Motor-driven shutter or sun-shading device

Abstract

The motorized shutter, blind or sun-protection device comprises at least one roll-up element (2; 20), one end of which is kinematically linked to a roll-up element drive roller (1) and the other end of which is attached to pulling strands (3, 4; 15, 16; 22, 23) kinematically linked to a strand drive roller (1; 17, 18; 24, 25), at least one strand return roller (6; 19), and an elastic means (7; 29) keeping the roll-up element and the strands tensioned. It constitutes a balanced system.

Description

The invention relates to a motorized shutter, blind or sun-protection device comprising at least one roll-up element, one end of which is kinematically linked to a roll-up element drive roller and the other end of which is attached to pulling strands kinematically linked to a strand drive roller, at least one strand return roller, and an elastic means keeping the roll-up element and the strands tensioned.

In devices of this type, the variation in diameter of the roll-up element, in this case the rolled-up fabric, causes a variation in the torque exerted by the elastic means on the fabric drive roller. Assuming the system to be balanced in the rolled-up position, the decrease in resistive torque during unrolling gives rise to a resultant torque which tends to cause the fabric to roll up again. If the pulling strands consist of straps that roll up on themselves as the fabric unrolls, the increase in torque on the strap drive roller is added to the decrease in resistive torque on the fabric drive roller, thus further increasing the resultant torque that tends to cause the fabric to roll up again. An increasing level of force is therefore necessary to unroll the fabric. There is a high consumption of current that reduces the service life of batteries. Furthermore, a brake is needed to keep the fabric unrolled. This brake generally consists of an electromagnetic brake or a permanent friction brake and this also consumes power when the fabric is moving. Hence, it is virtually impossible to power such devices by means of an independent source, such as a battery, of reasonable size.

U.S. Pat. No. 262,398, granted on Aug. 8, 1882, discloses a manually-driven awning whose fabric unrolls from a drum to which the fabric is fastened via one end, the other end being linked to a pulling strand passing around a return pulley and rolled up on a frustoconical drum with a helical groove, a spring keeping the return pulley tensioned. With the pulling strands being helically rolled up around the frustoconical drum, this balances the system in all positions of the fabric. The aim of this arrangement is to ensure that the fabric stays in the position in which it is placed whether it is totally or partially unrolled.

Although this document has been known for 120 years, until now nobody appears to have appreciated the advantage such a device could have in terms of energy savings.

The aim of the present invention is to produce a shutter, blind or sun-protection device as defined above whose electric motor is powered by an independent current source. For such a device to be practically advantageous it must have a low current consumption.

The device of the invention is characterized in that it constitutes a balanced system.

Because the system is balanced, the torque resulting from the action of the roll-up element, on the one hand, and the pulling strands on the other, and, if present, the auxiliary means, is always zero. The tension force is therefore always the same, ensuring better distribution of the useful power, which is constant throughout the time the roll-up element is in motion. By avoiding high consumption levels, the overall consumption is reduced, and if batteries are used as power source, the service life of these batteries is lengthened. Furthermore, there is no need to use a brake to keep the roll-up element in position. It is therefore possible to replace the brake motors generally used by more simple, less expensive and more compact motors. Current consumption is also lowered. The situation is the same in the case of a permanent-friction brake.

In some embodiments, the linear weight of the roll-up element, in particular of the fabric, and the linear weight of the pulling strands, taken together, are equal.

For the sake of simplification, the term “fabric” will be used below but it is understood that this term could also be replaced by “roll-up element”.

In the embodiments with a fabric, the fabric drive roller and the strand drive roller are advantageously coaxial and rotate as one. They may consist of a single roller.

If the fabric has an end bar, the pulling strands have at least one counterweight compensating for the weight of the bar.

According to one embodiment, the fabric drive rollers and strand drive rollers have the same diameter, one of the ends of the fabric and of the strands is free, the device comprises a press roller bearing against the drive rollers and the fabric and the strands pass in opposite directions between the drive rollers and the press roller so that they are driven in opposite directions and the device comprises at least one store in which the fabric accumulates when the device is opened and the strands accumulate when the device is closed.

According to another embodiment, in which one of the ends of the fabric and of the strands is attached to the drive rollers so that the pulling strands, consisting of tapes, roll up in a spiral when the fabric unrolls, the device comprises conical pulleys with a helical groove that rotate as one with the fabric drive roller, on which pulleys cords with counterweights are rolled up and unroll, in opposite directions, the torques generated by these counterweights compensating for the variations in torque generated by the variations in the roll-up diameters of the fabric and of the pulling strands.

