Leak detection and alarm system

• US 5,091,715 A
• Filed: 02/01/1991
• Issued: 02/25/1992
• Est. Priority Date: 01/08/1990
• Status: Expired due to Fees

• Current Assignee: Murphy, Anthony J.
• Original Assignee: Murphy, Anthony J.
• Inventors: Murphy, Anthony J.
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): HOFSASS, JEFFERY A
• Application Number:
  US07/649,141
• Time in Patent Office: 389 Days
• Field of Search: 340/604, 340/605, 340/693, 200/61.04, 200/61.05, 73/290 R, 73/304 R
• US Class Current: 340/604
• CPC Class Codes: G01F 23/242 Mounting arrangements for electrodes
• 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

Abstract

A leak alarm system monitors the wetness of a floor. The alarm system comprises a housing having a flat bottom surface and support feet for supporting the housing off the floor such that each one of the support feet is in contact with the floor. Each support foot comprises an electrode of the alarm system. A low resistance condition between two electrodes of opposite polarity, such as occurs in the presence of a water leak, activates the alarm.

Claims

1. A liquid detection and alarm system for monitoring the wetness of a floor, the alarm system comprising:

a housing having a flat bottom surface;

at least three spaced-apart support feet for supporting the bottom surface of the housing above the floor, such that the bottom of each support foot is in contact with the floor, wherein the bottom of each support foot is constructed from an electrically conductive material, so as to have a single electrical polarity, such that at least one support foot is of opposite polarity from the others;

an electrically activated alarm indicator;

a battery connector for connecting a battery to the alarm system; and

an alarm circuit located within the housing for interconnecting all of the support feet, the alarm indicator, and the battery such that the alarm circuit activates the alarm indicator in response to a reduced resistance condition between any two separate support feet of opposite polarity.

2. An alarm system as recited in claim 1, wherein:

the housing is substantially rectangular, with four corners;

the alarm system includes four support feet, one support foot being located at each housing corner; and

the bottom of each support foot has an opposite polarity to the bottoms of the two adjacent corner support feet.

3. An alarm system as recited in claim 1, wherein the alarm system includes more than three support feet and the bottom of each support foot has an opposite polarity to the bottoms of the two adjacent support feet.

4. An alarm system as recited in claim 1, wherein the bottom surface of the housing is circular and the three support feet are located at substantially equally-spaced intervals on the periphery of the housing bottom surface.

5. An alarm system as recited in claim 1, wherein the alarm indicator includes a remote indicator and an electrically conductive cable for connecting the remote indicator to the alarm circuit.

6. An alarm system as recited in claim 1, wherein the support feet are constructed entirely from an electrically conductive material.

7. An alarm system as recited in claim 6, wherein the bottom surface of the housing includes an opening for each support foot such that each support foot extends through the housing.

8. A liquid detection and alarm system for monitoring the wetness of a floor, the alarm system comprising:

a housing having a flat bottom surface;

at least four spaced-apart separate support feet for supporting the bottom surface of the housing above the floor, such that each support foot is in contact with the floor, wherein the bottom of each support foot is an electrically conductive material such that each support foot has an opposite electrical polarity to that of the two adjacent support feet;

an electrically activated alarm indicator;

a battery connector for connecting a battery to the alarm system;

an alarm circuit located within the housing for interconnecting all of the support feet, the alarm indicator, and the battery such that the alarm circuit activates the alarm indicator in response to a reduced resistance condition between any two support feet of opposite polarity; and

an alarm test button operable from outside the housing such that the test button activates the alarm indicator when the button is depressed.