WO2005010313A1

WO2005010313A1 - System for shielding a building opening

Info

Publication number: WO2005010313A1
Application number: PCT/DK2004/000508
Authority: WO
Inventors: Preben Staehr
Original assignee: Turbovent A/S
Priority date: 2003-07-29
Filing date: 2004-07-20
Publication date: 2005-02-03

Abstract

The present invention concerns a shielding system (1) for shielding a number of building openings (2) and including a rotating support shaft (3) with a number of winding reels (4) for carrying straps (5) that are connected to an upper edge of a flexible shielding material (7), the support shaft (3) being supported by a building member (11) and drivingly connected with a number of stationary drive motors (13), support means (8) arranged to absorb transverse forces, e.g. wind forces on the shielding material (7) and a roller (18) for winding up and down the shielding material (7), which at a lower edge is connected to the roller (18), where the roller (18) is either drivingly connected with the support shaft (3) via a separate drive system or is directly drivingly connected with a number of separate drive motors (17). The invention furthermore describes a method for controlling a shielding system (1), where the shielding of the building openings (2) either occurs by the upper edge of the shielding material (7) being displaced upwards from a position close to the roller (18) by winding up the carrying straps (5) on the winding reels (4), or by the roller (18) being displaced downwards from a position close to the upper edge of the shielding material (7) by unwinding the shielding material (7) from the roller (18).

Description

SYSTEM FOR SHIELDING A BUILDING OPENING

Field of the Invention

The present invention concerns a shielding system for shielding a number of building openings and of the kind mentioned in claim 1.

The invention furthermore concerns a method for controlling the shielding system.

Background of the Invention

In the agricultural sector, the operation of animal farming is intensified, since loose housing stables are used for cattle, pigs, chickens and other domestic animals where the animals are held inside closed stable sections all the year round. Authorities and consumers are therefore beginning to demand documentation that care is shown for animal welfare. For example, it is required that each individual is to have a certain minimum area for its disposition in a stable environment that besides is not to be stressful and pathogenic.

In order to improve the welfare for the animals by intensive domestic animal farming, it is possible to use stables where there is natural ventilation, e.g. by some of the stable walls being substituted by a shielding material which can be removed in good weather, whereby the animal are provided access to fresh air. Hereby is achieved that the stable may be ventilated by natural ventilation, and that harmful dust and ammonia vapours are simultaneously discharged to the surroundings.

It appears that animal welfare may be improved considerably in this way, simultane- ously with the farmer keeping control over each individual.

For easy opening and closing the said walls of the stables, e.g. in case of bad weather or at night, the shielding material is often made as roller blinds that are mounted along the openings in a number of the stable walls so that the roller blinds, when unwinded, may block or close the openings in the stable walls. A stable may thus be constructed with a foundation and gables and a number of rafters and a roof, where the roller blinds are mounted along the sidewalls of the stable and thereby partially constitute the sidewalls of the stable.

In large parts of the year, the heat from the animals in the stable will contribute to elevate the temperature in the stable to an unhealthy level. Therefore, it is necessary to ventilate the stable by means of electric ventilation systems, thus increasing the costs for the farmer. By means of roller blinds it will be possible to ventilate the stable without using electric ventilation systems.

Since warm air rises, the roller blinds are often made so that the curtains are rolled upwards from the foundation of the stable. In order to lower the temperature in the stable, the roller blinds may be slightly lowered so that the warm air will be substituted by natural ventilation while at the same time the animals are continuously pro- tected against wind and bad weather. Therefore, the roller blinds are made so that they are typically rolled upwards from the foundation of the stable.

It is prior art to use roller blind systems with up and down rolling rollers at both top and bottom of the roller blind, entailing the drawback that it is difficult to control the mutual speed of the two rollers, since the peripheral speed changes in dependence of how large part of the shielding material rolled up on respective rollers.

It is important to control the speed of the two rollers in order that the shielding material is kept extended all the time, so that it does not fold or bulge that may cause in- convenience for the animals, or which may reduce the service life of the shielding material.

