EP3091168A1

EP3091168A1 - A screening device for a window, a method for operating an electric screening device and use of a screening device

Info

Publication number: EP3091168A1
Application number: EP16168140.8A
Authority: EP
Inventors: Jan Thomsen
Original assignee: VKR Holding AS
Current assignee: VKR Holding AS
Priority date: 2015-05-07
Filing date: 2016-05-03
Publication date: 2016-11-09
Anticipated expiration: 2036-05-03
Also published as: EP3091168B1

Abstract

Disclosed is a screening device (1) for a window (2). The screening device (1) comprises a drive unit (3) including a transversal profile (4) arranged to run along guide means (5) extending transversally at the longitudinal ends of the transversal profile (4), wherein the transversal profile (4) comprises an electrical motor (6) arranged to move the transversal profile (4) along the guide means (5) by means of engaging means (7) arranged to engage the guide means (5). The transversal profile (4) further comprises position means (8) arranged for detecting at least a motorized change of the position of the transversal profile (4) in relation to the guide means (5) and at least one end position sensor (9) for detecting an end position of the guide means (5). The screening device (1) also comprises screening means (10) including a first end (11) being connected to the transversal profile (4) and a second end (12) comprising connection means (13) for being fixed at an end of the guide means (5) and release means (14) arranged to selectively engage or disengage the electric motor (6) from the guide means (5) to enable both manual and motorized displacement of the transversal profile (4) in relation to the guide means (5). Furthermore, the screening device (1) comprises control means (15) arranged for controlling the operation of the electrical motor (6) in accordance with input from the position means (8) and the end position sensor (9).

A method for operating an electric screening device (1) for a window (2) and use of a screening device (1) is also disclosed.

Description

Background of the invention

The invention relates to a screening device for a window. The screening device comprises a drive unit including a transversal profile, wherein the transversal profile comprises an electrical motor arranged to move the transversal profile.
A method for operating an electric screening device for a window and use of a screening device is also disclosed.

Description of the Related Art

Motorised screening devices for windows are known in the art e.g. to quickly black out a room or just to simplify the operation of curtains, blinds or the like. Typically, in relation with some sort of wired or wireless remote control. And particularly in relation with roof windows and skylights the demand for motorized screening devices is pronounced because these types of window usually are mounted in a relatively remote part of a building and therefore often is difficult to reach or access.
However, sometimes it is necessary or desirable to manually operate such motorised screening devices and from US 4,807,686 it is therefore known to provide a motorised window shading device with means for manually disengaging the drive means to enable manual operation of the shading device. However, the functionally of this shading device is quite limited.
An object of the invention is therefore to provide for an advantageous shading device technique having more functionality.

