WO2005033463A1

WO2005033463A1 - System for moving blinds

Info

Publication number: WO2005033463A1
Application number: PCT/NL2004/000712
Authority: WO
Inventors: Marinus Henricus Maria Schoonen
Original assignee: Holding Nutsbedrijf Westland NV
Current assignee: Holding Nutsbedrijf Westland NV
Priority date: 2003-10-09
Filing date: 2004-10-08
Publication date: 2005-04-14
Anticipated expiration: 2006-04-09
Also published as: EP1678405A1; NL1024498C2

Abstract

Assembly consisting of a roller and a drive. The roller serves for winding or, alternatively, unwinding a fabric blind thereon/therefrom. When the fully opened or fully closed position is reached a mechanical switch is operated in the drive between electric motor and roller by means of an end tab fitted on the fabric blind. This drive has a slipping clutch. As a result of the operation by the end tab, the drive to the roller is interrupted. The slipping clutch is so designed that the electric motor can continue to run for some time without actual damage.

Description

Title: System for moving blinds

The present invention relates to an assembly comprising a roller for accommodating a fabric blind and a drive positioned in line therewith, said drive comprising an electric drive motor, wherein limit switching means are present for stopping the rotation of said roller in an end position thereof.

Such an assembly is generally known in the state of the art. This is used, for example, in a tube motor, that is to say a construction where the electric motor including drive is accommodated in the roller. To determine the end positions of the roller, that is to say the fully rolled up and fully lowered position of the blind, there is a construction that counts the number of revolutions of the roller and halts the operation of the motor by electronic means.

Such a construction is expensive to produce. Moreover, it has been found that this construction does not function well in practice. After all, if for some reason or other the blind does not move between the end positions the motor will remain energised. Such energising continues until the motor has been damaged. In the state of the art it has been proposed to propose electronic protection measures, but it has been found that these, on the one hand, substantially increase the cost price and, on the other hand, still do not guarantee optimum operation of the assembly.

This problem is even more apparent if various blinds controlled simultaneously by different drives are opened or, alternatively, closed with the aid of a central control unit. With this arrangement malfunctions are found to occur regularly, with damage to the motors.

GB 1 067 371 discloses a system for rolling up heavy metal panels. This consists of a motor drive with drum component permanently mounted on a wall. There is another drum component on the other wall and this is driven by the motor drive via an auxiliary shaft. There is a return spring. Furthermore, there is a clutch. This clutch is cable-operated and can be used if the motor has to be decoupled from the roller parts for any reason. The problems mentioned above cannot be solved by this means. The aim is to overcome these disadvantages and this aim is realised in an assembly as described above in that the limit switching means comprise a clutch, between said drive motor and said roller, that limits transmission moment, and operating means for said clutch.

According to the present invention a slipping clutch is fitted between the electric motor and the roller. Should the movement of the roller be stopped for any reason and the motor still be operated, as a result of the slipping clutch the motor can continue to run without damage occurring to it in the longer term. That is to say the maximum moment that can be transmitted by the motor to the roller is limited, as a result of which damage to the motor is prevented. Moreover, according to the present invention the clutch is operated when the end point of the blind is reached. According to an advantageous method, said operation comprises locking means coming into effect. That is to say when an end position is reached the roller is locked and is not able to perform any further movement. The electric motor can then continue to run for some time, with slipping of the clutch, without damage. This operation can be either electrical or mechanical. A particularly simple embodiment can be achieved mechanically by fitting tabs or the like on the blind that engage on a lever or the like fitted on the drive, which lever, in turn, engages on, that is to say locks, the part of the clutch connected to the roller. The various features are preferably so constructed that locking can be obtained in two directions. That is to say, both locking against further unrolling and locking against further rolling up of the blind is achieved.

The clutch preferably comprises a spring-loaded clutch. More particularly, this spring loading is adjustable. Depending on the weight of the blind, the length thereof and the like, the spring force on the clutch can be so adjusted that slipping already occurs when the electric motor is slightly overloaded. By this means damage to both the electric motor and to the blind can be prevented in situations where the blind is not guided upwards or downwards in the correct manner.

The drive can be accommodated either inside or outside the roller.

With the present invention time-controlled switching of the electric motor is possible. That is to say if a blind, for example, has to be opened, the electric motor is operated for a relatively long period. The blind will have reached the open position in a relatively short time and in that position the clutch at the side of the roller will be locked so that force is no longer exerted on the roller. The electric motor then continues to run for some time, slipping with the clutch, without this, however, causing damage.

Such a construction is interesting in particular if a system is used that comprises at least two assemblies as described above. After all, at that point in time the control of the electric motors is no longer critical and a relatively long time can be taken for moving the blinds both upwards and downwards. Each blind will cut out in the correct position when the lowest point is reached. Everything is determined on the basis of movement and not on the basis of time or number of revolutions completed. In this way (various blinds) problems are solved that arise from the fact that some blinds move more rapidly and/or move further than other blinds.

In general, no or hardly any drive moment will be transmitted by the motor when unwinding the blind. In such a case it is possible, as an alternative, to measure the movement of the blind and to switch off the motor depending on that movement. Such movement can be measured by counting the number of revolutions of the roller on which the fabric has been wound, h this way provision can be made that the blind always reaches a completely closed position, as a result of which complete light-tightness can be achieved.

As a result of use of the locking, which is effective both in the rolled-up and lowered position of the blind, it is no longer necessary to provide the system with self-braking capability. That is to say it is not necessary to use self-braking electric motors. After all, the weight of the blind can easily be supported by the locking mechanism. The motor is further protected by this means as well.

