Liquid leak detector and alarm system

• US 6,414,598 B2
• Filed: 12/15/2000
• Issued: 07/02/2002
• Est. Priority Date: 12/16/1999
• Status: Expired due to Term

• Current Assignee: Michael R.G. Freill, Peter E. Freill
• Original Assignee: Michael R.G. Freill, Peter E. Freill
• Inventors: Freill, Michael R. G., Freill, Peter E.
• Primary Examiner(s): Wu, Daniel J.
• Application Number:
  US09/736,783
• Publication Number:
  US 20010004240A1
• Time in Patent Office: 564 Days
• Field of Search: 340/539, 340/618, 340/623, 340/624, 340/625, 340/636, 340/691.1, 340/691.7, 340/693.2, 733/08
• US Class Current: 340/623
• CPC Class Codes: G01F 23/36 using electrically actuated indicating means G01F23/38 takes precedence
• CPC Class Codes: G08B 21/20 responsive to moisture

Abstract

The alarm system is capable of detecting both conductive and non-conductive liquid level increases, designed for indoor operation, and ideally suited for detecting basement flooding or leaky domestic steel oil tanks or other fluid containment devices. A float, positioned above any surface such as a contained area (sump or drip pan), rises with the presence of a liquid, allowing a spring-loaded switch to rise, triggering a 9-volt powered battery electric circuit. The electric circuit, enclosed in a plastic enclosure, activates an audible pulsating alarm when triggered. A battery voltage monitor incorporated in the electric circuit, tests the battery voltage on a continuous bases, and will trigger the unit into the alarm mode when the battery voltage is insufficient to sustain continuous operation. A simple convenient self check feature allows the user to simply check the unit at any time. An external connection is provided to allow the unit to be connected to a home security system or other external device to allow extended protection or secondary operations.

Claims

1. A combustible liquid level alarm device for indicating the leakage of a rising combustible liquid, said device comprising:

a housing,

an electronic circuit within said housing, including an alarm means;

a trigger means for detecting a rising combustible liquid level;

said trigger means comprising;

a lever switch within said housing;

a lever operatively attached to said lever switch, biased towards an alarm-triggering position by a biasing means;

a float assembly hanging from said lever, the weight of said float assembly being sufficient to downwardly overcome said upward biasing of said lever, such that said alarm means is not triggered until when and if said float assembly is elevated by said liquid rising to a height sufficient to float said float assembly; and

a low voltage power source for said electronic circuit and alarm means to limit the heat generated by a current drawn from said power supply, thus allowing said alarm to be used for indicating the leakage of said rising combustible liquid,

said alarm means being arranged to emit a pulsed beeping sound allowing the alarm to be differentiated from other domestic type alarms and to provide longer battery life.

2. A liquid level alarm device according to claim 1, wherein said housing has an external connection for remote alarming and/or for auxiliary control, operatively connected to said electronic circuit.

3. A liquid level alarm device according to claim 1, wherein said electronic circuit includes a power supply monitoring circuit operatively connected to said power supply for monitoring the strength of said power supply and for triggering a low power supply alarm should the power supply strength drop below a predetermined level.

4. A liquid level alarm device according to claim 1, wherein said pulsed beeping sound lasts approximately 1 second at 10 second intervals.

5. A liquid level alarm device according to claim 1, wherein the height of said float is adjustable.

6. A liquid level alarm device according to claim 1, wherein a string of adjustable length, is attached between said lever and said float assembly, to position said float assembly at a height at which said alarm is desired to be triggered.