This invention deals with parabolic solar reflectors used to focus waves on a single focal point.
A parabolic reflector is a device used to collect waves of energy including light waves, radio waves or sound waves. Waves of energy striking the surface of the parabolic reflector are reflected off of the surface of the reflector and focused on a focal point of the collector. The parabolic reflector can be used to concentrate waves to a single focal point which can be transmitted as a single beam transmitted parallel to the axis of the parabola. Parabolic collectors are currently used in solar collectors, radio wave collectors, lighting devices, radio telescopes and other applications where the collection of waves is of importance.
Currently, parabolic reflectors require a rigid support framework to hold the reflector in the shape of a parabola. Because of this rigid framework, parabolic reflectors are not very mobile and require extensive manpower and materials to install. Further, once installed, typical parabolic collectors are difficult to move. In addition, the support rigid framework increases the cost of using a typical parabolic collector due to the additional cost of material and manpower to assemble the reflector.
It would be beneficial to have an inexpensive mobile parabolic collector which will allow for a simplified assembly and better mobility.
Systems, methods, features, and advantages of the present invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
One embodiment consistent with the present invention includes a reflection device comprising a sheet made of a flexible material with at least one surface having reflective properties including a first edge and a second edge on opposite sides of a center line of the sheet, where the first edge and the second edge of the sheet are shaped such that the flexible material is formed into a mostly parabolic shape in cross section when bent about a line perpendicular to the center line and the sheet is secured at two points along the center line.
In another embodiment consistent with the present invention, the first edge and second edge are offset from each other in a vertical direction such that the mostly parabolic shape is inclined by an angle θ.
In another embodiment consistent with the present invention, the length of the flexible material is defined by the equation
where A is a scaling factor defined by the equation
and F is the distance from the horizontal axis to the focal point of the parabola.
In another embodiment consistent with the present invention, the flexible material is made from a material that does not have memory capabilities, and
the shape of the first edge conforms to a line formed by a plurality of points defined by the equations
where a is a coordinate point in the vertical direction, b is a coordinate point in the horizontal direction, X1′ is a starting position in the horizontal position and X′ is a position along the horizontal direction, cutting the material along a line formed by the plurality of plotted points.
In another embodiment consistent with the present invention, at least one surface of the flexible material reflects light.
In another embodiment consistent with the present invention, at least one surface of the flexible material reflects energy waves.
In another embodiment consistent with the present invention, the reflection device includes a plurality of sheets which overlap one another to form a trough.
In another embodiment consistent with the present invention, the flexible material is made from a material that has memory capabilities, and
the shape of the first edge conforms to a line formed by a plurality of points defined by the equations
where a is a coordinate point in the vertical direction, b is a coordinate point in the horizontal direction, X1′ is a starting coordinate point in the horizontal position, X2′ is the ending coordinate point in the horizontal direction, X′ is a position between X1′ and X2′ in the horizontal direction.
In another embodiment consistent with the present invention, the flexible material is made of, Plexiglas, Lexan, fiberglass or carbon fiber.
In another embodiment consistent with the present invention, a plurality of flexible sheets are overlapped to form a trough structure.
Another embodiment consistent with the present invention include a method of producing a reflection device including the steps of shaping a first edge and a second edge on opposite sides of a center line of a sheet made of flexible material such that the flexible material is formed into a mostly parabolic shape in cross section when bent about a line perpendicular to a center line of the sheet and the sheet is secured at two points along the center line, where the sheet has at least one surface having reflective properties.
In another embodiment consistent with the present invention, the first edge and second edge are offset from each other in a vertical direction such that the mostly parabolic shape is inclined by an angle θ.
the length of the flexible material is defined by the equation
where A is a scaling factor defined by the equation
where F is the distance from the horizontal axis to the focal point of the parabola.
In another embodiment consistent with the present invention, the flexible material is made from a material that does not have memory capabilities, and the shape of the first edge conforms to a line formed by a plurality of points defined by the equations
where a is a coordinate point in the vertical direction, b is a coordinate point in the horizontal direction, X1′ is a starting position in the horizontal position and X′ is a position along the horizontal direction, cutting the material along a line formed by the plurality of plotted points.
In another embodiment consistent with the present invention, at least one surface of the flexible material reflects light.
In another embodiment consistent with the present invention, at least one surface of the flexible material reflects light.
In another embodiment consistent with the present invention, at least one surface of the flexible material reflects energy waves.
In another embodiment consistent with the present invention, where a plurality of sheets overlap one another to form a trough.
In another embodiment consistent with the present invention, the flexible material is made from a material that has memory capabilities, and the shape of the first edge conforms to a line formed by a plurality of points defined by the equations
where a is a coordinate point in the vertical direction, b is a coordinate point in the horizontal direction, X1′ is a starting coordinate point in the horizontal position, X2′ is the ending coordinate point in the horizontal direction, X′ is a position between X1′ and X2′ in the horizontal direction.
In another embodiment consistent with the present invention, the flexible material is made of, Plexiglas, Lexan, fiberglass or carbon fiber.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of the present invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings:
While various embodiments of the present invention are described herein, it will be apparent to those of skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. Accordingly, the present invention is not to be restricted except in light of the attached claims and their equivalents.
As disclosed in further detail herein, is a parabolic reflector consisting of a sheet of material secured at two edges. The width of the material is configured such the material self-forming into a geometrically correct parabola when secured along two edges of the material. Further, the present invention also entails a method of forming the sheet of material such that the material forms a geometrically correct parabola opposed to a centenary. By producing a geometrically correct parabola, energy waves are tightly focused on a focal point which improves the performance of the reflector without requiring a rigid support structure to form the parabola.
