STEPPED LAMELLA FOR GUIDING LIGHT RADIATION

Abstract: The present invention relates to lamellae for light deflection and for scattering radiation, particularly sun radiation. The lamellae comprise two portions wherein the first portion is graded like stairs. It serves for scattering sun radiation. The second portion is oriented towards the interior space and is preferably convexly arched ascending towards the interior space. Sun radiation impinging onto the second portion is deflected to the ceiling of the interior space and into the space depth. The tread-board and the second lamella portion are disposed at an angle OMEGA relative to each other.

Description: STEPPED LAMELLA FOR GUIDING LIGHT RADIATION The present invention relates to lamellae for light deflection and for radiation scattering com- prising a first portion, located in the area of irra¬ diation E, including a step-shaped gradation of the lamella leaf consisting of a treadboard and a riser wherein the inclination β of the treadboard forms an incline from the area of irradiation to the interior space, and a second portion. From U.S. Patent Specification No. 2,103,788, it has been known to shape sun shade lamellae like steps and to arrange the lamellae horizontally. The disad¬ vantage of such arrangement is that, both in summer and in winter, direct sun radiation is completely scattered. A further disadvantage is seen in that the lamellae are so tightly next to each other that transparency from within to the outside is not possi¬ ble. An additional disadvantage is that only bottom radiation can penetrate between the lamellae into the interior space so that the interior space is not sufficiently illuminated. It has furtheron been known to shape the lamel¬ lae for radiation screens as steps where the indi¬ vidual steps are arranged at different angles rela- tive to each other and the treadboard and the riser are arranged in various lengths (German Offenlegungs- schrift No. 27 32 592). From German Offenlegungs- schrift No. 42 39 003 Al, too, sun shade lamellae have been known which are shaped as steps on the upper side and are disposed at right angles relative to each other. At the underside, the sun shade la¬ mellae described are also shaped as steps. The indi¬ vidual steps on the underside of the lamella leaf are partly shaped concavely or convexly. The gradings on the upper side of the sun shade lamella are shaped level or plane. This causes reflection of the light radiation from the upper side of a lamella onto the underside of the upper lamella. On the underside of the upper lamella, the light radiation is then de- fleeted by a corresponding concave shape so that controlled light deflection onto the working or ground area is obtained. Light deflection to the ceiling and into the depth of the room is only re- strictedly possible. The double light deflection to the upper or the underside, respectively, of the sun shade lamellae is considered a disadvantage since each reflection, even on specular surfaces, leads to an absorption at the lamellae. The absorption leads to undesired heating up and reduction of the light radiation. If only the underside is arched and the upper side is plane or level, high angles of inci¬ dence of the sun in summer may lead to a plurality of reflections between the lamella leafs until the ray is reflected into the interior space or again to the outside. This leads to considerable warming up of the lamellae which, particularly in summer, is expe¬ rienced, as inconvenient heat radiation in the interi- or space. In case of a reflection movement between the lamellae, one cannot guarantee that light inci¬ dence is deflected to the ceiling and, in order to illuminate the depth of the room, into the interior depth. Glaring at the working place might even be experienced since no exact control over the angle of the light incidence into the interior space can be exerted. It is, therefore, the aim of the present inven- tion to provide lamellae on which, in summer, the sun light with high angles of incidence of the sun is completely scattered without resetting the lamellae, and flat sun radiation in winter and diffuse radia- tion is partly deflected to the ceiling and into the depth of the interior space while the lamellae need not necessarily be turned to a horizontal axis. This problem is solved in accordance with char¬ acterizing clause of claim 1. The advantage of the innovation is that, con¬ trary to all prior art sun shade lamellae, they may remain even in case of high angles of incidence in a flat opened position so that light penetration and light deflection is warranted at an optimum in favor of interior