GB2362675A

GB2362675A - Motorised blind control apparatus

Info

Publication number: GB2362675A
Application number: GB0104484A
Authority: GB
Inventors: Derek Hepburn
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-05-23
Filing date: 2001-02-23
Publication date: 2001-11-28
Anticipated expiration: 2021-02-23
Also published as: GB0104484D0; GB0012305D0; GB2362675B

Abstract

A drive mechanism for the operation of a pull cord for blinds or curtains comprises a drive wheel 20 adapted to drive a pull cord 100. The wheel is powered by an electric motor (60, figure 1) and the mechanism can be mounted via means 40. The position of the drive wheel is adjustable, allowing it to be disengaged from the pull cord to permit manual operation. This may be achieved via the mounting means which, in a preferred embodiment, are doglegged 42, 44 allowing the mechanism to be shifted both horizontally and vertically. An electronic control unit may be included to control the rotation of the motor and may incorporate a timer 62 and a load or position sensor. The motor may run for a fixed time, the size of the drive wheel being changed to alter the distance travelled by the blind. Remote control and a solar power supply may be provided.

Description

2362675 1 1 The invention relates to a drive mechanism for the operation

of blinds or curtains. In particular, the invention relates to a drive mechanism which can be switched between an automatic mode and a manual mode.

4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 Drive mechanisms for the operation of blinds or curtains are known from the prior art. GB 2146066 describes an automatic curtain shutter, which can open or close blinds or curtains in response to the quantity of sunlight striking a sensor. No manual mode of operation is possible. US 4896713 describes a drive unit for blinds. Manual operation requires the incorporation of a clutch mechanism between the drive motor and the pinion or, alternatively, a gear of the reduction gear may be spline mounted for manual displacement.

2 2 3 4 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Automatic blind or curtain operation may increase the security of a building since it can be used to create the impression that an unoccupied building is occupied. However, it is a disadvantage of such automatic operation that it can be difficult to override manually, without providing expensive electronic controls.

It is an object of the present invention to provide a drive mechanism for the operation of blinds or curtains which may be simply and conveniently switched between an automatic mode and a manual mode of operation, and which can be readily retrofitted to existing blinds or curtains.

According to a first aspect of the present invention there is provided a drive mechanism for the operation of a pull cord for blinds or curtains comprising: an electric motor unit, a drive wheel adapted to be driven by the electric motor unit and to drive the pull cord, a mounting means for attachment of the drive mechanism to a fixed surface, and positional adjustment means adapted to allow adjustment of the drive wheel between a first position in which the drive wheel engages the pull cord and a second position in which the drive wheel is disengaged from the pull cord such that the pull cord can be manually operated independently of the drive wheel.

3 1 2 3 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 The mode of operation in which the drive wheel is in its first position, such that the drive wheel engages the pull cord, is termed the automatic mode. The mode of operation in which the drive wheel is second position, such that the drive wheel is disengaged from the pull cord and the pull cord can be manually operated, is termed the manual mode.

In a preferred embodiment, the mounting means serves as the positional adjustment means. Preferably t he mounting means comprises one or more retaining members, each retaining member engaging with a mounting slot provided in the drive mechanism. Preferably each mounting slot comprises a vertical portion and first and second substantially horizontal detent portions. Preferably, when the drive wheel is in the first position, the retaining member engages with the first detent portion, thereby preventing vertical movement of the drive mechanism. Preferably, when the drive wheel is in the second position, the retaining member engages with the second detent portion, thereby preventing vertical movement of the drive mechanism.

The retaining members may be screws or fasteners secured to the fixed surface, for example a wall or a mounting plate. When the drive wheel is in the first position, the first detent portion prevents vertical movement of the drive mechanism, while allowing a limited horizontal movement of the drive mechanism. Upon horizontal movement of the drive mechanism the 4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 retaining member moves from the first detent portion to the vertical slot, which then allows vertical and upwards movement of the drive mechanism. When the retaining member.reaches the limit of the vertical slot, further horizontal movement of the drive mechanism causes the retaining member to engage with the second detent portion, such that the drive mechanism is then in the second position. It is appreciated that a wide variety of mounting slot designs can achieve the adjustment of the drive wheel described above.

