BACKGROUND OF THE INVENTION

[0001] The present disclosure relates to a motor for deploying and retrieving a curtain or shutter (such motors often, but not exclusively, being known as tubular motors).

[0002] The present invention concerns the deployment and retrieval of shutters and curtains, such as fire curtains and safety shutters. More particularly, but not exclusively, this invention concerns a motor for deploying and retrieving a shutter or curtain. The invention also concerns an apparatus for deploying and retrieving a curtain or shutter. The invention also concerns a method of deploying a shutter or curtain.

[0003] GB2320944 describes a motor and brake arrangement for a blind, such as a fire curtain. The blind is dropped under the influence of gravity in the event that there is no electrical power. It has been found that some such blinds fall very quickly, depending on the weight of the weighting bar which is typically attached to the blind. Deployment at high speed may present an injury risk or even a risk of death to anyone beneath the blind at the time of deployment. Furthermore, such high speed deployment may cause wear and/or damage to components such as the motor.

[0004] The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved motor and apparatus for deploying and retrieving a shutter or curtain.

SUMMARY OF THE INVENTION

[0005] In accordance with a first aspect of the present invention there is provided a motor for deploying and retrieving a shutter or curtain, the motor comprising: a rotor and a stator, the rotor being rotatable to cause movement of a shutter or curtain, a brake for inhibiting movement of the rotor, the brake comprising a first brake portion coupled to the stator, a second brake portion coupled to the rotor, and a bias means, the brake being operable between a braking mode in which the first and second brake portions are in a closed configuration and in which rotation of the rotor is inhibited and a release mode in which the first and second brake portions are in an open configuration and in which rotation of the rotor is permitted, the brake being arranged to be in the release mode in the absence of electrical power being supplied to the brake; the brake being configured so that in the release mode the bias means urges the first and second brake portions into contact with one another to resist, but not prevent, rotation of the rotor.

[0006] In use, deployment of a shutter or curtain when the brake is released in the absence of electrical power being supplied to the brake is typically under the influence of gravity. The rotational speed of the rotor and the translational speed of a shutter or curtain associated with the motor increases as the curtain or shutter falls. It is been discovered that a bias means may be used to urge the first and second brake portions into light contact with one another to provide a braking force which permits the deployment of a curtain or shutter using the motor, but also limits the speed of rotation of the rotor, and therefore the speed of deployment of a shutter or curtain should the shutter or curtain be deployed under the influence of gravity (for example, in the event of a power failure), and therefore decrease the risk of injury associated with such deployment of the shutter or curtain.

[0007] In the release mode, the first and second brake portions are optionally urged away from one another, for example, by a spring. The bias means which urges the first and second brake portions into contact with one another can therefore be seen as working against the spring or other such urging means which urges the first and second brake portions away from one another.

[0008] For the avoidance of doubt, it is hereby stated that the curtain or shutter is not part of the motor for deploying and retrieving a shutter or curtain. However, the motor is suitable for deploying and retrieving a shutter or curtain, such as a fire-resistant curtain. Such fire-resistant curtains are typically weighted to ensure that the curtain is properly deployed and to ensure that the curtain hangs properly. The weighting used would depend on the size of the curtain. The motor may be suitable for deploying and retrieving a shutter, such as a security shutter. Such security shutters may comprise a plurality of laths. The motor of the first aspect of the present invention may optionally be of a type known as a tubular motor, due to the generally tubular shape of the motor.

[0009] The motor may comprise a casing, optionally shaped to be received within a carrier for carrying a shutter or curtain, optionally in a sleeve-like manner. For example, the shape and size of an external surface of the casing may be arranged to correspond to the shape and size of an internal surface of a carrier. While it would be possible to rely on frictional engagement between a carrier and casing to ensure that rotational movement of the rotor is satisfactorily transferred to the carrier, it would be usual to fix the carrier to the casing, for example, using screws or bolts. The rotor may be coupled to the casing so that rotation of the rotor causes rotation of the casing (and therefore any drum coupled to the casing).

