Photovoltaic blind assembly for use in double glazing units

Abstract

The invention relates to a photovoltaic blind assembly (1) adapted for use in a double glazing unit comprising: - a plurality of blind slats (3) with photovoltaic elements (9), each blind slat (3) being provided with at least two through-holes (7), the through-holes (7) of the blind slats (3) being in use aligned along a vertical axis, said photovoltaic elements (9) comprising a contact electrode (8) surrounding at least partially each through-hole (7), - at least two ladder cords (4), - a tilt mechanism (2) coupled to the ladder cords (4) to provide control of the tilt angle of the blind slats (3), - at least two bare electrical wires (5) with each bare electrical wire (5) crossing the blind slats (3) through the aligned through-holes (7), said bare electrical wires (5) being in direct or indirect physical contact with the contact electrode (8) for at least one given tilt angle to provide the electrical connection between the different photovoltaic elements (9) of the blind slats (3) and to allow the extraction of the generated electrical current.

Description

PHOTOVOLTAIC BLIND ASSEMBLY FOR USE IN DOUBLE GLAZING UNITSFIELD OF THE INVENTION

[0001] The invention relates to a photovoltaic blind assembly, more specifically a photovoltaic Venetian blind assembly, particularly but not exclusively adapted for use in double glazing units.BACKGROUND OF THE INVENTION

[0002] The field of movable blinds associated to a window space is strongly felt especially when the blind is seated within a sealed double glazing unit, and therefore not directly accessible by the user.

[0003] A blind of the above type is typically very light and subtle. Its uniform and balanced movement is subject to the distribution of forces and tensions along the ladder cords. This is of special interest in photovoltaic blinds where the slats are electrically connected. Traditional interconnection methods through plug assemblies, welding or gluing distort the stress distribution along the ladder cords and considerably limit the movement of the blind. To prevent damaging the traditional blinds and therefore preserving the duration thereof over time, its movement must be as reliable and accurate as possible.

[0004] The building photovoltaic shutters integrate building shutter shading and photovoltaic power generation. The dual functions of shading and photovoltaic power generation should thereof be considered in the design for a proper motion control of the slats that does not impair the electrical connections between the blind slats.

[0005] To this end, the document GB 2419369 discloses an energy blind using conductive tracks in the slats to carry the electrical energy produced to some conductive support cords arranged on the edges of the slats. The conductive support cord also provides the power bus carrying the power up to a head rail. The inverter is normally fitted into the head rail and connected to the mains via a plug.

[0006] An alternative to the invention of the document GB 2419369 is disclosed in the document CN 110094153, where a building photovoltaic shutter overcomes some of the challenges of the prior art in the field of photovoltaic shutters. The powertransmission wires are arranged so that the photovoltaic shutters will not be easily damaged after long-term use, what greatly reduces the maintenance cost of the building photovoltaic shutters. The disclosed invention proposes multiple photovoltaic slats connected in parallel by setting slat projections at both ends of the slats with guide conductive structures, thereby avoiding dedicated wiring between the slats.

[0007] The previous photovoltaic shutters address the challenges of wiring using electrical connectors and plug assemblies. The disclosed solutions might be suitable for external blinds where the weight of the wires and connectors might be much less respect to the blind slats and therefore limitations for the movement disturbances are negligible. However, these solutions are not applicable in light blinds for use in double glazing units, where electrical connectors and plug assemblies represent a considerable weight with respect to the blind slats. These solutions introduce rigidity and additional weight that considerably limit the movement of the slats, compromising the reliability of the movement over the time.SUMMARY OF THE INVENTION

[0008] The present invention aims to provide a photovoltaic blind assembly allowing a simple and easy movement to the blind for use in a double-glazing unit.

[0009] The photovoltaic blind assembly according to the present invention provides an unconventional electrical connection system between the contact electrodes of the photovoltaic elements in the blind slats using tensioned straight bare electrical wires crossing through-holes of the photovoltaic blind slats. The contact electrodes get in direct or indirect physical contact with the bare electrical wires at least for a certain tilt angle of the blind slat. The bare electrical wires carry then the photo-generated current and distribute it to the outgoing feeders.

[0010] More specifically, the invention relates to a photovoltaic blind assembly adapted for use in a double-glazing unit comprising:- a plurality of blind slats with photovoltaic elements, each blind slat being provided with at least two through-holes, the through-holes of the blind slats being in use aligned along a vertical axis, said photovoltaic elements comprising a contact electrode surrounding at least partially each through-hole,- at least two ladder cords,- a tilt mechanism coupled to the ladder cords to provide control of the tilt angle of the blind slats,- at least two bare electrical wires with each bare electrical wire crossing the blind slats through the aligned through-holes, said bare electrical wires being in direct or indirect physical contact with the contact electrode for at least one given tilt angle to provide the electrical connection between the different photovoltaic elements of the blind slats and to allow the extraction of the generated electrical current.