Preferably, the electric motor unit is provided with drive shaft. Preferably, the drive wheel comprises pulley unit and the pull cord comprises a cord of substantially uniform cross-section. Alternatively, the drive wheel may comprise a pinion and the pull cord may comprise a chain. Preferably, the drive wheel further comprises a rubber insert to facilitate grip of the pull cord.

Preferably, the drive mechanism further comprises a housing adapted to house at least the electric motor unit. Preferably the mounting slots are located on the housing. Alternatively, the drive mechanism further comprises a backing plate on which the mounting slots are located. Protrusions on the housing are provided to connect with the mounting slots of the backing plate.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Preferably, the housing comprises a releasable cover adapted to conceal the pulley unit. Apertures or cut-outs in the releasable cover may be provided to prevent interference.of the cover with the pull cord.

Preferably, the drive mechanism further comprises an electronic control means to control operation of the electric motor. The electronic control means may control the rotation of the electric motor such that the rotation is clockwise or anti-clockwise. Preferably, the electronic control means comprises an electronic timer to allow operation of the electric motor, and thus operation of the blinds or curtains, at times pre-selected by the user.

Preferably, the rotation of the electric motor is such as to operate the pull cord so that the blinds or curtains reach their fully open or fully closed positions and then no further rotation is attempted. This may be achieved by setting the electronic control means to effect operation of the electric motor for a pre-set duration of time. The various degrees of travel required by different types of blinds or curtains may be accommodated by the supplying of a number of sizes of drive wheel. For example the travel required may be a small travel required to rotate vanes of a blind between an open position and a closed position and vice versa, or the travel required may be a large travel required to pull a curtain or the vanes of a blind from a closed position in front of a window to an open position at 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 6 the side of a window and vice versa. Alternatively, the electronic control means may be adapted such that the duration of time that operation of the electric motor is effected may be varied by the user. Alternatively, the drive mechanism may further comprise a sensor adapted to sense either the position of the drive shaft or drive wheel or the load on the electric motor. The electronic control means may be further adapted to monitor the signal from the sensor and cease operation of the electric motor when the signal exceeds a specific magnitude. Alternatively, a combination of two or more of the duration of time, the size of the drive wheel and the signal from the sensor may be used to control the operation of the electric motor.

The electronic control means may also allow the user to instantly activate the drive mechanism independent of the timer function. This may be achieved by providing an operating switch or switches. The switch may be integral to the drive mechanism or it may be located at a remote distance. A remote switch may be connected to the electronic control means by wiring or by another means such as infra-red.

Preferably, the drive mechanism further comprises a power supply means for providing power to at least the electric motor. Preferably, the power supply means comprises a low voltage transformer. The transformer may be adapted to be connected to a standard electrical mains socket. Low voltage 7 1 3 6 cabling may be provided to supply power to the electronic control means. The power supply means may further comprise a back up battery. The battery may 4 be rechargeable. The drive mechanism may be adapted such that the rechargeable battery is being charged while the drive mechanism receives power from the mains supply. The power supply means may comprise other power sources such as solar power. The other sources may be used in addition or as an alternative to a mains source or battery power.

7 8 9 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 31 An embodiment of the invention will now be described, by way of example only, with reference to the accompanying figures, where:

Fig. 1 is a cross sectional side view of a drive mechanism according to the invention; Fig. 2 is a front view of the drive mechanism of Fig. 1 with the cover removed; Fig. 3 is a detailed sectional view showing the mounting of the drive mechanism of Fig. 1 to a wall; Fig. 4 is an isometric view of the drive mechanism of Fig. 1 with the cover in place.

Referring to Fig. 1 there is shown a drive mechanism 1 comprising an electric motor unit 10, a drive wheel 20, a mounting means for mounting of the drive mechanism 1 and positional means to allow adjustment 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 of the drive wheel between a first and second position.

The electric motor unit 10 is provided with a drive shaft 12. The drive wheel comprises a pulley unit 20 which is fitted to the drive shaft 12. The pulley unit 20 comprises two outer rims 22 and an inner section 24 of substantially smaller diameter than the outer rims 22. A rubber insert (not shown) is fitted to the inner section 24 of the pulley 20. The pull cord 100 of the blinds or curtains is looped around the lower portion of the circumference of the rubber insert.

It is to be understood that the invention is not limited to a drive wheel of the type illustrated in Fig. 1. Instead the drive wheel 20 may comprise a pinion (not shown) which engages a chain-type pull cord 100 of the type known in the art.