EP-B1-0 982 466 describes a roller blind system, where a building opening may be shielded by means of shielding material, a gear motor, a number of rollers and support means. In several of the described and shown embodiments there is indicated a solution, where a gear motor via right-angle gear unit and universal joint shafts are connected to the rollers to which the shielding material is connected and rolled up. The disclosed solution, however, has the drawback that a wire system is used which includes a number of winding reels mounted in a complicated configuration, and where the wire system connects the uppermost roller with the gear motor so that the shielding material may be elevated/lowered uniformly along its entire length.

The use of universal joint shafts and right-angle gear units result in a disadvantageous complicated mechanical construction with some mechanical parts that may break and in which there is a unfavourable energy loss at the transmitting of the torque of the gear motor to the rollers. The prior art system in question will also entail increase of both acquisition and operation costs.

EP-B 1-0982 466 Bl furthermore indicates an alternative embodiment where a gear motor via two right-angle gear units are connected to fixed upper and lower rollers. The drawback by this solution is that from the gear motor and to the two shafts right- angle gear units are used in which there is a disadvantageous energy loss, and that the shielding material may only be unrolled upwards from the lower roller.

Object of the Invention

On that background, the present invention has the object of indicating a shielding sys- tem of the kind mentioned in the introduction, which is not provided with the indicated drawbacks but has a simple mechanical structure and which is easy to mount in building openings.

It is furthermore the purpose of the present invention to indicate a shielding system which is flexible and which may shield any through-going parts of building openings.

Short Description of the Invention

According to the present invention, this may be achieved with a shielding system as described in the preamble of claim 1, and where the said roller is drivingly connected with a number of separate drive motors, and with a method where the shielding/blanking of the said building openings or apertures is effected either in that the said upper edge of the shielding material is displaced upwards from a position close to the said roller by rolling up the carrying straps on the winding reels, or in that the roller is displaced downwards from a position close to the upper edge of the shielding material by unrolling the shielding material from the roller.

In order to provide a shielding system where the drive arrangement is mechanically simple for both the rotating support shaft and for the lower roller, the roller is either drivingly connected with the support shaft via a separate drive system or the shaft is directly drivingly connected with a number of separate drive motors. Hereby is achieved in a simple way that one can avoid fragile mechanical links, such as univer- sal joint shafts and right-angle gear units.

With regard to control, it will furthermore be advantageous that support shaft and roller each have their drive motor since they often are to run with different speeds/rpm, depending on where the shielding material is to be placed in relation to building opening or aperture.

Large-scale animal farming has caused the stables to be larger and larger; a stable may be up to 100 m long. It is therefore much cheaper to erect a stable with a shielding system as described, where the shielding system substitutes one or more sidewalls, than it is to erect a fully built up stable.

Independently of the length of the shielding material, the shielding material is designed so that the support shaft is drivingly connected at one end with a stationary drive motor, and the lowermost roller is drivingly connected with a separate drive mo- tor at one end, where these drive motors elevate/lower the shielding material over the entire length.

In an alternative embodiment of the invention, both the rotating support shaft and the lowermost shaft are drivingly connected with drive motors at both ends. The needed size of the drive motors are thereby reduced when there are two drive motors at each their end of the support shaft/roller. Furthermore, torsional actions on the rotating support shaft and the lowermost shaft to be overcome by the drive motors are reduced. In a further, alternative embodiment of the invention, the rotating support shaft is made with a number of integrated drive motors which are evenly distributed along the length of the rotating support shaft.

In order to avoid a complicated wire system for elevating/lower the shielding material, the shielding system is designed so that the rotating support shaft on which there is mounted a number of evenly distributed winding reels for carrying straps, the winding reels being mounted in the vicinity of the uppermost edge of the building opening, e.g. at the head of the roof or a cast girder covered with masonry.

The carrying straps are connected to the winding reels at one end and connected to an upper edge of the flexible shielding material at the opposite end, so that the carrying strap will either be unrolled or rolled up on the winding reels by rotation of the sup- port shaft, whereby the shielding material is lowered or elevated, respectively. I.e. the support straps are running directly from the winding reels to the upper edge of the flexible shielding material.

The carrying straps may either be wires that are readily rolled up on the winding reels, or tape which has approximately the same width as the winding reels, so that they, when rolled up, will contribute to guide the movement of the shielding material in the longitudinal direction, whereby one achieves a more even operation of unrolling and rolling up of the shielding material.

