DEVICE FOR ROLLING AND UNROLLING ROLL-UP BLINDS AND SIMILAR

Abstract

A device for winding and unwinding Alicantina shutters (12) and the like, which are raised by being wound onto themselves by means of at least a first cord (3) connected to a first elastic element (10) which is attached at one end to the head (1) of the shutter and at the other end to the end of the cord (3) which allows the unwound segment of the shutter (12) to be kept in a stretched position. The device includes at least a second cord (3′) related to a second elastic element or spring (10′) located at another point of the width of the shutter such that the elastic elements (10, 10′) are retracted onto themselves during the process of unwinding the shutter due to the instantaneous tension difference supported by each of the elastic elements (10, 10′). The shutter (12) can be motorized.

Claims

1. A device for winding and unwinding Alicantina shutters (12), which are raised by being wound onto themselves by actuating at least a first cord (3) connected to a first elastic element (10) which is attached at one end to the head (1) of the shutter and at the other end to the end of the cord (3) which allows the unwound segment of the shutter (12) to be kept in a stretched position, characterised in that it comprises at least one second cord (3′) related to a second elastic element or spring (10′) located at another point of the width of the shutter such that the elastic elements (10, 10′) are at least partially retracted at any time during the lowering of the shutter and consequently during the raising process, and regardless of whether the raising process is started with the shutter half-lowered, the elastic elements (10, 10′) can be tensioned again and keep the unwound segment of the shutter stretched, thus avoiding the formation of a curvature that prevents the correct winding thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] As a complement to the description that will be provided herein, and for the purpose of helping to make the features of the invention more readily understandable, according to a preferred practical exemplary embodiment thereof, said description is accompanied by a set of drawings constituting an integral part thereof in which, by way of illustration and not limitation, the following is represented:

[0023] FIG. 1 shows a representation corresponding to a schematic profile view of a shutter with the conventional winding system, in inoperative or at rest status.

[0024] FIG. 2 shows a view of the set of the preceding figure before a pulling of the actuation cord of the same, being possible to see how a curvature is formed that prevents the correct winding of the shutter.

[0025] FIG. 3 shows a view as in the preceding figures but with the cord associated to an elastic element, in use status, showing how the shutter manages to wind correctly by keeping the unwound shutter segment stretched.

[0026] FIGS. 4, 5, 6, and 7 show respective schematic details of the manner in which the cords and the corresponding elastic elements thereof are linked, such that FIG. 4 represents the raised or semi-raised shutter, FIG. 5 corresponds to the shutter in the initial lowering phase, FIG. 6 representing the tensioning and balancing of the two elastic elements, while FIG. 7 shows the lowering of the cord opposite to that which is shown in FIG. 5.

[0027] FIG. 8 shows a schematic view of the manner in which the drum for winding the cord is mounted with respect to the ring attached to the head of the shutter and wherein a device is involved for unwinding cords for raising/lowering shutters made in accordance with the present invention.

[0028] FIG. 9 shows a longitudinal cross-sectional view of the assembly of the preceding figure.

[0029] FIG. 10 shows a detail of the manner in which the cord is passed through the ring for winding thereof onto the drum.

PREFERRED EMBODIMENT OF THE INVENTION

[0030] As can be seen in the figures referred to, with specific reference to FIGS. 1 and 2, in an Alicantina shutter or the like (12), the winding of which is carried out by means of a pulling cord (3), which at one end is attached to an upper anchorage, while at the other end it passes over a pulley located at the upper portion, embracing the shutter assembly (12), to define a free segment through which the pulling is carried out.

[0031] Well, FIG. 2 shows the manner in which the unwound portion of the shutter (1), during the process of winding or raising the shutter, suffers a curvature that prevents the correct winding thereof.

[0032] From this structure, and according to FIG. 3, a solution to the problem of poor winding of the shutter (12) is shown, consisting in the fact that the shutter (1), mounted suspended from an anchoring element, as is conventional, and wrapped by the corresponding pulling cord (3), presents the particularity that between the upper anchoring point and the end of the cord (3) an elastic element (10) is inserted, which allows to keep the unwound segment of the shutter stretched, thus avoiding the formation of a curvature that prevents the correct winding thereof.

[0033] In view of FIGS. 4-7, it can be seen how the device of the invention comprises at least two cords (3-3′) associated with the respective elastic elements, in this case made up of two springs (10-10′).

