MULTIPLE BLADE CURTAIN, IN PARTICULAR VENETIAN BLIND

Abstract: A Venetian blind (1) is accommodated within the sealed interspace (5) defined by two glass surfaces (7,8) of a glass-­ box (6), the glass surfaces being spaced apart by an aluminum frame (4) which contains a molecular sieve (10). The Venetian blind is provided with control members (12-37) which allow adjustment of packing and/or inclination of its blades (2) from outside the glass-box (6) without altering the seal, and therefore the functionality, of the same. Operation from the outside of the control members inside the glass-box is achieved, for each adjustment, by magnetic coupling, through one of the glass surfaces of the glass-box, between a first magnet (22,32), positioned inside the glass-box and dir­ ectly connected to the respective control system, and a second external magnet (23,35).

Description: The present invention relates to a multiple blade curtain, in particular a Venetian blind. The problems which arise in using a Venetian blind installed on a window are known; among them, the most evident reside in the fact that such blinds require frequent cleaning operations and are often subject to accidental damage. In order to overcome these problems, two kinds of solutions are mostly used at present: a first solution consists of accommodating the Venetian blind between two separate window-frames; the second entails the use of a single frame with double shutters, inside which the Venetian blind is inserted. However, both these solutions present some disadvantages and inconveniences, such as a high cost and a considerable weight, as well as the fact that, since the accommodation is not hermetic, dust and condensed fumes can still deposit on the blades, thus requiring frequent cleaning operations which can cause damage to the blades. Conversely, since very frequent cleaning (or washing) cannot be performed, the aesthetical aspect of the blind is obviously compromised. It should be furthermore noted that such known solutions also entail large dimensions and restrict the use of the product. Also known from EP-A-0 109 382 is a Venetian blind with magnetic means for packing the blades and magnetic means for inclining the blades, both means and blades being enclosed in a glass box. The packing means and inclining means, however, are of the conventional type comprising cables and pulleys which give unsatisfactory results in the packing and inclination of the blades. Unsureness in operation and a tendency for breakdowns are commonly encountered with such conventional devices, and furthermore the force required to pack the blades increases as the blades are lifted and more blades are set upon one another. The main aim of the present invention is to eliminate the above described disadvantages of known Venetian blinds, by devising a blind which, by virtue of its peculiar characteristics, after being installed is not subject either to becoming dirty or to the possibility of accidental damage, so as to completely eliminate the need for cleaning or maintenance operations. Within this aim, a particular object of the invention is to provide a Venetian blind which can be accommodated in a hermetical seat and nevertheless is provided with an operation system which allows a rapid and functional adjustment of packing and inclination of the blades, without jeopardizing tightness of the accommodation. Specifically, the functional assuredness of the inclination of the blades is obtained, and the force required to lift and pack the blades remains constant regardless of the degree of packing of said blades. Not least object is to devise a Venetian blind or the like having an accommodation with a very simplified structure, which can be easily obtained starting from commonly available elements, furthermore the Venetian blind should be able to have very small dimensions to allow a wide utilization. The above aim and objects as well as others which will become apparent hereinafter, are achieved, according to the invention, by a Venetian blind as claimed in the appended claims. Further features and advantages of the invention will become apparent from the description of a preferred, but not exclusive, embodiment of a Venetian blind, according to the invention, illustrated only by way of non-limitative example in the accompanying drawing, where: Fig. 1 is a front view of the entire Venetian blind; Fig. 2 is a view of a peripheral portion of the blind of Fig. 1, illustrating the blade inclination control means; Fig. 3 is a side view, in enlarged scale, of a detail of the control means shown in Fig. 2; Fig. 4 is a view of a peripheral portion, opposite to the portion of Fig. 2, illustrating the blade packing control means; Fig. 5 is a side view, in enlarged scale, of a detail illustrating the magnetic coupling for blade packing adjusting; and Fig. 6 is a cross section view, in enlarged scale, along line VI-VI of Fig. 4, where the position of the upright of the window-frame has been indicated schematically by a broken line. With reference to the figures, a Venetian blind according to the invention, generally indicated at 1, comprises a plurality of blades 2 connected to the upper side 3 of a perimetral frame 4, suitably formed, as is better illustrated in Fig. 6, of a C-shaped profile having a thickness dimensions which is approximately the same as the inner interspace 5 of a glass-box 6 accomodating the frame 4. This glass-box 6, as is known, essentially comprises of a pair of glass surfaces, respectively outer 7 and inner 8, kept spaced apart from one another by an aluminum framework 9 which contains a molecular sieve 10 and is sealingly connected to the glass surfaces by means of sealing elements 11. The Venetian blind 1 is provided with blade inclination adjustment means which, as is better illustrated in Fig. 2, comprise a shaft 12, of a usual kind, extending inside the upper side 3 and bearing, rigidly connected thereto, supports 13 for winding thereon small cables 14 which, through their vertical motion, rotate all the blades 2 in a synchronized manner about a blade longitudinal axis. According to the invention, the shaft 12 receives its motion from a second rotating shaft 15, which extends within a first side portion 16 of the frame 4, through an angular return transmission suitably comprising a toothed wheel 17 keyed onto the shaft 12 and meshing with