As
For a parabola supported at Cartesian positions (−D1, H1) and (D2, H2) with a span S parallel to the X′ axis, a parabola is defined on the same Cartesian coordinate system between the positions X1′ 104 and X2′ 106 using a scaling factor A calculated by the equation:
Where F is the distance from the X′ axis to the focal point of the parabola 108.
The length of the parabolic reflector is defined by the following equation:
An operator may select a piece of material longer than the length calculated using the above mentioned equation.
Next, an equation for cutting two edges of a piece of material that will form the parabolic shape when the material is suspended from two edges is determined.
The width, W, of the parabolic reflector 100 varies along the horizontal X axis such that the distribution of weight across the reflector is proportional to the equation
which results in the slack of the material 102 forming a parabolic shape with a focal point offset by the angle theta 0 when viewed from the side. To produce this effect, the sides of a rectangular sheet 206 of material are manipulated such that the shape of the material distributes the weight in such a manner as to form the material into a parabola with a focal point offset by the angle theta Θ.
The curve defining the sides of the sheet of material 206 is created by sequentially plotting positions along the a and b axis for the interval X1′ to X2′, as shown in
and the position b is determined by the equation:
Where B is scale factor calculated by the equation:
When the two lines defining the sides of the parabola in plan view are determined using the above equations, the material 102 may be suspended, without tension, by two parallel rods and the material 102 will form a parabola which is effective to reflect light in such a manner that the light is focused on the focal point of the parabola 108.
Each of the first ends 202 of the parabolic reflectors 206 are secured to a first support unit 302 and each of the second ends 204 of the parabolic reflectors 206 are secured to a second support unit 304. The parabolic reflectors 206 are each secured to the support units using securing methods including, but not limited to, nailing each of the ends 202 and 204 to the support units 302 and 304, gluing each of the ends 202 and 204 to the support units 302 and 304, stapling each of the ends 202 and 204 to the support units 302 and 304, or any other acceptable method of securing the ends 202 and 204 to the support units.
In one embodiment consistent with the present invention, the length of the material 206 is increased by an amount equal to the circumference of the support unit 302 or 304.
In another embodiment consistent with the present invention, a plurality of parabolic reflectors 100 are arranged such that each of the parabolic reflectors 100 overlaps the adjacent parabolic reflector creating a trough 308, as shown in
The present embodiment has numerous applications including, but not limited to, a solar trough for use in high temperature solar collection, a daylight reflector for daylight harvesting of light, as a reflector for artificial lighting system, or as a mobile solar or radio wave collector. Because the present embodiment does not require a support structure, it can be assembled and disassembled quickly making it ideal for portable or temporary applications. Further, since the present embodiment does not require a support structure, the cost of manufacturing the parabolic reflector is reduced.
The parabolic sheet is cut from an elastic bendable flat sheet 402 having a W as selected by an operator. The length of the sheet L is a function of the profile of parabola as shown in
Where A is a scaling factor calculated by the equation:
as discussed above.
The curve defining each side of the Sheet is created by sequentially plotting positions along the a and b axis for the interval X1′ to X2′, as shown in
and the position b is determined by the equation:
Where B is a scale factor given by the equation:
The length of the cable or string required to connect the ends of the parabola, 404 and 406, is defined by the following equation:
√{square root over ((H2−H1)2+S2)}
The securing mechanism 410 is coupled to the parabolic reflectors at securing points 404 and 408 using a coupling method including, but not limited to, gluing the securing mechanism 410 to a securing point 404 or 408, gluing the securing mechanism to a securing point 404 or 408, welding the securing mechanism 410 to a securing point 404 or 408, or by any other suitable method of coupling the securing mechanism 410 to a securing point 404 or 408.
In one embodiment consistent with the present invention, a collector 602 is situated at the focal point of the parabola to collect rays reflected from the parabola.
Once the length and width of the reflector are calculated between both of the securing points, the selected piece of material is loaded into the cutting system (Step 706). The material is automatically fed into the cutting system via a material feeding unit. The cutting system then identifies the position on the material where the securing units will be positioned and cuts the material to the desired length (Step 708). The cutting system then moves a cutting unit in the horizontal direction and shapes the sides of the material based on the horizontal position of the cutting unit based on the equations listed above (Step 710).
Once the material is cut, the parabolic reflector is secured in position using a securing unit, including, but not limited to a baton, roller or any other suitable securing mechanism. Once secured, the reflector will assume a parabolic shape due to the weight distribution of the material.
In another embodiment consistent with the present invention, an elastic bendable parabolic reflector is produced using the same method depicted in
The present embodiment has numerous applications including, but not limited to, a solar trough for use in high temperature solar collection, a daylight reflector for daylight harvesting of light, as a reflector for artificial lighting system, as a mobile solar collector or radio wave collector or as a lunar high temperature solar collector which can be used in a zero gravity environment. Because the present embodiment does not require a support structure, it can be assembled and disassembled quickly making it ideal for portable or temporary applications. Further, since the present embodiment does not require a support structure, the cost of manufacturing the parabolic reflector is reduced.
This application claims the benefit of the filing date of U.S. Provisional Application No. 61/299,476, entitled “A Parabolic Reflector,” filed on Jan. 29, 2010, which is incorporated herein by reference.
Number | Date | Country | |
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61299476 | Jan 2010 | US |