U.S. patent application number 09/207789 was filed with the patent office on 2002-01-24 for sun protection installation comprising sun protection lamellae having a toothed upper side.
Invention is credited to KOSTER, HELMUT.
Application Number | 20020008915 09/207789 |
Document ID | / |
Family ID | 26042299 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020008915 |
Kind Code |
A1 |
KOSTER, HELMUT |
January 24, 2002 |
SUN PROTECTION INSTALLATION COMPRISING SUN PROTECTION LAMELLAE
HAVING A TOOTHED UPPER SIDE
Abstract
The invention relates to sun protection installations comprising
reflective sun protection lamellae consisting of portions having a
toothed upper side disposed at least towards sun radiation influx
wherein the individual teeth are formed of at least two tooth
sides, and at least one first tooth side is, at least partly,
exposed to sun light irradiation. Sun light irradiation, at least
within the first lamella portions, can be retro-reflected by one
single reflection into the outer space by the first tooth side
having an angle of impact .alpha..sub.1. The tooth angle of impact
.alpha..sub.1 of the tooth sides exposed to the sun light are so
selected within the first lamella portions facing the irradiation
area that in case of parallel sun light larger angles of impact
.beta. of the sun radiation are obtained so that inciding sun light
may be reflected back, by one single reflection, to the outer
space. Second or further lamella portions are so arranged at an
angle .alpha..sub.1 that small angles of impact .beta. on the tooth
sides facing the sun will result but the sun light can be reflected
into the interior space. In any case, tooth angles of impact
.alpha..sub.1 within the lamellae differ from each other.
Inventors: |
KOSTER, HELMUT; (FRANKFURT,
DE) |
Correspondence
Address: |
KODA & ANDROLIA
2029 CENTURY PARK EAST
SUITE 3850
LOS ANGELES
CA
90067-3024
US
|
Family ID: |
26042299 |
Appl. No.: |
09/207789 |
Filed: |
December 9, 1998 |
Current U.S.
Class: |
359/601 |
Current CPC
Class: |
E06B 9/386 20130101 |
Class at
Publication: |
359/601 |
International
Class: |
G02B 027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 1997 |
DE |
DE19754575.0. |
Claims
1. Sun protection installations comprising reflective sun
protection lamellae (10, 11, 12, 35, 36, 37, 38, 39, 40, 42, 63,
64, 84, 85) a) including portions having a tooth upper side
disposed at least towards sun irradiation influx, wherein b)
individual teeth (13, 14, 15, 16, 66, 67, 68, 69, 70, 71, 72, 77,
78, 79, 80, 81) are formed of an essentially sun-irradiated tooth
side (17, 18, 19, 20) and an essentially shaded tooth side (21, 22,
23) and c) at least one sun-irradiated tooth side (17, 18, 93, 94)
is arranged, in normal position, at an angle .alpha..sub.1 to the
sun and is at least partially subjected to direct sun light
irradiation (25, 26), and d) tooth angles .alpha..sub.1 of
sun-irradiated tooth sides (17, 18) are selected steeper within the
first lamella portions (60, 75, 86, 91, 95) and are selected as
more flat within further lamella portions (61, 76, 87, 88, 93, 96),
and e) sun light irradiation (22, 23), at least within the first
lamella portions (60, 75, 86, 91, 95), can be retro-reflected from
the sun-irradiated tooth side (17, 18) by one single reflection to
the outer space:
2. Sun protection installations according to claim 1, characterised
in that the angles of impact .alpha..sub.1 of the sun-irradiated
tooth sides (17, 18) essentially increase with increasing distance
from the irradiation side.
3. Sun protection installations according to claim 1, characterised
in that at least within said first lamella portions (60, 76, 86,
91, 95), the tooth angles of impact .alpha..sub.2 of said tooth
portions in the shade (22, 19, 21) decrease starting from the
irradiation cross section and are arranged at an angle of
.alpha..sub.2<90.degree.>30.degree.- .
4. Sun protection installations according to claim 1, characterised
in that the first portions (91, 95) or further consist of at least
one tooth.
5. Sun protection installations according to claim 1, characterised
in that in the normal position said tooth angles of impact
.alpha..sub.1 at least for one of the first teeth (17, 18) of said
first portions (60, 75, 86, 91, 95) are formed >25.degree. and
that the angles of impact .beta. on further lamella portions (61,
76, 87, 88, 92, 93, 96) are so formed that the rays penetrating
into the interior space may be deflected at an angle >0 to the
horizontal H by one single reflection.