The invention

The invention provides for a screening device for a window. The screening device comprises a drive unit including a transversal profile arranged to run along guide means extending transversally at the longitudinal ends of the transversal profile, wherein the transversal profile comprises an electrical motor arranged to move the transversal profile along the guide means by means of engaging means arranged to engage the guide means. The transversal profile further comprises position means arranged for detecting at least a motorized change of the position of the transversal profile in relation to the guide means and at least one end position sensor for detecting an end position of the guide means. The screening device also comprises screening means including a first end being connected to the transversal profile and a second end comprising connection means for being fixed at an end of the guide means and release means arranged to selectively engage or disengage the electric motor from the guide means to enable both manual and motorized displacement of the transversal profile in relation to the guide means. Furthermore, the screening device comprises control means arranged for controlling the operation of the electrical motor in accordance with input from the position means and the end position sensor.
Controlling the operation of electrical motor on the basis of input from both the position means and the end position sensor is advantageous in that the position means enables that the transversal profile may be directed to any position in automated operation - not just fully open or fully closed. Since the position means continually detect the position of the transversal profile it is possible for an operator to order the screening device - e.g. by means of a remote control - to go to and stop when 30% of the window is covered.
Furthermore, the position means enables that the traveling speed of the transversal profile may be controlled according to its position - e.g. faster at the middle and slowing down when approaching an end position.
However, if the position means is disengaged - to enable manual operation - the position means will lose track of the exact position of the transversal profile. It is therefore advantageous to also control the operation of the electrical motor in accordance with input from the end position sensor in that this enables that the travel of the transversal profile may be stopped when an end position has been reached - even if the position means detect a different position - and because the end position sensor enable fast and simple re-calibration of the position means after manual operation.
It should be noted that the term "guide means" in this context should be interpreted as any kind of guide suited for being engaged by an electrical motor of a drive unit i.e. any kind of rail, rack, track, string, chain, timing belt or other or any combination thereof. Also, it should be underlined that the guide means are a part of the drive unit and therefore part of the screening device.
Further, it should be noted that the term "engaging means" in this context should be interpreted as any kind of engaging device suited for engaging the abovementioned guide means i.e. any kind of roll, wheel, toothed wheel, gear, disk, pulley or other or any combination thereof.
It should also be noted that the term "position means" in this context should be interpreted as any kind of position tracker suited for substantially continuous detection of a change of the position of the transversal profile in relation to the guide means at least when this change in position is performed by the electrical motor i.e. any kind of encoder, ultrasound sensor, radar, tachometer, revolution-counter or other or any combination thereof.
Furthermore, it should be noted that the term "screening means" in this context should be interpreted as any kind of screen suited for screening a window i.e. any kind of curtain, drape, blind, shade, shutter or other or any combination thereof.
It should also be noted that the term "release means" in this context should be interpreted as any kind of releaser suited for selectively engage or disengage the electric motor from the guide means i.e. any kind of coupling, link, connector, handle, magnet transfer, mutually displaceable meshing drive parts or other or any combination thereof.
Further, it should be noted that the term "control means" in this context should be interpreted as any kind of controller suited for controlling the operation of the electrical motor i.e. any kind of Programmable Logic Controller (PLC), Personal Computer (PC), circuit, regulation or other or any combination thereof.
In an aspect of the invention, the position means comprises a position sensing encoder.
Using a position sensing encoder as position means is advantageous in that position sensing encoders are compact and relatively inexpensive means for detecting a position and therefore particularly suited in this case.
It should be noted that the term "position sensing encoder" in this context should be interpreted as any kind encoder such as a rotary encoder, a linear encoder, a shaft encoder any other kind of encoder suitable for detecting a position of a moving object.
It should also be understood that a rotatory encoder is an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analog or digital code and a linear encoder is a sensor, transducer or readhead paired with a scale that encodes position. The sensor reads the scale in order to convert the encoded position into an analog or digital signal, which can then be decoded into position by a digital readout or motion controller.
In an aspect of the invention, the position sensing encoder comprises a rotary encoder connected directly or indirectly to a drive shaft of the electrical motor.
Forming the position sensing encoder as a rotary encoder substantially separate from the other components of the screening device is advantageous in that it simplifies assembly and maintenance.
In an aspect of the invention, the position sensing encoder comprises a linear encoder including scale means extending along at least a part of the guide means.
Forming the position sensing encoder as a linear encoder is advantageous in that a linear encoder can be mounted completely separate from the drive train thus ensuring simplified assembly and maintenance.
In an aspect of the invention, the position sensing encoder is an incremental position sensing encoder.
The output of an incremental encoder provides information about the motion of a part - to which the encoder is attached - in relation to another part - i.e. the position output is relative.
Thus, it is advantageous to use an incremental encoder in relation to a screening device according to the present invention in that the relative position detection provides more accurate information regarding the position and in that a screening device with the same incremental encoder can be used with guide means of different length.
