Flexible reflective sheet concentrating reflector

Abstract

A concentrating reflector, comprising a transparent curved sheet; a flexible reflective sheet fastened to the convex outer side of the transparent curved sheet; optionally, a protective backing covering the flexible reflective sheet, including, optionally, an undercut on its rim; optionally, means for fastening concentrating reflector to an external structure; some variants: one comprising a plurality of petals or identical radial divisions of the above concentrating reflector and a central plate holder, including a plurality of insertion clips for holding each said petal; another variant, comprising a transparent parabolic trough; a flexible reflective sheet fastened to the convex outer side of the transparent parabolic trough; a backing support covering the flexible reflective sheet, a plurality of parabolic supports; and a structural beam; and another variant, comprising a transparent cylinder; flexible reflective sheet spread partly on and fastened to the convex outer side of the transparent cylinder; and, optionally, a backing support.

Description

[0001] Flexible Reflective Sheet Concentrating Reflector

[0002] DESCRIPTION

[0003] BACKGROUND OF THE INVENTION

[0004] Parabolic Dish and Parabolic Troughs

[0005] Concentrating reflectors are used for concentrating sunlight, heat or radio waves to a much smaller area or, practically, to a point focus or to a linear focus. Concentrating reflectors are usually in the form of a parabolic dish that concentrates light and heat to a point focus or slightly spread spot for heating a pot or pan, or a parabolic trough that concentrates light and heat to a linear focus, for heating a pipe or cylinder. Temperatures of 400 degrees Celsius (752 deg. Fahrenheit) are produced in solar cookers. Temperatures as high as 1 ,500 degrees Celsius (2,732 deg. Fahrenheit) are produced in industrial parabolic dishes and troughs. Concentrating reflectors are used in fire starters, solar cookers, industrial solar heaters, solar generating plants and communication antennas.

[0006] The following topics are discussed because they are related to the claims of the present invention:

[0007] Offset and Linear Concentrating Reflectors

[0008] A parabolic dish concentrating reflector that has its focal point, focus, or hottest spot, offset to the side of the reflector is called an offset parabolic dish or off-axis dish. This is in contrast to the common parabolic dish where the hottest point is in front of the dish, on its axis. In this Specification the term "parabolic" generally includes also the offset parabolic and (parabolic) trough or linearly bent parabolic, unless the context of a statement clearly refers only to a Gaussian or bowl-like curve of a parabolic dish.

[0009] Parabolic and Circle Arc or Curved Reflectors

[0010] A parabolic shape is commonly used in concentrating reflectors. In a parabola, the rounded curve near and before the focus or focal point can be approximated using an arc of a circle, so that some shallow solar cookers may have a circle arc curve instead of a parabolic curve to simplify production process. When a circle arc curve is used instead of a parabola the light is not focused to a point but to a linear focus that extends a short length along the axis of the concentrating reflector, thus some concentrated light and heat are slightly spread around the brightest or hottest spot along that short length. This linear focus that is surrounded by a slightly spread concentration of light or heat may be permissible or may even be desirable in solar cookers where the objective is usually to heat the spread area of a pot, pan or roasted meat, fish or chicken. In other words, for many solar heating applications where a spread spot heating is desired a concentrating reflector using a circle arc or a simple curve (instead of a really parabolic curve) will do the heating job satisfactorily. But if a solar cooker has a pre-manufactured reflector form, the parabolic shape is definitely better for concentrating solar light and heat. Not only can the user get slightly spread heating before or after the focus of the parabola, sometimes he might also find use for the very hot focus of a parabolic concentrating reflector. Parabolic Trough Concentrating Reflectors

[0011] Some concentrating reflectors called parabolic trough reflectors have a linearly bent parabolic reflecting sheet to concentrate sunlight to a linear pattern (let us call it focus) for heating a pipe or cylinder. Parabolic troughs have a linear bend or form similar to when you bend a cardboard with the hands, as differentiated from a Gaussian parabolic curve surface or parabolic dish that has an indentation like a bowl.

[0012] The Reflecting Surface

[0013] Some concentrating reflector solar cookers have a parabolic aluminum dish that is mirror-finished on the reflecting concave side. Other solar cookers have a parabolic steel or plastic sheet coated on the reflecting concave side with mirror-finished aluminum, chrome or silver. Other solar cookers are parabolic fiberglass or composite sheet forms that have a reflecting foil on the concave side. It is possible that some prior art concentrating reflector solar cookers might have a parabolic glass or transparent plastic coated on the convex outer side with a reflective coating, such as silver, chrome or aluminum.

[0014] Support and Tracking Mechanism

[0015] Some solar cookers have a means for adjustments to aim at or to track the sun. Some parabolic solar cookers also have supports to make them stand on the ground and a support for a cooking pot, pan, barbecue, meat or fish to be roasted.

[0016] Multi-Reflectors

[0017] Some solar cookers are made up of several smaller parabolic reflectors or parabolic segments mounted on a common frame or on separate supports to have a common focus for the reflected light. The purpose of the multi-reflector design is convenience in that the components can be dismantled and shipped or stored together in a smaller package.

[0018] Parabolic Reflectors in Antennas

[0019] Parabolic concentrating reflectors are also used in antennas to concentrate radio signals to a point for stronger reception.

[0020] Beaming Light and Radio Waves to a Distant Target

[0021] Parabolic concentrating reflectors are also used to transform light or radio waves from a substantially point source, for example a light bulb or a compact antenna, into a practically parallel beam so it can be beamed to illuminate or be transmitted to a distant target.

[0022] Some disadvantages of prior art concentrating reflectors and solar cookers are:

[0023] 1 . They are generally expensive to buy in the market.

[0024] 2. If made at home the curved or parabolic shaped glass, plastic or metal sheet is difficult to make.

[0025] 3. If a reflective coating is made at home the mirror coating chemical is difficult to acquire because it is not readily available at stores, and even when the mirror coating chemical is available the application of a mirror coating on a parabolic glass, plastic or metal sheet is not easy to do.

[0026] New cheap flexible reflective sheets, foils, and thin sheets, such as aluminum foils and the alum inum-Mylar flexible reflective sheet laminate (also called space blanket), are now available in the market at relatively low price and can be used as reflective material, but they are difficult to install on the concave inner side of a curved or parabolic dish, as what is being done in prior art.

