AU2007101193A4 - Roller door drive assembly - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION Innovation Patent Applicant(s): Smart Openers Pty Ltd Invention Title: ROLLER DOOR DRIVE ASSEMBLY The following statement is a full description of this invention, including the best method for performing it known to me/us: 2 ROLLER DOOR DRIVE ASSEMBLY

U

SThis invention relates to a roller door drive Sassembly and relates particularly but not exclusively to such for use in domestic roller door installations.

SHitherto, roller door drive assemblies have been known for the purposes of imparting drive to permit up and down rolling of a curtain of the roller door installation.

Typically, such roller door drive assemblies have been manufactured to encompass both a drive which includes an electric motor together with an electric circuit control which permits the motor to drive clockwise or anticlockwise to move the curtain up or down in a rolling motion over a curtain drum.

A problem with such known roller door drive assemblies is that the thickness of the assembly is often too thick to permit mounting to the side edge of the roller door curtain for normal operation. This occurs because the space between the edge of the roller door curtain and an adjacent side wall is very limited. In such cases, roller door drive assemblies have not been able to be used. In such cases, the door must be opened and closed manually.

There is a need for the provision of an alternative roller door drive assembly to enable a greater number of installations to be powered by a roller door drive assembly.

Therefore according to a further broad aspect of the present invention there is provided a roller door drive assembly comprising a motor, and an output for effecting rolling of a door curtain, there being a drive train drive permitting output drive from the motor to rotate the output, N2\Meboume C as\Patcn:\76DDO-76999\P76236 AJ\Specis\P76236.AU Specification 2007-12-I1 doc 13/12107 3 said drive motor, said output and said drive train U all being mounted relative to a mount surface of said Sassembly, said output being, in use, on a side of said mount surface facing towards said curtain, at least a part of said drive train being on said M side of the mount surface, said motor having an axis of drive rotation directed mutually perpendicular to an axis of rotation of said output, and wherein a diameter of a stator of said motor extends partly from an opposite side of said mount surface CI and partly from said side of said mount surface, whereby to minimise the depth of the drive assembly relative to that if the motor were mounted completely on said opposite side of said mount surface.

Most preferably said output is a crown wheel which is hollow and wherein a diameter of said stator extends partly into said hollow.

Most preferably said mount surface supports a stator, spindle bearings and brushes of said motor, without said motor having a separate casing for supporting said stator, spindle bearings and brushes.

Most preferably drive train has a clutch mechanism to release drive between said motor and said output, whereby to permit the drive to be released in the event the curtain is to be manually raised or lowered by lifting or lowering the curtain.

In order that the invention can be more clearly ascertained, examples of preferred embodiments will now be described with reference to the accompanying drawings wherein: Figure 1 is a top perspective view of a roller door N \Melboure\Cass\Patcnt\76000-76999P76236 ALI\Specis\P76236 AU Specification 2007-12-12.doc 13112/07 4 O drive assembly according to a first embodiment and taken Sfrom an outside side; Figure 2 is an underneath perspective view of the roller door drive assembly shown in Figure 1 and taken from an underside inside side; Figure 3 is an exploded perspective view of a drive Smodule, and an electric module which collectively form the 10 roller door drive assembly shown in Figures 1 and 2; C Figure 4 is a close-up perspective view of a crown wheel used to impart drive to the roller door curtain; Figure 5 is a part cross sectional close-up side view showing the roller door drive assembly fitted at a right hand side edge of a roller door adjacent the roller door curtain; Figure 6 is a perspective view of an angle bracket that is used for mounting an axle shaft of the roller door relative to a facia wall or the like where the roller door is installed; Figure 7 is a view, similar to that shown in Figure showing how the drive module has been separated from the electrics module and wherein the drive module is inserted within a curtain drum of the roller door; Figure 8 is a view similar to Figure 3 showing a casing of the drive module separated and with components in semi-exploded view; Figure 9 is a view similar to Figure 8 and showing an exploded arrangement of a stator of the motor separated from a rotor of the motor; N:elboume\Cases\Patent\76000-76999\P76236.AU\Spcis\P76236AU Specification 2007-12-12d c 13/12107 O Figure 10 is a view similar to that in Figure 8 but U showing an exploded view taken from the opposite side of Sthe roller door drive assembly; Figure 11 is a close-up perspective view of rotor supports; Figure 12 is a perspective view of the rotor of the motor; Figure 13 is a close-up perspective view of the C stator of the motor; Figure 14 is a perspective view of a mount for brushes of the motor; Figure 15 is a perspective of brushes of the motor carried on a backing and held to the mount shown in Figure 14; Figure 16 is an assembled perspective view of part of the drive train of the assembly; Figure 17 is an exploded perspective view of the components of parts of the drive train shown in Figure 16; Figure 18 is a perspective view of a dog clutch release pin used in the drive train shown in Figure 16, and, Figure 19 is a close-up perspective view of a gear wheel used in the drive train shown in Figure 16.