6. Sun protection installations according to claim 1, characterised
in that lamellae (84, 86) consist of three, or more, portions (91,
92, 93, 86, 87, 88) wherein at least the first portion (86, 91) is
formed tooth-shaped for retro-reflection of the inciding sun
irradiation, at least one further portion (87, 92) is formed
area-shaped and for light deflection into the interior space and at
least the third portion (88, 93) disposed towards the interior
space is formed tooth-shaped and for steep light deflection to the
interior space ceiling.
7. Sun protection installations according to claim 1, characterised
in that at least one portion (93) disposed nearest to the interior
space is provided on the underside, at least partly, as a light
reflector for artificial light and has an angle of inclination
.sigma. of from 10.degree.-40.degree. and that at least underneath
of parts of said sun protection installation in the interior space
punctiform or strip-shaped artificial light sources are arranged
and light indirectly emanating therefrom and inciding from below
into said sun protection installation is reflected, according to
DIN 5035, essentially at an angle .gamma., at least by parts of
portion (93) disposed nearest to the interior space, and glare
limitation according to grade A. 1, 2, of DIN 5035, part 2, part 3,
and part 4 is observed.
8. Sun protection installations according to claim 1, characterised
in that lamellae of different tooth formation are arranged, at
least within the second or further portions (92 and 93, 95 and 96),
one under the other, wherein lamellae in the upper window area
(FIG. 11), at a minimum height of approximately 1.70 m headroom,
have at least an angle of inclination of .+-.5.degree. relative to
the horizontal and by which light radiation can be deflected at an
angle .sigma.<45.degree. relative to the horizontal into the
interior space, and that in the lower window area lamellae are
arranged with portions 96 oriented towards the interior space which
include exclusively receptor faces at an angle of inclination
>25.degree. relative to the horizontal and that sun light
radiation inciding on it is deflected at an angle of
.sigma.>45.degree. to the ceiling.
9. Sun protection installations according to claim 1, characterised
in that the lamellae include teeth on the underside thereof,
wherein the long portion (50 to 53) of the teeth faces day light
irradiation and the short side of the teeth (54 to 56) faces the
interior space.
10. Sun protection installations according to claim 1,
characterised in that said first portion (60, 75, 86, 91, 95) of
the teeth exposed to sun irradiation influx has a width b of <3
mm and the thickness d of the sun protection lamella is <3
mm.
11. Sun protection installations according to claim 1,
characterised in that said sun protection lamellae are orthogonally
penetrated by further toothed lamellae or lamellae having a smooth
surface and form a raster element.
12. Sun protection installations according to claim 1,
characterised in that said sun protection lamellae are covered, at
least on the upper side, by a light permeable layer or are cast in
a light permeable plastic material.
13. Sun protection installations according to claim 8,
characterised in that teeth of identical and/or different sun
protection lamellae (FIG. 11 and FIG. 12) form V-shaped structures
within one curtain (FIG. 13).
14. Sun protection installations according to claim 1,
characterised in that, disposed towards the outer space in front of
said first portions (60, 75, 86, 91, 95), a receptor reflector is
arranged at an angle .alpha..sub.2 of >0.degree. and by which
zenith radiation can be reflected into the interior space.
15. Production of sun protection installations according to claim
1, characterised in that said sun protection lamellae are produced
from transparent plastic material having a smooth upper surface and
the reverse side is tooth-shaped and made reflective by metal
vapour deposition or foil covering.
16. Production of sun protection installations according to claim
1, characterised in that said sun protection lamellae are produced
as individual lamellae or as plate-shaped lamella structure by
thermal softening of a plane plastic material plate and said plates
are inserted by vacuum process and/or by a mould stamp into a
counter mould and solidified in profile shape, wherein said plates
may be covered prior to heat deformation with reflective foils and
by said heat deformation may be solidly unified with said
plates.
17. Production of sun protection installations according to claim
1, characterised in that said lamellae are covered by a plastic
film in that they are inserted into a plastic hose and the film is
shrunk on by a thermal process.
Description
[0001] The invention relates to a sun protection installation in
accordance with claim 1.
[0002] From DE 42 39 003 A1, sun protection lamellae have been
known which have a toothed underside and a stepped upper side. The
step-shaped upper side is arranged like a staircase so that on the
irradiation side of the lamella the sun light incides in principle
on the treadboard and the riser, i.e. the whole first portion of
the lamella surface is exposed to sun irradiation. This is also the
case if the lamella is arched as a whole or sun irradiation
penetrates at a high, or flat, respectively, angle of incidence on
the lamella.
[0003] In DE 44 42 870 A1, sun protection lamellae have been shown
comprising two portions, a first step-shaped portion and a second
portion. The step-shaped portion is so shaped that light is
primarily reflected back into the outer space by two reflections on
the upper side of a lamella in that the light is reflected from the
treadboard onto the riser, or from the riser onto the treadboard,
respectively. Treadboard and riser are exposed to direct sun
irradiation.
