NZ200752A - Transparent inflatable roller-blind with valve - Google Patents

Description

200752 g •. ■— Priority Ocfte{s): Complete Specification Fiied;^. rJ .*?? Cldftft* I « i «Vl I I • I • • • > I < } Publication Date: ?.! .. f.O. Journal. No: ......I 2 7.*?:....

M-.Z. NO.

NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION "HEAT-INSULATING DEVICE" I, SVEN ALGOT JOEL LILtfENDAHL, of Gyllenstiernas vSg 8, S-175 76 Jflrffllla, Sweden, do hereby declare the invention, for which I pray that a Patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- ■20075-2 This invention relates to a heat-insulating device intended to be placed in front of a window.

With the realization.that energy supplies are limited, and that the cost of energy has risen considerably, it has become important to save on energy required for buildings. New building standards have been developed for the purpose of increasing the heat-insulating capacity of new houses and measures have been accepted for additional insulation of , existing houses. According to the new building standards, the window surface area can be limited to a certain percentage of the facade surface. Furthermore, triple glazed windows can be used in order to increase the heat-insulating capacity of the windows and thus to decrease.the heat loss through the window.

The object of the present invention is to facilitate savings in heating energy requirements in buildings.

Accordingly the invention.provides in one broad aspect a heat-insulating device intended to be placed in front of windows, comprising two transparent, congruent sheets enclosing a space, which sheets can be rolled up to uncover the window and a valve in one of the sheets for admission to said space of room air or a special gas, and outflow of air or gas when rolling up the device, characterized in that the sheets consist of a stiff but flexible material to form flat surfaces in front of the window not distorting the view therethrough when the device is rolled down, and in that the sheets at their outer edges are hermetically joined to form a single, continuous enclosed space, said outer edges being joined by soft and/or elastic border bands capable of absorbing the shifting between the sheets when the device is rolled up on a rod and with such a width that they can absorb the expansion between the sheets when gas or air is admitted, said valve being openable and closeable to enable, in its open position, admission to said space of room air or the special gas when manually separating the sheets, thus obtaining a heat-insulating air layer of substantially atmospheric pressure or a layer of gas between the sheets upon closure of the valve. 2 200752 The basic principle of the invention is that two or more thin sheets of a transparent material are joined to form a closed space so that the room-air can enter through a valve into the space enclosed by the sheets and, when the valve is closed, this gas remains inside and forms an immobile air layer of substantially atmospheric pressure with a heat-insulating capacity.

The effect of the device consists in that simul taneously as it lets the major portion of sunlight and thermal radiation into the room, it prevents the heat from going out of the window. This effect can be still improved by choosing suitable materials for the sheets. Thus the sheets are preferably formed of material which transmits incident solar radiation in the visible and infrared portion of the spectrum, but reflects back most of the long-wave, far infrared radiation, emitted by room temperature objects.

Such materials are commercially available. An example of a material having such advantageous properties is the polyester film "MELINEX" OW marketed by the company ICI. This polyester film has the additional advantageous property of reflecting the ultraviolet radiation in the incident solar energy.

Thus by using a device made of such a material, energy losses through the window by radiation are primarily prevented by the sheets themselves, whereas energy losses by conduction are primarily prevented by the enclosed gas or air layer. 2007 52 By using a sheet material which reflects incident ultraviolet radiation, this radiation cannot pass inside the window. Discomfort due to ultraviolet radiation is thus eliminated and therefore the window 5 can be completely uncovered, thus admitting a maximum of the visible and infrared portions of the incident solar spectrum. For such a material it has been found that as much as 88 % of the incident infrared radiation is admitted into the room.

Heat-insulating capacity in a structure is the resistance offered by the latter to the heat passage.

Heat passage number = k = ^ = 1/m = k, heat resistance which entails that the lower the k-value of a structure, the better the heat-insulating capacity of the structure.