[0010] The casing may have any shape, but typically has generally the same shape (and generally the same cross-sectional size) along its length.

[0011] An adaptor for coupling the rotor to a carrier for a curtain or shutter may be provided. The adaptor may comprise an annular or cylindrical surface for receiving a correspondingly-shaped portion of a surface of a carrier. The adaptor may comprise a flange for abutment of the end of a carrier. If a casing is present and it is intended to rotate said casing, the adaptor may be coupled to the casing so that rotation of the drive shaft is transmitted to the casing.

[0012] The brake is arranged to apply a braking force when electrical power is applied. The brake is arranged so that when there is a cut in electrical power to the brake, then the brake is released. This ensures that a shutter or curtain is deployed in the event of a power electrical failure. The motor may be connectable to a primary electrical power source (such as mains electricity) to provide power to the brake and may be connectable to a back-up power source arranged to provide power to the brake in the event of a failure of a primary power source. The back-up power source may comprise one or more batteries (typically rechargeable batteries). In use, the motor may optionally be connected to a primary power source and a back-up power source, and the brake will typically be arranged to operate on power provided by the back-up power source in the event that supply of power from the primary power source fails, therefore ensuring that the curtain or shutter is not deployed in the event of a short-term outage of the primary power source.

[0013] The first and second brake portions are typically moveable relative to one another between the braking and release modes. The second brake portion is optionally movable relative to the first brake portion. The bias means (and optionally the second brake portion) is optionally coupled to the rotor so that the bias means (and optionally the second brake portion) is rotatable with rotation of the rotor. In this connection, the bias means and optionally the second brake portion may be coupled to a shaft which is coupled to the rotor. The bias means is optionally coupled to the first or second portion of the brake, optionally the second portion. One of the first and second brake portions (typically the first brake portion) is capable of generating a magnetic field on the application of an electrical field, which causes the first and second brake portions to be moved into the braking mode. In this connection, the brake may comprise a magnetically- attracted member. This member may be associated with the bias means and the second brake portion so that movement of the magnetically-attracted member towards the first brake portion on the application of an electrical field to the first brake portion urges the second brake portion into engagement with the first brake portion. The magnetically- attracted member may be coupled to the bias means and the second brake portion, and may be mounted on a shaft along with the bias means and second brake portion. The second brake portion may comprise a braking component such as a brake pad which is biased into light contact with the first brake portion by the bias means.

[0014] The bias means may comprise a disk. The bias means may comprise one or more arms. The one or more arms may extend outwardly from a central region. The central portion may facilitate fixing of the bias means to a shaft, for example, with one or more of the arms being provided with an aperture therethrough in the central region of the bias means. The one or more arms may extend to a rim. At least a portion of an arm (or optionally more than one arm) may be curved. The bias means may, in an unstressed or unbiased state, be flat. [0015] The motor may comprise one or more gears coupled to the rotor; a gearbox may be provided.

[0016] The present invention provides a simple, yet elegant, solution to the problem which occurs when a curtain or shutter is deployed under the influence of gravity. Those skilled in the art will realise that the present invention may be adapted to any shutter or curtain, for example, by varying the stiffness of the bias means. A heavier shutter or curtain will typically require a stiffer spring to limit the speed of deployment of a curtain or shutter.

[0017] In accordance with a second aspect of the present invention, there is provided an apparatus for deploying a shutter or curtain, the apparatus comprising a motor in accordance with the first aspect of the present invention.

[0018] The apparatus may comprise a carrier for carrying a shutter or curtain. The carrier may be coupled to the motor rotor so that rotational motion of the rotor is transmitted to the carrier.

[0019] The apparatus may comprise a control module for controlling the motion of the carrier. The control module may control one or more of the rotor and brake.

[0020] The carrier may typically have a length of at least 0.5m, optionally of at least 0.75m, optionally of at least 1.0m, optionally at least 1.25m, optionally at least 1.5m, optionally at least 2.0mm and optionally at least 3.0m.