Referring now to Figures 1 7, it can be seen that the roller door drive assembly 1 has a drive module 3, being an upper part of the assembly 1, and an electrics module 5 forming a lower part of the module 1. The drive N:\Melboume\Cases\Patent\76OOO-76999\P76236.A1SpcisP76236 AU Specification 2007-I2-I1doc 13/12/07 6 O module 3 has a casing 7 and the electrics module 5 has a Scasing 9 both made from a suitable plastics material. The Sdrive module 3 carries a crown wheel 11 that has a pair of Sprotruding fingers 13. The fingers 13 extend axially aligned with a longitudinal central axis of a roller door as will become apparent. The fingers 13 are used to M locate between spokes of a drum wheel that forms part of the roller door. The curtain of the roller door, in turn, can roll onto and off the drum wheel in overlapping layers so that the curtain provides a curtain drum. The crown wheel 11 rotates the curtain drum so as to permit an up C and down rolling of the curtain. Instead of a crown wheel the drive module may carry an output such as suitable drive for rotating the curtain drum. Crown wheels 11, of the type disclosed herein, have been used previously in prior art roller door drive assemblies. An axle of the drum is held stationary relative to surrounding facia wall surfaces of an opening which the roller door curtain closes. Accordingly, the crown wheel 11 rotates about a stationary axle as will be described hereinafter. Figure 3 best shows that the drive module has a circular shaped mount surface 15 which is typically formed from sheet steel although it may be formed of other material such as industrial grade plastics. The mount surface 15 is generally planar and has approximately the same diameter as the external diameter of the crown wheel 11. The crown wheel is typically made from an industrial grade plastics material but may be made from metal or similar. Within the casing 7 of the drive module 3, there is provided a motor in the form of a DC motor. If required, an AC motor could be utilised, however, it is preferred to use a DC motor to facilitate easy reversal of rotation of the motor to, in turn, impart clockwise or anticlockwise drive of the crown wheel 11 to effect up and down rolling of the door curtain. This reversal of rotation is effected with a D.C. motor by a polarity reversal of the applied voltage. A drive train (to be referred to hereinafter) N:\Melboue\Caems\Patent\760076999\P76236 AI\Specis\P76236AU Specifcation 2007-12-12.doc 13/207 7 interconnects the motor with the internal surface of the crown wheel 11. The whole of interior of the crown wheel 11 is shown in Figure 8. In Figure 8, internal gear teeth on the internal perimeter of the crown wheel have not been shown in order to simplify the drawings. Figure 8 clearly shows that the crown wheel 11 is hollow. This provides a Sdepth across the crown wheel teeth sufficient to impart the necessary torque loadings to effect up and down movement of the door curtain. A spur gear (to be referred 1io to hereinafter) forms part of the drive train, and engages Swith the gear teeth on the internal surface of the crown C1 wheel 11. Figures 2 and 3 clearly show that the crown wheel 11 has a ball bearing race 17 embedded therein to form a bearing for smooth rolling movement relative to the axle of the door curtain. An annular cover plate 19 is press fitted into the crown wheel 11 to hold and seal the ball bearings against the ingress of dust. Whilst the crown wheel 11 is typically an internally toothed crown wheel, it may simply be a crown wheel without teeth and wherein friction drive from suitable drive wheel(s) is imparted to the internal circumferential surface to effect rotation.

Figure 5 shows the roller door drive assembly 1 fitted to the right hand side edge of a roller door 21.