According to another embodiment, in which the end of the fabric linked kinematically to the drive roller is attached to the drive roller such that the fabric rolls up around the roller, the pulling strand drive roller has two frustoconical parts with helical grooves in which the pulling strands roll up.

According to a variant of the above embodiment, the end of the fabric to which the pulling strands are linked has a hollow bar housing a spring working in tension, to whose ends the pulling strands are attached.

In some embodiments, the device comprises two fabrics and two fabric drive rollers each associated with a pulling strand drive roller and constituting two pairs of rollers, each of these pairs of rollers serving as return rollers for the rollers of the other pair.

The attached drawing shows, by way of example, a few embodiments of the invention.

FIG. 1 is a side view of a first embodiment.

FIG. 2 is a front-on view of this first embodiment.

FIG. 3 is a side view of a second embodiment.

FIG. 4 is a front-on view of this second embodiment.

FIG. 5 is a side view of a third embodiment, with the fabric half unrolled.

FIG. 6 is a front-on view of this third embodiment.

FIG. 7 shows the third embodiment with the fabric completely unrolled.

FIG. 8 is a side view of a fourth embodiment.

FIG. 9 is a front-on view of this fourth embodiment.

FIG. 10 is a side view of a fifth embodiment.

FIG. 11 is a front-on view of this fifth embodiment.

FIG. 12 shows a variant of the fifth embodiment.

FIG. 13 is a side view of a sixth embodiment.

FIG. 14 shows a variant of this sixth embodiment.

FIG. 15 is a front-on view of this variant.

The device shown in FIGS. 1 and 2 comprises a roller 1 which is the drive roller both for a fabric 2 and for two pulling strands 3 and 4 in the form of tapes. The fabric and strand drive rollers are therefore merged in this case and the fabric and the pulling strands, together, have the same linear weight. One of the ends of the fabric has a bar 5 whose end parts are fastened to the pulling strands 3 and 4, to which strands counterweights 31 and 32 are fastened, the total weight of these counterweights being equal to the weight of the bar 5. The pulling strands 3 and 4 pass around a return roller 6 which is parallel to the roller 1. Naturally, the rollers 1 and 6 are mounted on shafts which are themselves mounted in bearings (not shown).

While the axis of the shaft of the roller 1 is fixed, the shaft of the roller 6 can move transversely and this shaft is tensioned by an elastic tensioning means 7, for example a pair of springs attached to the ends of the shaft so as to maintain a degree of tension on the pulling strands and the fabric.

The particular feature of this embodiment is that one of the ends of the fabric 2 and of the strands 3 and 4 is free and that the fabric and the pulling strands are driven by adhesion by the drive roller 1. For this purpose, the device is equipped with a press roller 8 held against the roller 1 by an elastic pulling means, for example a pair of springs 9. The fabric 2 and the strands 3 and 4 pass between the drive roller 1 and the press roller 8. Beyond the rollers 1 and 8, the fabric 2 and the strands 3 and 4 pass into respective stores, the accumulation of the fabric and the strands in the stores being depicted diagrammatically by the folded parts 10 and 11 in FIG. 1. The fabric 2 and the strands 3 and 4 move between the rollers 1 and 8 in opposite directions such that the strands 3 and 4 accumulate in the stores when the fabric 2 is unfolded from its store.

The device is driven by a motor acting either on the roller 1 or on the press roller 8.

In this embodiment, the roll-up radii of the fabric and the strands on the roller 1 are identical and are constant whatever the position of the fabric 2 since there is no superposition of several turns of fabric and pulling strands. The torque resulting from the fabric and pulling strands pulling on the main roller 1 is therefore zero whatever the position of the fabric, such that the force exerted by the elastic tensioning means does not change. Furthermore, the linear speed of the fabric and the strands is identical at all times.

When the fabric 2 is used vertically or obliquely, the system is balanced whatever the position of the fabric because the weight of the unrolled fabric is always equal to the weight of the pulling strands and the weight of the bar 5 is balanced by the counterweights 31 and 32.

The pulling strands could consist of cables or cords. In this case, at least the roller 1 will have grooves for receiving these cables or cords. The depth of these grooves will be such that the pressure of the press roller 8 exerts sufficient pressure on the cables or cords to drive them. The fabric and the strands could be driven by pegs.