[0021] The carrier may typically have a length of up to 3.0m, optionally of up to 2.5m, optionally of up to 2.0m, optionally of up to 1.75m, optionally of up to 1.5m and optionally of up to 1.0m.

[0022] The carrier may have any suitable cross-sectional shape, but generally has essentially the same cross-sectional size and shape along its length. The carrier may, for example, be hexagonal in cross-section. The carrier, for example, may be circular in cross-section. If the carrier is circular in cross-section, the external diameter of the carrier may, for example, be at least 5cm, optionally at least 7cm, optionally at least 10cm, optionally at least 15cm and optionally at least 20cm. If the carrier is circular in cross- section, the external diameter of the carrier may, for example, be up to 30cm, optionally up to 25cm, optionally up to 20cm, optionally up to 15cm and optionally up to 10cm. [0023] The apparatus may be connectable to a primary power source, such as main electricity. The apparatus may comprise a back-up power source The back-up power source may comprise one or more batteries (typically rechargeable batteries). In use, the motor may optionally be connected to a back-up power source, and the brake will typically be arranged to operate on power provided by the back-up power source in the event that the primary power source fails, therefore ensuring that the curtain or shutter is not deployed in the event of a short-term outage of the primary power source.

[0024] The apparatus may comprise a shutter or curtain. The curtain may comprise a fire curtain.

[0025] A weight may be attached to the curtain or shutter, but particularly to a curtain, if a curtain is present. Such a weight assists in the deployment of the curtain under the influence of gravity, for example, in the event of a power failure as explained above in relation to the first aspect of the present invention. The weight also ensures that the curtain is properly deployed.

[0026] The apparatus may comprise one or more guides for the shutter or curtain, an edge of the deployed shutter or curtain being received in a guide. The apparatus may comprise two guides, one for each edge of a deployed curtain or shutter.

[0027] In accordance with a third aspect of the present invention, there is provided a method of deploying a curtain or shutter, the method comprising:

(i) providing a brake for controlling the deployment of the curtain or shutter, the brake being operable between a braking mode and a release mode, and a bias means arranged to urge surfaces of the brake into contact with one another when the brake is in the release mode so as to resist, but not prevent, motion of the curtain or shutter; and

(ii) in the absence of electrical power being supplied to the brake, the brake entering the release mode, thereby permitting deployment of the curtain or shutter through the action of gravity.

[0028] In accordance with a fourth aspect of the present invention, there is provided a motor for deploying and retrieving a shutter or curtain, the motor comprising: a rotor and a stator, the rotor being rotatable to cause movement of a shutter or curtain, a main brake for inhibiting movement of the rotor, the main brake comprising a first brake portion coupled to the stator, a second brake portion coupled to the rotor, the main brake being operable between a braking mode in which the first and second brake portions are in a closed configuration and in which rotation of the rotor is inhibited and a release mode in which the first and second brake portions are in an open configuration and in which rotation of the rotor is permitted; and an auxiliary brake which applies a force which resists, but not prevent, rotation of the rotor.

[0029] The motor of the fourth aspect of the present invention comprises a main brake which is used to control normal operation of the curtain and shutter. When the main brake is in a braking mode, rotation of the rotor is generally prevented under normal circumstances. When the main brake is in a release mode, there is no contact between the first and second main brake portions, and therefore no resistance to rotation of the rotor by virtue of contact between the first and second brake portions of the main brake. However, the auxiliary brake is effectively always on and providing resistance which resists, but does not prevent, rotation of the rotor.

[0030] The auxiliary brake may be coupled to the rotor, and may comprise first and second brake portions which are urged into contact with one another to resist, but not prevent, rotation of the rotor. The motor of the fourth aspect of the present invention may comprise those features described above in relation to the motor of the first aspect of the present invention.

[0031] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the fourth aspect of the present invention may incorporate any of the features described with reference to the motor of the first aspect of the present invention and/or the apparatus of the second aspect of the present invention and vice versa.

