Patent Description:
Tilt mechanisms are used to allow an object to be tilted to a desired orientation. Two-axis tilt mechanisms generally provide tilting about two orthogonal axes thereby allowing an object to be tilted into a wide variety of orientations.

Mirrors are often oriented using such tilt mechanisms to achieve a required alignment of the mirror within an optical instrument. Such tilt mechanisms frequently operate at a high level of precision, and so comprise mechanisms with small tolerances resulting in complexity and expense.

One contemplated use of the present invention is in an array of mirrored tiles that form a moving artwork in which the mirrored tiles may be tilted independently, in groups or all together to provide an attractive display. The array of mirrors may be provided as a decorative wall or as a decorative ceiling, or as decorative parts of a wall or ceiling.

<CIT> describes a device that comprises a tilt correction stage extending between a mirror plate and a support plate. The device consists of at least two connecting rods defining two approximately secant axes relative to the optical center of the mirror and at least one linear actuator adapted so that the mirror can pivot about its optical center.

In a first aspect, there is provided a tilting device comprising a base, an object that tilts relative to the base, and a tilt mechanism operable to cause the object to tilt relative to the base. The tilt mechanism comprises a flexible link, a support and an actuator. The flexible link extends from the base to the object to create a first separation between the base and object. The support extends from the base to the object via a joint to create a second separation between the base and object. The joint may be located between the support and the base, between the support and the object or may be part of the support. The flexible link meets the object in a position displaced from where the support meets the object. The actuator is joined to the flexible link and is operable to deform the flexible link thereby varying the first separation between the base and the object. As flexible link meets the object in a position displaced from where the support meets the object, changing the first separation between the base and the object across the flexible link causes the object to tilt about a first axis of rotation of the joint.

Thus, a simple mechanism is achieved that tilts an object using a compliant arrangement in the form of a flexible link that is deformed to change the separation of the object from the base. This simplicity provides several advantages. For example, such a simple mechanism can be made to be very reliable and so requires less servicing. This makes the tilting device <NUM> ideal for deployment in hard to access areas. The simple mechanism is also lightweight, resulting in easier and less expensive installation requirements. Also the use of a flexible link results in very quiet operation and also inherent vibration damping.

The tilting device may further comprising at least one further object that tilts relative to the base, and a tilt mechanism for each of the at least one further objects operable to cause the respective one of the at least one further objects to tilt relative to the base. In the following, optional features of the tilting device will be described with reference to embodiments having only a single object to be tilted. However, the optional features apply equally well to embodiments of the tilting device having more than one object to be tilted. In these embodiments, the optional features described below may be present in one of the objects and its associated tilt mechanism, in all of the objects and their associated tilt mechanisms, or in some but not all objects and their associated tilt mechanisms.

The actuator comprises a lead screw joined to the flexible link by a threaded nut. Such an arrangement provides a simple means for changing the curvature and hence height of the flexible link. The threaded nut may be attached part way along the length of the flexible link between the base and the object. For example, the threaded nut may be attached to the flexible link at a position midway, or substantially midway, along its length. The lead screw may extend in a direction transverse to the first separation between the base and the object across the flexible link and transverse to the first axis of rotation of the joint.

The threaded nut may be brass or made from a polymer, the latter being advantageous as it allows lubricant-free operation which lessens service requirements. The threaded nut may be a zero backlash nut. Optionally, the actuator further comprises a stepper motor arranged to drive the leadscrew.