In an aspect of the invention, the position sensing encoder comprises a magnet attached to a drive shaft of the electrical motor and a magnet sensor mounted in a fixed position in close proximity of the drive shaft.
Mounting one or more magnets on a drive shaft enables that the fixed magnet sensor, the control means or other, in a simple and inexpensive manner can count the number of impulses generated from the passing magnet and then convert this into a measurement of distance.
In an aspect of the invention, the position means comprises means for detecting a substantially exact position of the transversal profile in relation to the guide means.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect of the invention, the end position sensor comprises a Hall Effect sensor.
A Hall Effect sensor provides simple and precise means for detecting an end position.
It should be noted that a Hall Effect sensor is some kind of transducer that generates and/or varies its output voltage in response to a magnetic field.
In an aspect of the invention, the drive unit comprises at least one magnet arranged at the end position of the guide means, wherein the at least one magnet is arranged to be detected by the end position sensor.
Using a magnet in relation to detecting the end position is advantageous in that it reduces the risk of detection errors and in that magnets enable touch-free detection - thus reducing wear and prolonging life.
In an aspect of the invention, the drive unit comprises at least one first magnet arranged at a first end position of the guide means and at least one second magnet arranged at a second end position of the guide means, wherein the first magnet and the second magnet are arranged to be detected by the end position sensor.
Arranging magnets at both end positions of the guide means is advantageous in that the motion of the transversal profile hereby can be stopped - e.g. emergency stopped - and the position means can be calibrated not matter which direction the transversal profile travels in.
Furthermore, since the electrical motor has to move the transversal profile - and everything in and on it - around during operation, it is obviously advantageous to keep the weight of the transversal profile as low as possible. It is therefore advantageous to arrange the magnets at either end of the guide means so that they both can be detected by the same end position sensor - hereby reducing weight and cost.
In an aspect of the invention, the end position sensor comprises a limit switch.
Using a limit switch is a relatively accurate and inexpensive way of detecting an end position.
In this context a limit switch is a switch operated by the motion of a part or presence of an object. A limit switch typically requires physical contact to switch.
In an aspect of the invention, the end position sensor comprises proximity sensor.
Using a proximity sensor for detecting the end positions is advantageous in that a proximity sensor enables touch-free detection - thus reducing wear and prolonging life.
In this context a proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact, in that proximity sensor typically operates by the disturbance of an electromagnetic field, by capacitance, or by sensing a magnetic field.
In an aspect of the invention, the control means are located in the transversal profile.
Since the electrical motor, the position means and the end position sensor are all located in the transversal profile it is advantageous to also locate the control means in the transversal profile to simplify assembly and reduce cost.
In an aspect of the invention, the control means comprises counting means arranged for counting inputs from the position means.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect of the invention, the control means comprises means for resetting the counting means in response to an input from the end position sensor.
Resetting the counting means in response to an input from the end position sensor is advantageous in that it hereby is possible to re-calibrate the position means and the counting means in a simple and efficient manner.
In an aspect of the invention, the screening device comprises speed control means for controlling the traveling speed of the transversal profile in response to input from the position means.
Controlling the travelling speed of the transversal profile in response to its actual position is advantageous in that it hereby is possible to reduce traveling time and reduce power consumption in relation to braking.
In an aspect of the invention, the electrical motor is supplied by an electrical energy storage of the transversal profile.
Since the motor is located in the mobile transversal profile it would be difficult to power the motor by means of the power grid. It is therefore advantageous to power the motor by means of e.g. a battery, accumulator or capacitor located in the transversal profile to reduce wiring and cost. The lack of mains power is possible by a control and end position sensors that have low power consumption. In an aspect the end position sensors have substantially no standby power consumption.
In an aspect of the invention, the electrical motor is a direct current motor.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect of the invention, the electrical motor is a brushless motor, a stepper motor or a piezoelectric motor with rotation signal used as position means.
With these types of motors it is possible to detect how much the magnetic field in the motor is rotated. I.e. using these types of motors in relation to the present invention is advantageous in that this rotation of the internal magnetic field can be used as position means - thereby reducing weight, cost and/or power consumption.
In an aspect of the invention, the control means comprises current level means for detecting a current level of the electrical motor, in particular a direct current motor and in an aspect of the invention, the control means comprises comparing means for detecting if the input from the current level means exceeds a predefined level.
Providing current level means is advantageous in that it hereby is possible to stop the travel of the transversal profile if a current peak is detected - e.g. in case of collision with an unexpected object. Also the detection of current peaks enables redundancy of the end position sensors in that the current of the motor will be increased if the end of the guide means has been reached without the travel being stopped.
In an aspect of the invention, the control means is adapted for at least stopping the operation of the motor in accordance with input from the position means and the end position sensor.
Hereby is achieved an advantageous embodiment of the invention.
The invention further provides for a method for operating an electric screening device for a window. The method comprises the steps of:

