AU723075B2 - Folding blinds for windows and doors - Google Patents

Abstract

This invention relates to folding blinds for windows and doors, comprising a number of horizontally articulated slats connected to each other by means of hinged joints which, when the blind is raised, enable the slats to automatically fold like an accordion inside a box. Each slat features a pin terminating with a wheel, which is engaged by the teeth of two cams whose rotation allows the raising and lowering of the blind.

Description

Folding Blinds for Windows and Doors Technical Field This patent application relates to folding blinds for windows and doors.

Background Art It is well known that the most commonly used blinds for windows and doors are roller blinds, composed of horizontally articulated slats, which may be manually wound around a horizontal shaft with a belt, or automatically, by means of an electric motor.

The uppermost slat is integral with the shaft, which bears the entire weight of the blind, and this is the reason why it must be carried by strong supports, which are permanently fastened to the wall.

*oo* *oo* One of the drawbacks of roller blinds in particular, and of blinds in general, is precisely the complexity of the twofold installation procedure: first of all, it is necessary to fasten the shaft supports, and then to fix the wooden box enclosing the 20 space above the window/door housing the roller blind assembly.

Another drawback of roller blinds is the large amount of space required to house the blind when it is fully raised, ie. fully wound around the shaft; this space is generally larger than the thickness of the wall itself, and, therefore, it generally projects into the interior of the room, giving rise to a further two drawbacks: a purely aesthetic one and an essentially technical one, consisting in the fact that the greater the projection into the room, the further away from the window it will be necessary to hang the curtains, because the curtains generally cover the roller blind box, to hide it from view.

The final result is the overall reduction of the room's floor area, compared to the case where it were possible to hang the curtains right next to the wall.

Through the years various devices have been devised to remedy the above mentioned drawbacks; patent DE A 29 47501, for example, describes a folding blind for windows and doors where the slats are fastened the one to the other by means of connecting elements with curved ends, also featuring pins at the slat-ends, which pins run inside two lateral guides (17, 18), and a toothed wheel actuated by a motor or a belt, which engages the pins and either drags or pushes the slats to raise or lower the blind, respectively; when raised the slats should fold up one on top of the other.

According to this patent, the guides start at the bottom of the blind and end below the toothed wheel, so that above it the slats are unguided; this determines the disorderly arrangement of the slats, which may be prejudicial to the correct working of the blind.

The blind described in the above mentioned invention, in the best of cases and as suggested by the drawings, seems suitable for skylights, where the almost horizontal position helps the slats to arrange themselves in the desired manner, while in a vertical position the chances that the slats fall correctly into place are almost nil. In one of the S 15 illustrated embodiments of the invention, in fact, the slats are made to roll around a shaft, thus frustrating the advantage represented by the folding solution.

.The U.S. patent 4,303,117 describes an opening and closing device for folding blinds, according to which the slats, provided with pins at the ends, run inside two guides and 20 are weighted down so as to facilitate their descent; the blinds are then raised by pulling two cords fixed to the lowermost slat; the slats are folded by means of two Socables and two cams, which are required also to overcome the load at the joints, since the lifting cords keep the slat assembly tense at all times. To facilitate the lowering and raising of the blinds, in fact, a system of counterweights is required. The system 25 described in the U.S. patent 4,303,117 is quite complex, costly and leads to a large amount of friction during the movement of the blinds, due to: the sliding of the cables, the devices 25 and 26 for making the slats fold and the action of the counterweights; besides, the system described in the above mentioned patent also considerably increases the weight that has to be lifted and the counterweights hinder the uniform movement of the whole assembly. Last, but not least, the limited number of slats (6) and, therefore, their large size, requires a box which noticeably projects from the Nwall to house them.

The present invention relates to a folding blind for windows which, besides fitting inside a box which does not project from the wall, thanks to the folding arrangement of the slats, also remedies the above mentioned drawbacks enabling the smooth folding of the slats by means of a simple mechanism with scarcely no weights and minimum friction.

Disclosure of Invention This invention relates to window and door blinds which, when fully compacted, ie.

open, occupy less space than the current type of roller blinds and, in any case, less than the thickness of the wall in which they are contained, so that the box housing the blind is perfectly flush with the wall on the inside.

This invention also relates to window and door blinds whereby all the components may be installed and supported inside the relative box, so as to make it easier and faster to install the blinds, since all that is required is to place the box inside the space above the window/door and fasten it to the wall.

•*oo These results have been achieved thanks to the invention's special structure, 20 comprising a series of horizontally articulated slats which, when the blind is raised, automatically fold as they enter the box. Therefore, the width of the blind coincides o with the width of one slat, since all the slats lie precisely one on top of the other, forming a pile of constant width, regardless of the number of slats composing the blind, whereas in the case of roller blinds, the greater the number of slats composing 25 the blind, the larger the diameter of the spiral formed by the blind when open.

The first or uppermost slat is fastened directly to the top of the box or, alternatively, when the blind is fully raised, it is in contact with the top of the box, while when it is fully lowered it goes to lie, by means of a pin, on a support above the pin guide, so as to reduce the overall height of the blind.

ft 4 4 The blind is raised by rotating two cams, which engage the heads of the pins on the middle of each slat and either drag them upwards or push them downwards.

Alternatively, instead of the two cams, a chain-based or other similar system may be used, with the further advantage of requiring a smaller diameter than the cams and, therefore, enabling a further reduction of the box's width. Obviously, more than one pin may be applied at the ends of the slats, but the additional ones will not have rounded heads.