DESCRIPTION OF THE DRAWINGS [0032] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

[0033] Figure 1 shows an example of an embodiment of a motor and an apapratus for deploying and retrieving a curtain or shutter in accordance with the present invention;

[0034] Figure 2 shows a simplified, schematic perspective view of an example of an embodiment of a motor according to the present invention;

[0035] Figure 3 shows a perspective view of part of the motor of Fig. 2 showing the brake; and

[0036] Figure 4 shows a perspective view of a bias means used in the motor of Fig. 1, 2 and 3.

DETAILED DESCRIPTION

[0037] An example of an embodiment of a motor and apparatus for deploying and retrieving a curtain will now be described with reference to Fig. 1. The apparatus is denoted by the reference numeral 1 and comprises a curtain C which is deployed and retrieved by the apparatus 1. In the present case, the curtain C is a fire curtain. The apparatus 1 comprises a drum D for carrying the curtain and a motor 10 for controlling the drum D. The motor 10 comprises a rotor (not shown) arranged to rotate drum D so that the curtain is deployed and retrieved, a brake 3, a clutch 20 and a gearbox 6. Drum D is mounted on casing 50 which is coupled to the rotor. In a normal operating mode, electrical power is supplied to the apparatus. When electrical power is supplied to the apparatus, electrical power is supplied to the brake 3 which causes the brake to be applied and to therefore inhibit rotation of drum D and movement of curtain C. When it is desired to move the curtain C (for example, if a fire is detected or during a test of the apparatus 1), electrical power is removed from the brake 3 and the rotor is used to deploy or retrieve the curtain C. The curtain C is weighted by weight W to facilitate deployment of the curtain C in the event of a power failure (as explained below) and to ensure that, when deployed, the curtain C hangs properly. [0038] In the event of failure of the primary power source (e.g. a mains power outage), operation of the apparatus 1 is powered by a reserve power source (not shown) in the form of rechargeable batteries. The apparatus 1 is arranged so that the reserve power source operates automatically in the event that the mains power source fails. This reserve power source is useful in the event of short-term power outages, such as those experienced in the event of a power cut or short-term shutting down of an electrical circuit e.g. if a circuit fuse is "tripped". This reserve power source facilitates operation of the apparatus 1 for up to 2 days.

[0039] In the event of failure of the reserve power source, then the apparatus 1 is arranged to "fail safe" and deploy the curtain C. On failure of the reserve power source, there is no electrical power supplied to the brake 3 and the brake 3 enters the release mode which permits the curtain C to deploy under the influence of gravity on weight W.

[0040] A bias means 20 is provided which moderates the rotational speed of drum D and the speed of fall of the curtain C in the event of a power failure by causing the two braking surfaces (not shown) of the brake 3 to be urged into light contact with one another when the brake 3 is in the release mode. . In the event of the curtain falling due to there being no electrical power, the brake is in release mode and the curtain C falls. In this manner, the bias means moderates the rotational speed of the drum D and the speed of curtain C and weight W, thereby reducing the chance of injury to persons located underneath the curtain C.

[0041] The apparatus 1 further comprises guides 60, 70 which each receive an edge of the curtain C to ensure proper deployment and retrieval of the curtain C and a control panel 500 for controlling operation of the apparatus 1.

[0042] The system 1 and motor 10 for controlling the drum D will now be described in more detail with reference to Figs. 2, 3 and 4. The motor 10 for controlling the drum D comprises a brake 3, bias means 20 and a casing 50 for mounting the drum D. The motor 1 comprises a stator (not shown) and a rotor (not shown).. The casing 50 is coupled to the rotor (not shown) of the motor via a gearbox 6 so that the casing 50 is rotated by the motor 1. The casing 50 is received within the drum D in a sleeve-like manner, an outer surface of the casing having a shape and size that correspond to the shape and size of the inner surface of the drum D. Bolts (not shown) are used to attach the drum to the casing 50 so that rotation of the casing 50 causes rotation of the drum D.

