Automatic solar collector system

An automatic solar collector system useful for heating and storing a heating fluid such as, for example, water. The automatic solar collector system of this invention is characterized by its construction including a photo cell-actuated hydraulic cylinder whereby the collector panel may be positioned at an angle to focus the sun's rays onto the fluid conduit disposed within the collector panel. Overall operation of the automatic solar collector system of this invention is regulated by a clock timer, and the entire system is essentially self-contained so that it may easily be moved from one location to another, or put in parts to be attached to a home or a building with the tank and controls below the roof.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The automatic solar collector system of this invention is primarily 
intended for collecting solar energy in a heat transfer fluid and for 
storing the heated fluid for subsequent use. While not limited thereto, a 
primary utility for the automatic solar collector system of this invention 
is the use of the sun's rays for heating water. The collector system of 
this invention is characterized by its substantially self-contained 
construction and its inclusion of photo cell-actuated means for 
positioning the collector panel so that the sun's rays are focused through 
a plurality of lenses onto the fluid conduit through which the transfer 
fluid is caused to circulate. 
2. Description of the Prior Art 
Numerous prior art devices are, of course, well known for the purpose of 
utilizing solar energy for the purpose of transferring and collecting heat 
in a heat exchange fluid. Not surprisingly, the vast majority of such 
devices are often disclosed for use in providing hot water for both 
domestic and commercial purposes. In fact, patent literature disclosing 
various constructions for solar water heaters date at least from the late 
nineteenth century. 
Almost without exception, today's solar collectors intended for home and 
light commerical uses are designed for relatively permanent installation, 
usually on the roof of the structure to which the water will be supplied. 
Furthermore, virtually all solar water heaters comprise a panel for 
absorbing the sun's heat energy, for transferring that heat energy to a 
fluid, and for storing that fluid for subsequent end use. Recent 
engineering advances in the construction of solar collector panels have 
introduced the use of means for concentrating, magnifying, or focusing the 
sun's heat energy onto the heat transfer fluid. For example, U.S. Pat. No. 
4,071,016 discloses the use of a panel of triangular cross section having 
a series of magnifying glasses arranged to focus the sun on a heat 
absorbing material over which a stream of air is blown in order to absorb 
the heat from the heat absorbing material into the air. Yet another means 
for concentrating the sun's energy is disclosed in my prior U.S. Pat. No. 
4,324,227. According to the disclosure of that patent, a plurality of 
lenses are incorporated into the cover of the collector panel for focusing 
the sun's heat energy upon fluid flowing through the panel. 
Also disclosed in the prior art are various means whereby the collector 
panel may be caused to follow, or track, the sun's movement across the 
location of the collector. However, such tracking installations are of 
necessity quite complex and expensive, and are therefore not generally 
regarded as suitable for average residential and commercial installations. 
Thus, of necessity, most of today's residential and commercial solar water 
heating installations are of reduced efficiency because of their 
stationary installation. 
Thus, while a great variety of solar collector constructions are know 
according to the prior art, it is clear that there still remains 
significant room for improvement in means for enhancing not only the 
efficiency of collectors, but also their economy any availability in a 
variety of end use applications. 
SUMMARY OF THE INVENTION 
The automatic solar collector system of this invention is of the type 
primarily intended for use in collecting solar energy in a heat transfer 
fluid and in storing the heated fluid for subsequent use. While the solar 
collector system of this invention comprises a solar collector panel 
including means for focusing the sun's rays upon a fluid conduit 
containing the heat exchange fluid in a fashion somewhat analogous to that 
disclosed and claimed in my prior U.S. Patent referred to above, the 
system of this invention is automatic in that its operation is controlled 
by a clock timer, and in that the incidence angle defined by the front 
plane of the collector panel and the sun's rays is optimized by use of a 
photo cell operatively connected to an hydraulic cylinder which is 
utilized to position the collector panel in predetermined relation to 
those rays. 
The solar collector panel of this invention is defined by a substantially 
rectangular support frame, the side walls and back of which are insulated 
and front of which is enclosed by a plurality of, for example, fresnel 
lenses. Disposed within the collector panel is a continuous fluid conduit 
through which the transfer fluid is circulated. Accordingly, one end of 
the conduit is operatively connected to a fluid supply while the other end 
is operatively connected to the system's storage tank. The solar collector 
panel is pivotally mounted to a panel box, the interior of which contains 
temperature sensors, comparator units, and valves for regulating fluid 
flow through the fluid conduit as well as an insulated heated fluid 
storage tank. 
The means for positioning the solar collector panel in predetermined 
relation to the sun's rays comprises an hydraulic cylinder operatively 
disposed in interconnecting relation between the panel box and the 
collector panel. Operation of the hydraulic cylinder is regulated by a 
photo cell mounted on the collector panel and operatively connected to the 
cylinder whereby the plane of the collector panel lenses will be 
positioned in substantially normal relation to the sun's incidence rays. 