Optionally, the flexible link is a loop of flexible material whose curvature is changed as the flexible link is deformed by the actuator. The flexible link may be curved such as circular, part-circular, elliptical or part-elliptical in shape when viewed from the side when its relaxed state. The flexible link may be formed of two parts that together form a loop, for example two semi-circular parts. The actuator may extend across the loop and may be joined to the loop at opposed sides. Then, when the actuator is moved, the actuator may squeeze or relax the loop, hence providing the change in curvature and height of the loop. For example, the threaded nut may be secured to the loop at one side and a stepper motor may be secured to the opposite side of the loop. Conveniently, this allows the stepper motor, lead screw and threaded nut to move with the loop as the curvature of the loop and the first separation changes. Optionally, the loop is secured to the base and the object at opposed sides, such that the loop is joined to the base once, the object once and the actuator twice, at four positions which are equally spaced around the loop. To provide the required flexibility in the flexible link, it may comprise an elastomer such as polyurethane. The flexible link may have a hardness and/or thickness selected to provide the desired flexibility yet adequate support for the object to be tilted. For example, the flexible link may be an elastomer such as polyurethane with a Shore A hardness of <NUM> (or approximately <NUM>) and/or a thickness of <NUM> to <NUM> (the thickness may not be uniform around the loop).

The tilting device may provide tilting of the object about two axes, for example two orthogonal axes. In this case, the flexible link may be a first flexible link and the actuator may be a first actuator. The tilt mechanism may further comprise a second flexible link extending from the base to the object to create a third separation between the base and object. The second flexible link may meet the object in a position displaced from where the support meets the object and where the first flexible link meets the object. The tilt mechanism may also further comprise a second actuator joined to the second flexible link that is operable to deform the second flexible link thereby varying the third separation between the base and the object such that the object tilts about a second axis of rotation of the joint.

Optionally, the first joint and the second joint of the tilt mechanism may comprise a single universal joint. Alternatively, the joint may be a composite joint comprising a first constrained pivot whose constrained axis of rotation defines the first axis and a second constrained pivot whose constrained axis of rotation defines the second axis. The first and second axes may be arranged orthogonally. Optionally, the first joint and the second joint are arranged adjacent to each other along the support. When the tilting device comprises more than one object, the first axes of the supports of the tilt mechanisms may be aligned with each other. Also, where present, the second axes or rotation of the joints may be aligned with each other.

Optionally, the object comprises or consists of a tile such as a coloured, patterned, textured and/or contoured tile. The tile may be a reflective tile such as a mirror. Optionally, the object comprises a tile supported by a platform, and the support(s) and flexible link(s) of that object are attached to the platform. Optionally, the tile may comprise mirror supported by the platform, such as a polycarbonate mirror. The platform may comprise a substrate and a plate, and the tile may comprise a mirror bonded to the substrate that is in turn joined to the plate, with the support and flexible link attached to the plate. The mirror may be a polycarbonate mirror and/or the substrate may be a foamed PVC substrate.

Where the tilting device comprises more than one tile, the tiles may form an array such as an array of tiles in a regular, repeating pattern. The tiles may share a corresponding size and shape, or may be arranged into corresponding pairs of tiles, where the tiles of each pair are mirror images of each other. Non-repeating patterns of tiles may also be used.

There is also provided an array of tilting devices comprising a mount and a plurality of any of the tilting devices described above, wherein the base of each tilting device is supported by the mount. The plurality of tilting devices may be arranged in repeating pattern. Optionally, the first axes of rotation of all supports of the tilting devices may be aligned. Also, where the supports include second joints, the second axes may also be aligned.

The array may form part of a structure, for example a wall comprising the array of tilting devices or a ceiling comprising the array of tilting. Alternatively, the array may form part of a freestanding structure. In any event, the structure may be part of a building or a vehicle, for example a publicly-accessible building such as a hotel or office, or a publicly-accessible vehicle such as a boat, ship, cruise liner, aeroplane, train, coach or bus.

In order that the invention can be more readily understood, reference will now be made by way of example only, to the accompanying drawings in which:.

The figures show one particular application for tilting devices in accordance with embodiments of the present invention. While the tilting devices may be used in many different applications, <FIG> shows their use in an application where the objects to be tilted are mirrored tiles. In particular, <FIG> shows an array <NUM> of four tilting devices <NUM> each comprising a pair of mirrored tiles <NUM>.