[0043] The brake 3 comprises a first brake portion 30 and a second brake portion 31. The first brake portion 30 is coupled to the stator and therefore does not rotate during operation of the motor. Second brake portion 31 and bias means 20 are mounted on a shaft S which is coupled to the rotor so that when the rotor rotates, the second brake portion 31 and motion inhibitor 20 rotate. A steel member 35 is also mounted on shaft S. Second brake portion 31 comprises a brake pad 32.

[0044] First brake portion 30 comprises a magnetic field generating portion. . In the event that an electrical field is applied to the first brake portion 30, steel member 35 is attracted to first brake portion 30, urging second brake portion 31 (and brake pad 32) into contact with first brake portion 30, thereby applying a braking force to the casing 50 and therefore to drum D.

[0045] In the absence of an electrical field applied to the first brake portion 30, the first 30 and second 31 brake portions are biased into the open, release configuration by a spring (not shown). In this release configuration, the bias means urges the second brake portion 31 into contact with the first brake portion 30. The contact is light, however. The contact inhibits, but does not prevent, rotation of the rotor. Therefore, when the brake is disengaged (i.e. in the open, release configuration) in the event of power failure, deployment of the curtain or shutter is permitted, but the brake applies a force which reduces the speed at which the shutter or curtain would otherwise have fallen.

[0046] The bias means 20 is now described in more detail. The bias means 20 is (when not stressed) essentially flat and made of metal. Bias means 20 comprises arms 1003, 1004, 1005 which extend outwardly from a central region 1001 to a rim 1002 which is, in use, attached to second brake portion 31. The inner part of each arm is provided with an aperture to facilitate attachment of the bias means 1001 to steel member 35, thereby facilitating coupling of the bias means 1001 to shaft S. Arms 1003, 1004, 1005 facilitate the biasing of second brake portion 31 into contact with the first brake portion 30.

[0047] The bias means 20 is designed to apply an appropriate contact force between the first 30 and second 31 brake portions. The contact force will depend on the spring constant of the bias means; if the spring constant is too high, then the contact force between the first and second brake portions will be too high, and resistance to deployment and retrieval of the curtain or shutter under normal operating conditions (i.e. using the powered rotor to raise and lower the shutter or curtain) may be unacceptably high. Likewise, if the spring constant is too low, the contact force will be too low and the speed of fall of the curtain or shutter will be unacceptably high. Furthermore, the desired contact force will depend on the weight of the shutter or curtain; a heavier shutter or curtain will require a greater contact force to inhibit fall of the curtain or shutter.

[0048] The apparatus 1 comprises emergency escape functionality in which the curtain C may be raised from a deployed position for a predetermined period of time (say, 2 minutes) in order to permit persons to pass under the curtain C. A user-operable switch (not shown) is provided in the control panel 500 to apply the emergency escape functionality. The control panel provides the connections between the motor and the primary power source (mains electricity) and the location of the reserve power source (rechargeable batteries).

[0049] The apparatus 1 comprises parameter reset functionality in which the system can be reset to default operating parameters, typically by activation of a user operable switch (not shown) provided in the control panel 500. Default operating parameters would typically comprise the curtain C being in a retrieved, non-deployed position with the brake applied.

[0050] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

[0051] In the examples above, the apparatus is used to deploy and retrieve a fire curtain or fire blind. Those skilled in the art will realise that the apparatus may be used to deploy and retrieve a different type of curtain or a shutter, such as a security shutter.

[0052] In the motor and apparatus described above, the bias means is a flat disk with arms extending from a central region to a rim. Other bias means could, of course, be used. [0053] The example above describes the use of the main brake of the motor to provide resistance to rotation of the rotor, even when the main brake is in its release mode. Alternatively, the main brake may be arranged to provide no resistance to rotation when the main brake is in the release mode, in which case an auxiliary brake may be provided to provide some resistance to rotation of the rotor. The auxiliary brake may be coupled to the rotor (for example, by being mounted in a similar arrangement to the main brake in the example above) and may comprise two brake portions which are urged into contact with one another so as to resist, but not prevent, rotation of the rotor.

[0054] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.