providing a target position to control means of a motorized transversal profile extending substantially across the window, and
initiate travel of the transversal profile along guide means at a frame of the window to displace one end of screening means towards the target position,

Controlling the operation of the transversal profile in relation to both position means and an end position sensor is advantageous in that the position means enables travel to substantially any position along the guide means while the end position sensor ensures that the travel will be stopped if an end position is reached - even if the position means detects otherwise. Furthermore, the end position sensor is simple and efficient means for re-calibrating the position means and thereby optimizing the overall functionality of the position means.
In an aspect of the invention, the target position is selected from a number of predefined target positions.
Selecting the target position from a number of predefined target positions is advantageous in that it enables simple control and operation of the electric screening device.
In an aspect of the invention, the method further comprises the step of updating the position means if the end position sensor detects that the end position is reached before the target position is reached.
Updating the position means - either by resetting it and/or correcting the assumed position - when an end position has been reached is advantageous in that the position means hereby are more precise.
In an aspect of the invention, the transversal profile continues travel towards the target position after the updating.
Hereby simpler and more automated operation is ensured.
In an aspect of the invention, the position means comprises counting means and wherein the updating includes resetting or updating the counting means.
It is advantageous if the position means substantially always defines its position in relation to a fixed starting point. This starting point could advantageously be the top position in which the screening means are fully retracted - in that this is the most used position and in that this position would also be detected by the end position sensor. Thus, when the transversal profile travels upwards and reaches the upper end position - where the end position sensor is activated - the counting means will be reset. And when the transversal profile travels in the opposite direction - i.e. downwards - and reaches the lower end position - where the end position sensor is activated - the counting means could be updated with the lower position to ensure greater accuracy.
In an aspect of the invention, the counting means is part of control means controlling at least part of the operation of the electric screening device.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect of the invention, the travel is initiated in response to input from a user.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect of the invention, the travel direction of the transversal profile is reversed if the end position sensor detects that an end position of the guide means is reached.
Since the end position sensor detects that an end position has been reached; travel in that direction is no longer possible. It is therefore advantageous to reverse the direction of travel when an end position has been reached - no matter if this was reached during normal operation or unexpectedly - i.e. unexpected in relation to input from the position means.
In an aspect of the invention, the end position sensor is arranged to detect both a first end position and a second end position of the guide means.
Detecting both end positions ensures more reliable and efficient operation.
In an aspect of the invention, the method comprises that the transversal profile travels the full length between the first end position and the second end position to establish the full travel length of the transversal profile before the travel towards the target position is initiated.
Starting operation of the screening device by initiating a calibration run is advantageous in that when the screening device knows the distance between the end positions, it is possible to go to e.g. a 30% shaded position automatically and it is possible to optimize speed control in that the traveling speed can be reduced when approaching the target position and/or the end positions.
In an aspect of the invention, the method comprises reducing the travel speed of the transversal profile when the position means detects that the target position will soon be reached.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect of the invention, the method is a method for operating a screening device according to any of the previously mentioned screening devices.
Even further, the invention provides for use of a screening device according to any of the previously mentioned screening devices for screening a window mounted in an inclined surface of a building.
If the screening device was arranged to screen a window mounted in a vertical wall, the motor and other parts of the screening device could advantageously be mounted in a fixed upper position wherefrom the screening means could be raised and lowered. However, this is not possible - or at least relatively difficult - when the screening device is mounted in an inclined position. In such circumstances it is advantageous that the screening device comprises a driven transversal bottom profile and guide means so that the screening means can be maintained in close proximity of the window at all times and thereby ensure more efficient screening.

