62 are rigidly connected together in this embodiment by connector blocks 63. The leading vane 4a of the left hand group of vanes is coupled to the first sections 61 of the upper and lower drive rods 6 by means of upper and lower drive blocks 10, which include suitably threaded bores. The leading vane 4a comprises a blade 41 which is arranged to pivot about stub shafts 49 which extend into the drive blocks 10. Similarly, the leading vane 4a of the right group of vanes is coupled to and supported between the second sections 62 of the upper and lower drive bars 6. As the first and second sections 61, 62 of each drive rod are screw-threaded in opposite senses, rotation of the drive bars in the direction shown by the arrows R results in simultaneous movement of the left group's leading vane towards the right in the figure, and movement of the right group's leading vane towards the left in the figure. Thus, rotation in the direction shown by arrows R causes the leading vanes to be moved together, so as to close the blind, with the remaining vanes being drawn behind. Similarly, when the drive rods are rotated in the opposite direction, the leading vanes are driven apart to open the blind.

Although in the embodiment shown in Figure 6 the drive rods are formed from separate screw-threaded sections connected together, it will be appreciated that in alternative embodiments the drive bars may be formed by cutting opposing threads in opposing sections of a single, common bar.

Referring now to Figure 7, in this final embodiment a single screw-threaded drive rod 6 is housed within a side frame 2 which is secured next to a generally vertical, side surface of a window aperture W. A lower end of the drive rod 6 is accommodated in a bushing 8 to permit rotation. An upper end of the drive rod 6 is connected to a gearbox 7, and through the gearbox is driven by means of a motor 9 having a drive shaft 91. A leading vane 4a comprises a blade 41 a attached to a lateral rod 42a, which is itself supported by a drive block 10. The drive block 10 extends along the axis of the drive rod 6 and includes 2 separate lateral protrusions 101, each of which has a respective screw- threaded bore, engaging the threaded drive rod 6. A second vane is suspended from the rod 42a of the leading vane by means of flexible links, each of which comprises 2 generally rigid members 52, coupled together via a hinge pin 53. These flexible links suspend the rod 42 of the lower vane, on which a blade 41 is mounted. The rod 42 of the lower vane is connected to a guide block 10a which has a bore 101 a which accommodates and forms a sliding fit over the drive bar 6 thus, as the drive bar 6 is rotated by the motor 9, the leading vane is driven upwards or downwards depending on the direction of rotation. The lower vane is not directly driven, but simply follows the leading vane as a result of the flexible links. Although only two vanes are shown in the figure, it will be appreciated that a plurality of non-driven vanes may be used to obtain suitable closer of the window. It will also be appreciated that in certain preferred embodiments of the invention, the adjacent vanes may be arranged so as to overlap when suitably rotated about their longitudinal axes.

Claims

1. A shutter or blind comprising: a frame adapted to fit an opening; a plurality of vanes movably mounted relative to the frame; and drive means for moving the vanes to selectively cover/uncover the opening, the drive means comprising a screw-threaded rod coupled to drive at least one of the vanes.

2. A shutter or blind in accordance with Claim 1, wherein the frame comprises a side member, adapted to be secured to a substantially vertical sidewall of an opening, the screw-threaded rod being housed within the side member. 3. A shutter or blind in accordance with Claim 1 , wherein the frame comprises a lateral member, adapted to be secured to a substantially horizontal upper or lower wall of an opening, the screw-threaded rod being housed within the lateral member.

4. A shutter or blind in accordance with any preceding claim, wherein the screw-threaded rod is coupled to drive a first end of said at least one vane, and further comprising a second screw-threaded rod coupled to drive a second end of said at least one vane.

5. A shutter or blind in accordance with Claim 4, as dependent on Claim 2, wherein the first and second rods are housed in respective, opposing side members of the frame.

6. A shutter or blind in accordance with Claim 4, as dependent on Claim 3, wherein the first and second rods are housed in respective, opposing lateral members of the frame.

