Description

Anti-wind device for motorised external blinds

The present invention relates to an anti-wind device for motorised external blinds, such as sunshades or similar items.

Motorised external blinds are typically composed of a frame, for example with two extensible arms and a terminal bar, designed to receive a curtain that is unwound and rewound around a roll by an electric motor.

The blinds are designed to be projected from the wall of the building where they are installed, in order to perform their function better.

The surface of external blinds is subjected to the action of the wind, with sail-like effect. In particular, damages may occur in case of strong wind, including curtain breakage or frame damage/breakage.

In order to monitor the wind strength, the current models of blinds of the known art are provided with so-called anti-wind devices, which are characterised by some inconveniences.

A first type of anti-wind device according to the known art comprises an air-speed indicator, that is to say a device used to measure wind speed.

The most common and popular air-speed indicators comprise a blade propeller and a sensor, normally of reed bulb type, which measures the rotational speed of the propeller caused by the wind.

When the wind reaches a predefined speed value that corresponds to excessive stress for the curtain and/or its frame, a signal for partial or total closing is sent to the blind motor, which starts rewinding the curtain to prevent the risk of damaging the curtain and/or frame due the wind.

The operation of this solution according to the known art basically depends on the position of the air-speed indicator. In fact, the air-speed indicator can be positioned in the proximity of the roll used to unwind/rewind the curtain, that is to say in the proximity of the wall of the building. Because of this, the intensity value of the wind captured by the air-speed indicator is different from the intensity applied to the terminal bar

that is subjected to higher wind exposure, being situated at a certain distance from the building in completely unsheltered position.

Therefore, in such a case, the speed measured by the air-speed indicator is the speed of the wind in the proximity of the wall of the building and has a lower value than the value that would be measured if the air-speed indicator was exposed to full wind action, for example in the proximity of the terminal bar of the frame. Consequently, the closing signal is not sent despite of the fact that the wind speed in the proximity of the terminal bar of the blind has reached the value set for closing the curtain. Basically, the wind speed measured by the air-speed indicator is lower than the total speed of the wind that hits the blind, or in any case different, with high risks of breakage or damage both for frame and curtain.

Moreover, such a solution is not appreciated by the final user in terms of aesthetics. Alternatively, the air-speed indicator can be installed away from the blind structure, in a position exposed to full wind action to measure the real wind speed, such as, for example, in the ending section of the blind. This position, however, impairs the blind aesthetics and determines the difficult, expensive construction of the air-speed indicator. In fact, because of the remote position with respect to the blind, the air-speed indicator must be provided with power supply and a device to transmit the detected signals and/or the closing signal for the blind. To that end, self-powered air-speed indicators are used, although very expensive and difficult to install.

Another alternative executive embodiment of an anti-wind device according to the known art measures the vibrations and/or oscillations of the blind by measuring the oscillation of the terminal bar or curtain. Under the wind action, the external blind causes the oscillation of the terminal bar, and when the said oscillation exceeds a predefined value that is excessive for the integrity of the frame or curtain, a sensor provided with a vibration-sensitive microchip installed on the terminal bar sends a signal to the motor in order to close the curtain.

The sensor detects the oscillation of the terminal bar that depends on

the rigidity of the frame. With a very rigid frame, also under the effect of a very strong wind, the terminal bar is subjected to a small oscillation, which is lower than the predefined oscillation value set for closing the curtain. A possible, undesired consequence is that in this case no closing signal is sent by the sensor and the curtain is subjected to breakage.

For this reason, this anti-wind device is not very reliable when the rigidity of the frame is very high.

The purpose of the present invention is to realise an anti-wind device for motohsed external blinds able to provide a simple, inexpensive solution to the drawbacks of the known anti-wind devices.

The aforementioned purposes are achieved by the present invention by means of an anti-wind device for motohsed external blinds, in particular sunshades or similar items, which comprise a frame, a curtain positioned on the frame, which comprises optical means used to detect the displacement of the curtain and/or the frame of the blinds.

