US Patent No. 9,655,311

ABSORBENT RAIN SENSOR WITH RETENTION BASIN


Patent No. 9,655,311
Issue Date May 23, 2017
Title Absorbent Rain Sensor With Retention Basin
Inventorship James A. Bell, San Marcos, CA (US)
Assignee Hunter Industries, Inc., San Marcos, CA (US)

Claim of US Patent No. 9,655,311

1. An irrigation control system comprising:
a control unit; and
a rain sensor in communication with the control unit, the rain sensor comprising:
a sensor housing;
a first moisture-absorbent element within the sensor housing and in communication with ambient via a first aperture in the
sensor housing, the first moisture-absorbent element configured to expand to a wet state from a dry state as the first moisture-absorbent
element absorbs liquid, the first moisture-absorbent element having a first drying rate;

a moveable accumulator cup configured to move within the sensor housing, the accumulator cup having a liquid-impervious base
and one or more liquid-impervious sidewalls extending upward from the base, the liquid-impervious base and one or more liquid-impervious
sidewalls forming a cup volume;

a second moisture-absorbent element within the sensor housing and positioned at least partially within the cup volume, the
second moisture-absorbent element in communication with ambient via a second aperture in the sensor housing, the second moisture-absorbent
element configured to expand when transitioned from a dry state to a wet state, the second moisture-absorbent element having
a second drying rate slower than the first drying rate, wherein the moveable accumulator cup is configured to transition between
a first position and a second position with respect to the sensor housing in response to transition of the second moisture-absorbent
element between the dry state and the wet state; and

a signal actuator configured to transition between a first position and a second position, the signal actuator biased to the
first position when the moveable accumulator cup is in its first position, the signal actuator transitions to the second position
when one or more of the first moisture-absorbent element and the second moisture-absorbent element is in its wet state;

the accumulator cup configured to store a volume of liquid in excess of the liquid within the fully saturated second moisture-absorbent
element, the volume of excess liquid in contact with at least a portion of the second moisture-absorbent element.