The carrying straps are either connected to the upper edge of the flexible shielding material by means of eye connections or by fastening to an edge list attached along the upper edge of the shielding material.

In order to protect the shielding material when unrolled, so that it does not flutter and strikes against the fixed building parts of the stable due to wind action and thereby increases the risk of the shielding material being worn unnecessarily and breaking, the shielding system is provided with support means that are disposed with evenly distrib- uted interspaces along the length of the shielding material. The support means thereby absorb transverse forces arising, e.g. from the wind action, and keep the shielding material in place. This entails that no bulging of the shielding material will occur in case of strong wind.

It is important that the shielding material is as tight as possible, so that it does not flutter in the wind or form bulges which can be inconvenient for animals or for people working in the stable or its whereabouts. The said roller is therefore movably suspended between the said support means, whereby by means of the force of gravity is possible to use the said roller to keep the shielding material tensioned.

The support means are typically designed with two upright support rods that are disposed at each their side of the shielding material so that irrespectively of the wind direction there will be support rods that absorb the transverse forces from the shielding material.

It will be possible to mount support means opposite rafters with only one support rod, whereby the rafter constitutes a part of the support means.

In order to ensure that the shielding material covers the entire building opening, the rotating support shaft is, as mentioned, mounted on a building part over the building opening, and space is made for the lowermost roller to pass by the lowermost edge of the building opening.

For example, the shielding system is mounted at an outer side of a building so that the lowermost roller may pass freely down in front of the foundation, whereby it is ensured that the entire building opening is shut off.

The foundation may alternatively be designed with a groove, into which the lower- most roller can be lowered, or may be designed with a step with an upper and lower step surface, where the lowermost roller can pass by the uppermost step surface and lie down on the lower step surface. In order to prevent that the shielding material is hanging loose and becomes torn apart, or noise arising as a consequence of wind catching the outer edges of the shielding material, or problems arising with rolling up the shielding material, the roller is ar- ranged to keep the shielding material tense.

Due to the dead weight of the roller and the weight of the rolled up shielding material on the roller, a shielding material suspended in carrying straps to an upper support shaft will automatically be tightened if the lower roller hangs freely and cannot touch the earth.

In order to ensure that the lower roller is hanging freely so that it is the action of gravity that tightens the shielding material, the said roller is movably suspended between the support means.

If the separate drive motor is drivingly connected with the lower roller and is permanently mounted on a building part, it will not be possible to make advantage of the force of gravity to stretch out the shielding material.

It is necessary that the drive motors are mounted so that they, by a drive connection to the shielding material, does not influence the lower roller by weight. Therefore, the separate drive motors are mounted movably in a guide fitting, as the separate drive motor is suspended in a wire running about a number of wire pulleys and connected with a counterweight.

A balanced and neutral suspension of the drive motor is achieved by the separate drive motor being suspended in the guide fitting with a wire running about a number of wire pulleys and connected with a counterweight which is balanced by weight.

This provides that the drive motor, by a direct drive connection to the lower roller, does not influence the free suspension of this roller, and it is thus possible to utilise the force of gravity in order to tense the shielding material. The guide fitting is designed so that it is possible that the drive motor is mounted movably in a guide fitting so that the drive motor may move vertically in the guide fitting by a vertical movement of the lower drive reel when the shielding material is tensioned due to the force of gravity.

The counterweight for suspending the drive motor in the guide fitting may be provided with various weights so that the drive motors can be mounted movably and balanced in the guide fitting, depending on e.g. the maximum height and length of the shielding material.

In order to protect the separate drive motor, the guide fitting is arranged for mounting a protective box so that the suspension arrangement of the drive motors is not damaged by e.g. weather and wind or by collision.

In an embodiment of the invention, the guide fitting is permanently mounted on a building part, e.g. the foundation or a corner arrangement of the building, so that the drive motors are disposed in direct extension of the lower roller.

Alternatively, this guide fitting may be designed so that it can stand directly on the earth, as it stands in a stand or is cast in the ground.

An important detail clearly distinguishing this shielding system from previously known shielding systems is the flexibility with regard to where the lowermost roller can be placed.