[0004] The disadvantage of this design is an undesirable heating up
at the lamella and hence of the interior space since each
reflection process is accompanied by a certain absorption.
Particularly in the case of interior venetian blinds comprising
lamellae, such multiple reflection should be avoided, because it
leads to unnecessary heating up and thermal stress of the interior
space.
[0005] A further problem consists in that this lamella cannot be
compacted to vertically suspended lamella packages. While the
lamella may be laid one into the other, they slide to the side
because of the essentially vertically arranged risers. The
disadvantage is that these lamella packages cannot be slid into a
venetian-blind chute.
[0006] A further disadvantage is that because of the inciding sun,
even in case of geometrically correct design of the light
deflection on the riser, a glare effect occurs when looking on the
venetian blind lamella from above, as is for instance the case when
standing behind a lamella curtain in the interior space. Small
unevennesses in the reflective surface namely lead to light
scattering or an undefined light deflection to the interior space
which is experienced as a glare.
[0007] It is therefore the aim of the present invention to develop
a sun protection installation comprising reflective lamellae having
a step-shaped surface which can reflect sun irradiation, at least
for high angles of incidence, by one single reflection again into
the outer space while in case of flat angles of incidence,
illumination of the space depth is possible as well. A further aim
is to provide a reflective lamella which does not lead to glare
effects in the interior nor in the outer space.
[0008] This problem is solved in accordance with claim 1.
[0009] The advantage of the invention lies in the optical heat
regulation by the formation according to he invention of the teeth
of the first portions in favour of thermal comfort and in the
formation according to the invention of the second portions in
favour of visual comfort in the interior space. The teeth include a
sun-irradiated side and a shaded side The high overheating summer
sun incides on the sun-irradiated side and, apart from a few
exceptions, is reflected therefrom by one single reflection into
the outer space. To this end, the tooth angles .alpha..sub.1 within
the first portions should be shaped preferably >30.degree.
increasing relative to the second portion. For the critical high
positions of the sun, it can thereby be avoided that the light
irradiation on the upper side of a lamella is subjected to double
reflection. More flatly inciding sun is also subjected, primarily
in winter, to a second or further reflections, however on the
underside of the upper lamella. By a defined angle of impact
.alpha..sub.1 of the irradiated tooth sides relative to the
horizontal H, the process or the timing of the deflection of the
sun light, i.e. the optical behaviour of the lamella, can exactly
be defined.
[0010] A further advantage of the invention is to be seen in the
freedom from glare of the sun protection lamella. In accordance
with the invention, the tooth side facing the sun light takes a
deflecting function, the tooth side facing the interior space takes
a dimming function. From the interior space, at least in the first
portion, it is namely not the irradiated side but rather the shaded
side of the teeth which is visible. The latter becomes darker and
is glare-free since it is irradiated by sun light only
immaterially, if at all. With a view to this property, it is
possible to provide the lamella either with a reflective surface or
with a white or diffuse surface while no glare effect occurs when
looking at the lamella. Glare in the outer space, for instance in
an opposite building, is avoided in particular because of the
different angles of inclination .alpha..sub.1 and/or by an arched
tooth shape of the sun-irradiated upper sides of the teeth since
light deflection occurs diffusely. Second and/or further portions,
because of the more flat angle of impact .alpha..sub.1 of the
sun-irradiated tooth sides, take charge of a light deflection
function to the interior space. Preferably, the angles
.alpha..sub.1 are selected .alpha..sub.1>0 and more flat than in
the first portion. One exception from the rule may be the starting
point of the second portion following the first portion. It may be
inclined towards the interior space so that the light is deflected
in a very flat way to the interior space.
[0011] The sun protection lamella is also arranged as a venetian
blind behind a glazing in the interior. With a view to metal oxide
coverings, particularly sun protection and heat protection glazings
show an increased reflection of the incident light radiation. As a
result of retro-reflection of the first portion, reflections of the
retro-reflected light radiation on the inner side of the glazings
occur. These reflection provoke a glare in the interior space since
the sun light is reflected from the glass into the observer's eye.
By the different angles of impact .alpha..sub.1 of the individual
teeth relative to the horizontal in the first portion of the
lamellae, this glare is considerably reduced since retro-reflection
is scattered and is reflected, with increasing distance from the
inner facade, over a larger field of vision. A major part of the
reflected retro-reflection is also absorbed by the scattering on
the undersides of the upper lamellae. Thereby, too, the glare into
the observer's eye is reduced (FIG. 4).