The two lateral cams are driven manually, with a belt, or by means of a motor, through a set of cogged wheels connected the one to the other and to a driving shaft; the cogged wheels are housed inside an adequately sized metal box, capable of withstanding the effort required to raise and lower the blind; the whole assembly is contained inside the box.

Since the shaft is not required to support the weight of the blind, the relative supports may be fastened to the walls of the box, which, therefore, contains and supports both the blind and its driving mechanism. This means that the blind may be installed with a single operation, simply by introducing the box containing the blind into the space in :20 the wall above the window/door and fastening it in place.

"Brief Description of the Drawings "For a better understanding of the invention, the preferred embodiment will now be 25 described in detail, with reference to the accompanying drawings, in which: Fig. 1 shows a perspective and schematic view of the blind, when it is fully raised inside the box; Figs. 2, 3 and 4 show a couple of slats in the following positions, respectively: coplanar and detached; coplanar and touching; and superimposed, the one on top of the other; Fig. 5 shows the RH part of the box with some of the folded slats; Fig. 6 is Fig. 5 shown from the left toward the right; Fig. 7 shows a cross-section of a slat near its end; Fig. 8 shows a cross-section of the lateral guides; Fig. 9 shows the slats with the hooks grouped together; Fig. 10 shows the slats in Fig. 8, but separated; and Fig. 11 gives a different view of the slats.

Detailed Description of the Preferred Embodiments With reference to the Figures, the present blind comprises a series of slats hinged the one to the others by means of connecting elements with curved ends (2a), which hook into the slots on the edges of each slat.

In particular, on the upper edge of each slat there is a semi-circular slot (la), closed by a rounded rib which engages the curved lower end of the connecting element while on the lower edge of each slat there is a larger almost rectangular slot which also features a rib (lb) similar to the one mentioned above, and which engages the curved upper end of the connecting element The slot (1c) is large enough to accommodate a part of the connecting element when two slanted and coplanar slats come into contact (see Fig. for construction purposes, the slots la and ic may also be centred (see Fig. 11).

It must be pointed out that the slots (la and lc) are decentralised and located at the opposite ends of each slat therefore the slats must be alternately arranged so 25 that the upper slot (Ic) of one slat perfectly interfaces with the lower slot (la) of the slat immediately above.

At each end of the slats there is a pin with a rounded head (3a or 3b), enabling the cams to engage the slats when the blind is raised or lowered; outside the box the slats assume a slanted position.

Once inside the box the slats are folded and arranged one on top of the other, being forced into this position by the upward thrust of the cams and the pin-heads (3a and 3b) running in the guides (8a and 8b) fixed to the two box-shaped partitions With reference to Fig. 7, the lateral guides feature a specific housing (7a) in which the rounded heads (3a and 3b) of the pins slide.

Inside the box besides the cams and the driving shaft there are also specific guides (8a, 8b and 8c) fixed to the inside walls of the two box-shaped partitions The guides continue inside the box on the RH and LH sides, above the cams where the guide (8a) splits into two arms (8b and 8c), at different heights, each 15 arm facilitating the engagement of the wheels (3a and 3b) at the ends of the pins (3) with the cams and each of the two arms of the guide being such as to oblige the slats to fold like an accordion; the pins integral with the slats placed at different heights (see Fig. oblige the wheels when the blind is lowered, to arrange themselves in the space between the guide and the preceding wheel thus 20 reducing the space occupied by the totality of the wheels when the blind is raised.

°ee* On the inside wall of the box-shaped partition as previously mentioned, are fixed the guides (8a, 8b and 8c) for guiding the wheels (3a) at the ends of the pins while the slat and cam assembly remains outside of and precisely centred between the 25 pair of box-shaped partitions The hollow space inside the box-shaped partitions houses the cogwheels which are suitably protected and may act as reducers.

The guides (8a, 8b and 8c) on the inside wall of the box-shaped partition are so shaped and sized as to oblige the slats to fold pair by pair, and to unfold in a likewise manner, to allow the pins when the blind is raised or lowered, to engage with the cams at the same distance, thus achieving the uniform raising and lowering of the slats 7 On the outside of one of the two box-shaped partitions precisely, on the wall opposite the guide there is attached the motor for driving the blind or the pulley activated by the belt.

*o* e o

Claims (3)

1. A folding blind for windows and doors composed of a box a shaft two cams and a set of slats articulated by means of a flat connecting element (2) with curved ends which hook into specific slots (la and Ic) on the edges of the slats which slats also feature a pin at each end terminating at the head with a wheel (3a-3b), which pin engages the above mentioned cams which cams are supported inside the box by two box-shaped partitions right next to the slats and the cams there is a guide shaped and joined in two points by a guide- arm capable of housing the pin-heads; the toothed wheels (10) are housed inside the box-shaped partitions while the slots are decentralised and located on the opposite parts of each slat characterised in that the jointing arm (8b) is higher than the guide (8a) and the pins have different heights and receive the rounded heads (3a and 3b) at different heights, thus being obliged to follow the guide-arms (8a and 15 8b, respectively) at the appropriate height. boo

2. Folding blinds for windows and doors, according to claim 1, characterised in that the slot (la) on the upper edge of each slat is semicircular and closed by a rounded rib while the slot on the lower edge of each slat is practically 20 rectangular and is also closed by a rounded rib similar to the one mentioned above the slot (Ic) is large enough to accommodate a part of the connecting element when two adjacent slats take on a slanted position and come into contact the one with the other. 25

3. Folding blinds according to the preceding claims, characterised in that when the blind is raised the pin-head (3a) fits snugly into the space between the guide and the preceding pin-head (3b).