GB2056536A

GB2056536A - A combined solar and heat protective device for windows

Info

Publication number: GB2056536A
Application number: GB8026148A
Authority: GB
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1979-08-18
Filing date: 1980-08-11
Publication date: 1981-03-18
Also published as: CH649344A5; DE2933583A1

Abstract

A combined solar and heat protective device for windows consists of a heat protective foil (11) which reflects infra-red radiation and a solar protective foil (12) opaque or translucent to visible light each of which can be arranged in the region of a window (13) according to requirements. The foils may be applied to different sections of a common backing foil (10) to form a roller blind. Alternatively the device may be a vertical slat blind wherein the different types of foil (20, 21) are arranged at right angles to each other and are directed parallel to the window according to requirements. <IMAGE>

Description

SPECIFICATION A combined solar & heat protective device for windows The invention originates from a device according to the type set forth in the main claim. Such devices are already known which either serve as solar protection or as heat protection. In so doing, it is mostly a question of transparent foils provided with a vapour deposited metal layer which are installed on the inside of a room in front of a window. However, different requirements as regards the metalised foils are needed for solar protection and heat protection, that is to say the foils must have different properties.

A foil serving for solar protection must have a high reflection factor for light. However, in so doing, a reduced transparency, that is to say light transmission, must be accepted.

For heat protective foils, a high reflection efficiency in the longwave infrared region (5 to 50 clam) is necessary. Simultaneously, a high transparency or light transmission is desired in that case.

It has been shown that the above properties may only be combined incompletely. A solar protective foil can indeed be made so that it acts as heat protection, however the lack of transparency or light transmission is disadvantageous in winter, that is to say internal illumination is necessary. On the other hand, a heat protective foil can only be used with little effect as solar protection.

As opposed to this, the device in accordance with the invention comprising the characterising features of the main claim has the advantage that, use can be made of a solar protective foil and also a heat protective foil according to requirements. In this way, the properties of both kinds of foil are utilised optimally.

Because of the combination of the solar and heat protective foils lower costs exist for the combined suspended arrangement, whereby the particular best possible effect is achieved.

An advantageous further development and improvement of the device set forth in the main claim is made possible by the measures set forth in the sub-claims. It is of particular advantage that, due to the use of a common backing foil on which the solar protective film and the heat protective film is arranged in two sections, it can be wound up in the form of a roll whereby, according to weather conditions, one or the other layer can be arranged in front of the window.

The use of such solar protective and heat protective foils in the form of a vertical venetian blind also appears advantageous wherein the different protective foils are arranged at right angles to each other.

By rotating a suspension in the form of a cross, either the solar protective foil or the heat protective foil can be directed parallel to the window.

Further advantages and embodiments of the invention are illustrated in the drawing by way of example and are described in detail in the following specification. Figure 1 shows a diagrammatic representation of a common backing foil with separately arranged solar protective and heat protective films and a possible manner in which it can be arranged, Figure 2 is an arrangement according to Figure 1 but with upper and lower windings on rollers and Figure 3 is the arrangement of the solar and heat protective foils in the form of a vertical venetian blind.

In Figures 1 and 2, a heat protective film 11, for example of a silver or gold layer, is applied to a common backing foil 10, for example of polyester foil, in the upper region Wand in the lower region S is applied a solar protective film 12, for example of an aluminium layer. The application of a metal layer takes place by vapour deposition knownperse. The common backing foil 10 is arranged on the inside of a room in front of the window 13. The winding of the common backing foil like a roller blind as illustrated in Figure 1, is thoroughly suitable where the over- hanging section of the blind can hang freely in front of the wall below the window.

The overhanging blind section can even possibly penetrate into a slot in a wall unit or radiator cover.

The foil is retained in its particular position and at the correcttension by the falling rod 14 (see Figure 1) arranged at the lower end of the common backing foil 10. The region W or S illustrated in Figures 1 and 2 is arranged in front of the window 13 according as to whether solar protection or heat protection is required.

