Abstract A switch assembly activated by conductive liquids, typically water, and based upon use of a longitudinally slit resilient cylinder, carrying one of a pair of spaced, parallel rod-shaped electrodes at each side of the cylinder wall slit. A bolt passed transversely through the cylinder may be adjusted as to constrict or relax the resilient cylinder to thereby vary the spacing of the parallel electrode rods and the sensitivity characteristics of the switch. Moisture, for example, in the form of sprinkler produced water droplets, or the level of surface irrigation water, may bridge the electrode gap by impinging thereon and spreading longitudinally by surface tension effects. The resulting change in current may be utilized to trip a relay in an irrigation system supplying the activating water droplets, orwhere the switch is used in a level detector system- to provide a precise indicating signal that the monitored liquid level has become accessible to the electrode gap.
An irrigation system comprising in combination: a. means for supplying water to an area to be irrigated; b. a water source and supply conduit connected to said means; c. normally open solenoid valve means in said supply conduit; d. relay means for activating said solenoid valve; e. power supply means for said solenoid valve and relay; and f. a normally open liquid activated switch assembly positioned in said irrigated area to receive incident water, said switch assembly being adapted to activate said relay upon closing by incident water, whereby to discontinue said supply of water, said switch assembly comprising: (1) a resilient insulating cylinder having a longitudinal slit extending the length thereof; (2) a pair of conductive rodshaped electrodes secured to the cylinder edges bounding said slit to define a pair of parallel spaced electrodes; and (3) conductor means connected to said electrode pair and disposing said switch in circuit with said relay, whereby water impinging upon said electrodes and bridging the gap and spreading therebetween by surface tension effects, provides a conductive path to close said switch.
Claim 2
Dependent Claim
178 words
An irrigation system comprising in combination: a. means for supplying water to an area to be irrigated; b. a water source and supply conduit connected to said means; c. normally open solenoid valve means in said supply conduit; d. relay means for activating said solenoid valve; e. power supply means for said solenoid valve and relay; and f. a normally open liquid activated switch assembly positioned in said irrigated area to receive incident water, said switch assembly being adapted to activate said relay upon closing by incident water, whereby to discontinue said supply of water, said switch assembly comprising: (1) a resilient insulating cylinder having a longitudinal slit extending the length thereof; (2) a pair of conductive rodshaped electrodes secured to the cylinder edges bounding said slit to define a pair of parallel spaced electrodes; and (3) conductor means connected to said electrode pair and disposing said switch in circuit with said relay, whereby water impinging upon said electrodes and bridging the gap and spreading therebetween by surface tension effects, provides a conductive path to close said switch.
Claim 3
Dependent Claim
34 words
Apparatus in accordance with claim 1, further including means to adjustably constrict the said cylinder, whereby to vary the spacing between said electrodes and the resultant sensitivity of said switch assembly to incident liquid.
Claim 4
Dependent Claim
12 words
Apparatus in accordance with claim 2, wherein said electrodes are black surfaced.
Claim 5
Dependent Claim
15 words
Apparatus in accordance with claim 1 wherein said water supply means comprises a spray nozzle.