In the present invention, the lowermost roller can be moved from a bottom position at the lower edge of the building opening and right up to an upper position in immediate vicinity of the rotating support shaft.

This results in that: - the shielding material may be lowered from an upper position by retaining the upper edge of the shielding material in immediate vicinity of the rotating support shaft and unrolling the shielding material from the lower roller; - the shielding material may be elevated from a bottom position by retaining the lower roller in immediate vicinity of the lower edge of the building opening and unrolling the shielding material from the lower roller by rolling up the carrying straps on the winding reels mounted on the support shaft; - the shielding material may unrolled form an arbitrary middle position by unrolling the shielding material from the lower roller and at the same time rolling up the carrying straps on the winding reels mounted on the support shaft.

In order to achieve this flexibility of the shielding system, the said guide fitting is mounted vertically displaceable in a guide rail.

A vertical movement of the lowermost roller up against an upper position in immedi- ate vicinity of the upper support roller may either happen when the drive motor associated with the support shaft rolls up the carrying straps on the winding reels and is then stopped, and that the drive motor associated with the roller rolls up the shielding material, whereby the guide fitting is displaced upwards in the guide rail, or in that in connection with the drive motors a gearing to e.g. spindle is provided so that the run- ning of the drive motor simultaneously with rolling up of the shielding material on the roller causes elevation of the guide fitting in the guide rail.

In certain situations, it is a great advantage that the lowermost roller may be brought up at a position in immediate vicinity of the uppermost support shaft, e.g.:

- when cleaning the stable area, the lowermost roller of the shielding system will be moved up in the top so that it is possible to drive tractors/small machines across the foundation; - at times where the stable is empty or where it is possible to have uncovered building openings all the day, the lowermost roller in the shielding system will be moved up in the top so that the shielding material is not dirtied. In order to use the lowermost drive motor of the shielding system for stretching out the shielding material, the shielding system is designed so that it includes a preferably electronic control with a number of sensors and signal emitters that are arranged for detecting the vertical position of the separate drive motor in relation to the guide fit- ting.

The sensors are either placed on the drive motor or on the guide fitting, and the signal emitters are disposed on the opposing part, so that the signal emitters will influence the sensors when a vertical change of the drive motors occurs in relation to the said guide fitting.

On the basis of the signals which the sensors are receiving from the signal emitter, the electronic control may transmit a signal to the drive motor which decides if the drive motor is to stand still and thereby brake a rolling up or down of the shielding material, or if the drive motor is to run so that either rolling down or up of the shielding material is effected.

For example, rolling up of the shielding material is effected in that the drive motor for the support shaft rolls up the carrying straps, whereby the roller with the shielding material is elevated. Since the roller is directly drivingly connected with the drive motor suspended in the guide fitting, this drive motor will elevate itself in the guide fitting.

The sensors detect that the signal emitters move. When the upwards directed travel of the drive motor in the guide fitting has reached a certain length, the drive motor associated with the roller begins to unroll the shielding material, so that the drive motor achieves a downwards directed travel in the guide fitting.

The drive motor unrolls the shielding material until the sensors detect that the signal emitters and the drive motor are moved down into a predetermined position in the guide fitting. Then the drive motor of the roller stops unrolling the shielding material, whereby the cycle is resumed, and the drive motor/roller with the shielding material is elevated in that the drive motor for the support shaft continues rolling up the carrying straps on the winding reels.

The opposite takes place when the shielding material is lowered. The drive motor for the support shaft unrolls the carrying straps from winding reels, whereby the roller with the shielding material is lowered, and the drive motor sinks vertically in the guide fitting.

The sensors detect when the signal emitters move, and when the downwards directed travel of the drive motor in the guide fitting has reached a certain length, the drive motor associated with the roller begins to roll up the shielding material so that the drive motor is provided an upwards directed travel in the guide fitting.

The drive motor rolls up the shielding material until the sensors detect that the signal emitters and the drive motor are moved up to a predetermined position in the guide fitting. Then the drive motor of the roller stops the rolling up of the shielding material, whereby the cycle is resumed again, and the drive motor/roller with the shielding material are lowered in that the drive motor for the support shaft continues the unrolling of the carrying straps on the winding reels.