[0027] For reflecting radio waves, aluminum foil, alum inum-Mylar flexible reflective sheet laminate, and metal sheets, metal screens and mesh and metallic fabric may also be used.

[0028] Flexible reflective sheets are also used on some rigid parabolic dish concentrating reflectors. But they are difficult to install on a concave surface, as is done with prior art concentrating reflectors. Fastening by paste or glue and at the same time tightening the flexible reflective sheet on a concave surface is difficult and produces a lot of folds and creases on the flexible reflective sheet.

[0029] One such prior art concentrating reflector was shown by another innovator on Youtube.com using a laborious process (https: / / www. youtube. com / watch?v=8CLRTa_ocmo, How to Make Parabolic Mirrors From Space Blankets - Nighthawk in light). [Please note: For the link to function “Nighthawk in light” should be one word without any space in between words.]

[0030] He made a fiberglass parabolic concentrating reflector lined on the concave side with reflective flexible sheet. He made the fiberglass parabolic concentrating reflector by stretching a flexible reflective sheet on and fastening it air-tightly to a square frame that was backed by a rigid board. The rigid board was also fastened air-tightly to the frame. An air valve was installed on the rigid board. Then the flexible reflective sheet was inflated through the valve so that it formed a parabolic bulge. He then fabricated a fiberglass parabolic dish on top of the parabolic flexible reflective sheet, and later reinforced the fiberglass parabolic dish by mounting it in a cylindrical sheet frame. His parabolic concentrating reflector appeared to work well, but to an ordinary do-it-yourselfer his build process still looks difficult to do.

[0031] Another prior art concentrating reflector was shown on Youtube.com by another innovator (https: / / www. youtube. com / watch?v=emxuLuJGmkY). He stretched a reflective aluminum foil stretched over a roughly parabolic wire mesh so that the reflective aluminum foil reflected sunlight through the wire mesh and concentrated it to a linear focus.

[0032] However, there are problems with this wire mesh-and-foil concentrating reflector:

[0033] 1 . The wire mesh blocks some of the reflected sunlight;

[0034] 2. The rough outlines of the wires can easily tear through the reflective aluminum foil and damage it; and,

[0035] 3. The reflective aluminum foil is exposed to dirt, dust, moisture and other corrosive elements in the air. Soon, the reflective aluminum surface will corrode and the reflectivity of the surface will be reduced significantly. So, at present, the main problems concerning rigid concentrating reflectors and parabolic or curved concentrating reflectors can be listed as:

[0036] 1 . How to use a flexible reflective sheet efficiently in a concentrating reflector;

[0037] 2. How to produce an inexpensive curved or parabolic concentrating reflector for concentrating sunlight, light, or radio waves to a focal point, a desired spread spot for cooking, or to a linear area for heating a pipe or cylinder;

[0038] 3. For a Do-It-Yourselfer, how to make or acquire a cheap parabolic or curved form; and

[0039] 4. How to apply a reflective surface to the curved or parabolic form in an easier and more efficient way.

[0040] SUMMARY OF THE INVENTION

[0041] The present invention relates to concentrating reflectors. The object of the invention is to provide a concentrating reflector as a finished product or a Do-It-Yourself kit that efficiently uses a flexible reflective sheet as the reflecting and concentrating surface in an assembly process that involves an easier and more efficient way of fastening the flexible reflective sheet to the curved or parabolic form of the concentrating reflector.

[0042] Particularly, the present invention relates to a concentrating reflector comprising a pre-manufactured, preferably vacuum formed, plastic transparent curved sheet, a flexible reflective sheet spread on and fastened to the convex outer side of the transparent curved sheet, and, optionally, a pre-manufactured, preferably vacuum formed plastic, protective backing covering the flexible reflective sheet.

[0043] The transparent parabolic sheet and protective backing are pre-manufactured, preferably by a vacuum forming process, which allows economical runs of a hundred to a few thousand pieces. The flexible reflective sheet may be an aluminum-and-Mylar film laminate, an aluminum foil, or any flexible sheet or fabric that reflects light or radio waves.

[0044] The flexible reflective sheet is applied to the transparent parabolic dish by spreading it tightly on and fastening it to the convex outer side of the transparent parabolic dish using glue, paste or other means.

[0045] By fastening the flexible reflective sheet to the convex outer side of the transparent parabolic dish instead of to the concave inner side the reflecting surface is installed with few or no undesirable creases. The assembly process is made simpler, much easier, does not require much skill, and saves assembly time and money. The application of a flexible reflective sheet on the convex outer side of a transparent parabolic dish opens up a new range of dual-use or after-empty-use opportunities in common consumer products if they are manufactured transparent and are later covered on their convex outer side by users with a flexible reflective sheet. So that fire starter concentrating reflectors can be made from transparent parabolic pot covers, transparent partly parabolic bowls, transparent partly parabolic basins, and transparent big container covers. And solar cookers can be made from transparent umbrellas and other products that are or can be made transparent and curved, parabolic or partly parabolic, cylindrical or partly cylindrical. Another object of the invention is to provide a concentrating reflector that can be assembled from smaller components for convenience in shipping and storing a smaller package, comprising: a plurality of petals, that are identical outer radial divisions of a curved dish concentrating reflector, and a central plate holder, including a plurality of built- in insertion clips for holding each said petal, so that each petal may be inserted or removed easily from the insertion clips, and means for fastening to an external support or tracking mechanism. The variant concentrating reflector can be assembled easily by just inserting the petals on the insertion clips or dismantled for shipment or storage.

[0046] Another object of the present invention is to provide a concentrating reflector similar to the transparent curved sheet concentrating reflector, wherein the transparent curved sheet is a parabolic trough.

[0047] Another object of the present invention is to provide a concentrating reflector comprising: a transparent cylinder; a flexible reflective sheet spread partly on and fastened to the convex outer side of the transparent cylinder; optionally, a protective backing covering the reflective sheet and fastened to the transparent cylinder; optionally, a pipe or cylinder to be heated disposed inside the transparent cylinder; optionally, a pair of heat insulator bushings on the pipe or cylinder to be heated; optionally, means at the ends of the transparent cylinder for supporting it and connecting it to the pair of heat insulator bushings or to the pipe or cylinder to be heated; and, optionally, means for supporting the concentrating reflector on the ground and for tracking the sun, a distant object or a radio signal source.