Thus: a single window = a window with one window pane has a k-value = = 7.2; a double window = a window with two panes + the enclosed air layer has a k-value = 2.9 20 The k-value for a composite structure of the heat-insulating roller-blind according to the invention may by means of the established calculation methods be theoretically calculated according to the following: Surface resistance m^ + mu = 0.150 Resistance of the window pane = 0.010 Resistance of the air space of 2.5 cms = 0.180 Resistance of the window pane = 0.010 Resistance of the air space of 12 cms = 0.180 Resistance of the plastic sheet = 0.005 Resistance of the air space of 6 cms = 0.200 Resistance of the plastic sheet = 0.005 Total heat resistance = m = 0.740 .... k = 1/m = 1/0.74 = k-value = 1.35 m^ and in the above table indicate the internal and the 35 external surface resistance, respectively. 200752 The device according to the invention is suspended from a curtain rod of conventional design above a window in a manner permitting it to be rolled up.

The device according to the invention is expected to remain 5 pulled down during the day and for this reason it is transparent. The device is thus suitably manufactured of a glass-clear material of such hardness that the sheets are sufficiently stiff to form flat surfaces in front of the window when the blind is down, so that the view through the window is not distorted. Suitably the sheets consist of a 10 plastic material with good thermal properties, so that they do not melt or catch fire through an accidental contact, for example with an electric heat radiator.

It is usually desirable that as great a portion as possible of the sun's luminous flux should enter through the window. A sheet therefore 15 consists of a material which has +he greatest possible transmission, 85% to 90%, in other words, a transparent material.

In certain cases (for example in . areas with cold nights) it may be desirable to bar the thermal radiation but to allow the entrance of the luminous radiation or visible light. In this case sheets 20 of a plastic material are used which reflect (bar) the infrared light (=the thermal radiation). In such case the blind serves as a heat-insulator during the night.

According to the invention the ;device. should have a surface ris - which 110 to 20% larger than the surface of the window which 25 it is to cover.

To obtain special structural properties of the device ^ according to the invention a special gas may be introduced between the sheets instead of dry air. For example a) a gas which is lighter that the air, to facilitate the erection of the construction with skylights in the roof, 30 in which case the blind is supported by the air pressure and consequently only needs to be stabilized in the horizontal plane, b) carbon dioxide (CO2), which is capable of extinguishing fire, c) argon (Ar) or sulphur hexafluoride (SFg) or mixtures thereof which gases have the properties of reflecting back the far infrared radiation 35 emitted by room temperature objects, but transmitting other portion of the spectrum of the incident solar radiation. 200755 When the device according to the invention is to be rolled up on the curtain rod the air valves are opened, so that the air may be squeezed out when the device is rolled up. In order that the deviceshould be able to be rolled up swiftly and conveniently the valve must have a 5 very high evacuation capacity. In an advantageous embodiment of the device according to the invention the valve Is designed as a slit-valve which runs along a considerable length of the device's lower edge.

As already mentioned the device according to the invention should be manufactured of a material which is\»e hard that the sheets have a 10 . certain degree of stiffness. When two such congruent sheets are rolled up for example around a curtain rod, a certain displacement between the sheets occurs In the direction of the rolling-up- Therefore, the sheets cannot be unresiliently connected to each other at the edges, for example by welding. This problem is solved according to the invention in that a 15 soft and/or elastic edge-band which may absorb the displacement is attached at the edges on all the external sides of the sheets.

In order to achieve a further air layer between the window and the device stretching devices may be installed to squeeze the air-filled and thus elastic <5evice in such a manner that it connects hermetically to the 20 window embrasure and/or to the linings around the window.

When the thickness of an air layer exceeds a certain maximum value air currents may originate within the layer, resulting in decreased heat-insulating capacity of the layer to the same extent as the increase of the thickness of the layer and with that the increase of the air 25 currents. There are windows in which the distance between the panes is so great that this phenomenon is taking place. By placing a device- ui ' according to the invention in such a space between the panes one obtains three heat-insulating layers with a considerable total heat-insulating capacity.

An embodiment chosen as an example will be described below in detail with reference to the appended drawings in which Fig. 1 shows an embodiment of the device according to the invention pulled down over a window. Fig. 2 shows a lateral view of the device according to Fig. 1 seen in cross-section and Fig. 3 shows a detailed view of the % a A . 200752 grasping device (catch) for the separation of the sheets of the device . for the filling with air. Fig.. 4 is a detailed view of the device in the air-filled condition in lateral view and in cross-section, and Fig. 5 shows a detailed view according to Fig. 4 with the device 5 in its deflated condition.

