BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to the plastics industry, and more specifically to a system and method for producing corrugated semi-transparent structures which automatically change their transparency to the Sun's rays during the hours of the day, and the resulting structures.
BACKGROUND
Corrugated transparent or semi-transparent structures, typically from Polycarbonate or Acrylic, are typically used for creating for example various transparent or semi-transparent walls or roofs for example in large buildings or for creating greenhouses (hothouses) for plants. Polycarbonate has better impact resistance than Acrylic but is also more expensive and less transparent. For example in Russia and other European countries such structures are used for greenhouses since they have the advantage of being stronger than nylon tents, so that for example in the winter they can resist better wind, snow or hail. In fact these structures are typically even stronger than glass, and also they have better heat retaining abilities than glass. Typically these structures include materials that provide UV protection and they can last 10 or even 20 years in the Sun. Also, these structures have an advantage over glass in that they are more flexible and thus can be more easily fitted for example for round structures such as for example domes, and also they are easier to ship for this reason since such corrugated plates an be for example rolled up for shipment. However, especially for example during the summer, this can cause overheating of the greenhouse effect, so that too much heat is caught inside, which can have undesirable effects. Of course it is possible to use for example chemical materials that change their transparency according to the amount of light as is used for example in some optical glasses, or for example to change mechanically the amount of exposure to the Sun's rays for example by using various light sensors and/or heat sensors and/or by using temporal control (for example by programming certain hours in advance), however these solutions are more expensive. The typical solution used in such greenhouses is covering them during the summer with a thin layer of Sun blocking material, such as for example white lime, which reduces the exposure to the Sun during the summer and is washed away by rain in the winter, but this is a messy and less aesthetic solution and creates extra work. On the other hand, there is for example a solution offered by Danpal—http://www.danpal.com/brochure/Controlite.pdf, which is based on a twin-walled Polycarbonate panel in which each elongated cell contains an inner revolving louver with an opaque upper flat surface, so that the louvers in each panel can be controlled for example manually or by a light sensor. However this is considerably more expensive since it involves inserting the louvers in each cell and a mechanism for rotating all the louvers of the panel at the same time. Also, it reduces the efficiency of sunlight utilization, since according to their own brochure even in the fully open state only 58% of the sunlight can penetrate.
Therefore, it would be desirable to have a much cheaper solution for automatically regulating the amount of exposure to the Sun, that can be preferably mass-produced.
SUMMARY OF THE INVENTION
The present invention shows a very cheap solution for automatically regulating the penetration of the Sun's rays through such structures during the day, so that for example at noon the Sun's penetration is automatically lowered. This is preferably achieved by using a sandwich in which two external transparent plates are connected by preferably non-transparent (or at least less transparent) inner bridges and preferably using appropriate orientations so that when the Sun rises or sets the Sun's rays can easily enter more directly and when the sun rises at noon the non-transparent or less transparent inner bridges block direct light from the Sun. This way automatically less heat is generated at mid-day inside the building or greenhouse or other structure that uses these corrugated structures in the roof and/or in the walls. This can have the further advantage that for example less energy might be needed for cooling the enclosure. To the best of our knowledge this has not been done before, so in the prior art these corrugated structures are either made from transparent or from non-transparent materials (for example for creating plastics storage cases, etc.).
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1
a-c show a few examples of various typical types of Greenhouses built of a corrugated transparent plastic material (prior art).
FIGS. 2
a-f show a few examples of a side view of preferable corrugated structures based on preferably two transparent or semi-transparent plates separated by non-transparent or less transparent internal walls/bridges.
IMPORTANT CLARIFICATION AND GLOSSARY
Throughout the patent when possible variations or solutions are mentioned, it is also possible to use combinations of these variations or of elements in them, and when combinations are used, it is also possible to use at least some elements in them separately or in other combinations. These variations are preferably in different embodiments. In other words: certain features of the invention, which are described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. All these drawings are just exemplary diagrams. They should not be interpreted as literal positioning, shapes, angles, or sizes of the various elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
All of the descriptions in this and other sections are intended to be illustrative examples and not limiting.
Referring to FIGS. 1a-c we show a few examples of various typical types of Greenhouses built of a corrugated transparent plastic material (prior art). The example shown in FIG. 1a is an example of a personal home-use greenhouse available from http://www.sunshinegreenhouse.com/. As can be seen the structure is more or less similarly transparent in all directions. Although they claim that the angles of the roof at 45 degrees themselves help by reflection to let more light in from the lower winter Sun and less light in from the higher summer sun, the differences that can be achieved by the present invention are much bigger. Also their solution does not use variable light penetration through the vertical walls. The greenhouses shown in FIGS. 1b-c are typical industrial-scale greenhouses, available for example from http://www.palram.com/. As can be seen they are typically much larger and usually elongated—they can be for example with a length of dozens or even hundreds of meters and typically contain also metal framework support.