[0012] The advantage of the toothed surfaces is particularly to be
seen in that the lamella leaf may be arranged in a horizontal
position so that good transparency and diffuse light entrance
between the lamellae arranged in opened position is safeguarded
while, nevertheless, direct sun is deflected out. Would one try to
obtain the same optical effect of light deflection by means of a
commercially available venetian blind, the lamellae would at least
have to be positioned at an angle .alpha..sub.1 resulting in that
the venetian blind would become intransparent and diffuse light
entrance into the interior would be prevented. This common lamella
position is for instance shown by dash-dotted line 32 of FIG. 1.
The lamella according to the invention is suited for stationarily
fixed sun protection installations, for instance also in the shape
of a single lamella. In case of rotatable suspension of the sun
protection lamellae, for instance in the shape of a venetian blind,
the lamella leaf may, in case of high-inciding sun in summer, even
be bent inwardly (FIG. 5) so that out-reflection of direct
radiation incidence and shading of the interior space occurs, a
particularly high permeability for diffuse sun radiation and an
even improved transparency of the lamella curtain, however, is
safeguarded. This is desirable in order not to darken the interior
in spite of the shading. In this way, the lamella may also be
continued towards the interior space with a plurality of portions
which effect aimed light incidence either into the depth of the
interior space or to the interior space ceiling.
[0013] Under first portion, one should understand in principle that
first portion having a toothed upper side by which in the normal
position sun incidence can be back-reflected to the sky by one
single reflection. Under further portions, one should understand
those lamella portions by which light radiation can be reflected,
preferably by one single, or a plurality of, reflections, into the
interior space. Under normal position, one should understand a
starting angular position of the lamellae for which they are
calculated. When pivoting the lamella into a different position,
light guiding effects and angular data different from those of the
description for the normal position may occur. Usually, the normal
position refers to a lamella angular position of from 0-30.degree.
to the sun whereby the angular position is determined by a centre
line through the lamella relative to the horizontal. However,
different lamella position angles are possible as well.
[0014] Further advantages will be explained based on the drawings
of advantageous embodiment variants.
[0015] FIG. 1 shows a perspective section through three sun
protection lamellae in the normal position for a vertical
facade.
[0016] FIGS. 2, 3, 4 and 5 show the optical behaviour of lamellae,
two each arranged one above the other, for different sun angles of
incidence and lamella positions.
[0017] FIG. 6 shows the toothed sun protection lamellae in normal
position in an inclined roof surface as a raster element.
[0018] FIG. 7 shows a cross section through a lamella having a
staggered tooth arrangement on the lamella upper and underside.
[0019] FIG. 8 shows the cross section through a concavely arched
lamella pair having a second arched lamella portion without
teeth.
[0020] FIG. 9 shows a lamella convexly shaped in its first portion
and concavely shaped in its second portion.
[0021] FIG. 10 shows a lamella pair having three portions of convex
shape.
[0022] FIGS. 11/12 show a lamella having parallel upper and
undersides.
[0023] FIG. 13 shows a lamella package consisting of lamellae for
the upper window area and the lower window area.
[0024] FIG. 14 shows the cross section through a window zone with
the light-technological requirements for light deflection of the
daylight.
[0025] FIG. 15 shows the deflection angle of the day light system
for the indirect artificial light.
[0026] FIG. 1 shows lamellae 10, 11, 12 each having four teeth 13,
14, 15 and 16. The teeth have a side 17, 18, 19, 20 facing
radiation incidence and a teeth side 21, 22, 23, 24 on the shade
side. Tooth side 17 to 20 facing the sun light is arranged at an
angle .alpha..sub.1 and tooth side 21 to 24 on the shade side at an
angle .alpha..sub.2. For the determination of angles .alpha..sub.1
and .alpha..sub.2, it is assumed that the lamella is in the normal
position, in the particular case of FIG. 1, in the horizontal
position. For this lamella position, it is assumed that
.alpha..sub.1<.alpha..sub.2, at least within the first portion.
Following this rule, then it is possible that the high sun
radiation can substantially be reflected to the sky by one single
reflection. Of advantage is a shape of the lamella angles
.alpha..sub.1 of about 30.degree. and larger and .alpha..sub.2 of
about 60.degree.. Within the second portion, .alpha..sub.2 could
also take an angular inclination of <0.degree.. As a
construction specification, it should be considered valid that
.alpha..sub.1 increases from the incident area to the second
portion and that .alpha..sub.2 decreases from the incident area to
the second portion.
