Fail-safe leak detector

• US 5,357,241 A
• Filed: 05/17/1993
• Issued: 10/18/1994
• Est. Priority Date: 08/02/1991
• Status: Expired due to Fees

• Current Assignee: Demetrius Vassiliou, James G. Welch Jr, James W. Simmons
• Original Assignee: Demetrius Vassiliou, James G. Welch Jr, James W. Simmons
• Inventors: Simmons, James W., Vassiliou, Demetrius, Welch, James G. Jr.
• Primary Examiner(s): Hofsass, Jeffery A.
• Application Number:
  US08/061,748
• Time in Patent Office: 519 Days
• Field of Search: 340/603, 340/604, 340/605, 122/504, 122/507, 126/374, 137/551, 73/304 R, 73/308, 73/40
• US Class Current: 340/605
• 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: G01F 23/70 for sensing changes in level only at discrete points
• 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: G01M 3/186 for containers, e.g. radiators
• CPC Class Codes: G08B 21/20 responsive to moisture
• CPC Class Codes: Y10T 137/8158 With indicator, register, recorder, alarm or inspection means

Abstract

A fail-safe system for the detection of water leaks, and for the prevention of damage therefrom. In a home or building which includes a hot-water tank and a water tank for a toilet, e.g., the damage-prevention system comprises valves for shutting off the supply of water to the tanks, and other valves for draining the tanks through discharge lines to the outside of the home or building. At the same time, power to the hot-water tank is shut off. A fail-safe water detector comprises a float with a metal cap, a first pair of electrical probes below the float, and a second pair of electrical probes above the metal cap and separated from the cap by an air gap. A circuit is closed in any of three ways: (1) when water contacts the first pair of probes, (2) when water raises the float and makes contact between the metal cap and the second pair of probes, and (3) when water contacts the second pair of probes.

Claims

1. A fail-safe hot-water tank having a source for supplying water thereto, the fail-safe hot-water tank comprising:

(a) a tank for holding water;

(b) means for heating the contained water;

(c) a first passageway from the source of water to the tank;

(d) a first valve for keeping the first passageway open in the absence of detection of a water leak, and for keeping the passageway closed in response to the detection of a water leak from the tank;

(e) means for closing the first valve in response to the detection of a water leak from the tank, thereby shutting off the supply of water to the tank;

(f) a second valve for draining water from the tank to the external environment in response to the detection of a water leak from the tank;

(g) a second passageway from the second valve to the external environment;

(h) means for disconnecting the heating means in response to the detection of a water leak from the tank, thereby discontinuing the heating of the contained water; and

(i) a plurality of independent and repetetive means for detecting leakage of water from the tank, said detecting means being critically and sequentially dependent on differences of water level and so constructed and arranged that all of the independent and repetetive detecting means would have to fail in order for a leakage of water from the tank not to be detected, thereby providing and ensuring fail-safe leak detection.

2. A fail-safe hot-water tank having a source for supplying water thereto, the fail-safe hot-water tank comprising:

(a) a tank for holding water;

(b) means for heating the contained water;

(c) a first passageway from the source of water to the tank;

(d) a first valve for keeping the first passageway open in the absence of detection of a water leak, and for keeping the passageway closed in response to the detection of a water leak from the tank;

(e) a second valve for draining water from the tank to the external environment in response to the detection of a water leak from the tank;

(f) a second passageway from the second valve to the external environment; and

(g) a water detector for detecting leakage of water from the tank, the detector comprising

(h) a float having an electrically-conductive top;

(i) a first pair of electrical conductors disposed below the float and connected in parallel to a relay which controls the first and second valves; and

(j) a second pair of electrical conductors disposed directly above and spaced apart from the float'"'"'s conductive top, and connected in parallel to the relay;

the individual conductors of each pair of conductors being spaced apart from one another to form an open circuit in the absence of a water leak;

the distance separating the individual conductors of the second pair of conductors being less than the width of the conductive top of the float, to provide an open circuit in the absence of contact between the top and the second pair of conductors or between water and the second pair of conductors;

whereby a first electrical circuit is closed by water contacting the first pair of conductors, thereby closing the first valve and the first passageway, opening the second valve to drain the tank, discharging the water from the tank to the external environment, and disconnecting the heating means for the tank;

a second electrical circuit is closed by rising water raising the float to a level at which electrical contact is made between the second pair of conductors and the conductive top of the float, thereby closing the first valve, opening the second valve, and disconnecting the heating means, if these functions have not been performed in response to water contact with the first pair of conductors; and

the second electrical circuit is closed by rising water contacting the second pair of conductors, thereby closing the second valve, opening the third valve, and disconnecting the heating means, if these functions have not been performed in response to electrical contact between the second pair of conductors and the conductive top of the float.

