AN ARRANGEMENT IN A LAMELLAR VENETIAN BLIND

Abstract: An arrangement in lamellar venetian blinds which are provided between the window panes of a double-glazed window, and with a device for rotating lamellae (7) about their longitudinal axes and to displace them across their longitudinal axes. Said lamellae are mounted at their ends in two opposite frame sides (4, 6), in guides (14, 15) permitting movement of lamellae (7) across their longitudinal axes to prevent movement in their longitudinal direction. At said opposite frame sides (4, 6) two parallel threaded spindles (12, 13) are provided at a mutual distance and are driven by the aid of a driving means with reversible direction of rotation. At the ends of each lamella (7) a crosspiece (9) is provided, the two ends of which engage threads (11) in a spindle (12, 13, resp.). Said driving means is designed to permit the spindles to rotate at different speeds, or to permit spindle (12) to be driven, whereas the other spindle (13) is at standstill for a short period so as to achieve rotation of lamellae (7) about their own axes.

Description: An arrangement in a lamellar Venetian blind The present invention relates to an arrangement in a lamell Venetian blind which is provided between the window panes a double-glazed window, with a device for turning the lamell about its longitudinal axis and to displace it across sai axis, in which the lamellae are mounted at their ends in t opposite window frame sides, in guides permitting movement the lamellae across their longitudinal direction b preventing movement in the longitudinal direction, and i which elongated driving means are provided at two opposit frame sides to extend in parallel with the frame sides, whic means are driven by at least one motor and are designed t cause synchronous movement of the lamellae ends across thei longitudinal direction. Lamellar Venetian blinds have been known and used for a lon time. Such Venetian blinds mainly serve two purposes, viz screening against observation and screening against to strong sunlight, also they serve as a thermoshade to improv heat insulation of the window. In to day's buildings insulation is improved in walls, roof and floors, whereas the coefficience of thermal transmittanc of the window surfaces is far less satisfactory, even i double-glazed thermo-windows. By providing a Venetian blin it is, e.g. possible to close the Venetian blind at night t improve insulation considerably at the window surfaces. I office buildings the Venetian blinds may be closed all th time when there are no people in the offices. A disadvantage of Venetian blinds which are mounted outside window is that they will rapidly get dusty and dirty and wil require much cleaning. Venetian blinds to be provided between the window panes of double-glazed thermo-windows are known, e.g. from EPC application 0109382. The previously known Venetian blinds were driven by cord drives. There are several disadvantages connected with this. For one thing, there will be wear of the cords in case of a cord drives, and such wear may cause destruction of the Venetian blinds so that it is necessary to replace the entire double-glazing. Also, wear will cause result in dust which may settle on the internal window surfaces. Another and essential disadvantage is that window which has Venetian blinds that are suspended by cords may only be vertically mounted. Such windows, thus, cannot be mounted in an inclined or horizontal position, and the cannot be used for skylights and the like. It is an object of the present invention to propose Venetian blind to be provided between two window panes in a insulation glass window, in which the above mentione disadvantages are avoided, so that a window which is provide with such Venetian blinds may be mounted in an inclined or horizontal position, and in which operational dependabilit is secured for a very long time with no dust resulting fro use. According to the invention this is achieved by the aid of a arrangement of the kind mentioned above which is charact erized by the features appearing from the characterizing par of claim 1. Further features will appear from the dependen claims 2 - 10. The invention will be disclosed in more detail below wit reference to a preferred embodiment which will appear from the drawings, in which Figure 1 is a diagrammatical view of a window wit insulation glass, which is provided with venetial blind according to the invention, Figure 2 shows a detail at the end of both parall spindles, Figure 3 shows the end of the threaded portion of spindle in more detail, Figure 4 is a cross sectional view of a frame side i which the spindle is mounted, Figure 5 is a diagrammatical view of the drive means fo the spindles, Figure 6 shows the free running arrangement of on spindle, and Figure 7 shows one single lamella. Figure 1 shows an insulation glass window . which i double-glazed 2. Both panes of the double-glazed window ar sealed to each other and secured in a window frame 3, 4, 5 6. Frame members 4, 6 are especially designed for receivin the Venetian blinds according to the invention. Frame member 4, 6 show a C-shaped profile as will appear from Figure 4. The Venetian blind consists of thin lamellae 7. At both end of the lamellae 7 T-shaped members 8 are provided with crosspiece 9 and