The invention will be explained in more detail below with reference to an illustrative embodiment shown in the drawing, hi the drawing:

Fig. 1 shows, diagrammatically, a perspective view of a system comprising two assemblies according to the invention; Fig. 2 shows a detail of the drive/roller according to the present invention in a first embodiment;

Fig. 3 shows an exploded view of various components of part of the drive according to Fig. 2; and

Fig. 4 shows a variant of the drive.

In Fig. 1 a system consisting of two assemblies 1, each comprising a blind 5 that has to be wound around a roller 4 with the aid of a drive 6, is indicated in its entirety by 2. These two assemblies 1 are controlled with a controller 7. The system is fitted in a wall, the columns of which are indicated by 3. The blind 5 is wound up or, alternatively, unwound by rotating roller 4. The blind 5 is provided with end tabs 33 and 34.

Details of the drive 6 and the part of the roller 4 are shown in Fig. 2. The drive consists of an electric motor 8, a clutch 9 and a reduction gear 10 com ected after these.

The reduction gear 10 is a conventional double planetary transmission 24 with the conventional satellites, sun gears and the like. The fixed housing is indicated by 26.

As can be seen from comparison of Figure 2 and 3, the output shaft 11 of motor 8 is joined to a sleeve 13 such that these cannot turn with respect to one another. This sleeve 13 is provided at one end with a cheek 15 and is provided at the other end with a screw thread 14 onto which a milled nut 12 can be screwed over a greater or lesser distance. The sleeve 13 is provided with toothing 16. Clutch plates 19 are provided with corresponding internal toothing, that is to say are fitted on the sleeve 13 such that they cannot turn. Clutch plates 20 that can rotate freely around sleeve 13 but are provided with external toothing are located between the clutch plates 19.

There is a spring group 23 that at one end bears on the clutch plates 19, 20 and at the other end bears on nut 12 with a sleeve 25 positioned between them. The sleeve 25 runs with milled nut 12 in the longitudinal direction of the sleeve 13 along the screw thread 14. There is a groove 21 in which a circlip 22 has been fitted. The sleeve 25 strikes this so that it is not possible to tension the spring packet 23 to an unlimited extent. This means that the maximum spring loading is determined by specifying the strength of the springs and the position of groove 21 and that, starting from this, the spring loading can be reduced by unscrewing the nut 12.

The external toothing on the clutch plates 20 engages a clutch housing 17 and more particularly on internal toothing 18 thereof. The clutch housing 17 is joined to the input gear of the first planetary transmission 24 such that these cannot turn with respect to one another.

External recesses 29 have been made on the clutch housing 17. A locking projection 30 can be moved therein. This movement is controlled by movement in the direction of arrow 31 caused by lever 32. As can be seen from Fig. 1, lever 32 is so positioned that it can be operated by the end tabs 33, 34.

The construction described above functions as follows. Starting from the blind in the rolled-up position it is decided to lower the blind completely. For this purpose the two motors 8 in the construction shown in Fig. 1 are operated with the control unit 7 for a sufficiently long time that it is always ensured that the blind 5 completely unwinds.

When the lever 32 is operated by end tab 34, the clutch 9, and more particularly the clutch housing 17, will be locked. As a result the blind is in a fixed end position. However, the various features are arranged in such a way that at that point in time the electric motor has not yet been switched off. This then continues to run, as a result of which the clutch 9 slips without this causing damage to either the clutch or the motor 8.

If a relatively heavy blind has to be moved or the movement does not proceed easily, the nut 12 can be tightened by adjustment so as by this means to set the spring force on the clutch group and delay the slip moment.

In this way the blinds 5 can be lowered to a specific point with individual control and are then locked. Such a construction is particularly simple and inexpensive to produce. A variant of the construction shown in Figs 2 and 3 is shown in Fig. 4. hi this variant the roller 4 moves together with the drive 36 up and down along column 3 (see Fig. 1). That is to say, the blind is fixed at the top and when it rolls up on roller 44 the drive 38 also moves up and down. To this end there is a guide section 40 provided with wheels 41 that can move along column 3. In the embodiment according to Fig. 4 the electric motor 3S is connected to the clutch via a right-angled transmission 39. hi other respects tins construction functions correspondingly to what has been described above.

Any clutch plate material used in the state of the art can be used for the clutch described above. Examples of such materials are sintered bronze plates and plates with any other lining. Moreover, the clutch plates can be provided with grooves and the like.

After reading the above, variants will be immediately apparent to those skilled in the art. These fall within the scope of the present claims.

Claims

1. Assembly (1) comprising a roller (4) for accommodating a fabric blind (5) and a drive (6, 36) positioned in line therewith, said drive (6, 36) comprising an electric drive motor (8, 38), wherein limit switcmng means are present for stopping the rotation of said roller in an end position thereof, characterised in that the limit switching means comprise a clutch, (9) between said drive motor and said roller, that limits transmission moment, and operating means (30-34) for said clutch.

2. Assembly according to Claim 1, wherein said operating means comprise locking means for said roller.

3. Assembly according to one of the preceding claims, wherein said operating means comprise mechanical operating means.

4. Assembly according to one of the preceding claims, wherein said operating means comprise a stop lever (32) and the blind is provided with stop tabs (33, 34) interacting therewith.

5. Assembly according to one of the preceding claims, wherein said clutch comprises a spring (23) loaded clutch.

6. Assembly according to Claim 5, wherein said spring loading is adjustable.

7. Assembly according to one of the preceding claims, wherein said drive is accommodated in said roller.

8. System comprising at least two assemblies according to one of the preceding claims as well as a central controller (7), wherein said controller is designed to drive each of said electric motors (8, 38) at the same time.

9. System according to Claim 8, wherein at movement of said blind, said controller operates said motors for longer than is necessary for said movement of said blind.