[0011] According to embodiments of the invention, the photovoltaic blind assembly comprises a first tensioning mechanism attached to the bare electrical wires for keeping said bare electrical wires straight along the vertical axis.

[0012] According to embodiments of the invention, the first tensioning mechanism comprises an electrically isolated weight or a fixed frame, and a screw for attaching a lower end of the bare electrical wires to the electrically isolated weight or to the fixed frame.

[0013] According to embodiments of the invention, the given tilt angle is comprised between 70 and 80 degrees, preferably it is of 75 degrees, with respect to a horizontal axis perpendicular to said vertical axis, the given tilt angle corresponding to the position where the user cannot see through the windows and where the photovoltaic elements are facing towards the light source side.

[0014] According to embodiments of the invention, the photovoltaic blind assembly comprises at least two lift cords controlling the raising and lowering of the blind slats, said lift cords passing through the same through-holes as the bare electrical wires or through other through-holes.

[0015] According to embodiments of the invention, the photovoltaic blind assembly comprises a second tensioning mechanism for keeping straight the lift cords along the vertical axis.

[0016] According to embodiments of the invention, the lift cords are made up of an electrically conductive material so as to act as bar electrical wires as well, only the first tensioning mechanism being then required.

[0017] According to embodiments of the invention, the through-holes are oval or oblong-shaped.

[0018] According to embodiments of the invention, said bare electrical wires are in indirect physical contact with the contact electrode, the photovoltaic blind assembly comprising an element made up of an electrically conductive material disposed between the bare electrical wire and a side of the through-hole.

[0019] According to embodiments of the invention, said element is a sphere provided with a through-opening for receiving the bare electrical wire, a washer or a flexure structure such as a tape or a spring.

[0020] According to embodiments of the invention, notches accommodating the ladder cords are provided in the edges of the blind slats to improve the alignment of the ladder cords along the vertical axis.

[0021] The main advantage of the present invention lies in the possibility of operate and control the motion of the photovoltaic blind and provide electrical connection at the same time. Thus avoiding the drawbacks of traditional photovoltaic shutters where the Venetian blinds are large and their electrical connection systems do not allow reliable and stable motion for long term performance and useful life of the photovoltaic blind assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG.1 is a partial vertical cross-section view of the photovoltaic blind assembly.

[0023] FIG.2 is a partial perspective view of a variant of the photovoltaic blind assembly according to the invention.

[0024] FIG.3 is a partial vertical cross-section view of the photovoltaic blind assembly illustrating the tilt and tensioning mechanisms.

[0025] FIG.4 is a partial perspective view of the photovoltaic blind assembly of FIG.2 showing the physical contact between the contact electrodes of the photovoltaic elements and the bar electrical wire.

[0026] FIG.5 is a variant of FIG.4 with the physical contact between the contact electrodes and the bar electrical wire enhanced by notches in the edges of the blind slats.

[0027] FIG.6 is a variant of FIG.4 and FIG.5 with a partial vertical cross-section view showing the physical contact between the contact electrodes and the bar electrical wire enhanced by a metallic sphere.

[0028] FIG.7 is a partial vertical cross-section view of another variant of the photovoltaic blind assembly showing the bare electrical wire and the lift cord to perform the electrical connection with the photovoltaic blind slats and to control the raising and lowering of the blind.

[0029] FIG.8 is a partial front view of the photovoltaic blind assembly of FIG.7 embodying the application of the bare electrical wires and lift cord throughout different through-holes and tensioning mechanisms.

[0030] Legend1 : Photovoltaic blind assembly2: Tilt mechanism3: Photovoltaic blind slat, also called blind slat4: Ladder cord5: Bare electrical wire6: First tensioning mechanism for the bare electrical wire7: Through-hole8: Contact electrode9: Photovoltaic element10: Electrical connector11 : Sleeve tube12: Sleeve tube support13: Electrically isolated weight14: Screw15: Notch16: Sphere17: Lift cord18: Second tensioning mechanism, in particular weight or spring element, for the lift cord19: Fixed frame20: TubeDESCRIPTION OF THE INVENTION

[0031] The invention relates to a photovoltaic blind assembly particularly but not exclusively adapted for use in double glazing unit.

[0032] Hereafter, the vertical axis or position corresponds to the vertical direction when the photovoltaic blind assembly is in use and the horizontal axis or position corresponds to the perpendicular to the vertical axis or position.

