QUICK SHUT -OFF EXTENDED RANGE HYGROSCOPIC RAIN SENSOR FOR IRRIGATION SYSTEMS
First Claim
1. A rain sensor for use with an irrigation control system, comprising:
- a housing;
an electric switch mounted within the housing and having a spring biased actuating member movable between a first position in which the switch is in a first state and a second position in which the switch is in a second state;
a first moisture absorptive element mounted within the housing adjacent a first opening therein for receiving rainfall and rapidly expanding a sufficient amount to move the actuating member of the switch from its first position to its second position; and
a second moisture absorptive element mounted in the housing for receiving rainfall through a second opening in the housing for slowly expanding and maintaining the actuating member of the switch in the second position after the first moisture absorbing element has dried and contracted.
1 Assignment
0 Petitions
Accused Products
Abstract
A micro-switch is mounted within a housing and is electrically connectable to an irrigation controller. The switch has a spring biased actuating lever pivotable between ON and OFF positions. A single disc made of a hygroscopic material is mounted within the housing adjacent the inner end of the lever for absorbing rainfall and rapidly expanding a sufficient amount to move the actuating lever from its ON position to its OFF position to thereby cause the watering program of the irrigation controller to be interrupted. A stack of moisture absorptive discs made of the same hygroscopic material is mounted in the housing adjacent an outer end of the lever. When the stack of discs receives rainfall it slowly expands and maintains the actuating lever in its OFF position after the single hygroscopic disc has dried and contracted to ensure that watering is not re-initiated too soon after a storm.
25 Citations
20 Claims
-
1. A rain sensor for use with an irrigation control system, comprising:
-
a housing;
an electric switch mounted within the housing and having a spring biased actuating member movable between a first position in which the switch is in a first state and a second position in which the switch is in a second state;
a first moisture absorptive element mounted within the housing adjacent a first opening therein for receiving rainfall and rapidly expanding a sufficient amount to move the actuating member of the switch from its first position to its second position; and
a second moisture absorptive element mounted in the housing for receiving rainfall through a second opening in the housing for slowly expanding and maintaining the actuating member of the switch in the second position after the first moisture absorbing element has dried and contracted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A rain sensor for use with an irrigation control system, comprising:
-
a switch having an actuating member movable between a first position in which the switch is in a first state and a second position in which the switch is in a second state, the actuating member being biased to the first position;
a first moisture absorptive element having a first water absorption capacity, and being dimensioned, configured and positioned in a first location to receive rainfall and expand a sufficient amount to move the actuating member of the switch from its first position to its second position; and
a second moisture absorptive element having a second water absorption capacity greater than the water absorption capacity of the first element, and the second element being dimensioned, configured and positioned in a second location to receive rainfall and expand and maintain the actuating member of the switch in the second position after the first moisture absorbing element has dried and contracted so that it would no longer maintain the switch in the second position by itself. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A rain sensor for use with an irrigation control system, comprising:
-
a housing having first and second laterally spaced apart rainfall openings;
a switch mounted in the housing and having an actuating member lever pivotable between an ON position and an OFF position, the actuating member being biased toward the ON position;
a first hygroscopic element having a first water absorption capacity and being positioned in the housing to receive rainfall passing through the first opening in the housing and expand a sufficient amount to move the actuating lever of the switch from the ON position to the OFF position;
a second hygroscopic element having a second water absorption capacity greater than the water absorption capacity of the first element, the second element being positioned in the housing to receive rainfall passing through the second opening in the housing and expand to maintain the actuating lever of the switch in the OFF position after the first element has dried and contracted so that it would no longer maintain the switch in the OFF position by itself; and
means for pre-selecting a position of the second element in the housing to pre-determine an amount of rainfall that will maintain the actuating lever of the switch in the OFF position.
-
Specification