Overall operation of the automatic solar collector system of this invention 
in its heat collecting mode is controlled by means for regulating fluid 
flow through the fluid conduit contained in the collector panel by a clock 
timer. That is to say, the automatic solar collector system of this 
invention will commence operation and secure itself in response to 
predetermined start-stop commands from the clock timer. It is, of course, 
to be understood that intermittent control of fluid flow will also be 
effected by standard temperature sensors and comparator units incorporated 
within the circuit defining the means for regulating fluid flow. 
As will become apparent from the detailed description of a preferred 
embodiment presented hereinafter, the automatic solar collector system of 
this invention is essentially self-contained and may be mounted upon a 
movable support structure such as, for example, a trailer assembly. Thus, 
while providing a more efficient collector system primarily because of its 
means for positioning the solar collector panel, the system is extremely 
flexible and suitable for use in a great variety of end use applications. 
In face, all that is required to make the automatic solar collector system 
operational is to provide an inlet and an outlet for the heat exchange 
fluid and to provide electrical service to the means for regulating fluid 
flow. 
The invention accordingly comprises the features of construction, 
combination of elements, and arrangement of parts which will be 
exemplified in the preferred construction hereinafter set forth, and the 
scope of the invention will be indicated in the claims.

Similar reference characters refer to similar parts throughout the several 
views of the drawings. 
DETAILED DESCRIPTION 
The automatic solar collector system of the present invention is generally 
indicated as 10 in the views of FIGS. 1 and 2. As perhaps best seen in the 
side view of FIG. 2, the automatic solar collector system 10 comprises a 
solar collector panel 12 which is pivotally attached to panel box 14 as by 
pin 16 which passes through panel bracket 18 and box bracket 20. 
As indicated in the views of FIGS. 1 and 2, solar collector panel 12 is of 
substantially rectangular configuration defined by a support frame 
including side walls 22 and back 24. Back 24 is line with an insulating 
material such as, for example, styrofoam, and side walls 22 may be 
similarly lined. Disposed within the collector panel 12 is a continuous 
length of fluid conduit 26. Though not shown in the drawing figures, one 
end of fluid conduit 26 is provided with a fitting for connection to a 
fluid supply source, while the other end of fluid conduit 26 is 
operatively connected to a storage tank 28 mounted within panel box 14 as 
indicated in phantom in the view of FIG. 2. It is, of course, to be 
understood that an outlet line would extend from storage tank 28 whereby 
heated fluid could be withdrawn for end use. 
With reference to the view of FIG. 1, it can be seen that the open top of 
the solar collector panel 12 is provided with a plurality of lens racks 30 
disposed thereacross from side to side whereby fresnel lenses 32 may be 
inserted so that the focal point of each lens 32 will substantially 
coincide with a segment of fluid conduit 26. Overlying the plurality of 
lenses 32 is a continuous sheet of light-transmissive material such as, 
for example, sheet plastic 34. Plastic 34 not only serves to protect each 
of the lenses 32, but also provides a substantially airtight front closure 
for panel box 14. 
Referring once again to the view of FIG. 2, one may observe a preferred 
construction for the mechanical elements of the means for positioning 
solar collector panel 12 in predetermined relation to the sun's rays. The 
means for positioning comprises a photo cell 36 attached to one of the 
side walls 22 of collector panel 12 as by bracket 38. An electrical 
conduit 40 extends from cell 36 through aperture 42 formed in a wall of 
panel box 14, and then is electrically connected through the means for 
regulating fluid flow, generally indicated as 44, to hydraulic pump 46. 
Hydraulic pump 46 includes a source of hydraulic fluid (not shown) and is 
operatively connected to hydraulic cylinder 48 by hydraulic fluid conduit 
50 which extends from pump 46 through second aperture 52 to the cylinder 
48. A first end 54 of cylinder 48 is attached to panel box 14, and its 
second end 56 is attached to a side wall 22 of solar collector panel 12. 
By virtue of this construction, when timer clock 58, which is an element of 
the means for regulating fluid flow 44, reaches its pre-set start time, 
hydraulic pump 46 will be actuated to cause rod 60 of hydraulic cylinder 
48 to extend as shown in phantom in the view of FIG. 2. By virtue of the 
pivotal connection between solar collector panel 12 and panel box 14 by 
virtue of pin 16, the solar collector panel 12 will move in response to 
the extension of rod 60. Photo cell 36 will sense maximum sun ray 
intensity and secure the operation of hydraulic pump 46, thereby 
positioning the front plane of solar collector panel 12 in predetermined 
relation to the sun's rays, that predetermined relation being essentially 
normal. 