[0033] As represented in figures 1 and 2, the photovoltaic blind assembly 1 comprises a plurality of photovoltaic blind slats 3, at least two ladder cords 4 attached to the edges of the blind slats 3 and a tilt mechanism 2 in which the ladder cords are associated to provide control of the tilt angle of the photovoltaic blind slats. Thanks to the tilt mechanism, the blind slats can rotate from the horizontal position corresponding to a fully opened position wherein the user can see through the window to a nearly vertical position, typically 75 degrees with respect to the horizontal position, corresponding to a fully closed position wherein the user cannot see through the window. In addition, the photovoltaic blind assembly may optionally comprise at least two lift cords 17 visible in figures 7 and 8 controlling the raising and lowering of the blind slats.

[0034] Each photovoltaic blind slat 3 is provided with at least two through-holes 7, each one surrounded at least partially by a contact electrode 8 of the photovoltaic elements 9 of the blind slats (figures 2 and 4). These contact electrodes 8 are provided on the surrounding of the front, rear or front and rear side of the through-holes 7 of the photovoltaic blind slats. The through-holes are aligned on a same vertical axis for the different blind slats.

[0035] The photovoltaic blind assembly 1 comprises at least two bare electrical wires 5 kept straight and placed vertically thanks to a first tensioning mechanism 6 in order to cross the different blind slats 3 through the vertically aligned through-holes 7. There is at least one bare electrical wire per through-hole. It could be two electrical wires per through-hole. For example, they could be a twisted pair. The bare electrical wires 5 and the contact electrodes 8 have high conductive surface properties. For example, the bare electrical wires are made of copper or brass, both of which are silver plated, while the electrodes are obtained by evaporation or printing of a thin film of copper or silver. The contact electrodes 8 of the blind slat 3 and the bare electrical wires 5 are positioned to establish an electrical contact by tilting the angle of the photovoltaic blind slats 3. Similar to the working principle of a tilt switch, the contactelectrodes 8 of the blind slats come into direct or indirect physical contact with the bare electrical wires 5 for at least one tilt angle value, providing the electrical connection between the different photovoltaic elements of the photovoltaic blind slats and allowing the extraction of the generated electrical current through an electrical connector 10 visible on figures 2 and 8. The value of at least one angle of inclination for the electrical connection corresponds to the angle where the slats of the blind are in a nearly vertical position, typically comprises between 70 and 80 degrees, more specifically of 75 degrees with respect to the horizontal position, where the photovoltaic elements 9 are facing towards the light source side. The through-holes have preferably a shape partially fitting with the shape of the bare electrical wire but allowing the slate rotating. So, they have preferably an oval or oblong shape.

[0036] The photovoltaic blind assembly 1 comprises the first tensioning mechanism 6 that confers stiffness and stability to the bare electrical wire 5. In the variant of figure 3, the first tensioning mechanism 6 comprises an electrically isolated weight 13 attached to the lower end of the wire 5 through a dedicated screw 14. In the variant of figure 7, the first tensioning mechanism 6 comprises a fixed frame 19 attached to the lower end of the wire 5 through a dedicated screw 14.

[0037] In presence of lift cords 17, the photovoltaic blind assembly 1 further comprises a second tensioning mechanism 18 represented in figures 7 and 8 for keeping straight the lift cords. For example, the second tensioning mechanism can be a weight or a spring element.

[0038] The lift cords 17 pass through the same through-holes 7 as the bare electrical wires or in a variant through distinct through-holes. In another variant, the lift cords 17 are made up of an electrically conductive material, for example an electrically conductive textile, acting also as bare electrical wires 5 so that it is possible to conventionally fixed them to a single tensioning mechanism 6 to perform the electrical connections and to control the raising and lowering of the blind slats.

[0039] The ladder cords 4 are associated in per se known manner to a sleeve tube 11 for transmitting the movement to the blind slats 3 (figures 3 and 7). The sleeve tube support 12 serves as a passage for the bare electrical wires 5 that pass the photovoltaic blind slats 3 throughout the through-holes 7 to reach the first tensioning mechanism 6. In presence of lift cords 17, there is an additional tube 20 inside the sleeve tube 11 to roll up the lift cords 17 as shown in figure 7.

[0040] The electrical contact between the electrodes 8 in the blind slat 3 and the bare electrical wire 5 is established in the surrounding of the through-holes 7. The electrical contact is performed from at least one tilted angle and there are different approaches that can be combined to improve this electrical contact.

