A ROLLER SHUTTER

Abstract: The roller shutter (4) for screening the light-admitting area of a window sash (2) comprises a length of slats (5) which at their interspaces (6) are mutually articulated by means of hinge joints, a spring-loaded roller (10) rotationally embedded in a case (8) at the top member of the sash for rolling up the slats (5), a guide rail (7) mounted at each side member (2b) of the sash running in the direction of the roof inclination for guiding the ends of the slats (5) during rolling up and down of the slat length, and a drive mechanism (11) comprising a drive shaft (13) mounted parallel to the roller and a driving device (14) arranged at each guide rail (7) and having carriers (15) for driving engagement with the slat length. The carriers (15) of the driving device (14) engage the slat length at the interspaces (6) between the slats (5).

Description: A roller shutter The present invention relates to a roller shutter for screening an opening, in particular the light- admitting area of a sash for a window mounted in an inclined roof surface, which opening is limited by a first pair of mutually parallel members and a second pair of mutually parallel members which are perpendicular to said first pair, comprising a length of a plurality of slats running parallel to the first pair of members, said slats being mutually articulated at their interspaces by means of hinge joints, where the hinge joints between the slats have the form of flexible bands, a spring-loaded roller rotationally embedded at one member of the first pair for rolling up the slats, a guide rail mounted at each second pair member for guiding the slat ends when rolling up and down the slat length, and a drive mechanism for moving the slat length in the unrolling direction. The rolling down of vertically situated roller shutters is normally effected in that the slat length moves by means of the gravity in the direction of the bottom of the opening during simultaneous successive unrolling of the slats from the roller. The unrolling may, however, entail some problems, especially in the beginning of the rolling down operation where only few slats are rolled out from the roller and thus form part of the unrolling force. This also applies to roof windows where the friction between the guide rails and the slat ends can be so large that it surpasses the gravity component in the rolling down direction. Roller shutters whose slats are mutually articulated by means of hinge joints in the form of flexible bands are known among other from GB 2 246 805 and GB 2 113 749 where roller shutters of the initially stated kind are described. This design of the hinge joints provides a relatively noiseless operation of the roller shutter and no supplementary sealing at the hinge joints is required which may be the case by roller shutters with conventional hinge joints. The drive mechanism which contributes to the unrolling movement has in these design further the function that it keeps the slat length extended and in the latter document, comprises e.g. an operating device in the form of a handle by which the slat length is drawn out by surmounting the force from the spring- loaded roller. The unrolling of the roller shutter by drawing the slat length in this way is thus well-known and has the advantage that the hinge joints are kept stretched thus preventing that the slats are placed edgeways and the movement is blocked. However, such a solution requires a rather extensive cord arrangement which may be a considerable drawback as regards limited place on the site of incorpor- ation which is the case with e.g. roller shutters used in connection with roof windows and/or a positioning of the drive mechanism or its operating device which is not compatible with a need for a compact design of the roller shutter. In conventional roller shutters, it is suggested to solve this problem by means of drive mechanism arranged close to the roller and which so to speak pushes the slat length in the unrolling direction of which examples are known from EP 0 145 628, EP 0 317 461 and DE 40 00 908. Such a solution, however, requires that demands are made to the design of the slats and/or that modifications of the very slats have to be made which, besides an increase in the costs of production, implies that the existing roller shutters cannot, or only after considerable adjustments, be provided with such a drive mechanism. A further drawback with this unrolling method is that a good driving engagement is dependant on the positioning of the drive mechanism. Therefore, it is the object of the invention to procure a roller shutter of the initially stated kind where the slats may remain intact and where a safe engagement is still obtained between the drive mechan- ism and the slat length. This object is achieved by a roller shutter which is characterized in that the drive mechanism comprises a drive shaft mounted parallel with the roller and a driving device positioned at each guide rail and provided with carriers for driving engagement with the slat length, and that the carriers of the driving device engage the slat length at the interspaces between the slats. It appears that when using the interspaces between the slats in this way and combined with the