Attention is now invited to a description of the means for regulating fluid 
flow 44 as schematically depicted in the view of FIG. 3. While the scope 
of the present invention is not to be limited to the precise circuit 
illustrated in FIG. 3, it does illustrate temperature sensors, relays, and 
solenoid valves which, while desirable for efficient operation of the 
system 10, are well known and form no part of applicant's invention, and 
are thus not described in detail. The means for regulating fluid flow 44 
is powered by standard 115 volt alternating current initially supplied and 
regulated through main switch 62. A main fuse 64 protects the overall 
circuit, while four separate fuses are provided for internal sub-circuits. 
Hydraulic pump circuit 66 is protected by first fuse 68. 
The means for positioning solar collector panel 12 in predetermined 
relation to the sun's rays is generally indicated as sub-circuit 70 and is 
protected by second fuse 72. Operation of water pump 74 which is used to 
circulate water through fluid conduits 26 is controlled by sub-circuit 76, 
and that water pump sub-circuit 76 is protected by third fuse 78. Finally, 
a cycling temperature control sub-circuit 80, protected by fourth fuse 82 
is provided. 
Referring to the means for positioning sub-circuit 70, it can be seen that 
start and stop operations are controlled by timer clock 58 in combination 
with timer switch 84. When normally open timer switch 84 is closed by 
timer clock 58, sampling photo cell 86, if activated by ambient sunlight, 
will cause switches 88 and 90 to close, thereby permitting passage of 
hydraulic fluid through solenoid valve 92 to operate hydraulic cylinder 
48. Mechanical limits are imposed upon the extension of rod 60 from 
hydraulic cylinder 48 by down limit switch 94 and up limit switch 96. As 
already indicated above, photo cell 36 will operate to secure solenoid 
valve 92 when solar collector panel 12 is positioned to receive 
substantially normal incidence of the sun's rays. Signal light 98 
indicates normal operation of the means for positioning sub-circuit 70, 
and relays 100 provide electrical interconnection between sub-circuit 
elements. Finally, the means for positioning sub-circuit further comprises 
a high temperature thermostat 102 whereby the solar collector panel 12 
will be returned to its substantially vertical, non-functional position as 
indicated in solid lines in the view of FIG. 2 should the water temperture 
within fluid conduit 26 reach a predetermined upper limit. 
In combination with sub-circuits 66, 70 and 76, the cycling temperature 
control sub-circuit 80 regulates other relatively standard functions of 
the automatic solar collector system 10. A cycling thermostat is provided 
having a low temperture side 104 and a high temperature side 106. A cycle 
timer 108 permits the entry of water into fluid conduits 26 through 
solenoid valve 110 in predetermined quantities. Only when the water within 
conduit 26 has reached a predetermined temperature will circulating 
solenoid valve 112 open to permit passage of the heated water into storage 
tank 28. Furthermore, if the level of heated water within storage tank 28 
attains a predetermined high level, float switch 114 will prevent 
overfilling. A low, or less than full, level of heated water within 
storage tank 28 is indicated by low level indicator light 116, while full 
tank indicator light 118 will be energized to indicate that storage tank 
28 contains its preset capacity. The withdrawal of heated water for end 
use is sensed by utility pressure switch 120 which will close to open the 
normally closed utility solenoid valve 122. A plurality of relays 124 
provide electrical interconnection among the various sub-circuit elements. 
Having thus set forth a detailed description for a preferred embodiment of 
the automatic solar collector system 10, it can be seen that a compact, 
self-contained unit capable of significantly maximizing its heat transfer 
and storage capabilities through utilization of the means for positioning 
sub-circuit 70 is provided. It is again to be emphasized that the 
construction and circuitry shown in the drawing figures and described 
hereinabove are presented as a preferred embodiment so as to enable any 
person skilled in the art to make and use the system 10. Engineering or 
design modifications could obviously be made to both the hardware and the 
circuitry without departing from the scope of this invention. It is also 
to be understood that the automatic solar collector system 10 might be 
mounted on a movable frame for transportation among a variety of 
locations. It is further contemplated that the system 10 would also 
include freeze protection in the form of a freeze dump valve. The valve 
would be electrically controlled in response to outside air temperature. 
When the ambient temperature reached a predetermined minimum, the valve 
would be energized to drain water from fluid conduit 26. 
It will thus be seen that the objects set forth above, among those made 
apparent from the preceding description, are efficiently attained and, 
since certain changes may be made in the above construction without 
departing from the scope of the invention, it is intended that all matter 
contained in the above description or shown in the accompanying drawings 
shall be interpreted as illustrative and not in a limiting sense. 
It is also to be understood that the following claims are intended to cover 
all of the generic and specific features of the invention herein 
described, and all statements of the scope of the invention which, as a 
matter of language, might be said to fall therebetween.