Each pair of tiles <NUM> comprises a tile 12a having a first shape, and a tile 12b having a second shape that is the mirror image of the first shape. The eight tiles <NUM> fit together to leave only small gaps between adjacent tiles <NUM>.

The array <NUM> of mirrored tiles <NUM> are supported by a mount <NUM> that attaches to supporting structure (not shown) via four brackets <NUM>. Anti-vibration fixings <NUM>, for example including rubber blocks, may be used to attach the mount <NUM> to the supporting structure to help isolate vibrations in the supporting structure from being transmitted to the tilting tiles <NUM> and vice versa.

In this example, the array <NUM> of mirrored tiles <NUM> forms part of a suspended ceiling although many other applications are possible. Multiple arrays <NUM> may be arranged together to form a larger group of mirrored tiles <NUM>, and the arrays <NUM> may be aligned such that tiles <NUM> of adjacent arrays <NUM> fit together to leave only small gaps between the tiles <NUM> of adjacent arrays <NUM>. Plain ceiling panels may be provided around the peripheral tiles <NUM> such that the arrays <NUM> form an inset in the suspended ceiling.

In this exemplary embodiment, each pair of tiles <NUM> is mounted to a shared base <NUM>, and the four bases <NUM> are attached to the mount <NUM>. Each tile <NUM> is connected to the base <NUM> by a tilt mechanism <NUM>, as best seen in <FIG> and <FIG>. The tilt mechanism <NUM> comprises a support <NUM> that connects the tile <NUM> to the base <NUM> via a universal joint <NUM>. The support <NUM> attaches to a central point <NUM> on the tile <NUM>. The universal joint <NUM> acts as a fixed-point fulcrum that allows the mirrored tile <NUM> to pivot about two axes, as will be described in more detail below.

Movement about the two axes is effected using controlled deformation of compliant actuators, in this case a pair of flexible bands <NUM> driven by a lead screw <NUM>. As best seen in <FIG>, each band <NUM> is formed from a strip of material that is approximately circular in shape when viewed from the side. Each band <NUM> is attached to a tile <NUM> and a base <NUM> at opposed sides of the band <NUM>, thereby forming a flexible link to provide a first separation of the tile <NUM> from the base <NUM>. This first separation between the tile <NUM> and the base <NUM> may be varied by deforming the band <NUM> such that the shape of the band <NUM> is changed, for example by flattening the band <NUM> into an elliptical shape. The first separation is increased when the major axis of the ellipsis is aligned with the first separation between the tile <NUM> and the base <NUM>, and the first separation decreases when the minor axis of the ellipsis is aligned with the first separation. Each tile <NUM> is connected to one of the bases <NUM> by a pair of bands <NUM> that are oriented at right angles to each other.

Each band <NUM> is deformed by the action of the lead screw <NUM> driven by a stepper motor <NUM>. The stepper motor <NUM> attaches to one side of the band <NUM>, with the lead screw <NUM> extending through a pair of diametrically-opposed holes 112a, 112b provided in the band <NUM>. The lead screw <NUM> extends from the stepper motor <NUM> through the first hole 112a and engages with a nut <NUM> held captive in the second hole 112b. The lead screw <NUM> is rotated by the stepper motor <NUM> and because the nut <NUM> is held in position by the band <NUM> such that it cannot rotate, the nut <NUM> moves along the lead screw <NUM> towards or away from the stepper motor <NUM>. As the nut <NUM> moves closer towards or further away from the stepper motor <NUM>, the band <NUM> is deformed such that its eccentricity changes and the attached tile <NUM> is moved.

Although the array <NUM> may be mounted in any orientation, the lead screw <NUM> may be used as a convenient line of reference to define the width to the band <NUM> and hence also the height of the band <NUM> that runs transverse to this width. <FIG> and <FIG> show that each band <NUM> is connected to the base <NUM> and tile <NUM> across this height. Each band <NUM> attaches to the base <NUM> via a first fastener <NUM>, and each band <NUM> is attached to the tile <NUM> via a second fastener <NUM>. Each band <NUM> attaches to the tile <NUM> at respective off-centre points <NUM>, displaced from the central point <NUM> where the associated support <NUM> of the tilt mechanism <NUM> attaches to the tile <NUM>. This offset allows changes in the separation of the tile <NUM> and base <NUM> caused by deformation in one or both the bands <NUM> to effect a tilting of the tile <NUM> about the universal joint <NUM> of the support <NUM>.