special design of the hinge joints as flexible bands, the desired safe engagement is obtained between the carriers of the driving device and the slat length without using any price-raising reinforcement or insert elements and at the same time a larger freedom of choice when positioning of the drive mechanism and an essentially blockage- free movement of the drive mechanism are obtained. In an embodiment of the invention, the carriers of the driving device are constituted of the teeth of a gearwheel with a circular pitch corresponding to the distance between the adjacent slat interspaces where the gearwheel between the teeth has a form which is essentially complementary with the form of the slat sides facing the gearwheel. It is thus possible to secure the engagement between the drive mechanism and the slat length, irrespective of the form of the slats. In an alternative embodiment, the driving device comprises at least two shafts parallel to the slats entwined by a flexible band and the carriers are constituted of pins projecting from the band in distances corresponding to the distance between the slat interspaces where one of said shafts is the driving shaft of the drive mechanism. In order to increase the flexibility when building in the roller shutter, the drive mechanism can be arranged either on the side of the slats turned away from or on the one facing the light-admitting area. With a view to further improving the engagement between the drive device and the slat length, the side of the slats placed opposite in relation to the drive mechanism can preferably be provided with an abutment which cooperates with the carriers of the driving device and retains the engagement of the slats with the driving device. The invention will in the following be explained in more detail by means of an example of an embodiment and with reference to the schematic drawings, where Fig. 1 shows a perspective view of a roller shutter according to the invention mounted on a roof window, Fig. 2 is also a perspective view of a section of the left top corner of the roller shutter in Fig. 1, Fig. 3 is a sectional view along the line III-III in Fig. 1, Fig. 4 is a view corresponding to Fig. 2, however, of the right top corner of the roller shutter and with another placing of the drive mechanism for the roller shutter according to the invention, and Fig. 5 is a sectional view of an alternative embodiment for the roller shutter according to the invention . Fig. 1 shows a roof window of a per se conventional design with a window frame 1 comprising a top member, a bottom member la and two side members lb. A window sash 2 carrying a glass pane 3 in a top and a bottom member forming the members in a first pair, and two side members 2b forming the members in a second pair which together define a light-admitting area to be screened, is articulated with the window frame 1 either at the top member of the window frame and thus of the sash or at a centre line for the sash. A roller shutter 4 according to the invention is mounted above the window. In the Figure, the roller shutter 4 is shown in partly rolled out condition where a number of slats 5 screen a part of the light - admitting area of the sash 2. The slats 5 extend parallel with the top and bottom members and are connected with each other at their mutual interspaces 6 at the longitudinal side edges. At the ends, the slats 5 are guided in guide rails 7 extending along the side members lb, 2b of the frame and the sash. A case 8 for the roller shutter with side delimitations in the form of end plates 9 is posi- tioned above in the window. In Fig. 2, the upper part of the case 8 is removed. As shown in Fig. 3, the case contains a spring-loaded roller 10 for keeping the slats 5 in their rolled up condition, and a drive mechanism 11 effecting the movement of the slats 5 in the unrolling direction. In this Figure, only the outer slats 5 on the roller 10 are shown, and the non- shown remaining slats 5 are positioned in spiral and the inner slat is fastened to the roller 10 either directly or by means of an extra-wide hinge joint. From these figures further appears that at their interspaces 6, the slats 5 are connected with each other by means of hinge joints, here constituted of flexible bands 12 with a cross-sectional form of a dumbbell where the bands 12 at each of their side edges are inserted in longitudinal and in cross-section cylindrical grooves 5a in the slats 5. The hinge joints can, however, also be designed in other ways, e.g. as a piano hinge. The slats 5 are constructed as thin metal shells of e.g. aluminium with a foam-filled cavity. The drive mechanism 11 comprises a drive shaft 13 which in each end is embedded for rotation on the end plates 9 of the roller shutter case 8 and can be driven either manually or by an electric motor. The drive mechanism 11 further comprises a driving device which in the shown embodiment is a gearwheel 14 mounted in a rotationally locked manner on the drive shaft 13 and has a number of carriers in the form of teeth 15 positioned with mutual distances corresponding to the distance between adjacent slat interspaces 6. As is most obvious from Fig. 3, the gearwheel 14 between the teeth 15 has an essentially concave form in order to fit the