[0048] Another object of the present invention is to provide a concentrating reflector, comprising: a transparent umbrella; and a flexible reflective sheet fastened to the convex outer side of the umbrella, optionally, wherein the handle and part of the stem of the umbrella are removable, so that the umbrella can be used also as a solar cooker or as a fire starter.

[0049] Another object of the present invention is to provide a transparent cover, bowl, basin, or big container cover (such as the wide mouth cover or cap of a 1 -liter jar) including a parabolic side, and, optionally, a flexible reflective sheet fastened to its parabolic convex outer side, so that whenever it is needed as a fire starter the convex outer side of the transparent cover, bowl, basin, or big container cover may be covered with a flexible reflective sheet and be used as a parabolic concentrating reflector for lighting a cigarette, tinder or small fire.

[0050] BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Other features and advantages of the present invention will become clear from the following detailed description, which is given as a non-limiting example, with reference to the attached drawings, in which:

[0052] FIGS. 1A-1 F are views of a curved concentrating reflector 100;

[0053] FIG. 1 A is an exploded perspective view of the concentrating reflector 100 facing the sun in the upper left corner direction; FIG. 1 B is a schematic diagram, side view, of a flexible reflective sheet 120 being spread over the convex outer side of a transparent curved sheet 110;

[0054] FIG. 1 C is a perspective view of the assembled concentrating reflector 100 facing the sun;

[0055] FIG. 1 D is a perspective section view of the concentrating reflector 100 vertically cut along its axis;

[0056] FIG. 1 E is a detailed perspective section view of the rim of the concentrating reflector 100;

[0057] FIG. 1 F is a front view of the concentrating reflector 100;

[0058] FIGS. 1 G-1 J are views of a more light weight variant invention, a perforated or mesh concentrating reflector 101 ;

[0059] FIG. 1 G is an exploded perspective view of the perforated or mesh concentrating reflector 101 facing the sun in the upper left direction;

[0060] FIG. 1 H is a perspective view of the assembled concentrating reflector 101 facing the sun;

[0061] FIG. 11 is a perspective section view of the concentrating reflector 101 vertically cut along its axis;

[0062] FIG. 1 J is a detailed perspective section view of the rim of the concentrating reflector 101 ;

[0063] FIGS. 1 K-1 R are views of a variant invention, a 9-piece concentrating reflector 105;

[0064] FIG. 1 K is a perspective view of the assembled 9-piece parabolic concentrating reflector 105 facing the sun in the upper left direction;

[0065] FIG. 1 L is a front view of the 9-piece parabolic concentrating reflector 105;

[0066] FIG. 1 M is a side view of the 9-piece parabolic concentrating reflector 105;

[0067] FIG. 1 N is an exploded perspective view of the components of a petal 106 of the 9-piece parabolic concentrating reflector 105;

[0068] FIG. 10 is a perspective view of an assembled petal 106 of the 9-piece parabolic concentrating reflector 105;

[0069] FIG. 1 P is a close-up perspective view of an edge of the petal 106 of the 9-piece parabolic concentrating reflector 105;

[0070] FIG. 1 Q is a perspective view of a partially assembled 9-piece parabolic concentrating reflector 105 showing the insertion of two petals 106 on a central support plate 162;

[0071] FIG. 1 R is a close-up perspective partial view of the same but now a bare central support plate 162 of the 9-piece parabolic concentrating reflector 105 showing its insertion clips 163 and pairs of insertion clips 164, 165;

[0072] FIGS. 2A-2L are views of a variant invention, a parabolic trough concentrating reflector 200;

[0073] FIG. 2A is a perspective view of the parabolic trough concentrating reflector 200 facing the sun in the upper left direction;

[0074] FIG. 2B is a perspective back view of the oarabolic trough concentrating reflector 200; FIG. 2C is a side view of the parabolic trough concentrating reflector 200;

[0075] FIG. 2D is an exploded perspective back view of the parabolic trough concentrating reflector 200;

[0076] FIG. 2E is a perspective view of a parabolic support 270 of the parabolic trough concentrating reflector 200;

[0077] FIG. 2F is a perspective back view of a sheet clip 290 of a parabolic support 270 of the parabolic trough concentrating reflector 200 positioned to be inserted to a parabolic support 270;

[0078] FIG. 2G is a side view of a sheet clip 290 of a parabolic support 270 of the parabolic trough concentrating reflector 200 about to be inserted to fasten an assembled transparent sheet 210, flexible reflective sheet 220, and backing support 240 to the parabolic support 270;

[0079] FIG. 2H is a side view of the sheet clip 290 of a parabolic support 270 of the parabolic trough concentrating reflector 200 fastening an assembled transparent sheet 210, flexible reflective sheet 220, and backing support 240 to the parabolic support 270;

[0080] FIG. 2I is a perspective view of a beam clip 296 of a parabolic support 270 of the parabolic trough concentrating reflector 200;

[0081] FIG. 2J is a perspective back view of the beam clip 296 of a parabolic support 270 of the parabolic trough concentrating reflector 200 about to be inserted to fasten a parabolic support 270 to a structural beam 280;

[0082] FIG. 2K is a side view of the beam clip 296 of a parabolic support 270 of the parabolic trough concentrating reflector 200 about to be inserted to fasten a parabolic support 270 to a structural beam 280;

[0083] FIG. 2L is a side view of the beam clip 296 of a parabolic support 270 of the parabolic trough concentrating reflector 200 fastening a parabolic support 270 to a structural beam 280;

[0084] FIGS. 3A-3F are views of a variant invention, a cylindrical concentrating reflector 300;

[0085] FIG. 3A is a perspective view of the cylindrical concentrating reflector 300 facing the sun in the upper left direction, with broken lines showing the hidden parts inside;

[0086] FIG. 3B is a perspective section view of the cylindrical concentrating reflector 300 cut axially just above the heat insulator bushings 390;

[0087] FIG. 3C is a side view of the cylindrical concentrating reflector 300, with broken lines showing the hidden parts inside;

[0088] FIG. 3D is a perspective view of a cylindrical concentrating reflector 300 without ground supports 395 but with wooden chocks 398 and facing the sun in the upper left direction, with broken lines showing the hidden parts inside;