In connection with controlling the sensors and the signal emitters there is furthermore an emergency stop function which in an embodiment of the invention operates on a timer so that the drive motor of the roller stops if the vertical travel in the guide fitting exceeds a predetermined period of time.

Alternatively, other systems such as sensors may be used which by detecting maximum travel of the drive motor of the roller in the guide fitting stops the drive motor.

In order to reduce the necessary time for the mounting and simultaneously achieving a general relieving of the mounting of the shielding system, the support means are designed as prefabricated units including two support fittings, two upright support rods and an upper support bracket fitting. By the support means being designed with a lower support fitting and two upright support rods and upper support holder fitting, it is furthermore achieved that it is possible to prefabricate this unit so that the field engineer is only to set up the support means with regular spacing along the building opening in such a way that the support rods of the support means are disposed at each their side of the shielding material and supports it when it is rolled up/rolled down or in case of wind action.

The lower support fitting is designed so that it may be mounted on the foundation of the building, e.g. upon the foundation or at the outer side of the foundation. Alternatively, the lower support fitting may be designed so that it can be founded in the earth if the building does not have any through-going side foundation.

The two upright support rods are fastened to the lower support fitting and with such mutual spacing that there is just enough space for the lower roller including rolled up shielding material may move freely in vertical direction from the bottom of the support means to the top of the support means.

The upper support holder fitting may be designed so that they include at least one bearing in which the upper support shaft is mounted. In order that the support means can absorb the transverse forces occurring, e.g. in case of wind action, the upper support holder fitting is designed so that it may be fastened to the upper parts of the building, e.g. on the roof head or on a side edge of a building opening.

By means of said support rods up along both sides of the shielding material, wear is avoided on the shielding material by contact with building faces that typically will consist of bricks/concrete wearing hard on the shielding material if in direct contact when it is elevated and lowered.

As the roller, support shaft and edge list of the shielding system are made in modules with a length of up to 6 m, simultaneously with the shielding material being made in the desired length, the support means in the form of prefabricated units are designed so that it is possible to mount a support means, after which list/shaft/roller can be mounted and possibly joined/assembled with drive motor or lateral lists/shafts/rollers. Subsequently, the shielding material can be mounted in the lower roller and edge list, and the carrying straps are connected between the winding reels and the upper edge of the shielding material.

In an embodiment of the shielding system according to the invention, the support means are designed so that they may be mounted along the building opening, and one of the support rods may be removed while the shielding material is mounted, after which the last support rod is mounted and thereby retains the shielding material in the desired position.

Since said support means are designed as prefabricated units that are arranged for carrying the shielding material of the shielding system, roller and possibly edge list, the support holder fitting also includes a bearing for the said rotating support shaft. These bearings are fastened in the support holder fitting so that it is the upright guide rods that carry and support the entire shielding system. The bearings may e.g. be bronze bushings or the like.

For fixing and the sealing the side edges of the shielding material, the shielding system includes flashing sheets that are fastened along opposing sides of the building openings or apertures.

The flashing sheets are mounted at the opposite side of the building opening so that they at each their end of the shielding material provide that no draught arises in the interspace between the shielding material and the side edge of the building opening.

Furthermore, the flashing sheets prevent the wind from possibly getting hold of edge parts of the shielding material, thereby causing further transverse forces that are to be absorbed in the first support means which thereby will be subjected to greater forces than the support means down along the building opening. The flashing sheets are furthermore used for fixing the edge parts of the shielding material, so that it runs smoothly up and down along the side edges of the building opening.

The flashing sheets may be corrugated or just a single sheet. The important thing is that the sheets allow the lowermost roller to be moved freely in the support means.

Since the animals in the stable are to be protected against bad weather in the form of heavy showers and the like, it is important that the shielding material is designed in a material which is wind and water tight so that it may resist different weather. At the same time, the shielding material is to be flexible so that it may roll up on the lowermost roller.

Therefore, the said shielding material is either of a strong reinforced plastic film, or of several plastic films that are mutually joined for forming preferably vertical, air-filled ducts.

A strongly reinforced plastic film will be a preferred embodiment of the invention where the plastic film will easily cover the building opening wind tight and further- more prevent light from penetrating. The strongly reinforced plastic film is flexible and may easily be rolled up on a roller.