3. A fail-safe water tank for a toilet haing a source for supplying water thereto, the fail-safe water tank comprising:

(a) a tank for containing water;

(b) a first passageway from the source of water to the tank;

(c) a first valve for keeping open the first passageway in the absence of detection of a water leak from the tank, and for closing the first passageway in response to the detection of a water leak from the tank;

(d) means for closing the first valve in response to the detection of a water leak from the tank, thereby shutting off the supply of water to the tank;

(e) a second valve for draining water from the tank to the external environment in response to the detection of a water leak from the tank;

(f) a second passageway from the second valve to the external environment; and

(g) a plurality of independent and repetetive means for detecting leakage of water from the tank, said detecting means being critically and sequentially dependent on differences of water level and so constructed and arranged that all of the independent and repetetive detecting means would have to fail in order for a leakage of water from the tank not to be detected, thereby providing and ensuring fail-safe leak protection.

4. A fail-safe water tank for a toilet having a source for supplying water thereto, the fail-safe water tank comprising:

(a) a tank for holding water;

(b) a first passageway from the source of water to the tank;

(c) a first valve for keeping the first passageway open in the absence of detection of a water leak, and for keeping the passageway closed in response to the detection of a water leak from the tank;

(d) a second valve for draining water from the tank to the external environment in response to the detection of a water leak from the tank;

(e) a second passageway from the second valve to the external environment; and

(f) a water detector for detecting leakage of water from the tank, the detector comprising

(g) a float having an electrically-conductive top;

(h) a first pair of electrical conductors disposed below the float and connected in parallel to a relay which controls the first and second valves; and

(i) a second pair of electrical conductors disposed directly above and spaced apart from the float'"'"'s conductive top, and connected in parallel to the relay;

the individual conductors of each pair of conductors being spaced apart from one another to form an open circuit in the absence of a water leak from the tank;

the distance separating the individual conductors of the second pair of conductors being less than the width of the conductive top of the float, to provide an open circuit in the absence of contact between the second pair of conductors and the conductive top or water;

whereby a first electrical circuit is closed by water contacting the first pair of conductors, thereby closing the first valve, opening the second valve, emptying the tank, and discharging the water from the tank to the external environment;

a second electrical circuit is closed by rising water raising the float to a level at which electrical contact is made between the second pair of conductors and the conductive top of the float, thereby closing the first valve, opening the second valve, emptying the tank, and discharging the water to the external environment, if these functions have not been performed in response to water contact with the first pair of conductors; and

the second electrical circuit is closed by rising water contacting the second pair of conductors, thereby closing the first valve, opening the second valve, emptying the tank, and discharging the water to the external environment, if these functions have not been performed in response to electrical contact between the second pair of electrical conductors and the conductive top of the float.

5. A fail-safe system for preventing water damage to a building or home which includes a hot-water tank and a water tank for a toilet, the hot-water tank including (a) a first tank for holding water;

(b) means for heating the water contained in the first tank;

(c) a source for supplying water to the first tank; and

(d) a first passageway from the source of water to the first tank;

the water tank for the toilet including (e) a second tank for containing water;

(f) a source for supplying water to the second tank; and

(g) a second passageway from the source of water to the second tank;

the damage-prevention system comprising;

(h) a first valve for keeping the first passageway open in the absence of detection of a water leak, and for closing the first passageway in response to the detection of a water leak from the first tank;

(i) a second valve for draining the first tank to the external environment in response to the detection of a water leak from the first tank;

(j) a third passageway from the second valve to the external environment;

(k) means for disconnecting the heating means in response to the detection of a water leak from the first tank, thereby discontinuing the heating of the first tank;

(l) a third valve for keeping the second passageway from the source of water to the second tank open in the absence of detection of a water leak from the second tank, and for closing the second passageway in response to the detection of a water leak from the second tank;

(m) a fourth valve for draining the second tank to the external environment in response to the detection of a water leak from the second tank;

(n) a fourth passageway from the fourth valve to the external environment; and

(o) a first water detector for detecting water leakage from the first tank, the detector comprising

(p) a first float having an electrically-conductive top;

(q) a first pair of electrical conductors disposed below the first float and connected in parallel to a first relay which controls the first and second valves; and

(r) a second pair of electrical conductors disposed directly above and spaced apart from the first float'"'"'s conductive top, and connected in parallel to the first relay;