[0089] FIG. 3E is a perspective section view of a cylindrical concentrating reflector 300 without ground supports 395 and cut axially just above the heat insulator bushings 390; FIG. 3F is a side view of the cylindrical concentrating reflector 300 without ground supports 395, with broken lines showing the hidden parts inside;

[0090] FIG. 4A is an exploded view of a variant invention, a concentrating reflector 400, comprising a transparent umbrella 410 and a flexible reflective sheet cover 420 facing the sun in the upper left direction;

[0091] FIG. 4B is a perspective view of the transparent umbrella 410 (its 410 handle 415 and adjoining stem 416 removed) with the flexible reflective sheet 420 fastened to its convex outer side 412;

[0092] DETAILED DESCRIPTION OF THE INVENTION

[0093] One preferred embodiment of the invention is a concentrating reflector 100, shown in FIGS. 1A-1 F, comprising: a) a plurality of bolt or screw holes 108 as means for fastening to an external structure or mechanism (not shown in the FIGS.); b) a transparent curved sheet 110, that is transparent to light or to radio waves and includes an edge 112 and, optionally, a plurality of radial dents 113 that protrude inwards to enhance its 110 stiffness; c) a flexible reflective sheet 120 spread on and fastened to the convex outer side of the transparent curved sheet 110; and d) a protective backing 140 that generally conforms to the convex outer side of the transparent curved sheet 110, and includes, optionally, a plurality of radial dents 143 that protrude outwards to enhance its 140 stiffness, optionally, an undercut 144 (FIG. 1 E) near its 140 rim for holding on to the rim of the transparent curved sheet 110 (FIGS. 1 D-1 E), and, optionally, an outward extension 145 that extends outward beyond the undercut 144.

[0094] It can be observed that the undercut 144, without a similar outward extension 145, may also be placed on the transparent curved sheet 110 instead of on the protective backing 140. To save material and weight the outward extension 145 may also be in the form of only 2 to 4 short lengths distributed equidistantly on the rim of the protective backing 140.

[0095] The 3-dimensional curve of the transparent curved sheet 110 is preferably that of a central or offset parabolic, but may also be spherical, ellipsoidal, or any Gaussian curve in between, or a linear curve as in a parabolic trough, depending on the heating, beaming, or radio signal requirements for the concentrating reflector 100.

[0096] To lighten its 110 weight the transparent curved sheet 110 (in FIGS. 1 G-1 J renumbered as the perforated or mesh transparent curved sheet 111) may include a plurality of perforations 114 (or mesh).

[0097] The transparent curved sheet 110 is preferably pre-manufactured by vacuum forming plastic sheet, a process that allows economical production runs of a hundred to a few thousand pieces. However, for applications where high transparency of the sheet is necessary, glass can be used (to replace plastic) in the usual commercial manufacturing processes for glass. The concentrating reflector 100 is provided either as a finished ready-to-use product or as a Do-It-Yourself (DIY) kit, wherein the transparent curved sheet 110 and the formed protective backing 140 covering the flexible reflective sheet 120 are already included. For a vacuum forming manufacturing process the mold for the transparent curved sheet 110 or for the protective backing 140 may be accurately carved and finished using a computer-controlled CNC machine.

[0098] The transparent curved sheet 110 is preferably made of acrylic or Acrylonitrile Butadiene Styrene (ABS), both of which can be vacuum formed, trimmed and fabricated with ease.

[0099] Acrylonitrile Styrene Acrylate (ASA), a thermoplastic polymer known for its high resistance to weathering and ultraviolet (UV) light and some other UV and heat resistant plastics can also be used for the parabolic shape. Other transparent plastics, such as PE, PETG and PVC, may also be used.

[0100] The flexible reflective sheet 120 may be an aluminum-and-Mylar film laminate, an aluminum foil, a silver foil, or any flexible sheet or fabric that reflects light or radio waves, and, preferably, a little stretchable to conform to a convex surface with only minimal or no creases and folds.

[0101] FIGS. 1 A-1 B show a yet untrimmed flexible reflective sheet 120. Referring to FIG. 1 B, the flexible reflective sheet 120 is applied to the transparent curved sheet 110 by spreading it 120 tightly on the convex outer side of the transparent curved sheet 110 to minimize unwanted creases and folds. Referring to FIGS. 1 D and 1 E, then, it 120 is then fastened to the convex outer side of the transparent curved sheet 110 near or at the edge 112 using glue or paste (glue or paste not shown in the FIGS.). Then, the excess flexible reflective sheet 120 is trimmed off. Then the protective backing 140 is clamped on to the transparent curved sheet 110. When the protective backing 140 is clamped on to the transparent curved sheet 110 it 140 also helps to keep the flexible reflective sheet 120 in its 120 place.

[0102] Referring to FIG. 1 E, the clamping action of the undercut 144 on the edge 112 of the transparent curved sheet 110 might not appear obvious because the concentrating reflector 100 is slanted facing the sun, but it will be obvious if one turns the FIG. 1 E a bit counter clockwise, where it can be observed that the forward edge of the undercut 144 is on a smaller peripheral diameter than the rear of edge 112 of the transparent curved sheet 110 just before the outward extension 145 extends outward. So that when the protective backing 140 is clamped on to the transparent curved sheet 110 the forward corner of the undercut 144 will prevent the edge 112 of the transparent curved sheet 110 from coming out loose. Optionally, the outward extension 145 has a radial width wide enough to accommodate a user's fingers, so that, when needed, it 145 can be forced outwards or backwards by hand to unclamp the transparent curved sheet 110. To increase its 140 rigidity the protective backing 140 may include a plurality of radial dents 143 that protrude outwards so as not to interfere with the flexible reflective sheet 120.

[0103] The protective backing 140 covering the flexible reflective sheet 120 is also a premanufactured preferably vacuum formed plastic. Its 140 form and dimensions generally follow those of the convex outer side of the transparent curved sheet 110 with the flexible reflective sheet 120 added, so that both (110 and 120) should fit in it 140 snugly when the protective backing 140 is clamped on.

[0104] The concentrating reflector 100 includes plurality of bolt or screw holes 108 for fastening it 100 to an external structure or mechanism (not shown in the FIGS.) for tracking the sun, a distant target or a radio signal source.

[0105] Since the flexible reflective sheet 120 conforms to the form or shape of the transparent curved sheet 110, it 120 concentrates the light from the sun to a smaller spot or focus, where the reflected sunlight is hottest.