According to a preferred executive embodiment, the anti-wind device of the invention comprises optical displacement detection means comprising at least one emitter of luminous radiation and at least one receiver of luminous radiation. Alternatively, or in combination, at least one reflector is provided to reflect the optical ray from the emitter to the receiver. In this way, without leaving the protective scope and the precepts of the present invention, an flexible inexpensive anti-wind device characterised by easy installation is obtained, designed to measure the actual displacements or oscillations of the frame and/or curtain, in such a way to prevent damages or breakages of the blind caused by the wind.

Moreover, the device of the present invention can be advantageously installed on two or more blinds installed side by side, in addition to being installed on a single blind. According to different advantageous solutions provided alternatively or in combination on one or more blinds installed side by side, the emitter and/or receiver and at least one reflector are installed on the frame of the blind

and/or terminal bar.

Advantageously, the optical means are simple, reliable, easy to install and maintain.

Moreover, since the said anti-wind device also detects the displacement of the curtain, the same device can be advantageously and reliably used also with very rigid frames.

Further characteristics and improvements are the object of the appended claims and subclaims.

The characteristics of the invention and the consequent advantages will be more evident following to a detailed description of drawings, whereby: fig 1. is a diagrammatic view of a sunshade in open position provided with the anti-wind device of the invention not subjected to the stress of the wind. fig. 2 is a diagrammatic view of a blind in open position provided with the anti-wind device of the invention subjected to the stress caused by the wind blowing from up downwards. fig. 3 is a diagrammatic view of a blind in open position provided with the anti-wind device of the invention subjected to the stress caused by the wind blowing from down upwards. . fig. 4 is a top view of two blinds installed side by side provided with the anti-wind device of the present invention. figs. 5 and 6 are diagrammatic views of a roll blind in open position provided with the anti-wind device of the invention.

Fig. 1 illustrates a preferred embodiment of the anti-wind device for motohsed blinds of the invention, which is not subjected to stress caused by the wind on the curtain (7) and/or the frame (T) of the blind (1 ).

Motorised external blinds, with special reference to sunshades or similar items, comprise at least a frame (T) formed of a terminal bar (2) and two extensible arms (2a) joined by the terminal bar (2), a fixing support (4) to fix the frame (T) to the wall, a curtain (7), a roll (3) designed to unwind/rewind the said curtain (7) and a motor used to unwind/rewind the curtain (7) by means of the roll (3).

The anti-wind device according to the present invention comprises optical means to detect the displacement of the curtain (7) and/or the frame (T) of the blind (1 ). As illustrated in fig. 1 , the said optical displacement detection means are positioned in a fixed point of the blind (1 ), being for instance connected to the roll (3), and comprise at least one emitter of luminous radiation, one receiver of luminous radiation and one reflector.

According to the preferred executive embodiment of fig. 1 , the emitter and receiver of luminous radiation are integrated in a single emitter/receiver (5) positioned on the fixing support (4) used to fix the frame (T) to the wall, The terminal bar (2) is provided with a reflector (6) designed to reflect the signal received by the emitter of luminous radiation and send it to the receiver of luminous radiation.

The emitter of luminous radiation sends a luminous signal (8) that is reflected by the reflector (6), which sends it to the emitter/receiver (5) of luminous radiation.

In absence of wind, the luminous signal (8) is continuous because both the curtain (7) and the frame (T) of the blind (1 ) do not interfere with the luminous signal (8) and allow for the rectilinear propagation of the luminous signal, maintaining the receiver, the emitter and the luminous ray aligned, in such a way that the luminous ray falls on the receiver.

In this case, no signal is sent to the motor of the blind (1 ) to close the curtain (7).

According to alternative executive embodiments having a similar operation principle, the receiver (R) and the emitter (E) are separate and installed in two different positions, as illustrated for instance in fig. 4, thus contributing to the inexpensiveness of the present device.