The various components of the drive mechanism 1 are contained within a housing 30. The housing 30 includes a releasable cover 32 which fits over the pulley 20 and fastens to the main body of the housing 30 using any conventional means 34. The releasable cover 32 is provided for aesthetic and for safety reasons. The housing 30 also includes flanges 36 at the top and the bottom of the unit.

9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 The mounting means is provided by mounting slots 40 located at the flanges 36. The drive mechanism 1 may be mounted using conventional fasteners 38.

The drive mechanism 1 further comprises an electronic control means. The electronic control means comprises an electronic circuit 60, digital display 62 and programme setting buttons 64. The electronic circuit 60 includes timer circuitry (not shown).

The drive mechanism 1 further comprises a power supply means. The power supply means comprises a low voltage transformer 50, a back up battery 52 and the associated cabling (54, 55) and connectors (56, 57). The transformer 50 can be connected to a standard electrical mains socket. Low voltage cabling 54 connects the transformer 50 to a jack plug 56. This jack plug 56 may be connected to a jack socket 57 inserted in an aperture 39 at the base of the housing 30. Wiring 55 connects the jack socket 57 to the electronic control means. Wiring 55 also connects the back up battery 52 to the electronic control means. The battery 52 is rechargeable and is charged while the drive mechanism 1 receives power from the mains supply. Further wiring 55 connects the electronic control means to the electric motor 10.

Fig. 2 shows more clearly the digital display 62 on the front of the drive mechanism 1. A clock function is provided by the timer circuitry (not shown). The user may specify various times of the day associated 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 with the operations of closing or opening the blinds or curtains. This is done using the programme setting buttons 64.

Fig. 2 also shows the flanges 36 and mounting slots 40 of the drive mechanism 1. The mounting slots 40 provide the positional adjustment means of the drive mechanism 1. Each slot 40 comprises a vertical portion 43 and first and second horizontal detent portions 44, 42. Each slot 40 has an associated retaining member 38, which in the illustrated embodiment is a screw fastener 38 mounted to the wall. The fastener 38 is not screwed tight to the wall, so that it permits movement of the flange 36 relative to the fastener 38. When the fasteners 38 are each engaged in the first upper detent portion 44 of the corresponding slot 40, the drive mechanism 1 is in the first lower position, in which the drive mechanism is in automatic mode. When the fasteners 38 are each engaged in the second lower detent portion 42 of the corresponding slot 40, the drive mechanism 1 is in the second higher position, in which the drive mechanism is in manual mode.

The drive mechanism 1 may be mounted in a second position such that, when the housing fasteners 38 are engaged in the second detent portion 42 of the mounting slots 40, the pull cord 100 is slack on the pulley 20. This is termed the manual mode as manual operation of the pull cord 100 by the user will not cause rotation of the pulley 20. Although the pull 11 1 2 3 4 5 6 7 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 cord 100 is slack on the pulley 20, it remains connected to the pulley 20 because of the greater diameter of the outer rims 22 of the pulley 20.

The entire drive mechanism 1 may be moved horizontally to the left from the second position until it becomes possible to move the drive mechanism 8 1 downwards, when the fasteners 28 engage with the vertical portions 43 of the slots 40. Further horizontal movement to the left will then become possible when the fasteners 38 engage with the first upper detent portions 44 of the respective slots 40.

When the drive mechanism 1 is in this lower first position, it is in the automatic mode. The downwards movement of the drive mechanism 1 will have caused the pull cord 100 to become taut on the pulley 20.

Operation of the electric motor 10 will cause operation of the pull cord 100.

It is appreciated that many other designs for the mounting slot 40 could produce the same function of a manual and automatic mode of operation. For example the detent portions 42, 44 may be provided on the same side of the vertical slot. The detent portions could be inclined by a small angle from the horizontal. The apparatus could include a backing plate (not illustrated) which is secured independently to the wall and on which are provided retaining members 38 (for example integrally moulded retaining pins) which engage with the mounting slots 40 on the flanges 36.

12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 Text labels 49 may be provided to inform the user of the positions representing the manual and automatic modes.