As described above, each band <NUM> is approximately circular when in a relaxed state. For any band <NUM>, rotating the lead screw <NUM> such that the nut <NUM> moves towards the stepper motor <NUM> squeezes the band <NUM> such that its width narrows and its height increases. This sees an increase in the separation of the tile <NUM> from the base <NUM> at the off-centre point <NUM> where the band <NUM> is attached to the tile <NUM>. As the tile <NUM> is attached to the support <NUM> at the central point <NUM>, thereby fixing the separation at that point <NUM>, the tile <NUM> tilts about the joint <NUM> provided in the support <NUM>. Conversely, rotating the lead screw <NUM> in the other direction such that the nut <NUM> moves away from the stepper motor <NUM> forces the band <NUM> apart such that its width increases and its height decreases. This sees a decrease in the separation of the mirrored tile <NUM> from the base <NUM> at the off-centre point <NUM> where the band <NUM> is attached to the tile <NUM>, such that the tile <NUM> tilts about the joint <NUM> provided in the support <NUM> in the other direction. Hence, coordinated rotation of both lead screws <NUM> associated with a mirrored tile <NUM> causes the limited orbital motion of the tile <NUM> about the fixed point fulcrum provided by the support <NUM>.

Further features of preferred embodiments of the array <NUM> of tilting mirrored tiles <NUM> will now be described in more detail.

While a one-piece tile construction of each tile <NUM> may be used, <FIG> show a three-layer construction used for each tile <NUM>. Each tile <NUM> comprises a reflective layer <NUM> forming a mirror that is supported by a platform that comprises a plate <NUM> and a substrate <NUM>. The plate <NUM> may be made from aluminium, and may be <NUM> thick. The substrate <NUM> may be made from foamed PVC, and may be <NUM> thick. The reflective layer <NUM> may be a mirrored polycarbonate, and may be <NUM> thick. The substrate <NUM> and reflective layer <NUM> may have a corresponding shape and size (excluding thickness), and may be bonded together, for example using spray adhesive.

The plate <NUM> attaches to the base <NUM> via three mechanisms, namely through the support <NUM> and through each of the two bands <NUM>.

As best seen in <FIG>, the plate <NUM> attaches to each band <NUM> with fasteners <NUM>. Each fastener <NUM> comprises a nut 24a, bolt 24b and washer 24c, with the bolt 24b extending through the plate <NUM> and the band <NUM>, with the bolt head on the plate side, and the nut 24a on the band side. The head of the bolt 24b is received in a push-fit connection of a stand-off <NUM> that is received within a recess provided in the substrate <NUM>. The stand-off <NUM> provides a gap between the plate <NUM> and the substrate <NUM> of the tile <NUM>.

The plate <NUM> is approximately octagonal in shape, and is provided with four stand-offs <NUM> equally spaced around the plate <NUM>, thereby allowing easier assembly as any one of four orientations may be used. The pair of bands <NUM> of one tile <NUM> attach to two of the stand-offs <NUM>.

<FIG> shows that the plate <NUM> attaches to the support <NUM> through a central aperture provided at the point <NUM>. The support <NUM> is provided with a bolt <NUM> that screws into a threaded hole <NUM> provided in the end of the support <NUM>. The plate <NUM> is sandwiched between the head of the bolt <NUM> and the end <NUM> of the support <NUM>, and the head of the bolt <NUM> resides within a recess <NUM> provided in the substrate <NUM>.