According to a further executive embodiment of the present invention, the reflector (6) is positioned on the fixing support (4), while the emitter/receiver (5) is positioned on the terminal bar (2). According to another executive embodiment of the present invention, the emitter (E) of luminous radiation and the receiver (R) of luminous radiation are not integrated in a single emitter/receiver (5), being separated

and installed indifferently and alternatively one on the fixing support (4) and one on the terminal bar (2).

Advantageously, according to this executive embodiment, the emitter sends the luminous signal (8) directly to the receiver, without the reflector (6). In general, but not with limiting purposes, the emitter (E) of infrared luminous radiation is a laser, the receiver (R) of infrared luminous radiation is a photocell, and the reflector is (6) is a retro-reflector.

Figs. 2 and 3 illustrate the same executive embodiment as fig. 1 in the presence of stress caused by the wind on the blind (1 ). In fig. 2 , due to the presence of wind, the curtain (7) interferes with the luminous signal (8). The luminous signal (8) is interrupted and does not reach the reflector (6) that was supposed to send it to the receiver of luminous radiation. When the receiver of luminous radiations does not receive the luminous signal (8), a signal is sent, for instance via cable or radio, to the motor of the blind (1 ) or to a control circuit of the motor of the blind (1 ) in order to close the curtain (7).

In this way, the curtain (7) is rewound around the roll (3) to avoid damaging or breaking the blind (1 ).

In fig. 3, due to the stress caused by the wind, the terminal bar (2) is displaced with respect to its natural position in such a way that the reflector (6) on the terminal bar (2) is no longer aligned with the integrated emitter/receiver (5). In this case, the luminous signal (8) does not reach the reflector (6) that was supposed to send it to the receiver of luminous radiation. Also in this case, since the receiver does not receive the luminous signal (8), a signal is sent to the motor of the blind (1 ) or to a control circuit of the motor of the blind (1 ) in order to close the curtain (7).

According to an additional executive embodiment of the present invention, the optical detection means comprise two, three or multiple emitters of luminous radiation, two, three or multiple receivers of luminous radiation and two, three or multiple reflectors, as illustrated, without limiting purposes in fig. 4, in which two blinds are installed side by side and provided with a single emitter (E) and a single receiver (R) and two reflectors (6, 60), and in which the emitter (E) is associated with the first blind (1 ), the receiver

(R) is associated with the second blind (1 1 ) and two reflectors (6, 60) are associated with the two terminal bars (2, 20) of the two curtains (7, 70). The optical ray is emitted by the emitter (E) and reflected by the two reflectors (6, 60) to the receiver (R), thus advantageously providing for controlling two blinds with an inexpensive device characterised by easy construction and installation.

The same concept can be advantageously extended to a plurality of blinds by means of the precepts of the present invention.

In case of high stress caused by the wind, the curtain of the first blind and/or the curtain of the second blind interfere with the luminous signal, interrupting it, or alternatively the frame of the first or second blind does not maintain the alignment and correct transmission of the optical signal. When the optical signal is interrupted, both in the proximity of the first and second blind, a signal is sent to close the two curtains. In some instances, due to high stress caused by the wind, the terminal bar of the first blind and/or the terminal bar of the second blind are displaced from their natural position in such a way that the receiver is no longer aligned with the first reflector, or the first reflector is no longer aligned with the second reflector or, finally, the second reflector is no longer aligned with the receiver. In all the above cases, the luminous signal emitted by the emitter does not reach the receiver because it is interrupted. When the luminous signal is interrupted, a signal is sent to close the two curtains.

The sensitivity degree of the device of the present invention can be adjusted by increasing/decreasing the width of the luminous ray, for instance with a lens, or varying the width of the reflector area.

Different types of emitters or receivers are possible, such as for example laser, infrared, photocell, remote optical detector or similar items.

Finally, it must be noted that the anti-wind device of the invention can be installed, with the same efficacy level and operation modes, in blinds with vertical roll held in position by vertical tracks (30) and provided with a terminal bar (2) that guarantees the correct tension, as shown in figs. 5 and 6.