Fig. 3 is a more detailed view of the drive mechanism I fixed to a wall 102. With the drive mechanism 1 in position, the fasteners 38 are fastened to the wall 102 while within a spacer 46. The spacer 46 ensures that, when the fastener 38 is fully tightened, and the fastener head 47 is flush with the spacer 46, a gap 48 exists between the fastener head 47 and the flange 36 of the housing 30. The drive mechanism 1 is therefore free to move in the directions that the mounting slots 40 allow.

Fig. 4 is an isometric view of the drive mechanism 1 with the releasable cover 32 attached to the housing 30 (although no pull cord 100 is shown). The cutouts 33 on the releasable cover 32 prevent interference of the cover 32 with the pull cord.

Ventilation slats 35 are provided on the side of the housing 30 for cooling of the electronic control means.

Further modifications are possible without departing from the scope of the invention.

13 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Claims

1. A drive mechanism for the operation of a pull cord for blinds or curtains comprising: an electric motor unit, a drive wheel adapted to be driven by the electric motor unit and to drive the pull cord, a mounting means for attachment of the drive mechanism to a fixed surface, and positional adjustment means adapted to allow adjustment of the drive wheel between a first position in which the drive wheel engages the pull cord and a second position in which the drive wheel is disengaged from the pull cord such that the pull cord can be manually operated independently of the drive wheel.

2. A drive mechanism according to Claim 1 wherein: the mounting means comprises one or more retaining members and one or more mounting slots; and the mounting means serves as the positional adjustment means.

3. A drive mechanism according to Claim 2 wherein each mounting slot comprises a vertical portion and first and second substantially horizontal detent portions.

4. A drive mechanism according to Claim 2 or 3 wherein the mounting slot is located on the housing.

14 1 2 3 4

5 5. A drive mechanism according to Claim 2 or 3 further comprising a backing plate and wherein the mounting slot is located on the backing plate.

6. A drive mechanism according to any preceding 6 Claim wherein the drive wheel comprises a pulley unit

7 and the pull cord comprises a cord of substantially 8 uniform cross-section.

9 11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 7. A drive mechanism according to any of Claims 1 to 5 wherein the drive wheel comprises a pinion and wherein the pull cord comprises a chain.

8. A drive mechanism according to any preceding Claim wherein the drive mechanism further comprises an electronic control means to control operation of the electric motor.

9. A drive mechanism according to Claim 8 wherein the electronic control means comprises an electronic timer.

10. A drive mechanism according to Claim 8 or 9 wherein the electronic control means is adapted to control the rotation of the electric motor on both clockwise and anti-clockwise directions.

A drive mechanism according to Claim 10 wherein the electronic control means is adapted to control the rotation of the electric motor such as to cause the pull cord to move a predetermined amount so that 1 2 3 4 5 6 7 8 9

11 12 13 14 is 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 no further rotation of the motor takes place when the blinds or curtains reach their fully open or fully closed positions.

12. A drive mechanism according to Claim 11 wherein the electronic control means is adapted to control operation of the electric motor for a pre-set duration of time.

13. A drive mechanism according to Claim 12 further comprising a plurality of interchangeable drive wheels of different sizes so that the degree of travel of the blinds or curtains may be controlled by the use of drive wheels of different sizes.

14. A drive mechanism according to Claim 12 or 13 wherein the electronic control means is adapted such that the duration of time that operation of the electric motor is effected may be varied by the user.

15. A drive mechanism according to any of Claims 12 to 14 wherein the drive mechanism further comprises a sensor adapted to sense either the position of the pulley unit or the load on the electric motor, and wherein the electronic control means is further adapted to monitor the signal from the sensor and cease operation of the electric motor when the signal exceeds a specific magnitude.

16. A drive mechanism according to any preceding Claim wherein the electronic control means comprises 16 1 an operating switch or switches to allow the user to instantly activate the drive mechanism.

2 3 4 r,

17. A drive mechanism according to Claim 16 wherein the operating switch is located at a remote distance from the housing.

6 7 8 9 10 11 12 13 14 is

18. A drive mechanism according to Claim 17 wherein the operating switch communicates with the electronic control means using infra-red transmission.

19. A drive mechanism according to any preceding Claim wherein the drive mechanism further comprises a power supply means for providing power to at least the electric motor.

16 17 18 19

20 21 22 20. A drive mechanism according to Claim 19 wherein the power supply means comprises a solar power source.

21. The drive mechanism as hereinbefore described with reference to the accompanying drawings.