Figure 5 also shows an axle 23 of the curtain drum which extends generally horizontally and is fixed by an angle bracket 25 shown in Figure 6 to surrounding facia wall surfaces of an opening which closes the door. The vertical leg of the angle bracket 25 is fastened to the facia surfaces so that the upper horizontal leg 27 carries the axle 23 and the weight of the roller door 21. The upper leg 27 has two apertures 29 therein through which a bolt 31 can be passed and tightened to physically lock and hold the axle 23 in an operative position. A similar bracket 25 is provided on the opposite side of the door curtain. The roller door 21 has a right hand side drum N.Melboume\Ce\Pateni\760DO-76999P76236 AU'Spmi,\P76236.AU Spcification 2007.12-12dc 13/12107 -8 0 wheel 33 and a corresponding left hand side drum wheel not Sshown. The respective wheels 33 are rotatably mounted to Sthe axle 23 adjacent respective side edges of the roller door curtain 35. The drum wheels 33 are able to freely rotate axially about the longitudinal central axis of the axle 23. Suitable roller bearings (not shown) may be c provided in the drum wheels to facilitate such rotation, or alternatively the wheels 33 may have a loose tolerance fit relative to the axle 23. The drum wheels 33 have radially extending spokes 37 and the fingers 13 locate relative to the spokes 37 so that a clockwise and Cl anticlockwise rotational drive can be imparted from the drive module 3 to a drum wheel 33. The curtain 35 is attached relative to the outer surface of the drum wheels 33, and rotation of the drum wheels 33 causes the curtain to form a curtain drum, which, in turn, rolls or unrolls as the curtain is opened and closed.

Figure 3 shows that the mount surface 15 carries a mount 37. The mount 37, in turn, extends perpendicular to the plane of the mount surface 15 and has an upper arcuate shaped recess which receives the axle 23 therein. Thus, when the bolt 31 is fastened to the angle bracket the bolt 31 also clamps the axle 23 thereto and also clampingly holds the drive module 3 relative to the angle bracket 25. The bolt 31 therefore not only clampingly holds the axle 23 relative to the angle bracket 25, but it also holds the drive module 3 fixed relative to the angle bracket Typically, the roller door drive assembly 1 is mounted adjacent a side edge of the curtain 35 as shown in Figure 5. With this arrangement, a distance X is shown between the end of the curtain 35 and the end of the axle 23. The distance X represents the minimum side space required to mount the roller door 21 and the roller door drive assembly 1. In some installations, the available N \Melboumc\Caes\Patent\760-76999\P76236 AU'.Specis\P76236.AU Specification 2007-12-12doc 13/12/07 9 space is less than the distance X. Thus, in the prior U art, unless the roller door drive assembly 1 can be Smounted to the opposite side edge of the roller door 21, then a motor driven door opener cannot be provided. This has represented a serious problem for installers of roller door drive assemblies in the past.

Figure 1 4 show that the mount surface 15 has a radial external dimension that will enable the drive module 3 to be operatively fitted within the roller door Scurtain drum. In the example shown, the mount surface C is circular and has approximately the same external diameter as the external diameter of the crown wheel 11.

Figure 5 shows that the external diameter of the crown wheel 11 and the drive module 13 have approximately the same diameter as the outside diameter of the drum wheel 33. Thus, in this situation, the crown wheel 11 and the drive module 3 can be separated as a single unit from the electrics module 5, and the drive module 3 inserted wholly within the curtain drum of the curtain 35 as shown in Figure 7. Here, a further bolt 39 can be used to fasten the drive module 3 relative to the axle 23. Whilst the mount surface 15 has been shown circular, it may have other profiles. Importantly however, the radial external dimensions of the drive module 3 are such that they will enable the drive module 3 to be operatively fitted within the roller door curtain drum.

The mount surface 15 is sized to, in use, extend in a direction diametrically across the axle 23 of the curtain and wherein the casing 7 thereof is predominantly on one diametric side, and so the electrics module 5 can be mounted to the mount surface 15 on the diametrically opposite side.

Whilst Figure 5 shows the crown wheel 11 mounted outside of the side edge of the curtain 35, it should be N:\Melboume\Cascs\Patcn\76000-76999\P76236AU\Specis\P76236AU Specification 2007-I2-12.doc 13/12107 10 O appreciated that it may be mounted partly within the 0 curtain drum to further minimise the space X. However, as Swill be disclosed hereinafter, the minimum distance X is M then ultimately determined by the length along the longitudinal axis of the axle 23 that extends past the side edge of the curtain Known roller door drive assemblies have other Sinherent depth disadvantages which are overcome with 10 embodiments to be described.