[0027] Following now the radiation paths, it turns out that
high-inciding summer sun, represented by ray path 25, is reflected
back by one single reflection into the outer space. If the angle of
incidence .gamma. is greater than the angle of inclination
.alpha..sub.2 of the portion in the shade, then it turns out for a
few radiation portions on ray path 26 that a second reflection onto
the angled portion occurs and the light is deflected onto the
underside of the upper lamella. It is only from the underside of
the upper lamella that the light is deflected to the outside. Since
this concerns only a very small portion of the whole radiation
inciding onto the lamella, the basically explained advantages will
not be impaired by the multiple reflection at a small portion.
Incidentally, this multiple reflection could be avoided in that sun
protection lamellae 10, 11 and 12 each are pivoted from their
normal position about their horizontal axis 27, 28, 29 to the
inside until there is no longer any impact on saw tooth side 21 to
24. As a rule for angle .alpha..sub.2 it holds valid that it be
selected approximately corresponding to the highest direct sun
incidence to be expected on the corresponding tooth 13 to 16 and on
the 50th latitude about .alpha..sub.2=67.degree. decreasing towards
the second portion at the south facade.
[0028] The optical behaviour at low angles of incidence is shown on
lamella 12. A sun ray 30, 31 is reflected from the sunny side of
teeth 17 to 20, depending on the angle of impact, either to the
ceiling of the interior space or to the underside of upper lamella
11. Should this reaction be undesired, the lamellae can be pivoted
from their normal position about their horizontal axes 27 to 29 to
the outside so that a steeper angle of impact .beta. will result on
sun light-facing tooth sides 19, 20 of the second lamella portion.
By a steeper angle of impact it can be reached that the light can
also be reflected by one single reflection into the outer
space.
[0029] Particularly tooth sides 17 to 20 exposed to light incidence
may show a convex or concave arching in order to obtain better
scattering and hence better freedom from glare in case of
retro-reflection to the outer space. The dash-lined concave shape
17 is of advantage. The concave arching avoids that the sun light
triggers an extreme glare as parallel light, for instance on a
facade on the opposite side. Because of the arching of tooth sides
17-20, the glare effect is considerably smoothed by scattering of
the retro-reflection. As angle of incidence .alpha..sub.1, one
should assume, for a concave shape 17, a chord through the starting
and the end point. In this connection, inner and outer edge
roundings should be taken into consideration.
[0030] The upper sides of lamellae 10, 11, 12 in FIG. 1 are arched,
at least partly, so that for the first lamella portion a steeper
angle of impact .alpha..sub.1 of tooth sides 17, 18 facing the sun
and for the second portion a more flat angle of impact
.alpha..sub.1 of tooth sides 19, 20 facing the sun is obtained. By
arching the lamellae, portions 17 to 20 form segments of a curve
path of the arch formed for instance about a radius r of the
lamella. By the convex arching, larger angles of impact .beta. of
the sun onto first tooth sides 17, 18 in the radiation area, and
more flat angles of impact .beta. within the second lamella portion
on tooth sides 19, 20 are obtained. The advantageous effect
consists in that the sun radiation in the area of the first lamella
portion can be reflected back to the outer space because of the
larger angle of impact .beta. and the light radiation inciding onto
the second portion can be deflected, with a view to the smaller
angle of impact .beta., for improved space depth illumination into
the depth of the space and to the interior space ceiling. The
unambiguous surface contour of the teeth consisting of light
deflection tooth parts 17, 18, light guide-in tooth parts 19, 20,
and light dimming tooth parts 21, 22, 23 also permits that the
surface may be provided in white or reflector-mat while no
considerable scattering losses are experienced.
[0031] FIGS. 2, 3 and 4 show the optical behaviour of arched
lamella pairs 35 and 36, 37 and 38, 39 and 40 at different angles
of incidence of the sun. FIGS. 2 and 3 show the radiation path
between the lamellae at an angle of incidence of the sun of
20.degree. and 30.degree., respectively. It turns out that the
radiation reflected from the lamella surfaces is reflected via one,
or a plurality of, reflections either back into the outer space or
very steeply upward into the interior space.
[0032] FIG. 4 shows the optical behaviour at an angle of incidence
of 60.degree.. The high overheating sun is reflected by one single
reflection back into the outer space. Because of the arching of the
toothed lamella, the irradiation sides of the individual teeth (17,
18, 19, 20 in FIG. 1) follow a curve path like individual chords.
The advantage of the different angles of impact .alpha..sub.1 of
the individual teeth is the diffuse, or radial, correspondingly,
radiation of the retro-reflection so that glare in the outer space
is avoided.