depth illumination even if direct summer sun is scattered. At the same time, transparency of the sun shade is maintained. The disadvantage of sun shades normally experienced in the summer sun when they are tilted to a closed position and thus become non-transparent and light impermeable, is avoided. Further advantages will become apparent from the description based on the figures wherein Figure 1 is a perspective section through a plurality of lamellae disposed one upon the other, such as for instance of a sun shade; Figure 2 is a cross section through three hori¬ zontal sun shade lamellae disposed one upon the oth- er; Figure 3 is a cross section through a first portion of a stepped sun shade lamella in horizontal disposition; Figure 4 is the section through a lamellae hav- ing a glass covering; Figure 5 is the section through an insulating glass window for inclined roof surfaces having an inlet made of the lamellae according to the inven¬ tion; Figure 6 is the cross section through a large lamella; Figure 7 is the disposition of the large lamella in the high window area in an approximately horizon¬ tal position; Figures 8, 8.1 are further lamellae and the mounting thereof; and Figure 9 are magnetically controlled lamellae. Figure 1 illustrates the cross section through a horizontal sun shade comprising lamellae 10 through 13 disposed at an inclination to the sun 15. The lamellae are composed of a stepped first portion and an area-shaped second portion. The stepped portion is, on principle, oriented towards the outside space and the area-shaped portion towards the interior space. The sun shade may be mounted in the outside space, in the interior space or in the intermediate air space between an insulation glass window. The term sun shade as used in the present examples also includes all inelastic lamella systems, i.e. also such systems which cannot be moved together and are rotatably supported about an axis or which may be stationarily arranged. Light radiation 4 inciding from outside onto the stepped lamella portion is reflected back to radiation cross section E. Light radiation 15 inciding at a flat angle of incidence onto the area-shaped lamella portion oriented towards the interior space is reflected by means of beam 15.1 into the interior space. By inclination of the sec¬ ond portion, the reflected light radiation is reflec¬ ted into the interior space essentially at an angle r > 0. Treadboards 16 have an angle of inclination β relative to horizontal H. The treadboards show an inclination from radiation cross section E between the starting points of two superimposed lamellae to the interior space. The inclinations of the tread- board and of the second area-shaped portion 17 have an obtuse angle Ω relative to each other wherein, in most cases, the inclination y 2 of the second portion, as in the present case, is opposed to inclination β of the treadboard and is constant or, advantageously, increases, continuously or discontinuously, as can be taken from the following figures. This rule applies for all embodiments of the present invention. The starting point is in each case the point which is nearest to radiation cross section E. It is of advantage, if a line 7 through starting point 8 and end point 9 of lamella 13 takes an angle γ of γ - 0 - 30" . The total lamella may be convexly curved as in the present case. The end point 6 of the first portion 5 or the starting point of the second portion 4 is above a straight line 7. This point 6 may also be disposed on straight line 7 or below straight line 7, which essentially leads to a concave shape of the lamella. On the radiation side, the surfaces of the la- mellae are highly reflective, i.e. white or prefera¬ bly specular or for instance are provided with a dull silver, aluminum or gold luster. The underside of the lamellae may also be either specular or dull or colored, e.g. white or colorfully japanned. Figure 2 shows a cross section through three sun shade lamellae 23, 24, 25 disposed one upon the oth¬ er. The sun shade lamellae include a first portion 26, 27, 28 oriented towards the outside space 32 and a second portion 29, 30, 31 oriented towards the interior space 33. The first portion 26, 27, 28 is formed of a step-shaped reflector which is composed of a plurality of reflector portions 34, 35, 36, 37 and so on and, for instance, forms an angle of lead. The steps of the first portion include concavely shaped treadboards 35, 36, 45 and concavely shaped risers 34, 37, 46, 48. The risers 34, 37, 46, 48 may also be plane or convex. An inciding ray 44 impinges onto riser 45 of the first portion 26. At treadboard 45, ray 44 is reflec¬ ted onto riser 46. At the riser, ray 44 is reflect¬ ed back to the outside space 32. A flat sun ray 47 impinging onto riser 48 of first portion 28 is re- fleeted back by it directly into outside space 32. Riser 34, 37, 46, 48, in particular, is arched from the interior space so that it is not possible that the looker on from the interior space is reflected or is dazzled by reflection. By the arched formation of treadboard and risers of the first portion the sun shade lamellae according to the teaching of the present invention, it can be safeguarded that the complete radiation reflected back from the lamella to the outside space in favor of a passive cooling of the interior space is dif¬ fusely scattered. At the steps, the flat winter sun is only partly reflected to the outside while a further part which impinges onto the second portion 29 to 31 is deflect- able into the space depth. A similar case is the diffuse radiation. Diffuse radiation is deflected into the space depth as well. It constitutes part of the teaching of the present invention to so shape the second portion and bend it that radiation 65, 65.1 is not, or just somewhat, reflected onto the underside of the upper lamella but mainly directly onto the ceiling of the interior space. This shaping of the second portion may be made as a curve or in segments of straight or arched portions. The distance between the lamellae and the starting and end points of the lamellae is determined as follows: A shadow line 55 between starting point 51 of an upper lamella 23 and the end point 52 of a lower lamella 24 forms an angle of α 3 < 30 * . A shadow line 56 between starting point 51 of an upper lamella 53 of the first portion 27 of the lower lamella forms an angle of α 4 > 30° < 60°. These data refer to the normal position and may change if the lamellae are rotated about an horizon¬ tal axis. The first portion 26, 27, 28 and the second portion 29, 30, 31 have a width of Bj. and B 2 , respec¬ tively. The following proportions are valid: B = Bi + B 2 = 1. The portions are to the total width as B x B = 0.5 ± 0.1 and B 2 /B = 0.5 ± 0.1 When designing the second portion it is essen¬ tial that the reflection paths be so controlled by the tangent inclination of the curve points that the sun is not reflected onto the underside of the upper lamella. This process will be explained based on lamella 24 and 25: A shadow line 65 falling into the starting point 66 of second portion 31 of lamella 25 should reflect below end point 52 of upper lamella 24 into interior space 33. The construction of the tangent inclination in point 66 is performed in a manner known in the art by determining angle bisector 67 between inciding ray 65 and reflected ray 65.1. Similarly, the exact trace of the curve of the total second portion 29, 30,31 of lamella may be projected. The trace of the curve may of course be selected flatter by no means however steeper, as has been explained in connection with ray path 49, 49.1, un- less one allows reflection on the lower side of the upper lamella. Figure 3 serves for the exact definition of the shaping of the first graded portion. The maximum angle of incidence at facade α MX is determined. This is the highest angle of incidence in dependence on the degree of latitude and on the cardinal point of the faςade. A ray 117 inciding at an angle α MX into starting point 118 of treadboard 104 is reflected onto riser 103. As the outermost meeting point, the starting point 112 on riser 103 is determined so that it is avoided that a direct sun ray which might lead to overheating can penetrate into the interior space. From point 112, the ray is reflected back through radiation cross section E into the outside space. The angle bisector between inciding ray 117 and re¬ flecting ray 117.1 is constructed in point 118 and the tangent inclination t llβ is found perpendicular to angle bisector 118.1. Tangent t llβ may be steeper, at a steeper angle β, to horizontal H, should not, how¬ ever, be inclined more flatly. Diffuse zenith radia¬ tion 119, 119.1 at an angle of incidence > α,., is intentionally guided into the interior space. The construction of the riser is performed ac¬ cording to the same method: Ray 116 in point 112 is so guided by the inclination of tangent t lla that it is reflected back from riser 104 in point 113 into radiation cross section E. At a south faςade in Frankfurt, α max amounts to about 68°. Radiation 119 at an angle > α MJt is partly deflected into the inte¬ rior space and leads to an increased illumination with diffuse sky radiation from the zenith. It is obvious that a type designed for a south facade can also be employed on