A further fail-safe connection is provided between the plate <NUM> and the substrate <NUM>. A tether <NUM>, for example a fine-wire tether, links the plate <NUM> and the substrate <NUM>. The tether <NUM> attaches to a nut and bolt <NUM> provided through one of the spare stand-offs of the plate <NUM> and to another nut and bolt <NUM> provided in the substrate <NUM>. The substrate <NUM> is provided with a stepped through-hole <NUM> to receive the bolt such that its head sits within the through-hole and does not interfere with the reflective layer <NUM>.

The bands <NUM> must be flexible, and should be stiff enough not to sag under the weight of the tile <NUM>, but supple enough not to require an overly powerful stepper motor <NUM> to deform the band <NUM>. Also, the flexibility of the bands <NUM> contributes to damping vibrations that might otherwise be transmitted to the supporting structure. The flexibility of the bands <NUM> should also provide these advantageous properties over typical working temperatures experienced by the array <NUM> of mirrored tiles <NUM>.

To provide these advantageous properties, a band <NUM> formed of an elastomer, such as a polyurethane compound, may be used. For example, polyurethanes obtained from Alchemie with part numbers PU3547 and PU3548 have been found to work well. The bands <NUM> may be formed of a material having a <NUM> Shore A hardness (or approximately a <NUM> Shore A hardness), and may be <NUM> to <NUM> thick. As can best be seen from <FIG>, the bands <NUM> may have a varying thickness, with the parts of the band <NUM> around the connection points being thicker (e.g. <NUM>) and being separated by thinner portions (e.g. <NUM> thickness). The bands <NUM> may be 3D printed or vacuum cast, which conveniently allows formation of the shaped outer surface around the attachment points for the stepper motor <NUM>, the nut <NUM> and the fasteners <NUM> and <NUM> that are best seen in <FIG>.

Stepper motors <NUM> providing <NUM> of torque have been found sufficient to operate the tilt mechanisms <NUM>. An <NUM> diameter lead screw <NUM> having a <NUM> pitch thread may be used. An anti-backlash nut <NUM> may be used, and the nut <NUM> may be brass or polymer. Preferably a lubrication free lead screw <NUM> and nut <NUM> combination is used, as this reduces dust collection and servicing requirements.

<FIG> show a first type of support <NUM> that may be used in the tilt mechanisms <NUM> described above. The support <NUM> extends between the base <NUM> and the tile <NUM>. A bolt <NUM> is used to fasten the support <NUM> to the base <NUM>, and the bolt <NUM> fastens the support <NUM> to the plate <NUM> of the tile <NUM> as explained above.

In this embodiment, the support <NUM> includes a universal joint <NUM> that allows tilting about two axes, as will now be described. The support <NUM> includes a male part <NUM> and a female part <NUM>, forming a ball and socket joint. The male part <NUM> is provided with the ball <NUM> at one end and the bolt <NUM> for attaching the support <NUM> to the base <NUM> at the other end. The female part <NUM> is provided with the socket <NUM> at one end, and the bolt <NUM> that secures the plate <NUM> and substrate <NUM> to the support <NUM> at the other end.

The universal joint <NUM> is constrained to move about two axes by a bolt <NUM> that extends through the female part <NUM> and an aperture <NUM> provided in the ball <NUM> of the male part <NUM>. The aperture <NUM> is provided with wide ends and a narrow centre such that the bolt <NUM> may rock back and forth within the aperture <NUM>, as best seen in <FIG>. This rocking within the ball <NUM> allows the universal joint <NUM> to tilt about a first axis. The nut <NUM> and bolt <NUM> are received within recesses provided in the female part <NUM>, and the recesses are provided with rounded sides such that the nut <NUM> and bolt <NUM> do not engage with the sides of the recesses and so are free to rotate relative to the female part <NUM>. This rotation of the female part <NUM> relative to the bolt <NUM> allows the universal joint <NUM> to tilt about a second axis. This design prevents the universal joint <NUM> from spinning about the longitudinal axis of the support <NUM> which would otherwise allow the mirrored tiles <NUM> to twist. Such twisting risks adjacent tiles <NUM> colliding and diminishes the aesthetic effect achieved by the array <NUM> of mirror tiles <NUM>. A washer <NUM> made from a low-friction material like a plastic is also provided to ease rotation of the universal joint <NUM>.