Figures

The invention will be described in the following with reference to the figures in which

fig. 1: illustrates a screening device with the transversal profile in bottom position, as seen in perspective,
fig. 2: illustrates a screening device with the transversal profile in top position, as seen in perspective,
fig.3: illustrates a screening device comprising two limit switches, as seen from the side,
fig. 4: illustrates a screening device comprising a single limit switch, as seen from the side,
fig. 5: illustrates a screening device comprising a single proximity sensor, as seen from the side,
fig. 6: illustrates a screening device with the transversal profile in top position, as seen from the side,
fig. 7: illustrates a section view of a screening device with the transversal profile in top position, as seen from the side, and
fig. 8: illustrates a screening device and a window mounted in an inclined roof surface, as seen from the front.

Detailed description of the invention

Fig. 1 illustrates a screening device 1 with the transversal profile 4 in bottom position, as seen in perspective and fig. 2 illustrates a screening device 1 with the transversal profile 4 in top position, as seen in perspective.
In this embodiment the screening device 1 comprises a drive unit 3 including a transversal profile 4 arranged to run along two guide means 5 in the form of racks extending transversally at the longitudinal ends of the transversal profile 4. Thus, the guide means 5 are a part of the drive unit 3 and therefore part of the screening device 1.
In this embodiment the transversal profile 4 comprises an electrical motor 6 arranged to move said transversal profile 4 along the racks 5 by means of engaging means 7 which in this case includes gears arranged to mesh with the racks 5 so that the electrical motor 6 may drive the transversal profile 4 up and down along the guide means 5.
In this embodiment the transversal profile 4 is connected to a first end 11 of the screening means 10 and the other end 12 includes connection means 13 for fixing the second end 12 at the top of the window (not shown) or at the upper end of the guide means 5.
In principle the connection means 13 could simply comprise holes in the screening means 10 to allow the screening means to be nailed to an upper edge of the window frame (not shown) but in a preferred embodiment the connection means 13 would comprise some sort of rail, support, roller or other suited for holding and/or fixating the upper end of the screening means 10 in relation to the upper window frame and/or at the upper end of the guide means 5.
In this embodiment the transversal profile 4 also comprises control means 15 - in the form of a centrally arranged circuit board - arranged for controlling the operation of screening device - in particular the electrical motor 6. In another embodiment the control means 15 could be located at several different locations in the transversal profile 4 - e.g. at least partly integrated in other components of the transversal profile 4.
In the embodiment disclosed in fig. 1 the screening means 10 are a simple blind wherein the connection means 13 comprises a spring loaded roller for rolling up the upper end of the screening means 10 as the transversal profile 4 travels upwards.
And in the embodiment the disclosed in fig. 2 the screening means 10 are folding blinds but in another embodiment the screening means 10 could be venetian blinds or another type of blinds, shutters or curtains.
Fig. 3 illustrates a screening device 1 comprising two end position sensors 9 in the form of limit switches 9, as seen from the side.
In this embodiment the transversal profile 4 is provided with position means 8 arranged to detect motion of the drive shaft 17 of the motor 6. I.e. in this embodiment the position means 8 is an encoder 16 comprising an encoder magnet 30 mounted on the drive shaft 17 and an encoder sensor 31 fixedly mounted in relation to the transversal profile 4 so that the encoder sensor 31 detects when the encoder magnet 30 passes the sensor 31. Thus, in an embodiment the control means 15 would comprise counting means 22 arranged to count the input from the sensor 31 which then can be translated to a measure of distance when multiplied with a pre-defined measure of the distance traveled by the transversal profile 4 between two signals from the encoder sensor 31. And if the magnet 30 is mounted on a drive shaft 17 before a transmission (not shown) the accuracy of the position means 8 would be greatly improved in that one revolution of the engaging means 7 would require several revolution of the motor drive shaft 17.