[0033] The drawing shows a glass pane 43 on the surface of which
the retro-reflected radiation is reflected. This reflection
constitutes the source of glare when looking from the interior
through the window to the outside. By the arching of the lamella
and the different angles of impact .alpha..sub.1 of the individual
teeth, respectively, this glare is, however, considerably reduced
because scattering will occur. From the dashed radiation path one
can see that by the scattering a major part of the radiation is
reflected onto the underside of the upper lamella 40. Following the
retro-reflection in FIGS. 2, 3 and 5, one will recognise that the
retro-reflections are extremely diffuse because of the lamella
arching and partly occur onto the street level and/or into the sky.
The arching of the toothed lamella and the different angles of
impact .alpha..sub.1 of the individual teeth, respectively,
constitute a method for glare restriction when looking at the
system from a particular position, for instance the street level or
from the depth of the interior space
[0034] FIG. 5 shows the lamellae in a position pivoted towards the
interior space at a radiation entrance angle of 60.degree.. In this
position, a particular advantage of the lamella becomes evident.
While part of the overheating sun radiation is reflected on first
portion 41 into the outer space, a further part inciding onto
portion 42 situated towards the interior space is deflected onto
the interior space ceiling and into the depth of the interior
space.
[0035] FIG. 6 shows the arrangement of the sun protection lamellae
on an inclined roof surface. The advantages correspond to those
described in connection with FIG. 1. By the saw tooth-like shape,
an optical narrowing for the light entrance into the interior space
is obtained while no concentration cross section has to be formed
between the lamellae. The good transparency between the narrow
lamellae and a wide opening between the lamellae for the diffuse
light are therefore retained. In spite of the large opening, the
light entrance for the direct, glaring and overheating sun
radiation into the interior space is reduced.
[0036] The sun protection lamellae according to the invention can
also be shaped a raster element in that it is preferably
orthogonally penetrated, as shown in FIG. 6, by further lamellae
49. The orthogonally arranged lamellae, too, may be provided on one
or on both sides with a saw tooth profile. Such a raster element
may preferably be installed in insulating glass and arranged on a
roof surface so that the resulting light chutes open either to the
south for the generation of solar energy or to the north for
deflection of direct sun and are permeable only for the diffuse
zenith and northern light radiation. The raster element may also be
installed in the vertical facade. The horizontally arranged
lamellae may take any desired inclination relative to the facade
level. The orthogonally penetrating lamellae are preferably
arranged perpendicularly to the facade level.
[0037] For better deflection of side light, the orthogonal lamellae
49 may also be pivoted about their longitudinal axis from the
surface normal with an angular inclination relative to the roof or
facade level. It might for instance be necessary to pivot the
orthogonal lamellae 49 about their longitudinal axis in order to
deflect, for instance on a facade facing west, the sun from south
west. In this case, the lamellae are pivoted, for instance about
approximately 45.degree. with one flat side towards south west so
that the south west sun cannot penetrate and from the interior
space the view is open to north west direction. Similar design
considerations may also be realised for roof surfaces with the aim
of deflecting the direct sun from south east through south west and
to make the raster element permeable for northern light only.
[0038] FIG. 7 shows an advantageous embodiment of the underside.
Contrary to the figures described, the underside shows an opposed
arrangement of the teeth. The arrangement of a plurality of sun
protection lamellae one upon the other results again in an optical
narrowing for the light entrance from the outside while the
lamellae need not be suspended in narrowed arrangement or have to
form a concentration cross section. Light radiation 53 reflected
from the upper side of one lamella onto the underside of the upper
lamella may be guided by two reflections back into the radiation
direction while no multiple reflection between the lamella as in
FIGS. 2, 3 and 5 and hence undesired heating up of the lamellae
occurs since, at each reflection, a certain part of the radiation
is absorbed. A further advantage is the glare freedom in the
interior. Looking at the lamella from the interior space, one may
have in spite of the reflective surface a dark glare-free view of
the underside of the lamella since the tooth-shaped portions 54,
55, 56 are disposed in the shadow of the tooth portions 50, 51, 52,
or the day light, respectively.
[0039] FIG. 8 shows a lamella pair wherein the first portion of
lamellae 60 is toothed and the second portion 61 is concavely
shaped. Lamellae 63, 64 are completely concave-shaped. The sides of
teeth 66-72 radiated by direct sun follow an angular position
defined by segments on a parabola curve 73. Instead of a concave
curve, a convex curve is possible as well. The parabola has its
focus in the starting point of the first portion in the irradiation
area of the upper lamella, and the inclination of the parabola axis
corresponds to .delta..