A second type of support <NUM> that may be used in the tilt mechanisms <NUM> described above is shown in <FIG>. The support <NUM> of <FIG> is broadly similar to the support of Figured <NUM> and <NUM>, and like reference numerals are used to refer to like parts. The main difference between the supports resides in the details of the joints <NUM>. The support <NUM> of <FIG> employs two pinned pivots to connect the two parts <NUM> and <NUM> of the support <NUM>. One pin 170a connects two arms of one part <NUM> of the support <NUM>, while the other pin 170b connects two arms of the other part <NUM> of the support <NUM>. Both pins 170a,b are rotatably secured to the respective arms to allow the first part <NUM> to pivot relative to the second part <NUM>. The pins 170a,b meet at their middles where they are joined (or the pins 170a,b could be a unitary piece). The two pins 170a,b are aligned at right angles to each other to provide tilting about two orthogonal axes.

As a further alternative, a support <NUM> having a simple ball joint may be used to allow for the required tilting motion. This is particularly suitable where rotation of the tiles about the support's longitudinal axis is not a problem, for example where the tiles are symmetric about that axis such as when they are circular.

The tiles <NUM> are moved under the direction of one or more electronic controllers, for example one or more computer processors, or one or more printed circuit boards, or a combination of both. The control of the individual tiles <NUM> may be implemented locally or globally. For example, a common controller may be used to control the tiles <NUM> of an array <NUM> or of multiple arrays <NUM> arranged together. Alternatively, local controllers may be provided (for example, one for each array <NUM> where multiple arrays <NUM> are arranged together). Also, local controllers may be provided with one controller per base <NUM> to service multiple tiles <NUM>, or even one controller per tile <NUM>. An example arrangement will now be described.

In a currently contemplated embodiment, multiple arrays <NUM> like the array <NUM> of <FIG> are combined into an art installation. A master controller (not shown in the figures) provides global control of the mirrored tiles <NUM>. For example, the master controller may be a programmed computer processor that provides the required signals for individual tiles <NUM> to move to provide predetermined artistic effects. For example, the tiles <NUM> may be tilted to provide ripple or wave effects across the installation, or to adopt striped or chequer-board appearances. Light may be projected onto the mirrored tiles <NUM> to provide further lighting effects, akin to a glitter ball.

The signals provided by the master controller are transmitted, via wired and/or wireless connections, to local controllers. Each tile <NUM> has a dedicated local controller, and each tilting device <NUM> houses its pair of local controllers in a shared enclosure <NUM>. Each local controller may translate the signals received from the master controller into drive signals for the two stepper motors <NUM> associated with its tile <NUM>, as well as performing supervisory functions such as enforcing tilt rate limits and tilt angle limits. Each tile <NUM> may be provided with an accelerometer and/or inclinometer (not shown) to provide information about the movement and/or orientation of the tile <NUM>. This information may be provided to its local controller and/or a master controller to manage tilt rates and tilt angle of the tile <NUM>. For example, the accelerometer and/or inclinometer may be used to provide the tilt angle of the tile <NUM> to the local controller <NUM> as part of a feedback loop to ensure correct positioning of the tile <NUM>, and to mitigate drift in the tilt angle set for the tile <NUM> over time.

Arrays <NUM> of mirrored tiles <NUM> may be used in a variety of places, for example in dwellings such as hotels, holiday resorts, apartment complexes and domestic homes; in transport buildings such as railway, airport and shipping terminals; retail buildings like shopping centres and shops; and in work places such as office buildings and factories. Arrays <NUM> may also be used in transport vehicles such as planes, boats, buses and coaches.