In countries where the winter is cold, or where the weather is distinctly rainy and windy, it is necessary that the shielding material, besides shielding the stable from rain and wind, is insulating so that the warmth of the stable may be maintained.

In a second embodiment of the invention, the shielding material is made of a plurality of plastic film pieces, as more layers of plastic film increase the degree of insulation of the shielding material.

In order to attain better insulation ability of the shielding material, in an embodiment of the invention it is made of a plurality of plastic films that are mutually connected for forming preferably vertical air-filled ducts. With the intention of achieving maximum insulation ability, the vertical air-filled ducts may be mutually staggered in such a way that the vertical ducts are partly overlapping each other.

In order to achieve a good insulation ability of the shielding material, the produced ducts can be filled with air when the shielding material is rolled off the roller. The air supply for the ducts may either be arranged up along the side edges of the building opening or preferably be built into e.g. an edge list which is attached to an upper edge of the shielding material. Alternatively, the air supply to the vertical ducts may be es- tablished via the upper edge list or edge section which is possibly coimected with a flexible hose at opposite ends for supplying compressed air from a compressor.

The air used for inflating these air ducts in the shielding material may e.g. be supplied via a compressor which either is standing at the centre of the stable area or is supplied from a large common compressor from an external building.

Alternative ways of insulating the shielding material is to use a shielding material that e.g. consists of a forward film, which is wind and water tight, and an internal cover which is insulating. The internal cover may e.g. be a mat of textile, natural fibres, mineral wool, glass wool, paper, plastic or similar insulating materials. The most important feature is that the internal cover is rolled up together with the front film on the lowermost roller so that the building opening is opened and closed at once. This, however, implies that the support rods of the support means are to be disposed with greater mutual distance, since the rolled up shielding material on the lowermost roller will fill somewhat more. The simultaneous rolling up of the internal cover and the front film may possibly occur by rolling up on separate rollers.

Another possibility will be to place a shielding system on both sides of the building opening, which however entails greater costs for establishing such a double shielding system.

By using the shielding system as described above, it will be possible to control the shielding system in such a way that the shielding of the said building openings either occurs by the upper edge of the shielding material being displaced upwards from a position close to the roller by winding up the carrying straps on the winding reels, or by the roller being displaced downwards from a position close to the upper edge of the shielding material by unwinding the shielding material from the roller.

Irrespectively of the initial position of the lower roller, in one embodiment one may unroll the shielding material for covering a building opening, as well as one may naturally roll the shielding material together again when it is unfolded by using the roller for rolling up.

In a second embodiment, irrespectively of the position of the upper edge of the shielding material, it will be possible to lower the shielding material by letting the roller unroll the shielding material so as to cover. The reverse will also be feasible.

The method furthermore allows the lower roller to be placed at the centre of the building opening, and then it may unroll the shielding material. This occurs by placing e.g. the upper edge of the shielding material and the lower roller in such a position that the lower edge is placed at the centre of the building opening, after which the upper edge of the shielding material is moved upwards simultaneously with the roller unrolling the shielding material and moving downwards.

The present invention is described as a shielding system for shielding building openings, but the system is also suited for other purposes, e.g. covering for a terrace, mov- able advertising signs etc.

Short Description of the Drawing

The invention is explained in more detail in the following with reference to the drawing, on which:

Fig. 1 shows a perspective view of an embodiment of a shielding system for a building opening according to the invention; Fig. 2 shows a perspective view of a detail of the shielding system in Fig. 1 ;

Fig. 3 shows perspective views of a vertically displaceable drive motor mounted in a guide fitting; Fig. 4 shows a perspective detail of sensors and signal emitters on the drive motor and guide fittings;

Fig. 5 shows a perspective detail of the suspension of the drive motor in the guide fitting; Fig. 6 shows a perspective view of an alternative embodiment of the drive system by the shielding system according to the invention; and Fig. 7 shows an elementary sketch of yet an alternative embodiment of the drive system by the shielding system according to the invention.

Detailed Description of the Invention

Fig. 1 shows a perspective view of a shielding system 1 for shielding a building open- ing 2, where the shielding system 1 includes a rotating support shaft 3 on which there are mounted a number of winding reels 4 for carrying straps 5 that are connected to an edge list 6 in the upper edge of the shielding material 7.

