Solar collector-skylight assembly

A solar collector-skylight assembly having movable parabolic concentrators wherein, in one position the parabolic concentrators direct solar energy to a collector to heat fluid circulating therethrough to thereby provide a solar heater; and when the concentrators are moved to another position, the assembly functions as a skylight wherein the solar energy is allowed to pass through the collector, to thereby illuminate the interior of a building upon which the solar collector-skylight assembly is mounted.

BACKGROUND OF THE INVENTION 
Various solar collector - skylight assemblies have been proposed wherein 
the assembly is constructed and arranged to function not only as a solar 
heater, but also as a skylight to illuminate the interior of a building 
upon which the assembly is mounted. Examples of such assemblies are 
disclosed in U.S. Pat. Nos. 4,144,931 dated Mar. 20, 1979; and 4,219,008 
dated Aug. 26, 1980. These assemblies include shutters or vanes adapted 
for movement between a heat absorption position, wherein the assembly 
functions as a solar heater, to a second position allowing the sun rays to 
pass through the solar collector, whereby the assembly functions as a 
skylight. 
The solar collector - skylight assembly of the present invention is an 
improvement over the prior art solar collector - skylight assemblies, in 
that, in lieu of vanes or shutters, parabolic reflectors are employed for 
not only focusing the sun rays on the collector during the solar heater 
phase, but also for focusing the sun rays through the collector during the 
skylight phase of operation. By this construction and arrangement, the 
fluid flowing through the solar collector is more efficiently heated, and 
more sunlight is directed into the interior of the building than provided 
heretofore. 
The solar collector - skylight assembly of the present invention comprises 
essentially, a housing adapted to be mounted on the roof or wall of a 
building, the housing having a transparent top wall and a translucent 
bottom wall. A plurality of fluid circulating pipes, having heat absorbing 
plates secured thereto, are mounted within the housing, and a plurality of 
parabolic reflectors are slidably mounted within the housing in proximity 
to the fluid circulating pipes whereby the reflectors are shiftable from a 
heat absorbing position wherein the sun rays are focused on the pipe heat 
absorbing plates, to a skylight position wherein the sun's rays are 
focused into the interior of the building. A temperature responsive 
control mechanism is operatively connected to the reflectors for shifting 
the reflectors between full heat absorbing and skylight positions, and 
also to intermediate positions wherein simultaneous adjustment of the 
solar energy absorbed by the solar collector and amount of illumination in 
the building can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings and more particularly to FIGS. 1, 2 and 3 
thereof, the solar collector-skylight assembly 1 of the present invention 
comprises a rectangular housing formed by a pair of side channel members 2 
and 3, and end channel members 4 and 5. The top of the housing is provided 
with a clear, transparent low-iron glass cover 6 secured to the top of the 
channel members, and the bottom of the housing is covered with a 
translucent light-diffusing or non-diffusing glazing material 7, such as 
Rohm Haas-Twinwall material or glass. A plurality of transversely 
extending fluid circulating pipes 8 are mounted within the housing, the 
pipes being connected at one end to an air or water inlet manifold 9 and 
at the other end to an outlet manifold 10. 
Each pipe 8 has a dark coated heat absorbing plate 11 secured to the upper 
surface thereof in heat conducting relationship to the fluid flowing 
through the pipes 8, the remainder of each pipe having a suitable heat 
insulating material 12 such as fiberglass secured thereto. The outer 
surface of the insulation material is provided with a specular reflective 
or diffuse reflective material 13. 
While the heat absorbers shown in FIG. 2 employ flat absorber plates 11 
insulated on their back surfaces to prevent heat loss, the absorber shown 
in FIG. 4 can be employed wherein the pipe 8 and associated absorber plate 
11 are positioned within an evacuated transparent tube 14. 
