Fluid handling – Processes – Involving pressure control
Reexamination Certificate
2000-04-24
2001-04-24
Chambers, A. Michael (Department: 3753)
Fluid handling
Processes
Involving pressure control
C137S078300, C137S556000
Reexamination Certificate
active
06220268
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATIONS
There are none.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
There was no federally sponsored research that contributed to this invention or this application.
REFERENCE TO A MICROFICHE APPENDIX
None submitted.
FIELD OF THE INVENTION
This application relates to water flow valves, specifically irrigation valves controlled by ambient soil moisture.
BACKGROUND OF THE INVENTION
Irrigation devices spread water on the soil. A common irrigation method employed is a sprinkler which sprays water when pressurized water is supplied to the orifice.
Frequently watering is done by sprinklers connected to a main water supply line. Water flow into the main line can be controlled manually or by automatic timers connected to water supply valves.
Both methods waste a great deal of water. Plant needs and soil conditions are extremely variable over a field or yard. Soil variations such as ph, water evaporation, ambient light, ambient temperature, and drainage rate change the amount of external irrigation required to support optimum plant growth. Different plants have a wide range watering preferences. Usually, to be certain that the few plants with the maximum water needs are adequately served, users over-water the remaining plants. Automatic timers water indiscriminately, even when it is raining.
An obvious improvement would be a valve at each sprinkler that senses soil moisture and permits watering as required by the plants at that point, for those specific conditions, regardless if the water is controlled manually or automatically.
The term sprinkler will be used in this patent to refer to all plant watering devices, including, but not limited to, sprayers, misters, drip devices, and flood gates.
The terms sufficiently moist and insufficiently moist refer to moisture preferences of the plants for optimum growth as determined by the user of this device.
There are many substances that expand and contract in proportion to the amount of moisture they encounter. Some of these include hydrogels, flax, cotton, hair, leather, nylon, wood products and their derivatives such as pulp and paper. Weihe U.S. Pat. No. 4,655,076 (1987) lists over 40 materials that are moisture responsive in this way. Hatanaka U.S. Pat. No. 4,120,813 (1978) and Urry U.S. Pat. No. 5,520,672 (1996) describes how to make various others. Some moisture responsive materials can be incorporated to make a coil or thread which conveys the moisture level through movement. The term hygrometer will be used in this patent to refer to all of these substances and devices which expand and contract with changing moisture levels.
DESCRIPTION OF THE RELATED ART
Numerous inventors have attempted to describe a device to regulate watering for plants by using soil moisture to control an irrigation valve. The prior attempts have either one, or several of the following problems listed below.
(a) Some do not turn completely on and off, such as Gant U.S. Pat. No. 4,696,319 (1987) and Ornstein U.S. Pat. No. 4,182,357 (1980), forcing the sprinkler to dribble, instead of spray, during medium moisture soil conditions. This causes the plants near the sprinkler to drown and the plants just inches away from the sprinkler to die from lack of water. Also, these devices can not be used with drip systems, as there is not enough pressure to force water to the ends of the watering lines.
(b) Some require electricity, such as Lohoff U.S. Pat. No. 4,055,200 (1977), Jones U.S. Pat. No. 5,329,081 (1994), or Coward U.S. Pat. No. 4,256,133 (1981), which would be difficult to install, maintain, and could electrically shock the user.
(c) Some are plant weight based, such as Spelt U.S. Pat. No. 5,848,494 (1998), which is useless for any in ground crop, lawn, or garden.
(d) Some use materials that only respond to very limited ranges of moisture, such as Wild U.S. Pat. No. 4,095,458 (1978), which uses wood, a substance which expands to its maximum length at a 30% moisture content.
(e) Some are not small or simple, such as Lopic et al. U.S. Pat. No. 5,224,795 (1993) and Goldsmith U.S. Pat. No. 4,987,915 (1991), making them expensive to manufacture, and therefor purchase, as compared to the amount of water the device saves.
(f) Some use or suggest materials not suitable for long term operation because the hygrometer device decays and the valve becomes useless, such as the wood or other plant fibers used in Gumbmann, Jr. U.S. Pat. No. 4,648,555 (1987) and Waterson U.S. Pat. No. 3,898,843 (1975).
(g) Some do not respond within a resonable time. Dupont's nylon has a 180 day full cycle time, which would make both Fukami U.S. Pat. No. 4,489,603 (1984) and Watanabe U.S. Pat. No. 4,744,515 (1988) useless for daily changing moisture conditions.
(h) Some are not suitable for use with standard electric timers, as is the case with Nunn U.S. Pat. No. 5,794,848 (1998).
BRIEF SUMMARY OF THE INVENTION
A moisture controlled valve comprising a T pipe, a piston which forms a water tight seal in the pipe, and a piston controlling moisture indicator. The valve permits watering in an insufficiently moist soil condition and prevents watering in sufficiently moist soil conditions.
Object of this Invention
The object of this invention is to describe a valve which assesses the moisture level near the location of a plant and permits watering when the soil is relatively dry and the plant needs water, but will prevent watering when the soil has adequate moisture for the plant. In addition are the following objects and advantages:
(a) to describe a valve that is completely on or off, but never partly on;
(b) to describe a valve that can operate without electricity;
(c) to describe a valve that can work for in ground and potted plants;
(d) to describe a valve that responds to a broad range of moisture levels;
(e) to describe a valve which can be manufactured affordably, as compared to the amount of water the device saves;
(f) to describe a valve which survives for many cycles of moisture level changes;
(g) to describe a valve which responds within a resonable time;
(h) to describe a valve which can be used with presently used irrigation sprinklers and valves.
Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
REFERENCES:
patent: 3747399 (1973-07-01), Treirat
patent: 3898843 (1975-08-01), Waterson
patent: 4055200 (1977-10-01), Lohoff
patent: 4095458 (1978-06-01), Wild
patent: 4120813 (1978-10-01), Hatanaka
patent: 4182357 (1980-01-01), Ornstein
patent: 4256133 (1981-03-01), Coward
patent: 4489603 (1984-12-01), Fukami
patent: 4648555 (1987-03-01), Gumbmann, Jr.
patent: 4655076 (1987-04-01), Weihe
patent: 4696319 (1987-09-01), Gant
patent: 4744515 (1988-05-01), Watanbe
patent: 4987915 (1991-01-01), Goldsmith
patent: 4989628 (1991-02-01), Gil et al.
patent: 5100056 (1992-03-01), Theodorsen et al.
patent: 5156179 (1992-10-01), Peterson et al.
patent: 5224795 (1993-07-01), Lopic et al.
patent: 5329081 (1994-07-01), Jones
patent: 5520672 (1996-05-01), Urry
patent: 5794848 (1998-08-01), Nunn
patent: 5848494 (1998-12-01), Spelt
Bolton John Darcy
Bolton Ross Spencer
LandOfFree
Moisture controlled valve which does not permit partial... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Moisture controlled valve which does not permit partial..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Moisture controlled valve which does not permit partial... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2501540