[0034] FIG. 4 schematically shows the shutter partially or fully wound or raised, the springs (10-10′) being tensioned.

[0035] FIG. 5 shows the shutter as it begins to lower. Due to the lack of total horizontality, and thanks to the fact that there are at least two cords (3-3′), one of the cords will support more weight than the other, which will cause the elastic element associated with the cord with less tension to retract and return to its rest position at least partially. FIG. 5 shows that the cord (3) has more tension than the cord (3′) so that the spring (10′) will recover.

[0036] FIG. 6 shows the manner in which the shutter has continued to lower after the position in FIG. 5. At this point, the cord (3′), due to the recovery of the elastic element (10′), has less tension, a situation that causes the shutter to tend to lower by the end of the cord (3′)-elastic element (10′) assembly until it reaches a higher tension than the cord (3)-elastic element (10) assembly (FIG. 7), wherein the method will be repeated, which, during the entire lowering manoeuvre, will become alternative.

[0037] FIG. 7 shows the shutter at a later time than that which is shown in FIG. 6. Due to the retraction of the element associated with the cord that supported less tension, the shutter is now unbalanced in the opposite direction. Again, due to the lack of total horizontality, and thanks to the fact that there are at least two cords (3-3′), one of the cords will have more tension than the other which will cause the elastic element associated to the cord with less tension to retract (stop stretching) and at least partially return to its rest position. FIG. 7 shows that the cord (3) has more tension than the cord (3′) so that the spring (10′) will recover.

[0038] In this way, the elastic elements (10 and 10′) of the ropes or cords (3-3′) will be loosened during the lowering of the shutter, even if the shutter is not completely lowered.

[0039] This effect is not achieved with a device with a single rope because this difference in tension does not occur and the elastic element will always be tensioned by the weight of the shutter and therefore the shutter will need to be fully lowered in order to release the tension in the cord and allow the elastic element to fully loosen. Otherwise, i.e. if the shutter is not fully lowered, the elastic element will be as stretched as it was stretched during the raising of the shutter in the preceding operation, so that when the shutter is raised again the spring will be stretched even more, causing the elastic element to be stretched completely or at a tension higher than that required to prevent the formation of a curve in the segment of the shutter that is not wound yet.

[0040] In the event that the Alicantina shutter (12) or the like is motorised, the device for unwinding cords for raising/lowering shutters (12) comprises a head (1), a ring (7) attached to the head (1), and a drum (2) rotating within the ring (7) for winding or unwinding a cord (3). At one end (4) the cord (3) is attached to the same drum (2) and at the opposite end is passed through a hole (5) to allow the actuation thereof during unwinding onto the drum (2).

[0041] The ring (7) comprises a ramp (8) laterally which moves the first turn (3A) of cord (3) entering onto the drum (2) so that, the length of movement of the first turn (3A) will be the same or greater than the diameter of the same cord (3) to ensure that the last turn that has been wound does not hinder the cord entering the drum.

[0042] The drum (2) presents a conical segment (9) downstream of which the same drum is straight as represented in FIG. 9, with the particularity that the inside of the ring (7) in which the drum (2) angularly moves preferably presents a complementary taper to be suited to said conical segment (9).

[0043] According to the referred features, the device of the invention allows to improve the winding of the cord (3) entering through the hole of the head (5) and the hole of the ring (6) on a drum (2). By means of the ramp (8) of the ring (7) the first turn (3A) is moved along the axis of rotation (11), solidly attached to the same drum (2) as shown in FIG. 9, such that the length of movement of the first turn (3A) will be the same or greater than the diameter of the same cord (3) to ensure that the last turn that has been wound does not hinder the cord entering the drum.

[0044] The movement of the first turn (3A) causes the movement of the same wound turns on the drum (2), as shown in FIG. 8. The movement of the turns along the drum is carried out without too much opposition because part of them are positioned on the straight segment of the drum (2), of smaller diameter than the diameter of the first turn (3A) that enters on the conical segment of the drum (2).

[0045] As has already been said throughout the present specification, preferably the difference in size between the end diameter of the conical portion (9) of the drum (2) through which the cord (3) enters and the diameter of the straight or cylindrical portion of said drum is approximately equal to the diameter of the cord (3), thus ensuring that said cord wound on the straight portion is perfectly suited preventing some turns from mounting on others.