However, in another embodiment the position means 8 could be an independent encoder unit somehow connected to the drive shaft 17 - either directly or indirectly - or it could be incorporated or integrated in the motor 6 e.g. if the motor 6 was a brushless motor or stepper motor or a piezoelectric motor.
In this embodiment the transversal profile 4 also comprises two end position sensors 9 in the form of limit switches arranged so that when the transversal profile 4 reaches an end position 20, 21 of the guide means 5, one of the limit switches 9 will be physically activated and thereby send a signal to the control means 15 which in turn will stop the electrical motor 6 and thereby the travel of the transversal profile 4.
In this embodiment the control means 15 comprises counting means 22 arranged to count the impulses from the position means so that the control means may calculate the traveled distance and the current position. Thus, when the control means 15 receives an input from e.g. the upper end position sensor 9, the control means 15 could also initiate that the position means 8 is updated or reset - e.g. to ensure that the counting means 22 always started counting from zero from the top position.
This updating or resetting could be done every time an end position 20, 21 is detected, it could be done only when the first or only when the second end position 20, 21 is detected, it could be done only when an end position 20, 21 is unexpectedly reached, it could be done after a predefined operation time or at other times or any combination thereof.
In this embodiment the control means 15 are arranged for controlling the operation of the electrical motor 6 in accordance with input from the position means 8 and the end position sensor 9 as described above.
Once the control means detects that an end position 20, 21 has been reached it will also ensure, that once the transversal profile 4 continues operation, it will travel in the opposite direction - i.e. away from the just detected end position 20, 21.
In this embodiment the control means 15 also comprise speed control means 23 enabling that the traveling speed of the transversal profile 4 can be controlled - particularly in response to input from the position means 8. I.e. if the control means - based on input from the position means 8 - detects that the traveling transversal profile 4 is within e.g. 3 cm from a target position or an end position 20, 21, the speed control means 23 could enable deceleration of the travel speed so that the transversal profile 4 is stopped more smoothly. However, in another embodiment the traveling speed of the transversal profile 4 could be controlled in another way or the speed control means 23 would be absent.
Furthermore, in this embodiment the control means 15 also comprise current level means 25 for detecting the current through the electrical motor 6 and comparing means 26 arranged to compare the detected current with a predefined threshold. I.e. if the traveling transversal profile 4 collides with a foreign object, if an end position sensor 9 malfunctions or other the comparing means 26 will detect that the output from the current level means 25 is above the predefined level and the control means 15 will stop the electrical motor 6. However, in another embodiment collision or malfunction could be detected in another way or current level means 25 and comparing means 26 would not be present.
Fig. 4 illustrates a screening device 1 comprising a single end position sensor 9 in the form of a limit switch 9, as seen from the side. The single limit switch 9 is arranged on the transversal profile 4 so that it is able to detect both the first end position 20 and the second end position 21 of the guide means 5.
Fig. 5 illustrates a screening device 1 comprising a single end position sensor 9 in the form of a proximity sensor 9, as seen from the side.
In this embodiment the screening device 1 comprises a first magnet 18 arranged at first end position 20 and a second magnet 19 arranged at the second end position 21 of the guide means 5. The transversal profile 4 is then provided with a Hall Effect sensor arranged to detect the two magnets 18, 19.
