Water detection device

• US 4,297,686 A
• Filed: 10/01/1979
• Issued: 10/27/1981
• Est. Priority Date: 10/01/1979
• Status: Expired due to Term

• Current Assignee: Tom M. Dale
• Original Assignee: Tom M. Dale
• Inventors: Tom, M. Dale
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Myer, Daniel
• Application Number:
  US06/080,658
• Time in Patent Office: 757 Days
• Field of Search: 137/312, 137/558, 137/78.1, 174/117 A, 340/602, 340/604, 340/605, 340/693, 340/636, 340/620, 200/61.04, 200/61.05, 200/61.06
• US Class Current: 340/604
• CPC Class Codes: G01F 23/18 Indicating, recording or alarm devices actuated electrically
• CPC Class Codes: G01F 23/243 Schematic arrangements of probes combined with measuring circuits
• CPC Class Codes: G01M 3/16 using electric detection means G01M3/045, G01M3/06, G01M3/12, G01M3/20, G01M3/24, G01M3/26 take precedence
• CPC Class Codes: G08B 21/20 responsive to moisture
• CPC Class Codes: Y10T 137/1842 Ambient condition change responsive

Abstract

A resistive liquid detection and shut-off system is used to protect a floor area from water damage. An elongated sensor comprising a flexible plastic tape with an adhesive backing and a pair of conductive metal strips detects liquid drips, flows and trickles, but not liquid beads. A detection circuit measures resistivity changes in the sensor, and an output circuit activates a solenoid-operated water shut-off valve in response to predetermined resistivity changes in the sensor. A connector comprising a body of electrically insulating material with electrical terminals thereon connects portions of the elongated sensor together so that they can have any length and relative position. A battery may provide the power for the entire system, with a battery voltage monitoring circuit also provided.

Claims

1. A resistive liquid detection and shut-off system comprising:

means for detecting liquid drips, flows and trickles, but not liquid beads, on a floor area where liquid damage could result, said means including an elongated sensor comprising a flexible plastic tape with an adhesive backing and having a surface thereof with a pair of conductive metal strips thereon spaced apart in a dimension perpendicular to the dimension of elongation of said tape;

detection circuit means operatively connected to said elongated sensor for measuring resistance changes in said elongated sensor;

a solenoid-operated water shut-off valve;

output circuitry means operatively connected to said detection circuit means and said water shut-off valve for activating said water shut-off valve in response to predetermined resistivity changes in said elongated sensor;

a battery for providing power for said detection circuit means, solenoid valve operator, and said output circuitry means; and

battery monitoring circuitry means operatively connected to said battery and said shut-off valve for monitoring the strength of said battery and for operating said shut-off valve if said battery strength drops below a predetermined value.

2. A system as recited in claim 1 wherein the elongated sensor tape is formed in at least two pieces, and further comprising:

a connector for interconnecting the two pieces of the sensor tape, the connector comprising

a body of electrically insulating material having two pairs of electrically connected electrical terminals mounted thereon, the terminals of each pair being spaced apart a distance corresponding to the spacing of the conductive metal strips;

means defining a pair of slots in said body, each for receipt of a piece of said tape for allowing said conductive metal strips of said tape to contact said terminals within said body; and

adhesive means for maintaining each piece of said tape in contact with said connector body.

4. A system as recited in claims 3 or 2 wherein said pairs of electrical terminals are disposed with respect to each other at an angle other than 180°

.

3. A resistive liquid detection system comprising:

means for detecting liquid drips, flows and trickles, but not liquid beads, on a floor area where liquid damage could result, said means including an elongated sensor comprising a flexible plastic tape with an adhesive backing and having a surface thereof with a pair of conductive metal strips spaced apart in a dimension perpendicular to the dimension of elongation of said tape, said tape being formed in at least two pieces;

a connector for interconnecting said two pieces of said sensor tape, said connector comprising;

a body of electrically insulating material having two pairs of electrically connected electrical terminals mounted thereon, the terminals of each pair being spaced apart a distance corresponding to the spacing of said conductive metal strips;

means defining a pair of slots in said body, each for receipt of a piece of said tape for allowing said conductive metal strips of said tape to contact said terminals within said body; and

adhesive for maintaining each piece of said tape in contact with said connector body;

detection circuit means operatively connected to said elongated sensor for detecting changes in the resistivity thereof;

an alert means for alerting an individual to resistivity changes in said sensor means;

output circuitry means operatively connected to said detection circuit means and said alert means for activating said alert means in response to predetermined resistivity changes in said elongated sensor; and

power means for providing electrical current for powering said circuitry means and said alert means.