a stem 10 which stem is secured to th lamella end. This may be achieved by riveting, as shown i Figure 2, or in another suitable manner. Crosspieces 9 of the T-shaped members 8 engage the thread 1 of threaded spindles .12, 13, which are provided in paralle with frame members 4, 6. In Figure 1 frame members 4, 6 ar upper and lower frame members. Spindles 12, 13 are provide in frame members 4, and 6, respectively, and are supported b elongated arched beds or guides 14, 15. Stem 10 of T-shape member 8 extends upwards through a slot a 16. Spindles 12, 13 are provided with a left hand thread at the left hand side of Figure 1, and with a right hand thread at the right hand side of the Figure. The object of this arrangement is to ensure that the Venetian blind lamellae 7 on the right hand side will be moved towards the middle of the window by the aid of the right hand thread, and that the lamellae 7 on the left hand side of the window in Figure 1 will, simultaneously, be moved towards the midle by the aid of the left hand thread. The threaded spindles 12, 13 are, via toothed wheels 17, 18, 19 connected to a driving motor 20. Toothed wheels 17, 18, 19 are mutually engaged in such a manner that both spindles are driven in the same direction. Motor 20 is preferably an electrical motor. In a position of use lamellae 7 are provided at a mutual distance which is slightly smaller than the width of a lamella. When the Venetian blind lamellae are turned into a position in parallel with the window panes, they will, consequently, be in contact with overlapping edges. In this manner total screening of the window surface is achieved, sunlight is kept out, and the blind forms a barrier against heat radiation from the room, e.g. at night. When the lamellae are to be pulled aside, as shown in Figure 1, they should be placed as closely side-by-side as possible so as not to cover too much of the light area of the window. For this reason spindles 12, 13 are provided with a cylind¬ rical portion 21, 22, respectively, at each end, which portion is provided with a shallow threaded groove 23. When the Venetian blinds are to be pulled aside from a completely closed position, threaded spindles 12, 13 are rotated and lamellae 7 are by the aid of crosspieces 9 screwed towards the ends of the spindles. At the end of rough thread 11 crosspieces 9 will gradually be moved onto cylindrical portions 22, 23 with the shallow thread 23, which has a low pitch. Crosspieces 9 are then packed closely together. When the Venetian blind is to be pulled across the window again, threaded spindles 12, 13 are rotated in the opposite direction, and crosspieces 9 will be urged towards the end of thread 11 by the aid of a spring 24. As will appear especially from Figure 3, the end 25 of thread 11 i designed with a knife-like shape which will cause th leading crosspiece 9 of the packed staple of crosspieces t be separated from the next crosspiece and to enter thread 11 The next crosspiece is then separated from the following on upon thread 11 having rotated one complete turn, an crosspieces with lamellae 7 are, thus, distributed cor responding to the pitch of thread 11. Since threaded spindles 12, 13 rotate in the same directio and with equal speed, the crosspieces are moved in paralle back and forth on the threaded spindle. To be able to tur lamellae 7 one of the spindles, 13, is provided with freerunning means 26 with limited free running. Thi freerunning means will appear from Figure 6 and comprises central bore 27 at the end of cylindrical portion 22 o spindle 13. A pin 28 from toothed wheel 18 projects into sai bore. Pin 28 is provided with a thread 29 which ends blindl at both ends. In the sleeve-shaped portion 30, which i formed by bore 27 a slot 31 is formed. A ball 32 which ma run in slot 31 is provided to be engaged with thread 29. Whe toothed wheel 18 is rotated pin 28 wil run without takin spindle 13 along, until ball 32 reaches the end of thread 29 depending on the direction of rotation of the pin. Not unti then will pin 28 take spindle 13 along. Spindle 12 wil rotate during the period when spindle 13 rests and will tak crosspiece 9 along at the end which is in contact with threa 11 in spindle 12. Crosspiece 9 is, thus, inclined an lamellae 7 will turn. It may be suitable to subject lamellae 7 to a certai tensioning. Space between the panes of a double-glazed windo is most limited, and lamellae 7 should be received betwee the panes. In order to ensure that the packed Venetian blin does not cover too much of the window surface, lamellae 7 must be produced from a very thin material. For such lamella to have sufficient rigidity when a window is mounted horizontally, the lamellae must be subjected to a certain tensioning if they are produced from a very thin material. Tension of the lamellae may be achieved by making crosspieces 9 resilient and clamp them tightly between spindles 12, 13 of both frame memebers. Spring tension may also be achieved by designing one or both stems 10 with a hoop-shaped loop 10'. In Figure 1 of the drawing two motors 20 and 20' are shown. Motor 20 drives spindles 12, 13 at frame member 4, and motor 20' drives spindles 12, 13 at the other frame member 6. However, a common motor may be provided to operate all four spindles by the aid of angular transmissions.