C Figure 3 shows that the drive module 3 has a cooperating surface 41 forming part of the mount surface Figure 10 best shows that the electrics module 5 has corresponding mount surfaces 43. The electrics module has bolt apertures 35 which align with corresponding threaded bolt apertures 47 on the electrics module 5 and in the mount surface 15. Accordingly, the electrics module 5 can be held to the drive module 3 by suitable mounting means such as, for example, bolts 49. Thus, when the electrics module 5 is mounted relative to the drive module 3, the electrics module 5 extends radially outermost of radial external dimensions of the drive module 3. In such assembled relationship, the roller door drive assembly 1 cannot itself be fitted within the roller door drum curtain. Thus, if there is insufficient space at the side edge of the roller door, then the electrics module 5 can be separated from the drive module 3 enabling the drive module 3 to be fitted within the curtain drum.

The electrics module 5 can then be mounted at a distant position adjacent the roller door and electrically operatively interconnected with the drive module 3 such as by electric conduit leads Figure 7 clearly shows the arrangement where the drive module 3 is mounted within the drum curtain, and where the electrics module 5 is at a distant position N.\Mclboune\Cases\Patent\760D-76999\P76236AU\Specis\P76236AU Specification 2007-I2-I2doc 13/12/07 11 interconnected by electrical conduit leads 45. The Selectrics module 5 may itself be powered by mains power S(not shown) or by some other suitable energy source not shown.

Referring now generally to Figures 8 19, it can be Sseen that the roller door drive assembly 1 has the drive module 3 with a motor 51 that has an axis of drive rotation that is directed mutually perpendicular to an axis of rotation of the crown wheel 11. Here, a spindle 53 of a motor 15 carries an armature 55 with a commutator C 57. The electric windings have not been shown in order to aid clarity in the drawings. The rotor of the drive motor is best shown in Figure 12. The windings are terminated with the commutator 57 by tails 59 that can be suitably electrically fastened thereto such as by soldering or the like. Spindle 53 carries a worm thread 61 at one end, and each end of the spindle 53 carries a ball race 63. The spindle 53 is held relative to the mount surface 15 by mounting the ball races 63 in race supports 65 which are bolted relative to the mount surface 15 by bolts 67. The bolts 67 pass through openings 71 in the race supports The bolts 67 are screw threadably engaged in suitable apertures in the mount surface 15. The race supports are shown in Figure 11 and have circular cut-outs 67 which press-fittingly receive the race supports Typically, the race supports 65 are made from a suitable metal such as a die cast metal but they may be made from other suitable material such as industrial grade plastics.

Figures 8, 9 and 10 show that the mount surface 15 has a cut-out 73 of sufficiently large dimensions so that a part of the stator 75 and a part of the armature 55, forming a rotor of the motor 51, can be received therein. In other words, the diameter of the stator 75 of the motor 51 extends partly from one side of the mount surface 15 and partly from the opposite side and into the hollow interior of the crown wheel 11. With this arrangement, the spindle N:\Melboure\Cases\Patent\76OO-76999\P76236 AL\Speis\P76236AU Specification 2007-12-12.doc 13/12/07 12 O 53 of the motor 51 is spaced immediately adjacent the mount surface 15 and is closer to the surface thereof than Sif the rotor and the stator of the motor had to be accommodated wholly on one side of the mount surface Thus, the displacing of the rotor and the stator of the motor partly through the cut-out 73 in the mount surface utilises space within the hollow crown wheel that in the prior art was previously unused for reducing the thickness of the overall drive module. The arrangement also obviates the need for any complicated mounting housing of the motor relative to the mount surface 15. In C this arrangement, the stator 75 is essentially an annular sleeve as shown in Figure 13. Here, there is outer sleeve part 77 that may be made from metal or an industrial grade plastics. Figure 13 shows two half-circular permanent magnets 79 that form part of the stator 75. The permanent magnets 79 may be press fitted therein or alternatively may be adhered thereto by means of a suitable adhesive.

Figure 13 shows a first notch 81 and a second notch 83.