Fig. 1 shows a .device 2 pulled down in front of a window. The device ^ *s attached to a rod 4 which may be of a conventional kind and attached over the window in the usual way. At the lower edge of the device a catch designed as a brace is attached 10 - to hold the device' . under the window. The brace 6 must be attached at the two lateral edges of the . .device ' and at the middle of the device's bottom edge. At the bottom part of the device a slit valve is also arranged for filling the device with air and for emptying it. To give the valve great evacuation capacity it extends along a considerable 15 part of the bottom edge of the device 2.

As shown in Fig. 2 the device' 2 consists of two thin sheets 10, 12. The sheets 10, 12 consist of a transparent, hermetic material which is flexible but still has a certain stiffness in order to form flat surfaces in front of the window when the device is down so that the view 20 is not distorted. The sheets suitably consist of a plastic material, such as a polyester film (polyethyleneterephtalate). Suitable thickness of the film is within the range 50 - 125 microns..

A suitable sheet material Is the above mentioned polyester film "MELINEX" OW marketed by ICI. * The sheets are joined along their outer edges to form an enclosed space 14. The lateral and bottom edges of the sheets 10, 12 are joined by a border band 16, see also Figs. 4 and 5. The border bands 16 are soft and elastic so that they may absorb the displacement between the sheets 10, 12 when rolled up over the . rod 4. Furthermore, the border t bands are wide enough to absorb the expansion between the sheets 10, 12 when air flows In between them, as shown in Fig. 4.

The air valve 8 is suitably designed as a slit in the border band 16 at the lower edge of the device . 2. The slit contains a fast-lock j.8 or a device of locking type which is easy to open and close and which in 35 the closed position closes the slit hermetically so that an air-tight enclosed space 14 is obtained between the sheets 10, 12.

A magnetic lock of the type used e.g. injtefrigerator doors is well suited for this purpose 200752 At the bottom edge of the device a brace 6 is attached at the external side of the sheet 12 clos&st to the window panes 26 in order to to the wall.

On the sheet 10 facing the room , preferably at its middle portion and directly above the brace 6 a catch 22 is installed, suitably in the form of a flap of the same material as the sheet, in order to ensure in a simple way the separation of the sheets 10, 12 for filling the space with air.

When the device 2 is rolled up on the rod 4 the sheets 10, 12 lie close to each other and the valve 8 is open. To use the -device it is pulled down and attached by means of the brace 6. Then the grasping device is grasped and the sheet 10 is pulled away from the attached inner sheet 12, whereby air flows through the opened valve 8 into the space 14 between the sheets- When the required amount of air has / flowed in, the valve 8 is closed whereby a non-circulating and thus effective heat-insulating air layer of substantially atmospheric pressure is obtained in the space 14. When rolling up the device 2 the valve 8 is opened first so that the air may escape during the rolling-up. In order to make thedevice-rapid and convenient to use it has proved necessary in practice to have a valve which in its open position has a large opening for the inflow and outflow of air when the sheet 10 is pulled away from the sheet 12 and when the device is rolled up, respectively. The slit therefore extends along a considerable portion of the bottom edge of the -"device. the device 2 is attahced to the : - rod by attaching the upper edge of the sheets 10, 12 with double-adhesive tape on the rod of the . device - As seen in Fig. 1 the ^device) " 2 is somewhat wider than the window, suitably 10-20% wider.

The air-filled device 2 is normally so elastic that it adjoins with good air-tightness•to the contact surfaces around the window when it is attached by the brace 6. In this manner, a further non-circulating, heat-insulating air layer 28 is obtained between the device and the window pane 26- If the embrasure of the window or its linings do not have smooth, straight surfaces the device 2 can still be brought to good contact by using a holder 30 above the device, for example in the form of a hook, and Wretch aT>and or a string over the de 32 below the device. hold the .device . 2 to the wall 24, for example by a hook attached 200752 In this manner the air-filled device is pressed by means of its elasticity until good contact is achieved even against uneven contact surfaces.