(s) a second water detector for detecting water leakage from the second tank, the detector comprising

(t) a second float having an electrically-conductive top;

(u) a third pair of electrical conductors disposed below the second float and connected in parallel to a second relay which controls the third and fourth valves; and

(v) a fourth pair of electrical conductors disposed directly above and spaced apart from the second float'"'"'s conductive top, and connected in parallel to the second relay;

the individual conductors of each pair of conductors being spaced apart from one another to form an open circuit in the absence of the detection of a water leak;

the distance separating the individual conductors of the second and fourth pair of conductors being less than the widths of the conductive tops of the first and second floats, respectively, to provide an open circuit in the absence of a water leak;

whereby a first electrical circuit is closed by water contacting the first pair of conductors, thereby closing the first valve and the first passageway, opening the second valve to drain water from the first tank, disconnecting the heating means for the first tank, and discharging the water from the first tank to the external environment;

a second electrical circuit is closed by rising water raising the first float to a level at which electrical contact is made between the second pair of conductors and the conductive top of the first float, thereby closing the first valve, opening the second valve, disconnecting the heating means, and discharging water from the first tank, if these functions have not been performed in response to water contact with the first pair of conductors;

the second electrical circuit is closed by rising water contacting the second pair of conductors, thereby closing the first valve, opening the second valve, disconnecting the heating means, and discharging water from the first tank, if these functions have not been performed in response to electrical contact between the second pair of conductors and the conductive top of the first float;

a third electrical circuit is closed by water contacting the third pair of conductors, thereby closing the third valve and the second passageway, opening the fourth valve to drain water from the second tank, and discharging the water from the second tank to the external environment;

a fourth electrical circuit is closed by rising water raisin the second float to a level at which electrical contact is made between the fourth pair of conductors and the conductive top of the second float, thereby closing the third valve, opening the fourth valve, and discharging the water from the second tank if these functions have not been performed by water contacting the third pair of conductors; and

the fourth electrical circuit is closed by rising water contacting the fourth pair of conductors, thereby closing the third valve, opening the fourth valve, and discharging the water from the second tank if these functions have not been performed in response to electrical contact between the fourth pair of conductors and the conductive top of the second float.

6. A home-protection system, comprising:

(a) a hot-water tank;

(b) a cold-water tank which supplies water to a toilet;

(c) an electrical dish-washer;

(d) an electrical washing machine;

(e) an air-conditioner;

(f) a first water detector disposed proximate the hot-water tank;

(g) a second water detector disposed proximate the cold-water tank;

(h) a third water detector disposed proximate the dish-washer;

(i) a fourth water detector disposed proximate the washing machine;

(j) a fifth water detector disposed proximate the air-conditioner;

(k) a first water line leading from the hot-water tank to the exterior environment;

(l) a second water line leading from the cold-water tank to the external environment;

(m) a third water line for supplying water to the dish-washer;

(n) a fourth water line for supplying water to the washing machine;

(o) a first valve disposed in the first water line, the first valve being activated to open in response to detection of water by the first water detector, thereby draining the hot-water tank to the outside environment;

(p) a second valve disposed in the second water lined the second valve being activated to open in response to detection of water by the second water detector, thereby draining the cold-water tank to the outside environment;

(q) a third valve disposed in the third water line, the third valve being activated to close in response to the detection of water by the third water detector, thereby cutting off the supply of water to the dish-washer;

(r) a fourth valve disposed in the fourth water line, the fourth valve being activated to close in response to the detection of water by the fourth water detector, thereby shutting off the water supply to the washing machine; and

(s) an incandescent lamp being electrically powered in response to the detection of water by the fifth water detector, thereby providing a visual alarm indicating a water leak from the air-conditioner;

each of the first, second, third, fourth, and fifth water detectors comprising;

(t) a float having an electrically-conductive top;

(u) a first pair of electrical conductors disposed below the float; and

(v) a second pair of electrical conductors disposed directly above and spaced apart from the float'"'"'s conductive top;

the individual conductors of each pair of conductors being spaced apart from one another to form an open circuit in the absence of the detection of a water leak, the distance separating the individual conductors of the second pair of conductors being less than the width of the conductive top of the float, to provide an open circuit in the absence of a water leak, whereby a first electrical circuit is closed by water contacting the first pair of conductors, a second electrical circuit is closed by rising water raising the float to a level at which electrical contact is made between the second pair of conductors and the conductive top of the float, and the second electrical circuit is closed by rising water contacting the second pair of conductors.