[0106] If the transparent curved sheet 110 is a parabolic dish (it 110 is shown as parabolic in the FIGS.) the focus F will practically be a point focus (shown in the FIGS, as a broken line small circle) in front of it 110. With a parabolic dish for cooking purposes, a pot, pan or piece of meat (not shown in the FIGS.) may be placed before or after the focus F, where the light and heat are slightly spread.

[0107] If the transparent curved sheet 110 is a spherical dent or circle arc curve (instead of a parabolic curve) there will be a linear concentration of light and heat a short length along its 110 axis in front of it 110 and some less concentrated light around the linear concentration. A pot, pan or piece of meat (not shown in the FIGS.) may be placed anywhere along the linear concentration.

[0108] Although the preferred embodiment of the concentrating reflector 100 shows the curve of the transparent curved sheet 110 and protective backing 140 as that of a central parabola the curve can also be that of an offset parabola, a circle arc, or an ellipsoidal arc, and the frontal view section can be square, rectangular, hexagonal section or any form (when viewed from the front), and its shape can also be that of a parabolic trough.

[0109] From FIGS. 1 A-1 F it will be noted that the basic functional concentrating reflector 100 comprising only a transparent curved sheet 110 and a flexible reflective sheet 120 can already reflect and concentrate light, heat or radio waves, even without the other above- mentioned parts. However, to make the flexible reflective sheet 120 last longer, the protective backing 140 is a necessary component.

[0110] By spreading the flexible reflective sheet 120 tightly on the convex outer side of the transparent curved sheet 110 and then pasting or gluing it 120 at or near the edge 112 of the transparent curved sheet 110 the process of applying the reflective surface (of the flexible reflective sheet 120) to the transparent curved sheet 110 is made easier, more convenient, and more efficient than if the flexible reflective sheet 120 were applied on the concave inner side of the transparent curved sheet 110. Creases and folds on the flexible reflective sheet 120 are minimized. The application process is made simpler, easier, does not require much skill, and saves time and money.

[0111] FIGS. 1 G-1 J show a variant lighter weight flexible reflective film concentrating reflector 101 , comprising: a) optionally, bolt or screw holes 108 as means for fastening said concentrating reflector 101 to an external structure or tracking mechanism (not shown in the FIGS.), b) a perforated or mesh transparent curved sheet 111 including a plurality of perforations 114 or made of mesh, c) a flexible reflective sheet 120, d) optionally, a protective backing 141 , including an edge 142, e) optionally, an ll-seal 161 water proofing seal that is made of extruded plastic or rubber, and f) a transparent sheet 191 (FIGS. 1 G, 11, 1 J) installed in front of and glued to the rim of the perforated or mesh transparent curved sheet 111 to prevent it 111 from accumulating dust and dirt.

[0112] A plurality of bolt or screw holes 108 on the concentrating reflector 101 allow it 101 to be fastened to an external structure or tracking mechanism (not shown in the FIGS). Except for the perforated or mesh transparent curved sheet 111 , transparent sheet 191 , and the ll-seal 161 , all other parts and their functions remain basically the same as in the flexible reflective film concentrator 100. Although FIGS. 1 G-1 J show a perforated transparent curved sheet 111 , it is obvious that the same reduction in weight can also be achieved with a mesh transparent curved sheet 111 (not shown in the FIGS.).

[0113] Please note that FIG. 1 G shows a yet untrimmed flexible reflective sheet 120. After the flexible reflective sheet 120 has been glued or pasted to the convex outer side of the perforated or mesh transparent curved sheet 111 , it 120 is then trimmed off, and the protective backing 141 is fastened to the perforated or mesh transparent curved sheet 111 , optionally glued to the perforated or mesh transparent curved sheet 111 at or near the edge 142, and the ll-seal 161 installed on the rim of the concentrating reflector 101. Then, the transparent sheet 191 is glued or pasted to the ll-seal 161 (or to the rim of the protective backing 141 , if no ll-seal 161 is used).

[0114] If a protective backing, such as 141 , does not have an undercut 144 for clamping on to the edge 112 of the transparent curved sheet 111 , the concave side near its inner edge 142 may be fastened to the transparent curved sheet 111 by gluing it 142 to the convex outer side near the edge 112 of the transparent curved sheet 111 (as in FIG. 1 J). In this case the flexible reflective sheet 120 is preferably trimmed about 1 cm short of the edge 112 of the transparent curved sheet 111 , so that the concave side near the edge 142 of the protective backing 141 can be glued directly to the convex side near the edge 112 of the perforated or mesh transparent curved sheet 111 . Other means for fastening together the protective backing 141 and transparent curved sheet 111 may also be used, such as a ll-seal 161 peripheral clip that is an extruded plastic or rubber water proofing seal (shown in FIGS. 1 G-1J).

[0115] A silicone sealant or any water-proof glue (not shown in the FIGS.) may also be applied on the gap between the edges 112 and 142 of the transparent curved sheet 111 and the protective backing 141 , respectively, to fasten the two (111 and 140) together, and will function as both a seal to protect the flexible reflective sheet 120 from rain and a means for holding together the assembled transparent curved sheet 111 , flexible reflective sheet 120, and protective backing 141.

[0116] From FIGS. 1 G-1 J it will be noted that the basic functional flexible reflective film concentrator 101 can reflect and concentrate light and radio waves comprising only a) a perforated or mesh transparent curved sheet 111 and b) a flexible reflective sheet 120, even without the other above-mentioned parts.

[0117] However, to make the flexible reflective sheet 120 last longer, the protective backing 141 is a necessary component.

[0118] Small sizes of the transparent curved sheets 110 and 111 , protective backing 140 or 141 , for starting a fire, cigarette, or tinder can be made by blow molding or injection molding plastic, as well as by vacuum forming.

[0119] It can be observed from FIGS. 1 A-1 F that the transparent curved sheet 110 may also be a consumer product such as a transparent parabolic pot cover, basin, bowl, or big container cover (such as the wide mouth cover or cap of a 1 -liter jar), such that when a flexible reflective sheet 120 is fastened to its 110 parabolic convex outer side, it 110 may be used as a concentrating reflector; so that the same consumer product will be doubly attractive to buyers over similar conventional products that are not transparent and parabolic.