The embodiment shown in FIGS. 3 and 4 is derived from the first embodiment. The single return roller 6 is replaced by an assembly identical to that consisting of the drive roller 1, the press roller 8, the fabric 2 and the pulling strands 3 and 4. The components of this second assembly have therefore simply been designated using the same references plus the prime symbol ′. This second embodiment differs from the first embodiment also in that the end bar 5 of the first fabric 2 is attached to one of the ends of the pulling strands 3′ and 4′ of the second system and vice versa, and in that the gap between the pulling strands 3 and 4 is greater than the gap between the pulling strands 3′, 4′ so as to allow the pulling strands to cross in a plane. Each of the rollers 1 and 1′ acts as a return roller for the other roller, the pulling strands 3 and 4 returning via the fabric 2′ and vice versa. The elastic tensioning means 7 acts on one of the rollers 1 or 1′. However, both rollers 1 and 1′ could have an elastic tensioning means. The linear weight of the pulling strands may be equal to or different than that of the fabric.

The strands 3 and 4 of the first system are thus driven by the roller 1′ of the second system and vice versa. It could therefore also be said that there are no return rollers, only pulling rollers. As in the first embodiment, the free strands of each system are driven by the rollers 1 and 8, or 1′ and 8′, of the other system.

When used vertically, the system is always balanced because the weights of the unrolled fabric parts, the weights of the pulling strands and the weights of the bars 5 and 5′ compensate for one another.

This device may also be driven by a single motor acting on one of the rollers 1, 8, 1′ or 8′. The advantage of this embodiment is that the time needed to close and open the device is halved, since each fabric only travels over half the area to be shaded, while the masses moved are barely greater than in the first embodiment. This embodiment therefore provides an additional energy saving. Such is the case also for the embodiments according to FIGS. 8, 9 and 13 to 15.

The embodiment shown in FIGS. 5 and 6 differs from the preceding embodiments essentially in that the fabric 20 is rolled up around its drive roller 1 as the pulling strands 15 and 16 are unrolled from their drive rollers 17 and 18. As in the first embodiment, the linear weight of the fabric is equal to the linear weight of the pulling strands taken together and the bar 5 is balanced by counterweights 31 and 32.

One end of the fabric 20 is attached to the drive roller 1 while its other end, again having a bar 5, is attached by this bar to one of the ends of the pulling strands 15 and 16, the other ends of which are attached to drive rollers 17 and 18 that are coaxial and rotate as one with the fabric drive roller 1 and have a diameter equal to the diameter of the roller 1. The straps 15 and 16 constituting the pulling strands are rolled up in grooves. The straps 15 and 16 pass around returns 19 and 21, which are also grooved.

The roll-up diameter of the fabric and of the pulling strands varying in opposite directions, the torques exerted also vary in opposite directions and therefore tend to give rise to a nonzero resultant torque. In order to restore the torque balance in all positions, two counterweights 10 and 11 are provided, suspended from two cords 12 and 13, respectively, that roll up around two frustoconical helically-grooved pulleys 14 and 14′, respectively. The cord 13 rolls up when the fabric 20 is unrolled, and the rolled-up diameter of the cord 13 decreases with that of the fabric. As a result, the torque generated by the weight 11 decreases together with that generated by the fabric. The weight 11 and the conicity of the pulley 14′ are chosen such that the decrease in torque generated by the weight 11 compensates for the decrease in torque generated by the fabric, and vice versa. The same happens with the counterweight 10 and the straps 15 and 16. The system is therefore balanced in all positions of the fabric.

As in the preceding cases, it is possible to mount two assemblies head-to-tail, as shown in FIGS. 8 and 9. In this case, the first fabric 20 is attached to the straps 15′ and 16′ that roll up around the rollers 17′, 18′ of the second system, whereas the fabric 20′ is attached to the straps 15, 16 that roll up around the rollers of the first system. Because the system is symmetrical, the linear weights of the fabric and the pulling strands may differ and the pulling bars compensate for one another. Such is the case also for the embodiments according to FIGS. 3, 4 and 13 to 15.