the east or west faςade. Following various ray paths 120, 121, it can be observed that each treadboard and riser can be made differently depending on its location relative to the starting point of the upper lamella. Treadboards 104, 106, 108 become longer with increasing distance from the radiation cross section, risers 103, 105, 107 become shorter with increasing distance from the radiation cross section. This regularity refers to the relative sizes between an optically connected treadboard and a ris¬ er. Assuming the relative sizes of the first tread¬ board and riser in the radiation cross section equal to 1, the ratio of treadboard to riser of at least the last step is > 1. Figure 4 shows lamella 69 of the invention in combination with an outer cover 70 consisting for instance of glass or plexi glass or of a foil. Such a lamella is advantageously employed in the outside space in front of the facade. Connection between lamella 69 and outer pane 70 is brought about for instance by means of a water-vapor diffusion-tight glue 81 as known from insulation glass production. Starting points 75 to 79 of the treadboards and end- points 80 of the second portion are on a straight line. Treadboards 71 to 74 in their starting point 75 to 79 form an angle β relative to horizontal H which decreases with increasing distance from radia¬ tion cross section E. The tangents of the starting point of the treadboards and risers for an acute angle β. Figure 5 illustrates an insulation glazing in¬ cluding an outer pane 80 and an inner pane 81. With¬ in air space 82 of the insulation glazing, lamellae 83, 84 are installed which correspond to the form of the invention. Such insulation glazing is in- stalled into a roof glazing having an inclination. Figure 6 shows a large lamella which may for instance be installed between the lower window area and the high window area of an interior space. Es- sential for the construction is point 90 which corre¬ sponds to lintel edge 91 in Figure 7. The construc¬ tion of the lamella is performed in a manner known in the art with relative to such lintel edge 91. Ac- cording to the explanation made in Figure 2, lintel edge 91 corresponds to the starting point of an upper lamella. The particular advantage of the large la¬ mella is shown in Figure 7: The lamella may also serve for guiding the light of an indirect light source 92. The light source is arranged as an oblong lamp or as a spot light in the area of the window sill and radiates the light onto the underside of the lamella. On the underside, the light is deflected to the desk according to DIN. The particular feature of the lamella of Figures 6 and 7 is the horizontal expansion. Thus the lamella construction of the invention permits the provision of lamellae having horizontal alignment and lamellae having an inclina¬ tion towards the ground level which, nevertheless, show the desired radiation behavior in favor of a passive cooling effect in summer and a reduction of glare into the outside space. The advantage of this construction is seen inter alia in that the lamella, when in an opened position, offers a very good trans¬ parency and a very high diffuse light entrance into the interior space. The example shows that the lamella may also take an inclination of < 0 with an inclination towards the interior space. The lamella may be composed of a plurality of individual reflectors wherein for instance each treadboard and each riser forms one reflector strip all of which are composed to form a step-shaped structure. The second portion, too, may be composed of a plurality of arched lamellae disposed one next to the other. Figure 8 shows two lamellae 206, 207. The first portion 208, 209 includes steps which, starting from the radiation cross section, increase in size. The advantage of this design is that the lamella is very narrow. Transparency D between the lamellae is a multiple of the height h of the lamellae. Lamellae 206, 207 include a particularity: They include grooves 210, 211 into which a reinforcement, such as for instance sheet steel, may be inserted. The lamella may also be designed as a hollow profile in order to receive the reinforcement. At the same time, the grooves serve, in Figure 8.1, for receiving supporting bolts 214, 215 which are inserted into the grooves and which extend above the lamella and are kept in detent. Such detent is shown in Figure 8.1. The detent comprises a metal sheet disposed at the front sides and including the recesses 212, 213. In the recesses, supporting bolts 214, 215 can be seen extending at the front sides from the grooves. By the bolts, the profile is mounted in a fixed posi- tion. Figure 