Referring to FIGS. 2a-f, we show a few examples of a side view of preferable corrugated structures based on preferably two (or more) transparent or semi-transparent plates (1a & 1b) separated by non-transparent or less transparent internal walls/bridges (2). Preferably this structure is produced by extrusion by using for the internal bridges (2) that separate between the plates (1a & 1b) production slits that are fed by a separate non-transparent or less transparent material than the material fed for the external plates (1a & 1b ) . Of course this is just an example and the internal bridges can have also other shapes and/or angles and/or sizes, but internal bridges (2) at 90 degrees to the plates (1a & 1b), as shown in FIG. 2a, can be very convenient for using as vertical walls (4) in the structure shown in FIG. 2b. By using such a structure as the vertical walls (4) of a greenhouse for example, so that the two (or more) plates (1a & 1b) are vertical and the internal bridges (2) become horizontal, when the Sun is low (when rising or setting) (3a) the light from the Sun can enter directly, and when the Sun is higher in the sky at noon (3b) the internal bridges (2) block the direct light from the Sun. If the roof (5) is built from a similar for example horizontal structure then preferably the internal bridges within it are instead tilted. Preferably the direction and angles of this tilt of the internal bridges and/or the direction of the entire preferably elongated greenhouse take into account also the orientation relative to where the Sun is rising or setting in order to achieve the desired effects. Also, in the winter for example the Sun's orientation in the sky is lower than in the summer, so this is preferably also taken into consideration in the orientations and/or angles used, so that preferably also automatically more sunlight enters the structure in the winter than in the summer. Of course this is just an example and the inner bridges (2) between the vertical plates (1a & 1b) can be also for example in some diagonal orientation—depending on the most desired angles of Sun penetration, and not necessarily in the horizontal orientation that is shown, so that for example there are a few typical available angles which the buyer can choose from. Another possible variation, shown in FIG. 2c, is that the roof (5) is made for example from a corrugated structure with internal bridges that are also transparent and for example the bottom plate (5b) is transparent and the top plate (5a) is for example non-transparent or semi-transparent. Another possible variation, shown in FIG. 2d, is that the roof is constructed from two tilted corrugated structures (6 & 7) which also each have internal tilted bridges in them, so that their internal bridges become preferably horizontal (or at another convenient angle) in the final structure, thus working similarly to the internal bridges of the vertical walls (4) of the for example greenhouse. This or similar designs also have the advantage that snows for example can slide down easily without causing burden on the roof. On the other hand, a corrugated structure with tilted bridges might be weaker than a structure with bridges at 90 degrees to the external walls, so another possible variation is to enforce them for example with transparent bridges (6b) that cross them at least in some places. Of course these are just a few examples and many various other variations are also possible, and also the use for a greenhouse is also just an example. For example various combinations of different angles of the internal bridges (2) and different transparency levels of the internal bridges (2) and/or of the external plates can be used. Also, although typically such corrugated structures are made of Polycarbonate or Acrylic, other materials with the desired qualities or combinations of different materials can also be used. As can be seen in FIG. 2e, if the angle of the Sun is higher than R, no direct light penetrates directly. When the corrugated structure is used as a vertical wall, the height (H) between the internal bridges (2) and the distance between the two plates (D) create the radius that makes the Sun stop penetrating directly. Another possible variation is for example to keep the inner bridges (2) between the two (or more) plates (1a & 1b) transparent or semitransparent, but preferably cover them with a light-reflective material and use them in a convenient angle, so that they reflect back more or less Sun depending on the angle from which the Sun light hits them. The above solutions have the advantage that the desired angles can be chosen independently of the orientation of the external plates (1a & 1b). Of course another possible variation is that the greenhouse or other enclosure can have for example only the roof or only one or more of the walls made of the described corrugated structures. Of course the plates (1a & 1b) are not necessarily straight and may be instead for example wavy or with some other curves, but straight plates are usually more convenient. Another possible variation is to add one or more, preferably more or less horizontal, hinges (8), as shown for example in FIG. 2f, preferably with an additional frame-structure for support, so that at least some of the walls a section or sections of them and/or for example a section or sections of the roof can be rotated (i.e. an entire preferably double-walled panel or a section of it can be rotated), preferably independently, in order to change the angles in which the sun penetrates directly. This rotation can be controlled for example manually and/or for example by light and/or heat sensors, preferably together with one or more microprocessors that control the movement. This has the advantage of increasing the flexibility and control on the amount of exposure to heat and/or light, while still keeping the system cheap. However, if such hinges are used for example in the roof, then preferably each plane that can rotate is moving between 2 transparent side-walls that touch or almost touch its edges and/or there are additional transparent walls that complete the enclosure, so as not to allow heat to escape from the sides or through gaps caused by the rotation. Another possible variation is that if for example double-walls are used (in other words, for example two or more such corrugated structures are used next to each other, for example for better insulation or for example for better strength, for example in the walls and/or in the ceiling), then the bridges in the two corrugated structures can be for example at some preferably different diagonal angle and/or with an intermittent pattern of more or less transparent, so that simply moving one of the two corrugated structures a short distance compared to the other can increase or decrease the light level (However this is less efficient, since part of the light might be blocked in all positions). Of course various combinations of the above and other variations can also be used.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, expansions and other applications of the invention may be made which are included within the scope of the present invention, as would be obvious to those skilled in the art.
Patent Application
20050011145