The embodiment shown in FIGS. 10 and 11 is similar to the embodiment shown in FIGS. 5 and 6. Here again we have the fabric drive roller 1 with the fabric 20 attached to it and rolling up around it, the grooved returns 19 and 21 with the springs 7 retaining the axis of the returns 19 and 21, and the bar 5 fastened to one end of the fabric 20. The pulling strands consist of cords or cables 22 and 23 one end of which is attached to the bar 5, as previously, and the other end is attached to a roller drum 24 or 25, respectively, these drums being frustoconical and having a helical groove in which the pulling strands 22 and 23 roll up and unroll. The pulling strands 22 and 23 roll up around the drums 24 and 25 when the fabric 20 unrolls, and vice versa. The conicity of the drums 24 and 25 compensates for the decrease in roll-up diameter of the fabric 20 as it unrolls, such that the torques exerted by pulling on the fabric 20 and by pulling on the strands 22 and 23 are equal in all positions of the fabric. Furthermore, as in the first embodiment, the linear weights of the fabric and the pulling strands are equal and the weight of the bar 5 is balanced by counterweights 31, 32. The system is therefore balanced in all positions when used vertically or obliquely.

In the variant shown in FIG. 12, the axis 25 of the returns 19 and 21 is fixed. The bar 5 is replaced by a hollow bar 26 bearing return pulleys 27 and 28 at its ends and containing a spring 29 working in tension, to whose two ends are attached the ends of the pulling strands 22 and 23. The spring 29 replaces the springs 7 for keeping the pulling strands and the fabric tensioned.

As in the preceding embodiments, the variant shown in FIG. 12 may be implemented in a head-to-tail arrangement, as shown in FIGS. 13 and 15.

In the embodiment shown in FIG. 13, the pulling strands 22, 23 of the first fabric 20 cross the pulling strands 22′, 23′ of the second fabric 20′. The frustoconical drums 24′, 25′ serve as returns for the strands 22, 23 of the fabric 20, while the frustoconical drums 24, 25 serve as returns for the strands 22′, 23′ of the fabric 20′. A spring, such as the spring 29, is mounted in one of the bars 26 and 26′. In this embodiment, the awning is closed when the bars 26 and 26′ meet along the axis 30 passing through the point where the pulling strands cross.

In the variant shown in FIGS. 14 and 15, the pulling strands do not cross one another and the fabrics 20 and 20′ may be superposed, as in the embodiment shown in FIGS. 8 and 9.

It would of course be possible to provide a second spring like the spring 29 in the bar 26′. Since the tension on the spring 29 is practically constant, the pulleys 27 and 28 hardly turn at all. Obviously, the same happens with the pulleys 27′ and 28′. All these pulleys may therefore be replaced by a single curved groove.

Claims

1. A motorized shutter, blind or sun-protection device comprising at least one roll-up element (2; 20), one end of which is kinematically linked to a roll-up element drive roller (1) and the other end of which is attached to pulling strands (3, 4; 15, 16; 22, 23) kinematically linked to a strand drive roller (1; 17, 18; 24, 25), at least one strand return roller (6; 19), and an elastic means (7; 29) keeping the roll-up element and the strands tensioned, which device constitutes a balanced system.

2. The device as claimed in claim 1, wherein the roll-up element drive roller and the strand drive roller are coaxial and rotate as one.

3. The device as claimed in claim 1, which device comprises two roll-up elements (2, 2′; 20, 20′) and two roll-up element drive rollers (1, 1′) each associated with a pulling strand drive roller (1, 1′, 17, 18, 17′, 18′; 24, 25, 24′, 25′) and constituting two pairs of rollers, each of these pairs of rollers serving as return rollers for the rollers of the other pair.

4. The device as claimed in claim 1, wherein the linear weight of the roll-up element (2; 20) and the linear weight of the pulling strands (3, 4; 15, 16), taken together, are equal.

5. The device as claimed in claim 2, wherein the roll-up element has an end bar (5), and wherein the pulling strands have at least one counterweight (31, 32) compensating for the weight of the bar.

6. The device as claimed in claim 2, wherein the linear weight of the roll-up element (2; 20) and the linear weight of the pulling strands (3, 4; 15, 16), taken together, are equal, wherein the roll-up element has an end bar (5), wherein the pulling strands have at least one counterweight (31, 32) compensating for the weight of the bar, wherein the roll-up element drive rollers (1) and strand drive rollers (1) have the same diameter, wherein one of the ends of the roll-up element and of the strands is free, wherein the device comprises a press roller (8) bearing against the drive rollers and wherein the roll-up element (2) and the strands (3, 4) pass in opposite directions between the drive rollers (1) and the press roller (8) so that they are driven in opposite directions.