9 shows the same lamellae as in Figure 8 except that the lamellae are rotatably supported about a horizontal axis. They are depicted in base position A and in tilted position B. By tilting the lamellae to position B, the system closes against the flat sun 216. Tilting of the sun shade lamellae is performed either in a commercial way or by a magnetic pulse. This will be explained based on the upper lamella 217: Into grooves 210, 211 from Figure 8, bolts are inserted which have a bent arm 218. The tip of the arm touches magnet 219, 220. Depending on the current pulse, the arm is drawn to either alter¬ nating magnet 219 or 220 so that the lamella tilts into the desired position A or B. One could also think of a third tilted position which may be obtain¬ ed in a comparable way by means of a swivel arm pro¬ vided on the opposed front sides of the lamellae. Possible is also a base position A to which the system will tilt independently based on an imbalance in the superposition and also a position B, and per¬ haps even C, to which the system is turned by a mag¬ netic pulse. A further embodiment of the present invention not illustrated though very advantageous is consti¬ tuted by the penetration of spaced horizontal lamel¬ lae through orthogonally arranged further lamellae so that a raster-shaped area structure is obtained. The orthogonally penetrating lamellae may either be smooth or convexly shaped on the surface thereof or may also be shaped as steps. It is of particular advantage to provide such reflecting raster elements in the air intermediate space of insulation glazing on the roof or faςade area. The lamellae are made of steel, aluminum or a plastic material. Preferred production procedures include roll shaping from a steel or aluminum sheet, the aluminum pressing procedure, the drawing and/or rolling procedure or the plastic extrusion procedure. Lamellae produced by the roll shaping method prefera¬ bly show on the upper side thereof the same contour as on the underside thereof. Lamellae produced by the press or extrusion method or by the drawing and rolling process may show on the underside thereof a contour which is completely different from that on the upper side. It is for instance possible to pro- vide channels or grooves on the underside. The un¬ derside of the first portion may be smooth so that the stepped structure is not visible. The underside may have a course of the curve of its own developed by different optical laws such as for instance for the reflection of artificial light from the interior space or for the reflection of artificial light flooded onto the faςade back to the outside space.

Claims: Patent Claims 1. Lamellae (10, 11, 12, 13, 232, 24, 25. 69. 83. 84. 206. 207) for light deflection and scattering of radiation comprising a first portion (5, 26, 27, 28, 208, 209) disposed in radiation area E having a step-like gradation of the lamella leaf consisting of treadboard (6, 35, 36, 45, 71, 72, 73, 74, 104, 106, 108) and riser (34, 37, 46, 103, 105, 107) where the inclination β of at least the first treadboard at least in the starting point forms an incline from the radiation area to the interior space (33), and a second portion (4, 29, 30, 31), characterized in that (a) at least the upper side of said first por¬ tion includes at least one treadboard the inclination thereof deviating at least at the starting point (8, 51, 54, 118) relative to at least parts of said second portion (6, 66, 53, 29, 30, 31), (b) the inclinations of the tangents at least in the starting points (8, 51, 54) of the first treadboards (16) and at least parts of said second portion (6, 29, 30, 31, 66, 53) form an obtuse angle Ω relative to each other, (c) daylight radiation impinging onto the lamella (10, 11, 12, 13, 23, 24, 25, 69, 83, 84, 206, 207) is deflected by said first portion (5, 26, 27, 28, 208, 209) into radi- ation area E and daylight impinging onto said second portion (4, 29, 30, 31) may be deflected in the interior space (33). 2. Lamella according to claim 1, character¬ ized in that the tangent inclination of said second portion (17, 29, 30, 31) towards the interior space (33) is essentially ascending as the angle γ is con¬ tinually or discontinuously increasing between tan¬ gent and horizontal. 3. Lamella according to claim 1, characterized in that in the cross section, the starting point (8, 51, 54) of the lamella (10, 11, 12, 13, 23, 24, 25, 69, 83, 84, 206, 207) constitutes the starting point of said first portion (5, 26, 27, 28, 208, 209) and that the endpoint (9, 52, 80) of the lamella consti¬ tutes the endpoint of said second portion (4, 29, 30, 31) and that said first portion B,. and said second portion B 2 are in a width relation relative to the total width as B 2 /B ■ 0.5 ± 0.1. 