Notch 81 is disposed centrally along the longitudinal axis of the sleeve 77, and notch 83 is at one side edge of the sleeve 77 diametrically opposite notch 81. A similar notch 83 is provided on the other side of the sleeve 77 (this notch cannot be seen in Figure 13). Figure 8 shows an upstanding post 85 extending from the mount surface which has a head end tongue that fits in the notch 81.

Figure 8 also shows a mounting bracket 87 with two tongues 89. The mounting bracket 87 is bolted to the mount surface 15 and the two tongues 89 locate in the respective notches 83. This therefore holds the sleeve 77 captive relative to the mount surface 15. As an alternative, the mounting bracket 87 and the post 85 may be formed integrally with the material of the mount surface 15 so there can be snap lock press fitting engaging of the sleeve 77 relative to the mount surface Figure 14 shows an angle bracket 91 used for mounting N:\Melboue\Cases\Patent\76000.76999 \P76236AL\Specis\P76236AU Specification 2007-12-12doc 13/I1207 13 brushes 95 of the motor relative to the commutator 57.

SThe mounting bracket 91 is fastened relative to the mount Ssurface 15 so that an arm 93 extends mutually perpendicularly therefrom across the commutator 57.

Figure 15 shows the brushes 95 mounted in brush housings 97 mounted to a brush sub panel 99. The sub panel 99 can M be made from a suitable electrically insulating material.

The brush housings 97 can be fastened relative to the sub panel 99 by fingers that pass through suitable openings in the sub panel 99 and bent to hold the brush housings 97 captive on the sub panel 99. The brushes 95 may be spring CI loaded in a known manner and suitable electrical tails 101 connected therewith.

As the spindle 53 of the motor rotates, it, in turn, causes the worm thread 61 to rotate a gear wheel 103 (see Figure The gear wheel 103 has not been shown with teeth in order to aid clarity in the drawings. The gear wheel 103, in turn, drives a pinion gear 105 through a dog clutch mechanism to be described in due course. The gear wheel 103 is mounted on the same side of the mount surface as the spindle 53 of the motor. The pinion gear 105 is mounted on the opposite side as clearly shown in Figure Pinion gear 105 drive engages further pinion gear 107 which, in turn, drive engages with the teeth on the internal circumferential surface of the crown wheel 11.

Thus, a drive train is established between the motor 51 and the crown wheel 11.

Figures 9 and 10 show a further series of gears 109 that drive engage with the teeth on the internal surface of the crown wheel 11. These further gears 109 are used to activate limit sensing means for sensing the up and down stop positions of the curtain 35 of the roller door so that the motor can be switched OFF when the curtain reaches those positions. They have not been described in detail as they form one known type of means per se for N:\Melboume\CaSC\Patent\76000-76999\P76236 ASpeci3\P76236AU Specification 2007-12-I2do c 13/12/07 14 sensing the up and down limit positions.

SThe dog clutch mechanism for releasing drive between the motor and the crown wheel 11 will now be described with reference to Figures 16 19. It should be realised that it is necessary to disengage the drive train if the

M

r door is to be manually raised if there is a power failure as otherwise the mechanical advantage of the drive train would inhibit the manual opening of the door. The dog clutch arrangement is provided by a spindle 111 that can slide longitudinally axially within an axle part of the ^C gear wheel 103. Figure 17 shows an exploded view of the components of the dog clutch. Here, an axle 113 has a hollow longitudinal bore 115. The external diameter of is the axle 113 is such that the gear 103 can be fitted thereto so that it is rigidly drive connected with the axle 113. The external diameter of the axle 113 also corresponds with the internal diameter of a corresponding bush 117 fixed relative to the mount surface 15 (see Figure The pinion gear 105 is rotatably slidably received over the axle 113 so it can rotate independently of the axle 113. The spindle 111 has a head 119 extending in a radially outwardly direction from the central longitudinal axis of the spindle 111. Thus, the spindle 111 and the head 119 form a T shaped drive pin. This is shown in Figure 18. The drive pin is made from a suitable material such as metal. The dog clutch is held captive relative to the mount surface 15 by respective washers 121 and 123 and respective circlips that locate in respective circlip grooves 129/131 in the axle 113 and in the spindle 111. A coil compression spring 133 applies a force to pull the head 119 of the T shaped spindle 111 inwardly relative to the axle 113. Figure 17 and 19 clearly show that an internal side face of pinion gear 105 is provided with mutually perpendicular two pairs of slots 135.