[0040] As a construction definition, the following should be
considered. An angle of incidence .gamma., in the present case
.gamma.=30.degree., is defined starting from which complete
deflection of the incident, parallel sun light irradiation shall
occur by only one single reflection. Sun irradiation inciding at an
angle <30.degree. is retro-reflected, in FIG. 8, by at least 2
reflections from the upper side of a lower lamella on the underside
of an upper lamella into the outer space. As from an angle of
irradiation of .gamma..gtoreq.30.degree., the light is reflected
back into the outer space by one single reflection. Irradiation
inciding onto the second portion 61 is guided to the interior
space.
[0041] FIG. 9 shows a lamella formed in S-shape consisting of two
portions, 75 and 76. The first portion 75 comprises teeth 77-81
and, contrary to the lamella in FIG. 8, is convexly arched. The
angular position of the irradiation sides of teeth 77-81 follows
segments at a parabola 82. The tooth sides in the shade are
disposed so steeply that, if possible, they are subjected to no or
only little direct irradiation. This may for instance be obtained
in that the shaded tooth sides are designed as central projection
of edge 83 of the upper lamella.
[0042] Second portion 76 is shaped as a segmented concave
mirror.
[0043] FIG. 10 shows a further lamella pair 84, 85 wherein the
first portion 86 serves for light deflection, the second and third
portion, 87 and 88, serves for the light influx into the interior
space. While by the second portion 87 the light is flooded in a
very flat manner into the interior space, the light is deflected in
a very steep manner to the ceiling by the toothed third portion 88.
The lamellae are all provided in a convex shape. For the first
portion, a further design method was applied: The tooth sides
subjected to the sun light align into points F.sub.1 and F.sub.2.
In the case of projection of the tooth upper sides on a curve 89,
90, a discontinuous curve path is obtained. This leads to an
improved scattering of the retro-reflected radiation. The third
portion 88, too, is designed in that the individual irradiated
tooth sides align into a point F.sub.3. The angle of impact
.alpha..sub.1 increases within first portion 86 essentially towards
the second portion.
[0044] FIG. 11 again shows a further advantageous variant of the
lamella according to the invention, comprising three portion 91, 92
and 93. Analogously to FIG. 10, the first portion 91 is
tooth-shaped, the second portion 92 is convexly shaped for flat
light influx in the space depth and portion 93 again is
tooth-shaped for steep light influx into the interior space.
Portion 91 consists of only two teeth having irradiation sides 92
and 94 which are concave-shaped as circular arcs. The arrangement
and the shaping of the circular arcs is made according to the rules
explained in FIGS. 8 and 9 for the design of circular or parabola
arcs 73, 82, or in FIG. 10, of circular arcs 89 and 90,
respectively.
[0045] FIG. 12 shows a lamella analogously to the design in FIG. 11
having, however, an enlarged first portion 95 and a portion 96
analogously to portion 93 of FIG. 11. The lamella from FIG. 11 is
particularly suited for the upper area of a window since the flat
light influx leads via the second portion to a very good
illumination of the space depth. The lamella of FIG. 112 is better
suited for the lower window area. The light flooding into the
interior space via second portion 96 enters in such a steep manner
that the user of the interior space will not experience any glare.
In place of portion 92 from FIG. 11, the first portion in FIG. 12
was elongated and a third tooth for light deflection into the outer
space was provided. A lamella without second portion 96, i.e.
without light guidance into the interior space, constitutes an
object of the invention as well.
[0046] In FIG. 13, the lamellae from FIGS. 11 and 12 are shown as
venetian blind in a stacked state. The particular feature of this
design is seen in that the lamellae for the upper window area 120
and the lamellae for the lower window area 121 may be laid into
each other. A further particularity consists in that, because of
the special shape of the individual teeth, the lamellae intermesh
with each other so that the venetian blind in the stacked-together
state constitutes a perpendicularly suspended lamella package. This
is obtained by at least one V-shaped formation 122, in the present
case of first portion 91 or 95 from FIGS. 11 and 12,
respectively.
[0047] FIG. 14 shows the cross section through a window zone with
upper window area 101 and lower window area 100. By light arrows
102 and 103, the space illumination by the upper window lamella as
a result of the reflection on portion 92 and 95 from FIG. 11 is
shown, by light arrows 104 and 105 the light exit of the radiation
reflected on portion 96 to the interior space of the lamellae
according to FIG. 12 is shown. The portion(s) disposed towards the
interior space serve for visual comfort. By carefully designing the
lamella contours, it can be safeguarded that the lamellae are
deglared from the interior space, i.e. that light exit occurs, in a
controlled way, to the ceiling and into the depth of the space and
no glaring light radiation will enter the users' eyes 106, 107
through the undersides of the upper lamella since the design
according to the invention prevents that light radiation incides
onto the underside of the upper lamella.