[0120] Referring to FIGS. 1 K-1 R, another preferred embodiment of the invention is a variant concentrating reflector 105, comprising: a) a plurality of petals 106 (petal 106 shown particularly in FIGS. 1 N-1 P), that are identical outer radial divisions of the above concentrating reflectors 100, 101 , the transparent curved sheet 110 or 111 renumbered as 116, the flexible reflective sheet 120 renumbered as 126, and the protective backing 140 renumbered as 146; b) a central support plate 162 (shown particularly in FIGS. 1 Q-1 R), including a plurality of insertion clips 163 and pairs of insertion clips 164 and 165 for holding each said petal 106 in place (shown particularly in FIGS. 1 Q-1 R); and, c) optionally, bolt or screw holes 168 as means for fastening the central support plate 162 to an external structure or tracking mechanism.

[0121] Referring to FIGS. 1 N-1 P, each petal 106 comprises a transparent curved sheet 116, a flexible reflective sheet 126, and a protective backing 146, glued together at or near their (116, 126, 146) edges.

[0122] Referring to FIGS. 1Q-1 R, the variant concentrating reflector 105 can be assembled easily by just inserting the petals 106 on the insertion clips 163, 164, 165 or be dismantled for shipment or storage. Referring particularly to FIG. 1 P, and to FIGS. 10-1 R for context, at the smaller lower end of the petal 106 are slight cuts 166, 167 on the lower edges adjacent to the smaller lower end to allow insertion in the insertion clips 163, 164, 165 without getting snagged by the posts of pairs of insertion clips 164, 165.

[0123] Referring to FIGS. 1 Q-1 R, the central support plate 162 is preferably a formed aluminum plate (which inherently can reflect up to 98% of sunlight or radio waves), but may also be a) a formed plastic sheet, reflectorized on its front side with a flexible reflective sheet (reflectorized not shown in the FIGS.), or b) a lamination of a transparent plastic sheet, flexible reflective sheet, and protective backing (lamination not shown in the FIGS.), or c) a steel sheet reflectorized on its front side with a flexible reflective sheet or with a reflective coating (reflectorized not shown in the FIGS.). It can be observed that in each petal 106 a perforated or mesh type (not shown in the FIGS.) transparent curved sheet 116 may be used also to reduce the weight of the petal 106.

[0124] Another preferred embodiment of the present invention is a concentrating reflector 200, shown in FIGS. 2A-2L, wherein the transparent curved sheet is a parabolic trough, comprising: a) a transparent parabolic trough 210, that is an already-formed parabolic trough or a sheet that can be bent into a parabolic trough, including its edges 212; b) a flexible reflective sheet 220 spread tightly and fastened to the convex outer side and at the edges 212 of the transparent parabolic trough 210 using glue or paste (glue or paste not shown in the FIGS.); c) optionally, a backing support 240 for the flexible reflective sheet 220, including its edges 242, and the transparent parabolic trough 210; d) optionally, a plurality of equally spaced apart hollow parabolic supports 270 seating and holding in place the transparent parabolic trough 210, flexible reflective sheet 220, and backing support 240, each parabolic support 270 including a parabolic profile 271 for seating, and various forms at its 270 ends for fastening, the assembled transparent parabolic trough 210, flexible reflective sheet 220, and backing support 240; e) optionally, a structural beam 280 holding in place the plurality of parabolic supports 270, including a plurality of equally spaced bolt holes 281 to prevent the beam clips 296 and parabolic supports 270 from moving laterally; f) optionally, a plurality of sheet clips 290 fastening the transparent parabolic trough 210, flexible reflective sheet 220, and backing support 240 to the parabolic supports 270; g) optionally, a plurality of beam clips 296 fastening the parabolic supports 270 to the structural beam 280; and h) optionally, a plurality of bolts 282 to help fasten the beam clips 296 to the structural beam 280.

[0125] Referring particularly to FIG. 2D, the transparent parabolic trough 210 is a parabolic trough or a sheet that is bent or that can be bent into a parabolic trough when placed on the parabolic supports 270. Particularly, the transparent parabolic trough 210 need not be parabolic if it 210 can bend by its 210 own weight or with an outside help because, if so, it 210 will assume the parabolic profile 271 of the parabolic supports 270 when placed on them 270.

[0126] The backing support 240 also is a parabolic trough or a sheet that is bent or that can be bent into a parabolic trough when placed on the parabolic supports 270. Also, the backing support 240 need not be parabolic if it 240 can bend by its 240 own weight or with an outside help because, if so, it 240 will assume the parabolic profile 271 of the parabolic supports 270 when placed on them 270.

[0127] The flexible reflective sheet 220, sandwiched between the transparent parabolic trough 210 and the backing support 240, naturally assumes the parabolic profile 271 of the transparent parabolic trough 210 and the backing support 240. Referring to FIGS. 20, 2E, 2G, and 2H, each parabolic support 270 includes up- protruding tips 272 at the ends of its 270 parabolic profile 271 , the protrusion height (starting from the parabolic profile 271 ) is about equal to the combined thickness of the transparent sheet 210, flexible reflective sheet 220, and backing support 240, so as to restrain them in place.

[0128] Referring to FIGS. 2E and 2G, the parabolic support 270 also includes a pair of planar indentations 273 at each end to guide the sheet clip 290, a deep indentation 274 at the back of its ends for locking in place the sheet clip 290, a horizontal channel indentation 275 (Please see FIGS. 2C-2E and 2J-2L.) at the back to hold the structural beam 280, a pair of planar indentations 276 (Please see FIGS. 2E, 2J.) at the back to guide the beam clip 296 for insertion, and a pair of deep indentations 277 at the back to lock in place the beam clip 296.

[0129] As can be observed in FIGS. 2A-2D additional bolt holes (not shown in the FIGS.), if drilled on the structural beam 280, where needed, can also be used as means for fastening the concentrating reflector 200 to an external structure or tracking mechanism (not shown in the FIGS).

[0130] Referring to FIGS. 2E-2H the sheet clip 290 includes a circular bend 291 at each bent corner to add to its elasticity and a fold 292 near its 290 back end that drops into and locks on the deep indentation 274 at the ends of the parabolic support 270 when sheet clip 290 is pushed towards the middle of the parabolic support 270 to fasten in place the assembled transparent parabolic trough 210, flexible reflective sheet 220, and backing support 240.