In order to direct sun rays into the absorber plates 11 when the assembly 
of the present invention is being utilized as a solar heater, a parabolic 
reflector is provided for each plate. As will be seen in FIGS. 2 and 3, 
each reflector comprises a pair of parabolic segments 15 and 16, each 
segment 15 being integrally connected as at 17 to the next adjacent 
segment 16. The segments 15 and 16 are secured to a pair of longitudinally 
extending channels 18 forming a track engaged by rollers 19 secured to the 
housing channel members 4 and 5. By this construction and arrangement, 
when the segments 15 and 16 are in the solid line position, as shown in 
FIG. 2, the sun rays are focused on the absorber plate 11, to thereby heat 
the fluid flowing through the pipe 8. When the segments 15 and 16 are 
moved in the direction of the arrows shown in FIG. 2, to the dotted line 
position, the sun's rays are obstructed from the absorber plates 11 and 
focused through the bottom wall 7 of the housing into the interior of the 
building upon which the device is mounted, to thereby function as a 
skylight. 
The parabolic reflectors are designed to have an acceptance angle .alpha. 
shown in FIG. 2, selected sufficient to accommodate the solar altitude or 
zenith angle for the desired range of hours of operation in the particular 
locality in which the solar collector - skylight assembly is to be 
located. 
The mechanism for shifting or sliding the parabolic reflectors within the 
housing 1 is shown in FIGS. 5 and 6, wherein it will be seen that a 
tension spring 20 is connected between the end of each channel member 18 
and the adjacent side channel 2 of the housing. A pull cable 21 is 
connected to the opposite end of one of the channels 18 and extends around 
a pulley 22 and secured as at 23 to the free end of a rocker arm 24, the 
opposite end of the arm 24 being pivotally mounted as at 25 to a fixed 
support 26 within a housing 27. The rocker arm 24 is provided with a 
longitudinally extending slot 28 through which the free end of a pin 29 
extends, the opposite end of the pin being connected to a rotary disc 30 
connected to the drive shaft of a motor 31 (FIG. 8). By this construction 
and arrangement, when the motor 31 is energized, the disc 30 is caused to 
rotate in a counterclockwise direction to move the rocker arm 24 to the 
dotted line position shown in FIG. 6. As the rocker arm 24 moves, the 
cable 21 pulls the channel 18, thereby shifting the position of the 
parabolic reflectors to the position shown and described hereinabove in 
connection with FIG. 2, while extending the spring 20. Continued rotation 
of the disc 30 will cause the rocker arm 24 to pivot in the opposite 
direction, thereby slackening the cable 21, whereby the parabolic 
reflectors are shifted back to their original position by the restoring 
force of the tension spring 20. In order to limit the movement of the 
rocker arm 24 during the slackening of the cable 21, a tension spring 32 
is connected between the arm 24 and housing 27. While not shown, it will 
be understood that the pulley 22 and housing 27 are mounted on the side of 
the solar collector skylight housing 1. 
Another embodiment for moving the channel 18 and associated parabolic 
reflectors is shown in FIG. 7, wherein a rack 33 is secured to the bottom 
of channel 18 and meshes with a pinion 34 secured to a shaft 35 journalled 
in the housing end wall 4. A pulley 36 is also secured to the shaft 35, 
and the cable 21, having one end secured to the side wall of the housing, 
extends around the pulley and is connected to the rocker arm mechanism 
shown in FIG. 6. 
The circuit for controlling the operation of the solar collector - skylight 
assembly 1 is shown schematically in FIG. 8 wherein a control mechanism 37 
is electrically connected between a main switch 38 and a relay 39 to a 
pump 40 for circulating fluid to be heated through the pipes 8, the motor 
31, a dipole, double throw switch 41, and a manual limit switch 42. The 
control mechanism 37 is also connected to suitable sensors 43 which sense 
not only the temperature of the fluid flowing through the collector and 
the temperature in the interior of the building upon which the solar 
collector - skylight assembly is mounted, but also the light intensity 
within the building, whereby the information obtained by the control 
mechanism 37 is employed to control the pump 40 and motor 31, to thereby 
move the parabolic reflectors to full heat absorption position, to full 
light transmission position, or to a desired intermediate position. 
It is to be understood that the form of the invention herewith shown and 
described is to be taken as a preferred example of the same, and that 
various changes in the shape, size and arrangement of parts may be 
resorted to, without departing from the spirit of the invention or scope 
of the subjoined claims.