7. A shutter or blind in accordance with any preceding claim, further comprising linking means linking the remaining vanes to the at least one driven vane.

8. A shutter or blind in accordance with Claim 7, wherein the linking means comprises a series of flexible links, each link coupling a respective pair of adjacent vanes.

9. A shutter or blind in accordance with Claim 7 or Claim 8, wherein the frame comprises guide means arranged to guide at least one end of the remaining vanes. 10. A shutter or blind in accordance with Claim 7 or Claim 8, wherein at least one of the remaining vanes is coupled to the or each screw-threaded rod by a respective guide block, the guide block having a bore forming a sliding fit over the bar such that rotation of the bar does not drive the guide block.

1 1. A shutter or blind in accordance with any preceding claim, wherein the drive means is operable to move the vanes between a bunched arrangement and a spaced arrangement to selectively cover and uncover the opening.

12. A shutter or blind in accordance with any preceding claim, wherein the or each driven vane is coupled to the or each screw-threaded rod by a respective drive block or blocks, the or each drive block comprising a screw-threaded bore.

13. A shutter or blind in accordance with any preceding claim, wherein said plurality of vanes comprises a first group and a second group, each group including a driven vane coupled to be driven by the screw-threaded rod or rods, the or each rod comprising a first portion and a second portion, the first and second portions being screw- threaded in opposite senses, the driven vanes of the first and second groups being coupled respectively to the first and second portions of the rod, whereby rotation of the rod in one sense drives the groups together and rotation in the opposite sense drives the groups apart.

14. A shutter or blind in accordance with Claim 13, wherein the driven vanes are leading vanes of the first and second groups.

15. A shutter or blind in accordance with Claim 13 or Claim 14, wherein the first and second portions are coupled together by coupling means.

16. A shutter or blind in accordance with Claim 13 or Claim 14, wherein the first and second portions are formed on a common rod.

17. A shutter or blind in accordance with any preceding claim, wherein each vane is rotatable about a respective longitudinal axis, and further comprising control means for simultaneously rotating the vanes to selectively open or close spaces between adjacent vanes.

1 8. A shutter or blind in accordance with any preceding claim, wherein at least one of the vanes comprises a rigid bar, extending along the length of the vane, and a blade coupled to the bar. 1 . A shutter or blind in accordance with Claim 18, wherein at least one end of the bar is threaded and is screwed into a corresponding threaded receiving bore in a drive block, the drive block further comprising a threaded drive bore accommodating the or one of the screw-threaded rods.

20. A shutter or blind in accordance with Claim 18 or Claim 19, wherein the blade is adapted to rotate about the bar. 21. A shutter or blind in accordance with Claim 20, wherein the blade is hollow and the bar passes through the blade.

22. A shutter or blind in accordance with Claim 21 , wherein the blade is a hollow extrusion.

23. A shutter or blind in accordance with Claim 21 or Claim 22, wherein the blade comprises bearing means arranged to engage the bar and permit rotation of the blade around the bar.

24. A shutter or blind in accordance with any one of Claims 21 to 23, wherein the or each vane comprising a rigid bar and hollow blade further comprises a respective pair of end caps, capping opposite ends of the hollow vane and each comprising bearing means arranged to rotatably engage the bar.

25. A shutter or blind in accordance with Claims 24, wherein at least one of each pair of end caps comprises a lug coupled to control means for rotating the blade about the bar.

26. A shutter or blind in accordance with any preceding claim, wherein the drive means comprises a motor arranged to rotate the screw-threaded rod or rods.

27. A shutter or blind in accordance with Claim 26, further comprising sensing means arranged to detect the presence of a person in the vicinity of the shutter or blind, and control the means coupled to the sensing means and arranged to stop the motor in response to the detection of a person. 28. A shutter or blind in accordance with any preceding claim, wherein the drive means comprises a handle for manual rotation of the or each screw-threaded rod.