Generally, the end position sensor 9 may have substantially no stand-by power consumption. The end position sensor 9 may comprise for example a piezo element, reed switch, hall effect etc.
Fig. 6 illustrates a screening device 1 with the transversal profile 4 in top position, as seen from the side and fig. 7 illustrates a section view of a screening device 1 with the transversal profile 4 in top position, as seen from the side.
In these and the previously disclosed screening devices 1 the screening device 1 is provided with release means 14 arranged to selectively engage or disengage the electric motor 6 from the guide means 5 so that the transversal profile 4 may be manually displaced up or down along the guide means 5 e.g. in case of malfunction of the automated operation of the screening device 1, to reduce energy consumption, to enable faster displacement or other.
In this embodiment the release means 14 comprises a pivotal joint 32 around which the transversal profile 4 may pivot to disengage the gear 7 from the rack 5 to enable manual displacement of the transversal profile 4. In this embodiment this pivotal motion is biased by springs (not shown) to ensure a secure engagement between the guide means 5 and the engaging means 7 once the manual displacement has ended.
However, in another embodiment the release means 14 could comprise a coupling - e.g. arranged on a drive shaft 17 of the electrical motor 6 so that when the coupling is activated the motor will be disengaged but the guide means 5 will remain engaged with the engaging means 7 during manual operation. Or the release means 14 could be formed in a number of other ways. For example, the release means could be a non-self-locking transmission which enables manual movement of the screening. A non-self-locking transmission may be advantageous with a brushless motor which is able to deliver high torque.
Once the release means 14 is re-engaged after manual operation, the position means 8 will not be able to detect the correct position of the transversal profile 4. I.e. after re-engagement the position means 8 could automatically be reset as the first thing after re-engagement e.g. by always running the transversal profile 4 in a specific direction (e.g. at a specific reduced speed) until an end position 20, 21 was detected and the position means 8 could be reset. This would obviously require that engagement and/or re-engagement is detected.
In another embodiment the operation of the screening device 1 would continue substantially unchanged after re-engagement, so that if the control means 15 via the position means 8 has detected that the transversal profile 4 is in the middle between the first and the second end position 20, 21 and an order to travel to the first end position 20 was received, the transversal profile 4 would travel at full speed towards the first end position 20. However, during the manual operation, the transversal profile 4 was moved closer to the first end position 20 and the first end position 20 will therefore be reached sooner than expected. Once the end position 20 has been detected by the end position sensor 9 the motor 6 will be stopped by the control means 15 and the position means 8 will be reset so that if the control means 15 received an input - e.g. from an remote control - to move the transversal profile 4 to a position in the middle between the first and the second end position 20, 21, the transversal profile 4 will stop moving substantially when the correct position has been reached.
Fig. 8 illustrates a screening device 1 and a window 2 mounted in an inclined roof surface 28 of a building 29, as seen from the front.
When the screening means 10 is displaced by means of a moving transversal profile 4, the transversal profile 4 will in this embodiment also have to displace an electrical energy storage 24 located in the transversal profile 4. Thus, the electrical energy storage 24 will have to provide power to displace its own weight as well as the weight of the rest of the transversal profile 4. It is therefore important to reduce energy consumption during normal operation and it is therefore advantageous to detect the end positions 20, 21 of the guide means 5 by means of end position sensors 9.
The invention has been exemplified above with reference to specific examples of designs and embodiments of screening devices 1, transversal profiles 4, guide means 5 etc. However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