Accordingly, the head 119 is normally held withdrawn and engaged in a diametrically pair of slots 135. The head N \Melboure\Cases\Patent\76000-76999\P76236 AU\Specis\P76236.AU Spcification 2007-12-12.doc 13/1207 15 O 119 will also pass through a cut slot 137 in the axle 113.

SAccordingly, under this arrangement, rotation of the axle S113 from the gear wheel 103 will cause the head 119 to be driven through the engagement with the side walls of the slot 137 and will also, in turn, cause the pinion gear 105 to be drive engaged with the pinion gear. Accordingly, Swhen the spindle 111 is withdrawn internally longitudinally axially of the axle 113 there will be direct drive engagement between the gear wheel 103 and the pinion gear 105. If the spindle 111 is extended relative to the axle 113 by pressing on the remote end of the C spindle 111, then the head 119 will disengage from the side walls of the slot 137 and from the slots 135 in the pinion gear 105. Thus, under this arrangement, the drive train link will be interrupted. Accordingly, if there is interruption of electric power, then there can be disengagement of drive so that the pinion gear 105 can freely rotate relative to the axle 113 permitting manual raising and lowering of the curtain of the door.

Figure 1 shows a thumb wheel 139 that is screw threadably received into an arm 141 (see Figure that is, in turn, held relative to the mount surface 15. Thus, the thumb wheel 139 can be screwed inwardly which, in turn, causes the spindle 111 to be depressed so that the head 119 displaces from the slots 135 and 137 and permits disengagement of drive. Operation of the thumb wheel 139 in the opposite direction causes drive engagement.

The thumb wheel 139 represents a simple mechanism for displacing the spindle 111 to permit engagement and disengagement of drive from the motor through to the crown wheel 11.

Figure 10 shows that the electrics module 5 has user operable push button controls on a face of the casing of the electrics module 5 that faces towards the roller door N:\Meboumc\Cas\Paent\76000-76999\P76236 AU\Specis\P76236AU Spcification 2007.12-12doc 13/ 2/07 16 0 curtain. This is provided on that face so as to permit Srelatively easy access for interface for a person wishing to operate the roller door drive assembly directly from the electrics module 5. Typically, the electrics module contains a remote radio receiver device to permit remote radio control of operation of the roller door drive Sassembly.

SIt is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part Cl of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Modifications may be made to the embodiment described herein without departing from the ambit of the invention, the nature of which is to be determined from the foregoing description.

N \Melboume\Caws\Pant\76DOO-76999\P76236 ALNSpecis\P76236AU Spccification 2007. 2-12.doc 13/12/07

Claims (4)

1. A roller door drive assembly comprising a motor, and an output for effecting rolling of a door curtain, there s being a drive train drive permitting output drive from the motor to rotate the output, Ssaid drive motor, said output and said drive train all being mounted relative to a mount surface of said assembly, said output being, in use, on a side of said mount surface facing towards said curtain, C at least a part of said drive train being on said side of the mount surface, said motor having an axis of drive rotation directed mutually perpendicular to an axis of rotation of said output, and wherein a diameter of a stator of said motor extends partly from an opposite side of said mount surface and partly from said side of said mount surface, whereby to minimise the depth of the drive assembly relative to that if the motor were mounted completely on said opposite side of said mount surface.

2. An assembly as claimed in claim 6, wherein said output is a crown wheel which is hollow and wherein a diameter of said stator extends partly into said hollow.

3. An assembly as claimed in claim 6, wherein said mount surface supports a stator, spindle bearings and brushes of said motor, without said motor having a separate casing for supporting said stator, spindle bearings and brushes.

4. An assembly as claimed in claim 6, wherein said drive train has a clutch mechanism to release drive between said motor and said output, whereby to permit the drive to be released in the event the curtain is to be manually raised or lowered by lifting or lowering the curtain. N:\MclboumcCases\Patent\76000-76999P76236 AT\Spcis\P76236AU Specificaion 2007-12-I12doc 3/I 2/07 -18 An assembly as claimed in any one of the preceding claims and substantially as herein described with reference to the accompanying drawings. N 'Melboume\Cases\Patent\76000.76999\P76236 AtA\Specis\P76236.AU Specification 20071-2 2doc 13/1 2/07