The support shaft 3 is mounted in bearings (not shown) that are mounted in a support holder fitting 9 of a support means 8, as the support holder fitting 9 is mounted on a building part 11.

Support means 8 is mounted so that its support rods 10 run from a support fitting 12 mounted on building part 15 and up to the support holder fitting 9 and with a support- ing rod 10 at each side of the shielding material 7. The rotating support shaft 3 is drivingly connected to a gear motor 13 which is disposed on the building part 15.

A lower part of the shielding material 7 is connected to a lower roller 18 about which the shielding material may be rolled up. The lower roller 18 is connected to a gear motor 11 which is mounted in a guide fitting 12.

In order to prevent draught and to fix a side edge of the shielding material 7, there is mounted a flashing sheet 16 in connection with the transition between the building part 15 and the building opening 2, the sheet 16 projecting somewhat in over the side edge of the shielding material 7 - within the support rod 10 of the first support means 8.

In Fig. 2 is shown how the drive motor 11 is directly connected to the lower roller 18, to which a lower edge of the shielding material 7 is fastened. By rotating the roller 18, the shielding material 7 may thus roll it up.

On a lower support fitting 14 of the support means 8, there is furthermore mounted a support rod 10 that runs upwards and outside the flashing sheet 16 which is mounted on the building part 15. The guide fitting 12 is here mounted directly on the building part 15, implying that the drive motor 17 only can move in vertical direction within the height of the guide fitting 19.

In Fig. 3 is shown how the drive motor 17 is mounted in the guide fitting 19. A plate fitting 20 is fastened on the guide fitting 19 in order to make space for mounting sensors 22 that interact with signal emitter 21 which in the shown version has the shape of a sheet with a central projection or tongue 23 at an outer edge of the laminar signal emitter 21.

In Fig. 4 is shown a detail at the sensors 22 and signal emitter 21, where projections 23 are moved past the sensors 22, so that these hereby may detect a vertical movement of the drive motor 17 in the guide fitting 19. The sensors 22 may hereby transmit a signal to the control which then sends a signal to the control for the drive motor for either braking or rolling up or rolling down the shielding material (not shown).

Fig. 5 illustrates how the drive motor (not shown) is suspended balanced in the guide fitting 19 by means of a wire 24 running about wire pulley 25, and which is connected with a counterweight 26. Instead of the wire 24, a rope or a chain and an appropriate reversing wheel may of course be used. The invention is not limited to the embodiments shown on the Figures and described above. Other embodiments with other forms of support means, rollers, guide fittings, guide rails, shielding material and flashing sheet are imaginable within the scope of this invention and the matter indicated in the accompanying claims. E.g. it will fall within the scope of the invention to use the indicated shielding system for shielding window sections, e.g. in greenhouses or winter gardens.

By alternative drive system for the shielding system according to the invention shown in Fig. 6, only one drive motor is used in the shape of an electric gear motor 13 (as by the drive system shown in Fig. 1) for driving an upper shaft 3 with a number of winding reels 4 for a tape-like carrying strap 5. Between gear motor 13 and the upper shaft 3 there is inserted a universal joint for absorbing possible inaccuracies in mounting. For the upper shaft 3 there is fastened an elongated cylindric reel 27 that has greater diameter than the shaft 3 and which is intended for rolling up and unrolling a drive cord 28. The drive cord 28 extends from the reel 27 inclining downwards to a driving cylinder 29 on a lowermost tubular roller 30 on which the shielding material 7 is rolled on and off by lowering and elevating, respectively, the shielding material 7.

The tape-like carrying strap 5 runs downwards from the rear side of winding reel 4, while the drive cord 28 runs from the front side of the reel 27 downwards to the rear side of the drive reel 29. Correspondingly, the shielding material 7 runs from the front side of the lower roller 30 so that the shielding material 7 is rolled onto the roller 30 when the drive cord 28 is rolled off the drive reel 29. In the situation shown in Fig. 6, the shielding material 7 is about to be lowered by means of drive motor 13 so that the shaft 3 and the reel are turned clockwise, i.e. the carrying straps 5 are about to be rolled off the winding reels 4. The drive cord 28 is hereby rolled onto the reel 27 at the same time as the drive cord rotates the lower roller 30 counterclockwise for rolling up the shielding material 7 as the latter is lowered.