an endless screw 18 provided in the upper end 19 of the second shaft 15. The second shaft 15 is internally threaded and, at its lower end 20, is engaged by a complementarily shaped helical rod-like element 21, with a suitable pitch, which bears, downwardly rigidly connected therewith, a first inner magnet 22. This inner magnet 22 is associated with a second outer magnet 23, which is separated therefrom by the inner glass surface 8, so that by means of the magnetic connection therebetween it is possible to control rotation of the blinds 2 from the outside. Indeed, when the first external magnet 23 is moved vertically, it causes an equal movement of the inner magnet 22, and thus of the helical rod-like element 21, so that the second shaft 15 and therefore the first shaft 12 are caused to rotate in the desired direction. It is thus evident that by moving the outer magnet 23 the desired orientation of the Venetian blind is achieved between a maximum darkening, at the two ends of the stroke, and a partial darkening at an intermediate level. The Venetian blind 1 furthermore comprises control means which allow packing of the blinds 2 and therefore vertical extension of the blind to be varied from a total extension thereof, which corresponds to a complete darkening, up to the complete lifting, which corresponds to a full view. Now with particular reference to Figs. 4 and 5, the packing control means comprises a pair of cables 24 and 25 which are connected on one side to a rigid rod 26 which is located at the base of the blades 2 and which, after being wound on the respective guide ore return pulleys 27 and 28, and on an idle roller 29, extend inside a second side portion 30 of the perimetral frame 4, connecting at the other end to an inner slider 31, suitably composed of two magnets 32 rigidly fixed to a metallic plate 33. According to the invention, the inner slider 31 is magnetically conneted, through the inner glass surface 8, to an outer slider 34 which is also advantageously formed by a pair of outer magnets 35 joined to a metallic bracket 36. The stroke of the sliders 31 and 34 must be equal to the maximum extension of the blind 1, so that the motion of the inner slider 31, imparted from outside the glass-box 6 by means of a corresponding vertical motion of the outer slider 34, acting by means of the pair of cables 24 and 25, causes lifting or lowering of the rigid rod 26, accordingly varying the extension of the blind 1. It should be pointed out that, for example during lifting of the rigid rod 26, more and more blades 2 gradually rest on it, starting from the lower ones; for this reason, the weight which must be lifted by means of the cables 24 and 25 depends on the extension of the blind 1 and, precisely, increases as the rigid rod 26 rises. In other words, when the rod 26 is completely lowered the lifting force is minimal, while when the rod 26 is almost completely raised the force required for a further ascending motion is much greater. To solve this problem, a counterweight is used, the action whereof depends on the position of the rigid rod 26, so as to keep constant the effort required to raise the Venetian blind 1. According to the invention, the counterweight suitably comprises a track 37 which, connected at one first end 38 thereof to the inner slider 31, winds around the upper idle roller 29 and has the opposite end 39 connected to a return cable 40 which, by winding on a lower idle roller 41, is in turn connected to the inner slider 31. For the sake of descriptive completeness, it should be furthermore observed that, in order to achieve optimum system balancing, it is appropriate for the weight of the inner slider 31 to be equal to the sum of the weight of the rigid rod 26 and of half the weight of all the blades 2, reaching this value with a possible addition of ballast; in this case the track 37 will have a length equal to the entire extension of the blind 1 and a weight equal to half the weight of all the blades 2. In this manner, the system is exactly balanced in every position, and the sliders 31 and 34 may be placed at any intermediate level, with the blind 1 keeping the corresponding thus set extension. In practice, it has been observed that a Venetian blind according to the invention presents remarkable advantages with respect to other known solutions, since dust is absolutely prevented from entering the interspace 5, due to the latter remaining perfectly sealed, and the blades 2 are permanent clean, thus eliminating the need for any subsequent cleaning operation. The installation inside the glass-box 6 furthermore avoids that accidental deformations or breakages of the blades 2 may occur, and this, together with the foregoing, ensures a perfect unalterability of the Venetian blind 1 in time. It should be furthermore observed that with a blind according to the invention the overall dimensions are reduced to a minimum and the weight is also consequently smaller, thus increasing the possible utilizations of the Venetian blind according to the invention. A further advantage is determined by a low cost of installation, since with a single operation for fitting the glass-box, a Venetian blind is also simultaneously installed, thus eliminating the cost of a subsequent second fitting. The costs can be reduced further by taking into account the fact that the use of a window-frame with a glass-box accommodating therein a Venetian blind according to the invention allows elimination of the outer blinds of the windows. The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept. Thus, for example, the shape of the perimetral frame 4 may vary; the helical rod-like element 21 may be replaced by a helical thin plate; the outer face of the glass surface 8 may be provided with any guiding elements slidably engaged by the outer magnet 23 and/or the outer slider 34; the structure of the track 37 may be any, so long as the indispensable balance relationships are respected, and moreover, the motion transmission between the magnets may be non-linear, but also, for example, of a rotary type, so long as the internal control means for adjusting the Venetian blind may be operated without direct physical contact. Furthermore, in practice, the materials employed, so long as compatible with the contingent use, as well as the dimensions, may be any according to the requirements and to the state of the art.