By way of example, one contemplated application is in a cruise ship. Multiple arrays <NUM> may be installed to form part of the ceiling of an atrium in a cruise ship. Such an application presents particular problems. The cruise ship moves and adopts variable orientations as it pitches and rolls. Also, access to the arrays <NUM> once installed is problematic due to the ceiling height in atriums. Certain features of the embodiments described above and further adaptations may be made to accommodate these potential problems.

Lack of access can be addressed by ensuring high reliability and long service intervals. The simple nature of the flexible bands <NUM> driven by the lead screws <NUM> provides for good reliability and long service intervals, especially compared to more complex and sophisticated mechanisms found in mirror tilt mechanisms used in optical instruments. For example, traditional tilt mechanisms frequently use multiple high precision hinged joints, scissor mechanisms, and/or complex anti-backlash geared drive motors, all of which need more frequent servicing if they are to provide reliable operation. Also, adopting a lubrication free lead screw <NUM> and nut <NUM> combination extends service intervals.

Providing an accelerometer and/or inclinometer on each tile <NUM> allows the orientation of the tiles <NUM> to be determined. Providing suitable electronic control allows the orientation of the tiles <NUM> to be decoupled from any motion of the cruise ship. Hence, the array <NUM> may be operated to cause the tiles to tilt to positions relative to the cruise ship's structure or relative to the earth.

A person skilled in the art will appreciate that the above embodiments may be varied in many different respects without departing from the scope of the present invention that is defined by the appended claims.

For example, the object(s) to be tilted need not be mirrored tiles <NUM>. For example, non-mirrored tiles with various surface colours, patterns, contours and textures may be used. The tiles need not be tessellated, but could comprise various shapes and differing gaps.

The objects to be tilted, such as the tiles <NUM> described above, need not be provided with two-axis tilt mechanism <NUM>. For example, single-axis or three-axis tilt mechanisms may be provided. A single-axis tilt mechanism may be implemented in the embodiments described above by providing only a single band <NUM> per tile <NUM>.

While the embodiments shown in the figures comprise circular band <NUM>, other shapes may be used such as polygons (e.g. hexagons, octagons) or irregular polygons. For example, an octagonal band may be used with thickened sides for hosting the connections to the base <NUM>, tile <NUM> and lead screw <NUM>, and with the remaining sides being thinner: when deformed the thinner sides will curve more to accommodate the deformation. Moreover, the band need not comprise a complete loop of material. For example, broken loops may be used such as C-shaped bands <NUM>. The embodiment of <FIG> could be adapted such that the C-band extends from one fastener <NUM> to the other fastener <NUM> and to retain the nut <NUM>: the stepper motor <NUM> may then be mounted to the base <NUM> rather than the band, for example using a mechanism to allow the stepper motor <NUM> to rise and fall with the C-band such as pin and slot arrangements. Alternatively, two C-bands may be paired to form a circle.

The figures show embodiments with two tiles <NUM> per base <NUM>, but this may be freely varied with either fewer or more tiles <NUM> per base <NUM>. Also a single base <NUM> may be provided for all tiles <NUM>, and the mount <NUM> may provide such a common base <NUM>. As noted above, a complete installation might comprise multiple arrays <NUM> like those described above or just a single array <NUM>.

Claim 1:
A tilting device (<NUM>) comprising:
a base (<NUM>);
an object that tilts relative to the base; and
a tilt mechanism (<NUM>) operable to cause the object to tilt relative to the base;
wherein the tilt mechanism comprises:
a flexible link extending from the base to the object to create a first separation between the base and object;
a support (<NUM>) extending from the base to the object via a joint to create a second separation between the base and object, wherein the flexible link meets the object in a position displaced from where the support meets the object; and
an actuator joined to the flexible link that is operable to deform the flexible link thereby varying the first separation between the base and the object such that the object tilts about a first axis of rotation of the joint;
characterized in that, in the or each tilt mechanism, the actuator comprises a lead screw (<NUM>) joined to the flexible link by a threaded nut.