Moisture sensitive irrigation control system

• US 5,351,437 A
• Filed: 05/12/1992
• Issued: 10/04/1994
• Est. Priority Date: 05/12/1992
• Status: Expired due to Fees

• Current Assignee: Fred W. Lishman
• Original Assignee: Fred W. Lishman
• Inventors: Lishman, Fred W.
• Primary Examiner(s): Britts, Ramon S.
• Assistant Examiner(s): Downs, Joanne C.
• Application Number:
  US07/881,664
• Time in Patent Office: 875 Days
• Field of Search: 47/79, 47/67, 47/48.5
• US Class Current: 47/79
• CPC Class Codes: A01G 25/167 Control by humidity of the soil itself or of devices simulating soil or of the atmosphere; Soil humidity sensors
• CPC Class Codes: Y02A 40/22 Improving land use; Improving water use or availability; Controlling erosion

Abstract

A moisture sensitive irrigation control system provides automatic watering of potted plants, lawns, crops, etc. The system utilizes a control valve to effect watering of the soil upon automatic detection of a predetermined level of dryness in a control sample of the soil. The system uses a weight-based method of detecting the amount of moisture in the control sample to regulate the automatic release of a predetermined amount of water into the entire soil for rehydration thereof. As the weight of the control sample increases with the volume of water, the valve is automatically closed to terminate the irrigation process.

Claims

1. A moisture sensitive irrigation system for controlling irrigation of multiple volumes of soil, comprising:

a supply of water;

means for containing a control volume of soil, the moisture content of which is indicative of the moisture content of said multiple volumes of soil;

means for detecting the moisture content of said control volume of soil; and

means for irrigating each of said multiple volumes of soil including said control volume when said means for detecting has detected that the moisture content of said control volume of soil has reached a predetermined low threshold, and for terminating said irrigation when the moisture content of said control volume of soil has reached a predetermined high threshold;

wherein said means for detecting comprises spring-biased weight responsive means for operating said means for irrigating by operatively communicating with said means for irrigating upon said control volume of soil reaching a weight corresponding to said predetermined low and high thresholds.

2. The moisture sensitive irrigation system according to claim 1, wherein said means for containing a control volume of soil comprises a planter or pot filled with said soil.

3. The moisture sensitive irrigation system according to claim 2, wherein said planter or pot contains at least one plant planted in said soil.

4. The moisture sensitive irrigation system according to claim 1, wherein said means for containing a control volume of soil comprises a liner filled with said soil and installed in the ground surrounded by said multiple volumes of soil.

5. The moisture sensitive irrigation system according to claim 4, wherein said liner contains vegetation planted in said soil.

6. The moisture sensitive irrigation system according to claim 1, wherein said weight responsive means comprises a platform upon which said means for containing is mounted, adjustable compression springs providing a force on said platform in a direction opposite to the weight force of said control volume of soil, and switch means coupled to said means for irrigating for controlling operation thereof, said switch means being activated upon the weight of said control volume reaching a level corresponding to said low threshold, and said switch means being deactivated upon the weight of said control volume reaching a level corresponding to said high threshold.

7. The moisture sensitive irrigation system according to claim 6, wherein said means for irrigating comprises a solenoid valve coupled to said supply of water, and controlled by activation of said switch means.

8. The moisture sensitive irrigation system according to claim 1, wherein said weight responsive means comprises a platform upon which said means for containing is mounted, adjustable compression springs providing a force on said platform in a direction opposite to the weight force of said control volume of soil, and control means coupled to said means for irrigating for controlling operation thereof, said control means activating said means for irrigating upon the weight of said control volume reaching a level corresponding to said low threshold, and said control means deactivating said means for irrigating upon the weight of said control volume reaching a level corresponding to said high threshold.

9. The moisture sensitive irrigation system according to claim 8, wherein said means for irrigating comprises a valve having an inlet port coupled to said supply of water, an outlet port coupled to said multiple volumes of soil, and a passage communicating between said inlet and outlet ports to provide a path therebetween, said control means comprises a valve stem inserted into said passage and coupled at one end thereof to said platform, for blocking said path upon the weight of said control volume reaching a level corresponding to said high threshold, and for withdrawing out of said path upon the weight of said control volume reaching a level corresponding to said low threshold.

10. The moisture sensitive irrigation system according to claim 2, further comprising a base unit including a plurality of platforms each for holding a potted plant, and wherein said supply of water comprises a water tower mounted on said base unit, wherein one of said platforms comprises said means for detecting, and which is operatively coupled to said means for irrigating which is located within said water tower.

11. A moisture sensitive irrigation system, comprising:

a base unit including a plurality of platforms, each for holding a potted plant and soil, and a water tower including a supply of water and means for irrigating each of said potted plants;

wherein one of said plurality of platforms includes moisture detecting means for detecting the level of moisture of the soil in the pot held thereon, said level of moisture being indicative of the moisture levels of soil in other pots held on said plurality of platforms, which other pots do not include moisture detecting means, for activating said means for irrigating upon detection of said level of moisture reaching a predetermined low threshold to irrigate the soil in said other pots, ad for deactivating said means for irrigating upon detection of said level of moisture reaching a predetermined high level.

12. The moisture sensitive irrigation system according to claim 11, wherein said moisture detecting means comprises said one platform upon which said pot is held, adjustable compression springs providing a force on said platform in a direction opposite to the weight force of said pot, and switch means coupled to said means for irrigating for controlling operation thereof.

13. The moisture sensitive irrigation system according to claim 12, wherein said means for irrigating comprises a solenoid valve located within said water tower and coupled between said supply of water and said potted plants, said solenoid valve being controlled by said switch means.

14. The moisture sensitive irrigation system according to claim 11, wherein said moisture detecting means comprises said one platform upon which said pot is held, adjustable compression springs providing a force on said platform in a direction opposite to the weight force of said pot, and control means coupled to a valve having an inlet port coupled to said supply of water, an outlet port coupled to said multiple volumes of water, and a passage communicating between said inlet and outlet ports to provide a path therebetween;

said control means comprising a valve stem inserted into said passage and coupled at one end thereof to said platform, for blocking said path upon the weight of said pot reaching a level corresponding to said high threshold, and for withdrawing out of said path upon the weight of said control volume reaching a level corresponding to said low threshold.

15. The moisture sensitive irrigation system according to claim 14, wherein said means for irrigating comprises a manual shut-off valve mounted in said water tower and coupled between said valve and said supply of water, and flexible tubing coupling said manual shut-off valve to said valve, and coupling said valve to said plurality of potted plants.

16. A moisture sensitive irrigation system for controlling irrigation of a large area of soil, comprising:

a liner filled with a control volume of soil installed in the ground within said large area, the weight of said liner being representative of the moisture content of said large area;

a spring-biased platform on which said liner is mounted, the vertical level of said spring-biased platform varying according to the weight of said liner;

means for irrigating said entire large area upon activation;

activating means, coupled to said platform, for activating said means for irrigating when said platform reaches a first predetermined vertical level corresponding to a low moisture content of said soil, and for deactivating said means for irrigating when said platform reaches a second predetermined vertical level corresponding to a high moisture content of said soil.

17. The moisture sensitive irrigation system according to claim 16, wherein said means for irrigating comprises a solenoid valve for controlling the flow of a supply of water for said large area of soil, and a switch located under said platform for opening and closing said solenoid valve;

and

said means for activating comprises a column attached to said platform for opening said switch by contact to close said solenoid valve when said platform reaches said second predetermined vertical level, said switch being normally closed when said platform has reached said first predetermined vertical level.