[0131] The front end 293 of the sheet clip 290 is slightly angled from the rest of the sheet clip 290 on that end to enable it 290 to slide easily on the front planar indentation 273 at the ends of the parabolic profile 271 . Similarly, the back end 294 of the sheet clip 290 is markedly angled relative to the back planar indentation 273 to enable it to slide easily on it 273 and to drop down to lock on the deep indentation 274 at the ends of the parabolic support 270.

[0132] Optionally, but not shown in the FIGS., the up-protruding tips 272 of the parabolic support 270 may further extend sideward about 1 -2 cm towards the middle of the parabolic profile 271 so that the combined transparent sheet 210, flexible reflective sheet 220, and backing support 240 may just be inserted beneath the extensions and be restrained from flying upwards by the extensions without using the sheet clips 290.

[0133] Referring to FIGS. 2I-2L, the beam clip 296 includes a circular bend 297 at each bent corner to add to its elasticity, a pair of folds 298 opposite each other at each end that drop into and lock on the deep indentations 277 at the back of the parabolic support 270 when beam clip 296 is pushed towards the parabolic support 270 to fasten in place the parabolic support 270 to the structural beam 280, and a bolt hole 299. A plurality of equally spaced bolt holes 281 on the structural beam 280 and the bolted bolt hole 299 on each beam clip 296 add fastening strength to the beam clip 296, parabolic support 270 and structural beam 280.

[0134] Referring to FIG. 2E, the parabolic support 270 is a rotation molded (or blow molded) hollow plastic part that can be manufactured in limited production runs of a few hundred pieces to a few thousand pieces, but it 270 may also be a reinforced bent aluminum plate or steel sheet (not shown in the FIGS.), including similar insertion clips, instead of a hollow plastic form or other forms of fasteners to fasten the assembled transparent parabolic trough 210, flexible reflective sheet 220, and backing support 240 to the parabolic supports 270.

[0135] The concentrating reflector 200 concentrates sunlight to a linear focus F, shown in FIGS. 2A-2B as a double broken line and in FIG. 2C (side view) as a broken line small circle F in front of the parabolic trough concentrating reflector 200), where a pipe or cylinder to be heated (not shown in the FIGS.) may be positioned.

[0136] Another preferred embodiment of the invention is a concentrating reflector 300, shown in FIGS. 3A-3C, comprising a) a transparent cylinder 310, that is transparent to light or to radio waves, including its end edges 312 and axial edges 313, and including means 315 at its 310 ends for axial support; b) a flexible reflective sheet 320, spread tightly on and fastened at its edges to about half of the circumference of the convex outer side of the transparent cylinder 310 (and fastened also to the transparent cylinder 310 at edges 312) using glue or paste (glue or paste are not shown in the FIGS.), c) optionally, a pipe 330, including d) a plurality of holes 331 on its side, e) a plug 333 blocking its 330 middle portion, f) a cylinder 335 to be heated, disposed around the pipe 330 inside the transparent cylinder 310, g) optionally, a protective backing 340, covering the flexible reflective sheet 320 and conforming to the form of the transparent cylinder 310 and including axial edges 342 and end edges 343; h) optionally, a pair of ceramic heat insulator bushings 390 on the pipe 330 or cylinder 335 to be heated, i) optionally, ground support 395 or means 395 for supporting the concentrating reflector 300 on the ground and for tracking the sun, a distant object or a radio signal source (not shown in the FIGS.), including a threaded stopper bolt 396 on the bushing 397 of the ground support 395 as means for fixing the angular orientation of the flexible reflective sheet 320 (or the assembly of transparent cylinder 310, flexible reflective sheet 320, and protective backing 340).

[0137] The means 315 at the ends of the transparent cylinder 310 support and connect it 310 to the pair of heat insulator bushings 390 on the pipe 330 (or on a cylinder 335) to be heated.

[0138] FIGS. 3A-3C show a transparent cylinder 310. On its 310 lower outer side about half of it 310 circumferentially is covered by flexible reflective sheet 320, which is fastened at its 320 edges to the transparent cylinder 310 and also at or near the edges 312 using paste or glue (not shown in the FIGS.). A protective backing 340 covering the flexible reflective sheet 320 is fastened to the transparent cylinder 310 by means of glue (not shown in the FIGS.) at its axial edges 342 and end edges 343 or by other means. The width of the flexible reflective sheet 320 is slightly lesser than the width of the protective backing 340, so that the edges 342, 343 of the protective backing 340 may be glued directly to the convex outer side of the transparent cylinder 310.

[0139] Other means of fastening the protective backing 340 to the transparent cylinder 310 may be used, such as, for example, by a plurality of screws or other common fasteners (not shown in the FIGS.).

[0140] It can be imagined that when the protective backing 340 is fastened directly to the transparent cylinder 310 by screws or other removable means the flexible reflective sheet 320 may be removable for maintenance or replacement, being sandwiched between the protective backing 340 and the transparent cylinder 310.

[0141] The concentration of light and heat is inside the transparent cylinder 310, where the pipe 330 or the cylinder 335 to be heated is positioned.

[0142] The pipe 330 includes a plurality of holes 331 on its 330 upper and lower sides. The metal cylinder 335 to be heated is mounted on the pipe 330 and is welded air-tightly to it 330 at its 335 ends. A plug 333 in the middle of the pipe 330 obstructs the flow inside the pipe 330 such that water (or fluid) to be heated enters the heating cylinder 335 at the left portion of the pipe 330 and the heated fluid exits at the right portion through the holes 331 . The transparent cylinder 310 is mounted at its ends 315 on the pipe 330 on a pair of heat insulator bushings 390 to insulate it 310 from the heat of the pipe 330 and the cylinder 335 to be heated.

[0143] To use the concentrating reflector 300, water (or liquid, gas, or air) to be heated is pumped or blown from the left end of the pipe 330 towards the right end.

[0144] The transparent cylinder 310 may be rotated on its 310 shaft, the pipe 330, to face the sun (in the upper right direction), and the selected orientation fixed for some 10-20 minutes by tightening the threaded stopper bolt 396 on the bushing 397 of the ground support 395.

