Greenhouse construction and improved method of growing plants

• US 5,261,184 A
• Filed: 06/12/1991
• Issued: 11/16/1993
• Est. Priority Date: 06/12/1991
• Status: Expired due to Fees

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Cobb, Sanford Jr., Appeldorn, Roger H., Jaster, Paul A.
• Primary Examiner(s): Raduazo, Henry E.
• Application Number:
  US07/713,792
• Time in Patent Office: 888 Days
• Field of Search: 47/17, 52/473
• US Class Current: 47/17
• CPC Class Codes: A01G 9/222 Lamellar or like blinds in general E06B9/26
• CPC Class Codes: A01G 9/249 Lighting means with special arrangements for promoting growth A01G7/045
• CPC Class Codes: Y02A 40/25 Greenhouse technology, e.g. cooling systems therefor

Abstract

An improved greenhouse comprising a plurality of walls, a light-transmitting roof panel; and an optical system located inside the greenhouse is described. The optical system comprises a plurality of rows of elongate spaced optical panels generally adjacent and extending transversely across the light-transmitting roof panel. Each panel comprises a thin backing portion forming first and second concave, opposite sides, a first light reflecting means including light-reflecting surfaces attached to the first side of the backing and a second light reflecting means including light-reflecting surfaces attached to the second side of the backing such that the light-reflecting surfaces face generally oppositely.

Also disclosed is an improved method of growing plants utilizing such a greenhouse construction.

Claims

1. A greenhouse comprising:

a plurality of walls,

a light-transmitting roof panel; and

an optical system inside the greenhouse, the optical system comprising;

a plurality of rows of elongate spaced optical panels generally adjacent and extending transversely across the light-transmitting roof panel, each panel comprising;

a thin backing portion forming first and second opposite sides,

a first light reflecting means including light-reflecting surfaces attached to the first side of the backing and a second light reflecting means including light-reflecting surfaces attached to the second side of the backing such that the light-reflecting surfaces face generally oppositely,

said plurality of elongate spaced optical panels being positioned such that said first light reflecting means faces the second light reflecting means of an adjacent panel so that the first light-reflecting means receives light transmitted through the roof panel and reflects the light to the second light-reflecting means of said adjacent panel, the second light-reflecting means receives light from the first light-reflecting means and reflects the light substantially vertically downwardly, and wherein the first and second light reflecting means comprise reflectorized fresnel lenses.

2. The greenhouse according to claim 1 wherein said backing comprises a thin film of acrylic with a thickness in the range between 0.0625 and 0.125 inches.

3. The greenhouse according to claim 2 wherein said backing comprises a first concave thin film of acrylic and a second concave thin film of acrylic adhesively attached to said first thin film of acrylic.

4. The greenhouse according to claim 1 wherein the light-transmitting roof panel is sloped generally toward the equator.

5. The greenhouse according to claim 4 wherein the light-transmitting roof panel is sloped at an angle of between about 15°

and about 20°

with respect to horizontal.

6. The greenhouse according to claim 4 wherein the orientation of the first light reflecting means is adjustable to accommodate seasonal changes in the sun'"'"'s position in the sky.

7. The greenhouse according to claim 1 wherein the rows extend generally east-west, generally parallel to the apparent east-west motion of the sun.

8. The greenhouse according to claim 1 wherein the rows extend at an angle to east-west, to maximize the collection of sunlight during a particular time of the day.

9. The greenhouse according to claim 1 wherein sidewalls of the greenhouse are insulated.

10. The greenhouse according to claim 1 wherein the sidewalls of the greenhouse ar substantially opaque.