[0048] FIG. 15 shows a particularity of the lamellae from FIG. 11
and FIG. 12. The lamella curtain may for instance be irradiated
indirectly from below by artificial light radiation from the breast
height or from the window head height in that, at breast height or
window head height in parallel to the window level, a punctiform or
a linear light source 108 is arranged which radiates the light, at
least partly, indirectly into the lamellae. Indirect light
radiation incides essentially on the underside of the last portion
93 from FIG. 11 and 96 from FIG. 12, respectively, directed towards
the interior space. Not only are these portions shaped so that they
guide the daylight at the upper side into the interior space but
also the artificial light at the underside, free from glare, to the
work level, as in accordance with the regulations of DIN 5035. This
is at least valid for lamellae at a larger distance from the light
source. To this end, the last portion 93, 96 from FIGS. 11 and 12
is arranged at an angle of inclination of approximately
15-40.degree.. Tangent 111 for instance has at its end point 110 an
angle of inclination of 34.degree. for a shadow line 112 of
25.degree. through the starting point 113 of an upper lamella.
Hereby, it is reached that the artificial light in the area of
light radiation 120, 121 is deflected to working level 126.
[0049] A further embodiment variant is shown in dashed lines in
FIG. 11 and provides that, in front of first portion 91 towards the
outer space, a portion 97 is provided at an angle .alpha..sub.2 of
approximately 40.degree. through which zenith radiation can be
deflected in a flat manner between the lamellae into the interior
space. Very flat sun radiation at an angle of impact
.gamma.<.alpha..sub.2 is deflected from the underside to the
upper side of the lower lamella.
[0050] In FIG. 14, the light radiation penetrating from outside on
the facade is shown, wherein zenith radiation 123 and more flatly
occurring light 124 can be deflected into the interior space and
steeper summer sun 125 is reflected back at the first portion into
the outer space.
[0051] The lamellae may be manufactured by the aluminum extrusion
moulding method, the rolling form process or the roller process.
Lamellae produced by the roller process are for instance stamped
from a flat sheet by means of a calendar roll wherein, in a second
step, a stamped flat sheet is cut up to small lamellae. In a third
operation step, the lamellae are shaped to a concave or convex form
by a rolling form process. It is also possible to process band
material cut to lamella width as a coil and to feed the belts to a
rolling mill through which they are shaped, in one single working
step, to the concave or convex form, and at the same time the teeth
are embossed.
[0052] The lamellae may have any dimension. Sun protection lamellae
arranged behind the facade are for instance 20 to 100 mm wide while
lamellae of the kind of a venetian blind which are inserted into
the intermediate space of an insulating glass hardly exceed a
lamella width of from 10 to 25 mm. Lamella provided on the outside,
for instance as light guiding sword at window head height, may have
a width up to two meters or may extend, for instance as a two-part
element from the outer space in front of the facade to the interior
space behind the facade. It is of particular advantage to make the
saw tooth like shape of the surface extremely small so that edge
lengths for the saw teeth of b<1 mm up to even b<0.1 mm are
obtained. The thickness d of such a lamella would be only 0.3 to
2.0 mm in cross section. Teeth having a lateral length of <0.5
mm are hardly visible by the human eye and have the advantage that
in the valleys between the teeth no dust can assemble.
[0053] When used in the outer area, such thin lamella may also be
embedded as a non-arched element between two plane panes or may at
least be covered by a transparent or light-scattering pane. It is
also possible to cast, or co-extrude, respectively, the lamellae in
a transparent plastic material. An advantageous variant is also
seen in that at least the toothed side is coated with a transparent
film. The air spaces in the area of the teeth may be filled with a
transparent adhesive or a cast material, for instance of
polyurethane or acrylic. The lamellae may also be cast, extruded or
injected of a highly transparent plastic material and made
reflective on the reverse side, for instance by metallizing.
[0054] By the casting-in, the radiation path of retro-reflection
changes because of prismatic effects. The basic laws of light
deflection and shading, however, remain valid. It should, however,
be noted as an advantage that by the additional prismatic effects a
still better scattering of the radiation is experienced and the
lamella gains additional stiffness.
[0055] The calendar-processed thin metal plates may be applied, for
instance by gluing, onto a carrier lamella whereby the thickness d
may become substantially bigger. A lamella according to FIG. 7 may
be produced by gluing the reverse sides of 2 counter-twisted
sheets.
[0056] Further production methods for the lamellae include aluminum
extrusion moulding and polishing, plastic material extrusion
including reflective film covering or thermal methods such as deep
drawing or pressing of a plastified film in a tool wherein, in a
step before or after the process, the film material is coated with
a reflective foil. The lamella undersides may be coloured or
white.
* * * * *