Claims: A multiple blade curtain, in particular Venetian blind, comprising a plurality of blades (2) accommodated in a sealed interspace (5) defined by two glass surfaces (7,8) of a glass box (6), said curtain further comprising blade inclination control means (12-23) for adjusting the inclination of said blades (2) and preferably blade packing control means (24-36) for adjusting the packing of said blades (2) comprising an inner magnetic slider (31) being movable inside said interspace (5) by magnetic coupling through one (8) of said glass surfaces with an outer magnetic slider (34) located outside said glass box (6), said blade inclination control means (12-23) comprising a first magnet (22) being vertically movable without rotation thereof inside said interspace (5) by magnetic coupling through one (8) of said glass surfaces with a second magnet (23) located outside said glass box (6), characterized in that said blade inclination control means (12-23) further comprise a first upper shaft (12) provided with at least two supports (13) for blade inclination determining cables (14) associated with said blades (2) and a second substantially vertical shaft (15) connected to said first shaft (12) by angular return transmission means (17,18), said second vertical shaft (15) having a threaded portion at its own lower end (20), said second vertical shaft (15) engaging with a correspondent threaded portion of a threaded control element (21) which is rigidly connected to said first magnet (22), said threaded portions of said second vertical shaft (15) and said threaded control element (21) having a suitable pitch to cause a rotation of said second vertical shaft (15) upon a vertical linear movement of said threaded control element (21). A curtain according to claim 1, characterized in that said second shaft (15) is internally treaded for threaded engagement with a complimentarily shaped helical rod-like element (21) forming said threaded control element which downwardly bears said first magnet (22), said second magnet (23) being movable in a linear manner to adjust the inclination of said blades (2). A curtain according to any one of the preceding claims, characterized in that said blade packing control means comprise at least two cables (24,25) which, wound on upper return pulleys (27,28), are connected at one end to a rigid rod (26) placed below said blades (2) and at the other end are connected to said inner magnetic slider (31) which is magnetically coupled to and movable by, through one of said glass surfaces (8), said outer magnetic slider (34). A curtain according to claim 3, characterized in that said blade packing control means further comprise a counterweight (37-41) having an action depending on the position of said rigid rod (26), so as to keep constant the effort required to lift said rigid rod (26) during any position of said rigid rod (26). A curtain according to claim 4, characterized in that said counterweight comprises a track (37) which, being coupled at one end (38) to an upper side of said inner magnetic slider (31), winds around an upper idle roller (29) and is then connected at its other end (39) to a return cable (40), said return cable (40) winds on a lower idle roller (41) and is connected on a lower side to said inner magnetic slider (31). A curtain according to claim 5, characterized in that the overall weight of said inner magnetic slider (31), possibly suitably ballasted, is equal to the sum of the weight of said rigid rod (26) plus half of the weight of all said blades (2), said track (37) having a length equal to the entire extension of said curtain and having a weight equal to half the weight of all said blades (2). A curtain according to any one of the preceding claims, characterized in that said inner magnetic slider (31) is essentially composed of a pair of inner magnets (32) connected to a small metallic plate (33) and said outer magnetic slider (34) is composed of a pair of outer magnets (35) connected to a small metallic bracket (36). A curtain according to any one of the preceding claims, characterized in that said glass box (6) comprises an aluminium framework (9) containing a molecular sieve (10), said glass surfaces (7,8) being sealingly connected to said aluminium framework (9) by means of sealing elements (11), said glass box (6) therein accommodating a perimetral frame (4) having substantially the same thickness as said interspace (5) and including substantially vertical sides (16,30) with C-shaped transverse cross sections open towards one (8) of said glass surfaces, said substantially vertical sides (16,30) accommodating, linearly movable therein, respectively said first magnet (22) and said inner magnetic slider (31).

Inventors: ENCICLIATI, MARIO, ROSSINI, MAURO
Applicants: FINVETRO S.R.L.
Application year: 1987
Main classification: E06B9
IPC codes: E06B9