A drying agent is suitably placed between the sheets in the device in order to prevent a build-up of condensation.

Furthermore, the sheets are suitably treated to be antistatic so that no air-suspended particles cling to the sheets.

In order to enable the installation of a device according to the invention^ on the outside of a window the sheets should suitably be made of a material which is resistant to ultraviolet radiation.

In an alternative embodiment the braces at the lateral edges of the device may be replaced by a tightening device attached to the wall.

Claims (17)

20(3752 WHAT I CLAIM IS:

1. A heat-insulating device to be placed in front of a window, comprising two transparent, congruent sheets for enclosing a space, which sheets can be rolled up to uncover the window and a valve in one of the sheets for admission to said space of room air or a special gas, and outflow of air or gas when rolling up the device, characterized in that the sheets consist of a plane but rollable material to form flat surfaces in front of the window allowing visibility therethrough when the device is rolled down, and in that the sheets at their outer edges are hermetically joined to form a single, continuous enclosed space, said outer edges being joined by soft and/or elastic border bands capable of absorbing the shifting between the sheets when the device is rolled up on a rod and with said bands of a width that they can absorb the expansion between the sheets when gas or air is admitted, said valve being openable and closeable to enable, with the valve kept in its open position admission to said space of room air or the special gas when manually separating the sheets, thus obtaining a heat-insulating air layer of substantially atmospheric pressure or a layer of gas between the sheets upon closure of the valve.

2. A heat-insulating device according to claim 1, wherein the device is assembled to a window, characterized by stretching devices for securing airtight connection between the gas or air-filled device and the window embrasure or window linings, so that a heat-insulating gas or air layer is obtained between the window and the device. 10 200752

3. A heat-insulating device according to claim J. or 2, characterized in that the valve is designed as a slit yalve located at the bottom of the device, which valve, when the device is to be rolled up, can be opened to such a width that the contained gas or air can flow out rapidly while the device is rolled up on the rod.

4. A heat-insulating device according to claim 3, characterized in that said slit valve comprises a lock which is easily opened and closed.

5. A heat-insulating device according to claim 4, characterized in said lock is a magnetic lock comprising magnetic strips positioned along the borders of the valve slit.

6. A heat-insulating device according to any one of claims 1-5, assembled to a window, characterized in that a means is provided that in the rolled down position of the device makes a separation of the sheets possible for the suction into the enclosed space of room-air through the opened valve, so that an air-layer of substantially atmospheric pressure is obtained.

7. A heat-insulating device according to any one of claims 1-5, characterized in that said gas is carbon dioxide.

8. A heat-insulating device according to any one of claims 1-5, characterized in that said gas is a gas, which is lighter than air.

9. A heat-insulating device according to any one of claims 1-5, charaterized in that said gas is argon or sulphur hexa-fluoride or mixtures thereof.

10. A heat-insulating device according to any one of claims 1 -^9, characterized in that the sheets are formed of material :vrtiich 2.00752 transmits visible light and infrared heat radiation incident from outside, and reflects long-wave, infrared heat radiation reemitted by the room-temperature objects, said gas or air layer between the sheets counter-acting heat loss through the window by conduction.

11. A heat-insulating device according to any one of claims 1-9, characterized in that the sheets are formed of material which transmits visible light and reflects infrared heat radiation to form a heat insulator.

12. A heat-insulating device according to any one of claims 1-11, characterized in that said sheets are formed of material which reflects ultraviolet radiation.

13. A heat-insulating device according to any one of claims 1-12, characterized in that the sheets are formed of plastic material with a sufficiently high melting - point so as not to melt on contact with an electric radiator.

14. A heat-insulating device according to any one of claims 1-13, characterized in that the sheets are formed of material resistant to ultraviolet radiation.

15. A heat-insulating device according to any one of claims 1-14, characterized in that a drying agent is placed between the sheets in order to counteract the build-up of condensation.

16. A heat-insulating device according to any one of claims 1-15, characterized in that the sheets are anti-statically treated.

17. A heat-insulating device substantially as herein described with reference t brated in the accompanying drawings. SVEN ALGOT JOEL LILJENDAHL By His Attorneys HENRY HUGHES LIMITED By