Claims: PATENT CLAIMS: An arrangement in a lamellar Venetian blind which is provide between the window panes of a double-glazed window, and wit a device for turning the lamellae about their longitudinal axes and to displace them across their longitudinal axes, with lamellae (7) being mounted at their ends in two opposit frame sides (4, 6), in guides permitting movement of the lamellae across their longitudinal direction, but preventin movement in their longitudinal direction, and in which elongated driving means are provided at said opposite frame sides (4, 6) in parallel with said frame sides, which driving means engage the end portions of said lamellae and are driven by at least one motor which is designed to cause synchronous movement' of the lamellae ends across the longitudinal direction of the lamellae, c h a r a c t e r i z e d i n that the elongated driving means consist of two parallel threaded spindles (12, 13), which are mounted at a mutual distance and are driven by the aid of a driving means with reversible direction of rotation, that at the ends of each lamella (7) a crosspiece (9) is provided, which is at its two ends engaged with threads (11) of a spindle (12, and 13, resp.), and that said driving means is designed in such a manner that spindles (12, 13) for a short period of time may be rotated at different speeds or that one spindle (12) is driven, whereas the other is at standstill, to cause lamellae (7) to turn about their own axes. 2. An arrangement in a lamellar Venetian blind as stated in claim 1, c h a r a c t e r "i z e d i n that the drive means comprises an electric motor (20, 20'), and a gear system (17, 18, 19), and that between said gear system and one spindle (13) a freerunning means (26) is provided to cause free running of a limited number of rotations by reversal of the direction of rotation of said spindle. 3. An arrangement in a lamellar Venetian blind as stated in claim 2, c h a r a c t e r i z e d i n that said freerunning means (26) consists of a threaded pin (28) which is connected to one toothed wheel (18) in the driving direction, that the threaded spindle (13) is provided with a sleeve-shaped portion (30) gripping about said pin (28) at its end facing the driving means, that said sleeve-shaped portion (30) has an axial groove (31), and that a ball (32) is provided to engage said groove and is movabe in groove (31). 4. An arrangement in a lamellar Venetian blind, as stated in one or several of the preceding claims, c h a r a c t e r i z¬ e d i n that crosspiece (9) is in contact with spring pressure against threads (11) of spindles (12, 13),. the crosspiece proper being resilient, or the crosspiece being resiliently connected with lamella (7). 5. An arrangement in a lamellar Venetian blind as stated in one or several of the preceding claims, c h a r a c t e r i z¬ e d i n that crosspieces (9) are arranged to be inclined at an angle relative to the lamellae plane. 6. An arrangement in a lamellar Venetian blind as stated in one or several of the preceding claims, c h a r a c t e r i z¬ e d i n that spindles (12, 13) are provided with right hand threads on one half of their lengths, and with left hand threads on the other half. 7. An arrangement in a lamellar Venetian blind as stated in one or several of the preceding claims, c h a r a c t e r i z e d i n that at least one end of spindle (12, 13) portion (21, 22) with a shallow threaded groove (23) of smaller pitch than threads (11) on the spindles (12, 13) i provided. 8. An arrangement in a lamellar Venetian blind as stated In on or several of the preceding claims, c h a r a c t e r i z e d i n that threads (11) of spindles (12, 13) end in knife-shaped apex (25). 9. An arrangement in a lamellar Venetian blind as stated in on or several of the preceding claims, c h a r a c t e r i z e d i n that a compression spring (24) is provide between spindles (12, 13) at portions (21, 22) with threade groove (23), which spring is intended for urging crosspiece (9) of lamellae (7) outwards, towards knife-shaded end (25 of the spindle thread (11). 10. An arrangement in a lamellar Venetian blind as stated in on or several of the preceding claims, c h a r a c t e r i z e d i n that the frame sides (4, 6) for which paralle spindles (12, 13) are provided, are manufactured from C shaped profiles in which longitudinal supports (14, 15) wit arched bottoms are formed.

Inventors: LYNGHOLM TORE, LYNGHOLM, TORE
Applicants: LYNGHOLM TORE, LYNGHOLM, TORE
Application year: 1990
Main classification: E06B9
IPC codes: E06B9