List

1.: Screening device
2.: Window
3.: Drive unit
4.: Transversal profile
5.: Guide means
6.: Electrical motor
7.: Engaging means
8.: Position means
9.: End position sensor
10.: Screening means
11.: First end of screening means
12.: Second end of screening means
13.: Connection means
14.: Release means
15.: Control means
16.: Position sensing encoder
17.: Drive shaft
18.: First magnet
19.: Second magnet
20.: First end position of guide means
21.: Second end position of guide means
22.: Counting means
23.: Speed control means
24.: Electrical energy storage
25.: Current level means
26.: Comparing means
27.: Frame of window
28.: Inclined surface
29.: Building
30.: Encoder magnet
31.: Encoder sensor
32.: Pivotal joint

Claims

A screening device (1) for a window (2), said screening device (1) comprising
a drive unit (3) including a transversal profile (4) arranged to run along guide means (5) extending transversally at the longitudinal ends of said transversal profile (4), wherein said transversal profile (4) comprises an electrical motor (6) arranged to move said transversal profile (4) along said guide means (5) by means of engaging means (7) arranged to engage said guide means (5),
said transversal profile (4) further comprising position means (8) arranged for detecting at least a motorized change of the position of said transversal profile (4) in relation to said guide means (5) and at least one end position sensor (9) for detecting an end position of said guide means (5),
screening means (10) comprising a first end (11) being connected to said transversal profile (4) and a second end (12) including connection means (13) for being fixed at an end of said guide means (5),
release means (14) arranged to selectively engage or disengage said electric motor (6) from said guide means (5) to enable both manual and motorized displacement of said transversal profile (4) in relation to said guide means (5), and
control means (15) arranged for controlling the operation of said electrical motor (6) in accordance with input from said position means (8) and said end position sensor (9).
A screening device (1) according to claim 1, wherein said position means (8) comprises a position sensing encoder (16).
A screening device (1) according to claim 2, wherein said position sensing encoder (16) comprises a rotary encoder connected directly or indirectly to a drive shaft (17) of said electrical motor (6).
A screening device (1) according to any of the preceding claims, wherein said drive unit (3) comprises at least one magnet (18, 19) arranged at said end position (20, 21) of said guide means (5), wherein said at least one magnet (18, 19) is arranged to be detected by said end position sensor (9).
A screening device (1) according to any of the preceding claims, wherein said drive unit (3) comprises at least one first magnet (18) arranged at a first end position (20) of said guide means (5) and at least one second magnet (19) arranged at a second end position (21) of said guide means (5), wherein said first magnet (18) and said second magnet (19) are arranged to be detected by said end position sensor (9).
A screening device (1) according to any of the preceding claims, wherein said control means (15) are located in said transversal profile (4).
A screening device (1) according to any of the preceding claims, wherein said screening device (1) comprises speed control means (23) for controlling the traveling speed of said transversal profile (4) in response to input from said position means (8).
A screening device (1) according to any of the preceding claims, wherein said control means (15) comprises current level means (25) for detecting a current level of said electrical motor (6), in particular a direct current motor.
A screening device (1) according to claim 8, wherein said control means (15) comprises comparing means (26) for detecting if said input from said current level means (25) exceeds a predefined level.
A screening device (1) according to any of the preceding claims, wherein said control means (15) is adapted for at least stopping the operation of said motor (6) in accordance with input from said position means (8) and said end position sensor (9).
A method for operating an electric screening device (1) for a window (2), said method comprising the steps of:
• providing a target position to control means (15) of a motorized transversal profile (4) extending substantially across said window (2), and

• initiate travel of said transversal profile (4) along guide means (5) at a frame (27) of said window (2) to displace one end of screening means (10) towards said target position,
wherein said control means (15) is controlling the operation of said motorized transversal profile (4) in order to stop said travel of said transversal profile (4) if position means (8) of said transversal profile (4) detects that said target position has been reached and to stop said travel of said transversal profile (4) if an end position sensor (9) of said transversal profile (4) detects that an end position (18, 19) of said guide means (5) is reached.
A method according to claim 11, wherein said target position is selected from a number of predefined target positions.
A method according to claim 11 or 12, wherein said method further comprises the step of updating said position means (8) if said end position sensor (9) detects that said end position (18, 19) is reached before said target position is reached.
A method according to claim 13, wherein said transversal profile (4) continues travel towards said target position after said updating.
Use of a screening device (1) according to any of claims 1-10 for screening a window (2) mounted in an inclined surface (28) of a building (29).