convex top side of the slats 5. On the side of the slats 5 opposite in relation to the drive mechanism 11 in the roller shutter case 8, there is designed an abutment in the form of a ramp 16 which contributes to retaining the teeth 15 in engagement with the slat interspaces 6 when the slats 5 are unrolled from the roller 10. As shown in Fig. 4, the drive mechanism 21 can be positioned on the opposite side of the slats 5, i.e. on the side facing the light-admitting area. The gearwheel 24 has in this design a convex, essentially partly cylindrical form between the teeth 25 and thus fits the concave underside of the slats. The abutment has here the form of a separate block 26 which can be fastened to the top part of the case 8 or on the guide rail. Otherwise, the function is the same as described in connection with the above described embodiment, however, only the exterior slats are shown and the remaining slats are symbolized by the cylinder face 27. An alternative design of the drive mechanism 31 is shown in Fig. 5 where the driving device is constituted of a flexible band -34 entwining two rotationally embedded shafts 33 and 37 one of which is the drive shaft 33 of the drive mechanism. In distances corresponding to the slat interspaces 6, the band 34 has outwardly projecting pins 35 which, in the same way as the gearwheels in the above described embodiments, engage the slat length at its interspaces 6, the engagement between the pins 35 and the slat interspaces 6 being secured by the guide rails 7. The band 34 and the shafts 33 and 37 can of course with minor modifications be placed on the other side of the slat length and in that case, an abutment can be provided on the opposite side of the slat length in order to secure the engagement between the pins and the slat interspaces. In cases with wide and long roller shutters, it can be necessary to strengthen the side edges of the slats opposite the engagement of the driving device with the slats by removing the hinge joints at this place and insert hard cylindrical inserts in the grooves 5a.

Claims: P A T E N T C L A I M S 1. A roller shutter (4) for screening an opening, in particular the light-admitting area of a sash (2) for a window mounted in an inclined roof surface, which opening is limited by a first pair of mutually parallel members and a second pair of mutually parallel members which are perpendicular to said first pair, comprising a length of a plurality of slats (5) running parallel to the first pair of members, said slats being mutually articulated at their interspaces (6) by means of hinge joints, where the hinge joints between the slats (5) have the form of flexible bands (12), a spring- loaded roller (10) rotationally embedded at one member of the first pair for rolling up the slats (5) , a guide rail (7) mounted at each second pair member for guiding the slat ends (5) when rolling up and down the slat length, and a drive mechanism (11, 21, 31) for movement of the slat length in the unrolling direction c h a r a c t e r i z e d in that the drive mechanism comprises a drive shaft (13, 33) mounted parallel with the roller and a driving device (14, 24, 34) positioned at each guide rail (7) and provided with carriers (15, 25, 35) for driving engagement with the slat length, and that the carriers (15, 25, 35) of the driving device (14, 24, 34) engage the slat length at the interspaces (6) between the slats (5) . 2. A roller shutter according to claim 1, c h a r a c t e r i z e d in that the carriers of the driving device are constituted of the teeth (15, 25) of a gearwheel (14, 24) with a circular pitch corresponding to the distance between adjacent slat interspaces (6) , and that the gearwheel (14, 24) between the teeth (15, 25) has a form which is essentially complementary with the form of the slat sides (5) facing the gearwheel (14, 24). 3. A roller shutter according to claim 1, c h a r a c t e r i z e d in that the drive device comprises at least two shafts (33, 37) parallel to the slats entwined by a flexible band (34), and that the carriers are constituted of pins (35) projecting from the band in distances corresponding to the distance between the slat interspaces (6) and that one of said shafts is the driving shaft (33) of the driving mechanism. 4. A roller shutter according to claim 1, 2, or 3 , c h a r a c t e r i z e d in that the drive mechanism (11) is situated on the side of the slats (5) facing away from the light-admitting area. 5. A roller shutter according to claim 1, 2 or 3 , c h a r a c t e r i z e d in that the drive mechanism (21, 31) is situated on the side of the slats facing the light-admitting aperture. 6. A roller shutter according to any of the preceding claims, c h a r a c t e r i z e d in that an abutment (16, 26) is arranged on the side of the slats (5) placed opposite in relation to the driving mechan- ism (11, 21, 31) and cooperates with the carriers (15, 25, 35) of the driving device and retains the engagement of the slats (5) with the driving device.

Inventors: MORTENSEN MARTIN ARMAND, MORTENSEN, MARTIN, ARMAND
Applicants: MORTENSEN MARTIN ARMAND, RASMUSSEN KANN IND AS, MORTENSEN, MARTIN, ARMAND, V. KANN RASMUSSEN INDUSTRI A/S
Application year: 1997
Main classification: E06B9
IPC codes: E04D13, E06B9