7. The device as claimed in claim 3, wherein the linear weight of the roll-up element (2; 20) and the linear weight of the pulling strands (3, 4; 15, 16), taken together, are equal, wherein the roll-up element drive rollers (1) and strand drive rollers (1) have the same diameter, wherein one of the ends of the roll-up element and of the strands is free, wherein the device comprises a press roller (8) bearing against the drive rollers and wherein the roll-up element (2) and the strands (3, 4) pass in opposite directions between the drive rollers (1) and the press roller (8) so that they are driven in opposite directions.

8. The device as claimed in claim 6, wherein the device comprises at least one store in which the roll-up element accumulates when the device is opened and the strands accumulate when the device is closed.

9. The device as claimed in claim 7, wherein the device comprises at least one store in which the roll-up element accumulates when the device is opened and the strands accumulate when the device is closed.

10. The device as claimed in claims 2, wherein the linear weight of the roll-up element (2; 20) and the linear weight of the pulling strands (3, 4; 15, 16), taken together, are equal, wherein the roll-up element has an end bar (5), wherein the pulling strands have at least one counterweight (31, 32) compensating for the weight of the bar, wherein one of the ends of the roll-up element (20) and of the strands (15, 16) is attached to the drive rollers so that the pulling strands, consisting of tapes, roll up in a spiral when the roll-up element unrolls, which device comprises conical pulleys (14, 14′) with a helical groove that rotate as one with the roll-up element drive roller (1), on which pulleys cords with counterweights (10, 11) are rolled up and unroll, in opposite directions, the torques generated by these counterweights compensating for the variation in torque generated by the variations in the roll-up diameters of the roll-up element and of the pulling strands.

11. The device as claimed in claim 3, wherein one of the ends of the roll-up element (20) and of the strands (15, 16) is attached to the drive rollers so that the pulling strands, consisting of tapes, roll up in spiral when the roll-up element unrolls, which device comprises conical pulleys (14, 14′) with a helical groove that rotates as one with the roll-up element drive roller (1), on which pulleys cords with counterweights (10, 11) are rolled up and unroll, in opposite directions, the torques generated by these counterweights compensating for the variation in torque generated by the variations in the roll-up diameters of the roll-up element and of the pulling strands.

12. The device as claimed in claims 2, wherein the linear weight of the roll-up element (2; 20) and the linear weight of the pulling strands (3, 4; 15, 16), taken together, are equal, wherein the roll-up element has an end bar (5), wherein the pulling strands have at least one counterweight (31, 32) compensating for the weight of the bar, wherein the end of the roll-up element (20) linked kinematically to the drive roller (1) is attached to the drive roller (1) such that the roll-up element rolls up around the roller and wherein the pulling strand drive roller has two frustoconical parts (24, 25) with helical grooves in which the pulling strands (22, 23) roll up.

13. The device as claimed in claim 3, wherein the linear weight of the roll-up element (2; 20) and the linear weight of the pulling strands (3, 4; 15, 16), taken together, are equal, wherein the end of the roll-up element (20) linked kinematically to the drive roller (1) is attached to the drive roller (1) such that the roll-up element rolls up around the roller and wherein the pulling strand drive roller has two frustoconical parts (24,25) with helical grooves in which the pulling strands (22, 23) roll up.

14. The device as claimed in claim 12, wherein the end of the roll-up element to which the pulling strands are linked has a hollow bar (26) housing a traction-operated spring (29) to whose ends the pulling strands (22, 23) are attached.

15. The device as claimed in claim 13, wherein the end of the roll-up element to which the pulling strands are linked has a hollow bar (26) housing a traction-operated spring (29) to whose ends the pulling strands (22, 23) are attached.

16. The device as claimed in claim 2, wherein the coaxial roll-up element and strand drive rollers form a single roller (1).

17. The device as claimed in claim 3, wherein the ends of the two roll-up elements (20, 20′) have hollow bars (26, 26′) at whose ends are provided or formed returns (27, 28, 27′, 28′) for the pulling strands (22, 23, 22′, 23′) linked together in the bars, the pulling strands (22, 23) of at least one of the pairs of strands being linked by a spring (29) inside the hollow bar (26).