[0145] Referring to FIGS. 3D-3F, for some applications the ground supports 395 may be done away with to allow the transparent cylinder 310 to just rest on the ground and be fixed in its 310 orientation relative to the sun by placing at least 2 wheel chocks or wooden blocks 398 on its 310 opposite cylindrical sides.

[0146] It can be noted from FIGS. 3A-3F that the transparent cylinder 310 may also be made of plastic, glass or of inflatable sheet, such as but not limited to flexible polyethylene plastic sheet.

[0147] If the transparent cylinder 310 is made of inflatable sheet, then the protective backing 340, preferably, is also a flexible sheet or fabric, and the transparent cylinder 310 also needs to have an air valve (not shown in the FIGS.) to let air in, out, or enable the user to adjust the air pressure inside.

[0148] If the protective backing 340 is made of a transparent material, such as transparent polyethylene plastic, it 340 may also cover the entire circumference of the transparent cylinder 310 (or be another transparent cylinder) (340)) enclosing the transparent cylinder 310. From FIGS. 3A-3F it will be noted that the concentrating reflector 300 comprising only a transparent cylinder 310 and a flexible reflective sheet 320 can already reflect and concentrate light, heat or radio waves for heating fluids or other applications, even in the absence of the other above-mentioned parts. However, to make the flexible reflective sheet 320 last longer, the protective backing 340 is a necessary component.

[0149] Another preferred embodiment of the invention is a concentrating reflector 400, shown in FIGS. 4A-4B and comprising a) a transparent umbrella 410, including a convex outer side 412, its 410 edges 414, a handle 415, a stem 416, a plurality of ribs 417 and spokes 418 supporting the transparent umbrella 410 for folding and unfolding; and b) a flexible reflective sheet 420, including a hole 421 at the center, fastened to the convex outer side 412 of the umbrella 410 at the edges 414 and at the edge of the hole 421 at the center using glue or paste (glue or paste not shown in the FIGS.). The flexible reflective sheet 420 may or may not be removable. Preferably, for the user's convenience, the handle 415 and part of the stem 416 are removable.

[0150] Although an umbrella concentrating reflector 400 might not have a truly parabolic curve it 400 still has its 400 hottest concentrated reflected light in front of its 400 concave inner side 413, where a pot or pan (not shown in the FIGS.) to be heated may be positioned.

Claims

AMENDED CLAIMS received by the International Bureau on 3 May 2025 (03.05.2025)CLAIMSI claim:1 . A concentrating reflector, comprising: a) a transparent curved sheet, including: a convex outer side, and, optionally, radial dents that protrude inwards; b) a flexible reflective sheet, spread on and fastened to the convex outer side of the transparent curved sheet; c) a protective backing covering the flexible reflective sheet, including: a rim; optionally, an undercut on its rim for fastening to the transparent curved sheet and, optionally, radial dents that protrude outwards; and, d) optionally, means for fastening the flexible reflective sheet concentrating reflector to an external structure.

2. A concentrating reflector of claim 1 , wherein the transparent curved sheet is perforated or is a mesh.

3. A concentrating reflector, comprising: a) a plurality of petals, each petal being an identical outer radial division of the concentrating reflector of claim 1 or 2; b) a central plate holder, including a plurality of insertion clips for fastening each said petal; and, c) optionally, means for fastening to an external support.

4. A hollow parabolic support, including: a. a parabolic profile; b. up-protruding tips at the ends of the parabolic profile; c. a pair of planar indentations at each end to guide a sheet clip; d. a deep indentation at the back of its ends for locking in place the sheet clip; e. a horizontal channel indentation at the back to hold a structural beam; f. a pair of planar indentations at the back to guide a beam clip for insertion; g. a pair of deep indentations at the back to lock in place the beam clip; and h. wherein, the up-protruding tips may extend sideward about 1-2 cm towards the middle of the parabolic profile, so that the combined transparent sheet, flexible reflective sheet and backing support may just be inserted beneath the extensions and be restrained from flying upwards by the said extensions5. A concentrating reflector of claim 1 , wherein the transparent curved sheet is a parabolic trough, comprising: a) a transparent parabolic trough, including: a convex outer side; b) a flexible reflective sheet spread on and fastened to the convex outer side of the transparent parabolic trough; c) a backing support, covering the flexible reflective sheet and the transparent parabolic trough; d) a plurality of parabolic supports of claim 4; e) optionally, a structural beam, supporting the plurality of parabolic supports; f) optionally, a plurality of sheet clips, fastening the transparent parabolic trough; flexible reflective sheet, and backing support to the parabolic supports; g) optionally, a plurality of beam clips, fastening the parabolic supports to the structural beam; and, h) optionally, means for fastening the concentrating reflector to an external structure.

6. A concentrating reflector of claim 5, wherein the transparent parabolic trough is a sheet that can be bent into a parabolic trough, and wherein the backing support is a sheet that can be bent into a parabolic trough.

7. A concentrating reflector of claim 1 , wherein the transparent curved sheet is a cylinder, comprising: a) a transparent cylinder, including: a convex outer side and two ends; b) a flexible reflective sheet, spread partly on and fastened to the convex outer side of the transparent cylinder; c) a protective backing, covering the flexible reflective sheet; d) a pipe and / or cylinder to be heated, disposed inside the transparent cylinder; e) a pair of heat insulator bushings, on the pipe to be heated; f) end plates at the ends of the transparent cylinder for supporting it and connecting it to the pair of heat insulator bushings, or to the pipe, or to the cylinder to be heated; and, g) optionally, means for supporting the concentrating reflector on the ground.

8. A cylinder, including two end plates, containing: a pipe, including: a plurality of holes on its side, and a plug, blocking the middle portion of the pipe.

9. A concentrating reflector of claim 1 , wherein the transparent curved sheet is an umbrella, comprising: a) a transparent umbrella, including a convex outer side, its edges, a handle, a stem, a plurality of ribs and spokes supporting the transparent umbrella for folding and unfolding, wherein, the handle and stem may or may not be removable; and b) a flexible reflective sheet, including a hole at the center, fastened to the convex outer side of the umbrella, wherein, the flexible reflective sheet may or may not be removable10. A concentrating reflector of claim 1 , wherein the transparent curved sheet is a transparent pot cover, a basin, a bowl, or a container cover, including: a side that is parabolic; and, a flexible reflective sheet fastened to its parabolic convex outer side.

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