In order to compensate for the difference in peripheral speed of reel 27 and drive reel

29, respectively, the drive cord 28 runs with inclination between the reel 27 and the drive reel 29, whereby by winding up the drive cord 28 on the reel 27 there is also distance between the individual windings of the rolled up drive cord 28 so that thereby is also compensated further for the occurring difference in peripheral speed of the reel 27 and the drive reel 29 and the lower roller 30, respectively. In a simple way is thereby achieved an extra possibility of keeping the shielding material 7 tensioned during rolling up as well as rolling down from the roller 30.

In terms of price it means much that the shielding system according to the invention hereby may be made in a cheaper competition version, where only one drive motor is used. By larger facilities one may also save motors, as in such cases a drive motor may be used at the top at both ends of a common shaft and an arrangement with inclining drive cords, also at both ends of the shielding system.

By the further alternative drive system by a shielding system according to the invention shown in Fig. 7, there is only operated with one upper driven shaft with winding reels 4 for tape-like carrying straps (not shown) in which the shielding material (not shown) is suspended. Besides, a counterweight 31 is used, which is possibly located in a cavity wall, for keeping the shielding material tight and for also keeping the drive cords 32 tight. The drive cords 32 that run about a number of reversing pulleys 33 include, just as in the arrangement shown in Fig. 6, a drive cord 34 running inclining over a sub-distance between upper reels and lower drive reels 35 in order to aid compensating for the difference in peripheral speed between respective rollers, drive reels and reels.

Claims

1. Shielding system (1) for shielding a number of building openings (2) and including a rotating support shaft (33) with a number of winding reels (4) for carrying straps (5) that are connected to an upper edge of a flexible shielding material (7), the support shaft (3) being supported by a building member (11) and drivingly connected with a number of stationary drive motors (13), support means (8) arranged to absorb transverse forces, e.g. wind forces on the shielding material (7) and a roller (18) for winding up and down the shielding material (7), which at a lower edge is com ected to the roller (18), characterised in that the roller (18) is either drivingly connected with the support shaft (3) via a separate drive system or is directly drivingly connected with a number of separate drive motors (17).

2. Shielding system (1) according to claim 1, characterised in that the roller (18) is movably suspended between the support means (8) and is furthermore arranged to keep the shielding material (7) tight.

3. Shielding system (1) according to claim 1 and 2, characterised in that the separate drive motors (17) are mounted movable in a guide fitting (19), as the separate drive motors (17) are suspended in a wire or a chain (24) running about a number of wire wheels or chain wheels (25) and which are coimected with a counterweight (26).

4. Shielding system (1) according to claim 3, characterised in that the guide fitting (19) is mounted vertically displaceable in a guide rail.

5. Shielding system (1) according to claim 3, characterised in that it includes a preferably electronic control with a number of sensors (22) and signal emitters (21) arranged to register the vertical position of the separate drive motors (17) relative to the guide fitting (19).

6. Shielding system (1) according to claim 1, characterised in that the support means (8) are designed as pre-fabricated units including a lower support fitting (12), two up- right support rods (10) and an upper support holder fitting (9).

7. Shielding system according to claim 6, characterised in that the support holder fitting (9) includes a supporting bearing for the rotating support shaft (3).

8. Shielding system (1) according to claim 1, characterised in that for fixation and sealing the side edges of the shielding material (7) include cover plates (16) that are mounted along opposite sides of the building apertures (2).

9. Shielding system (1) according to claim 1, characterised in that the shielding material (7) either consists of a strongly reinforced plastic film or of a plurality of plastic films that are mutually connected for forming preferably vertical air-filled channels.

10. Method for controlling shielding system (1) according to any preceding claim, characterised in that the shielding of the building openings (2) either occurs by the upper edge of the shielding material (7) being displaced upwards from a position close to the roller (18) by winding up the carrying straps (5) on the winding reels (4), or by the roller (18) being displaced downwards from a position close to the upper edge of the shielding material (7) by unwinding the shielding material (7) from the roller (18).