In Figure 2, apart from a first upper winding device 15, a further lower winding device with a return spring 16 is provided which accepts the lower portion of the backing foil 10, The covers 17 and 18 of the winding devices 15, 16 are preferably fixed to the window frame (glass rebate) 19. The lower winding device 16 can be provided with a return spring whereby the foil always remains tensioned and is smooth.

A further embodiment of the combined solar and heat protective device is illustrated in Figure 3. In this embodiment, no common backing foil provided with a vapour deposited solar protective layer and a heat protective layer is used. The protective foils are suspended in front of the window in a similar manner to a vertical venetian blind wherein the solar protective foil 20 is arranged at right angles to the heat protective foil 21. For this purpose, guide crosses 22 are arranged in the upper and lower region of the protective foils 20, 21 which position the protective foils in their particular positions. The upper guide crosses 22 are fixed to a ceiling rail 24 by a mounting 23. By a corresponding rotary movement of a venetian blind cord 25, either the solar protective sheets 20 or the heat protective sheets 21 may be set parallel to the plane of the window.Thus, account can be taken of the various requirements.

The adjustability of the guide cross 22 is illustrated in Figures 3a and 3b. Apart from the possibility of rotating, through 90% the protective foils 20, 21 arranged at right angles to one another, a gathered together position corresponding to the representation of Figure 3b is also possible. In so doing, the venetian blind may be pushed entirely to one side and thus gathered together. For this purpose, the guide cross 22 is formed in the following manner: In the central region of the guide cross 22, the latter is provided with a spreading spring 26 and a try square 27 for a 900 setting. By actuating the cord 25, which engages at the outer ends 28 of the guide cross 22, the guide cross can not only be rotated through 900 but it may be collapsed according to Figure 3b.On drawing the venetian blind apart, the guide cross 22 is once again forced open up to the try, square 27 (90 ) by the spring force of the spreading springs 26.

The solar and heat protective foils may have the characteristics of their functional counterparts in our copending patent application No. 1699178 (Serial No.

the subject matter of which is herein incorporated by reference. Thus, the solar protective foil may give a screening of approximately 60% of the solar energy with a transparency of about 30%.

Again, the heat protective foil may have a reflective capacity of at least 80%, preferably 90% or more, with respect to the heat radiation fromthe interior of the room with a transmission capacity in the visible spectral region of at least 25%, and preferably 30%.

The polyester backing would also, of course, be partially transparent in the visible spectral region.

Claims

1. A combined solar and heat protective device for a window of a room, comprising a heat protective foil, a solar protective foil, means for mounting the foils within the room in the region of the window, and means for bringing either of the foils into an operative position, when so mounted, relative to the window so as to give either solar protection or heat protection in accordance with requirements.

2. A device according to claim 1, wherein the heat protective foil and the solar protective foil com prise heat protective and solar protective layers, respectively, which are applied at different sections to a commonbacking foil.

3. A device according to claim 2, wherein the common backing foil together with the solar protective layer and the heat protective layer can be wound up in the form of a roller blind wherein one or the other protective layer can be arranged in front of the window.

4. A device according to claim 3, wherein a rod is fixed at the lower region of the common backing foil.

5. A device according to claim 3 or claim 4, wherein the common backing foil can be transported by two oppositely operating winding devices.

6 A device according to claim 1, wherein the heat protective foil and the solar protective foil are constructed so as to serve in use as a kind of vertical venetian blind, the heat protective foil being arranged at right angles with respect to the solar protective foil

7. A device according to claim 6, wherein either the solar protective foil or the heat protective foil can be set parallel to the window in accordance with the position of a venetian blind cord.

8. A device according to claim 6 or claim 7, wherein a suspension cross for the foils can be folded up by means of a spreading spring and a try square.

9. A combined solar and heat protective device for windows, substantially as herein described with reference to Figure 1, Figure 2, or Figures 3, 3a and 3b of the accompanying drawings.