[0041] In a variant represented in figure 4, the through-holes are oval-shaped in order to increase the contact surface area and facilitate the electrical connection between the electrodes 8 and the bare electrical wires 5.

[0042] In another variant represented in figure 5, the electrical contact between the electrodes 8 in the blind slats 3 and the bare electrical wires 5 is enhanced by performing notches 15 in the edges of the photovoltaic blind slats 3, said notches 15 accommodating the ladder cord 4 for a better vertical alignment, favouring the approach of the contact electrode 8 in the surrounding of the through-holes 7 to the bare electrical wire 5.

[0043] In another variant represented in figure 6, the electrical connection between the electrodes 8 of the blind slats 3 and the bare electrical wires 5 is enhanced by introducing an additional metallic part such as small spheres 16 or washers between the electrodes 8 and the bare electrical wires 5. The bare electrical wires 5 pass through the perforated metallic part that seats on the borders of the through-holes 7 of the electrodes 8. The borders of the thought-holes can be deformed to enlarge the contact surface area. The metallic part fits the shape of the through- hole for an optimized contact. In this embodiment, the bare electrical wire is thus in indirect physical contact with the electrodes unlike in the previous variants.

[0044] In another variant, the electrical contact area is enlarged by using electrically conductive tapes, springs or more generally flexure structures instead of the metallic parts such as the aforementioned small spheres or washers.

Claims

CLAIMS1. A photovoltaic blind assembly (1 ) adapted for use in a double glazing unit comprising:- a plurality of blind slats (3) with photovoltaic elements (9), each blind slat (3) being provided with at least two through-holes (7), the through-holes (7) of the blind slats (3) being in use aligned along a vertical axis, said photovoltaic elements (9) comprising a contact electrode (8) surrounding at least partially each through-hole (7),- at least two ladder cords (4),- a tilt mechanism (2) coupled to the ladder cords (4) to provide control of the tilt angle of the blind slats (3),- at least two bare electrical wires (5) with each bare electrical wire (5) crossing the blind slats (3) through the aligned through-holes (7), said bare electrical wires (5) being in direct or indirect physical contact with the contact electrode (8) for at least one given tilt angle to provide the electrical connection between the different photovoltaic elements (9) of the blind slats (3) and to allow the extraction of the generated electrical current.

2. The photovoltaic blind assembly (1 ) according to claim 1 , wherein it comprises a first tensioning mechanism (6) attached to the bare electrical wires (5) for keeping said bare electrical wires (5) straight along the vertical axis.

3. The photovoltaic blind assembly (1 ) according to the previous claim, wherein the first tensioning mechanism (6) comprises an electrically isolated weight (13) or a fixed frame (19), and a screw (14) for attaching a lower end of the bare electrical wires (5) to the electrically isolated weight (13) or to the fixed frame (19).

4. The photovoltaic blind assembly (1 ) according to any previous claims, wherein the given tilt angle is comprised between 70 and 80 degrees, preferably is of 75 degrees, with respect to a horizontal axis perpendicular to said vertical axis, the given tilt angle corresponding to the position where the user cannot see through the windows and where the photovoltaic elements (9) are facing towards a light source side.

5. The photovoltaic blind assembly (1 ) according to any previous claims, wherein it comprises at least two lift cords (17) controlling the raising and lowering of the blind slats (3), said lift cords (17) passing through the same through-holes (7) as the bare electrical wires (5) or through other through-holes.

6. The photovoltaic blind assembly (1 ) according to the previous claim, wherein it comprises a second tensioning mechanism (18) for keeping straight the lift cords (17) along the vertical axis.

7. The photovoltaic blind assembly (1 ) according to claims 5 or 6, wherein the lift cords (17) are made up of an electrically conductive material so as to act as bar electrical wires (5) as well, only the first tensioning mechanism (6) being then required.

8. The photovoltaic blind assembly (1 ) according to any previous claims, wherein the through-holes (7) are oval or oblong-shaped.

9. The photovoltaic blind assembly (1 ) according to any previous claims, wherein said bare electrical wires (5) are in indirect physical contact with the contact electrode (8), the photovoltaic blind assembly (1 ) comprising an element made up of an electrically conductive material disposed between the bare electrical wire (5) and a side of the through-hole (7).

10. The photovoltaic blind assembly (1 ) according to the previous claim, wherein said element is a sphere (16) provided with a through-opening for receiving the bare electrical wire (5), a washer or a flexure structure such as a tape or a spring.11 . The photovoltaic blind assembly (1 ) according to any previous claims, wherein notches (15) accommodating the ladder cords (4) are provided in the edges of the blind slats (3) to improve the alignment of the ladder cords (4) along the vertical axis.

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