4. Lamella according to claim 1, characterized in that on the lamellae vertically arranged one upon the other, between the starting point (51) of an upper lamella (23) and the endpoint (52) of a lower lamella (24), a shadow line extends at an angle α 3 of α s < 30 * and that the inclination of a shadow line (56) be¬ tween said starting point (51) of an upper lamella (23) and said endpoint (53) of said step-like first portion (27) of a lower lamella (24) extends at an angle 2 of α 2 > 30° < 60 * . 5. Lamella according to claim 1, characterized in that at least the endpoint (75) of the last step of said first portion is on a straight line connect- ing the starting point (79) of said first portion with the endpoint (80) of said second portion. 6. Lamella according to claim 5, characterized in that a straight line (7) between the starting point (89 of a lamella (13) in radiation cross sec¬ tion E and the endpoint (9) of this lamella forms, to the interior space (33), an angle a x relative to the horizontal of α x = 0 to 30° . 7. Lamella according to claim 1, characterized in that said second portion (4, 29, 30, 31) forms a lamella strip disposed to the interior space (33), said lamella strip being arched or formed of segments or arched segments, and that the course of the curve of said second portion or of the segments thereof is ascending starting from said first portion towards the interior space. 8. Lamella according to claim 1, characterized in that risers (34, 37, 46, 103, 105, 107) and/or treadboards (16, 35, 36, 45, 71, 72, 73, 74, 104, 106, 108) of said first portion (5, 26, 27, 28, 208, 209) are concavely arched and that the ratio of treadboard to riser, at least at the last gradation (108/107), is larger than at the first gradation (104/103) in radiation area E. 9. Lamella according to claim 8, characterized in that at least risers of said first portion most distant from radiation cross section E are convexly shaped. 10. Lamella according to claim 1, characterized in that treadboards and risers (208, 209) of the lamellae (206, 207) become larger as from the radia- tion cross section E towards the direction of said second portion. 11. Lamella according to claim 1, characterized in that lamellae (83, 84) are installed in the air intermediate space of an insulation glazing (80, 81). 12. Lamella according to claim 1, characterized in that lamellae (69) on the sun inciding side are combined with a light permeable cover (70). 13. Lamella according to claim l, characterized in that lamellae (206, 207) include grooves, or hol- low cavities, respectively, at the underside thereof, which grooves, or hollow cavities, respectively, serve for receiving reinforcements and/or supporting elements (214, 215). 14. Lamella according to claim 1, characterized in that lamellae (206, 207) are tilted by magnetic pulse in that each individual lamella is rotated via swivel arms provided on the front side and in that said swivel arms are attracted by alternating mag¬ nets, or elements (219, 220) equipped as alternating magnets are attracted or repulsed from them. 15. Lamella according to claim 1, characterized in that lamellae are arranged horizontally and one upon the other and that the lamellae are installed and rotatably supported in the kind and size of a sun shade on the faςade or roof area. 16. Lamella according to claim 1, characterized in that the lamella is arranged as an individual lamella between high window area and window area and the lamella is composed of a plurality of elements and this lamella may have a width of up to more than 1 m. 17. Lamella according to claim 20, characterized in that below the lamella on the outside space side or inside space side a light source (92) is provided and the lamella is shaped and used as a reflector screen for artificial radiation on the lower side and for reflection of day light on the upper side. 18. Lamella according to claim 1, characterized in that the lamellae are orthogonally penetrated by further lamellae and by this penetration a raster element is formed. 19. Lamella according to claim 1, characterized in that sun radiation reflected from said first por¬ tion may be deflected essentially by one or two re¬ flections into radiation cross section E und that radiation reflected from said second portion may be deflected by one single reflection into the interior space at an angle > 0.

Inventors: KOESTER HELMUT, KOESTER, HELMUT
Applicants: KOESTER HELMUT, KOESTER, HELMUT
Application year: 1995
Main classification: E06B9
IPC codes: B21B1, E06B9