Shock hazard protection system

• US 5,406,436 A
• Filed: 02/01/1994
• Issued: 04/11/1995
• Est. Priority Date: 12/05/1983
• Status: Expired due to Fees

• Current Assignee: Leviton Manufacturing Company Incorporated
• Original Assignee: Leviton Manufacturing Company Incorporated
• Inventors: Rivera, Lester, Doyle, Richard C.
• Primary Examiner(s): DeBoer, Todd
• Application Number:
  US08/190,720
• Time in Patent Office: 434 Days
• Field of Search: 361/49, 361/45, 361/46, 361/50, 307/326
• US Class Current: 361/50
• CPC Class Codes: H01H 83/02 operated by earth fault currents H01H83/14 takes precedence
• CPC Class Codes: H02H 5/083 responsive to the entry or leakage of a liquid into an electrical appliance moisture alarm G08B21/20
• CPC Class Codes: H02H 5/105 responsive to deterioration or interruption of earth connection for preventing switching-on H02H11/001

Abstract

A new and novel system for protecting people and property against electrical shock. It includes a number of preferred and other embodiments which have this as their goal, but which represent a number of distinctive and novel approaches to solving prior art problems. By way of example only, and without limiting the scope of this invention, these approaches include novel immersion detecting circuits, broken wire test circuits, electromechanical circuit breaking means including coil/plunger arrangements, and relay circuit breaking mechanisms cooperative with associated circuitry, all of which are able to be incorporated as a system wholly within the load (appliance) and its associated cord set (including a "plug").

Claims

1. In combination with a load operatively connected to an A.C. power source by means of a first electrical conductor extending from said power source to said load, said first conductor having a first selectively positionable switch arm therein positionable from its normal first position where said first conductor is interrupted to a second position where said first conductor is complete and a second electrical conductor extending from said power source to said load, said second conductor having a second selectively positionable switch arm therein positionable from its normal first position where said first conductor is interrupted to a second position where said second conductor is complete, immersion detecting means, said immersion detecting means comprising:

a first water-related shock hazard detection conductor situated within said load and connected to said first electrical conductor;

a second water-related shock hazard detection conductor situated within said load and spaced apart from said first water-related shock hazard detection conductor;

said first and said second hazard conductors arranged to detect a water-related shock hazard condition existing within said load;

conducting means connected to said detecting means second water-related shock hazard detector conductor;

circuit interrupting means comprising;

a coil electrically connected to said to said conducting means;

said conducting means comprising a third electrical conductor directly connected to said second water-related shock hazard detector conductor and a diode, a resistor and an actuating circuit element connected in series with each other and in-line with said conducting means and said coil;

said actuating circuit element operating to cut off current to said coil when a water-related shock hazard condition is detected;

a magnetizable plunger member having portions thereof disposed within said coil and coupled to said first selectively positionable switch arm and said second selectively positionable switch arm movable in response to the application of current to said coil to move both of said first and second selectively positionable switch arms from said first position to said second position and upon the cut off of current to said coil to allow both of said first and second selectively positionable switch arms to return from said second position to said normal first position; and

latch means manually operable to move said plunger to cause both of said first and second selectively positionable switch arms to move from their normal first position to said second position.

2. The combination of claim 1 wherein said actuating electrical element comprises a thyristor having a gate element and an anode element, said gate element connected to said resistor at its end remote from said diode and said anode element connected to said coil.

3. The combination of claim 1 wherein said latch means comprises a reset button.

4. The combination of claim 1 wherein said actuating electrical element comprises a transistor having a base element and a collector element, said base element connected to said resistor at its end remote from said diode and said collector element connected to said coil.

5. In combination with a hair dryer operatively connected to an A.C. power source by means of a first electrical conductor extending from said power source to said hair dryer, said first conductor having a first selectively positionable switch arm therein positionable from its normal first position where said first conductor is interrupted to a second position where said first conductor is complete and a second electrical conductor extending from said power source to said hair dryer, said second conductor having a second selectively positionable switch arm therein positionable from its normal first position where said second conductor is interrupted to a second position where said second conductor is complete immersion detecting means, said immersion detecting means comprising:

a first water-related shock hazard detection conductor situated within said hair dryer and connected to said first electrical conductor;

a second water-related shock hazard detection conductor situated within said hair dryer and spaced apart from said first water-related shock hazard detection conductor contained within said hair dryer for detecting a water-related shock hazard condition within said hair dryer;

conducting means connected to said second water-related shock hazard detection conductor;

circuit interrupting means, comprising;

a coil electrically connected to said to said conducting means;

said conducting means comprising;

a third electrical conductor directly connected to said second water-related shock hazard detector conductor and a diode, a resistor and an actuating electrical element connected in series with each other and in-line with said conducting means and said coil;

said actuating electrical element operating to cut off current to said coil when a water-related shock hazard condition is detected; and

a magnetizable plunger member having portions disposed within said coil and coupled to said first selectively positionable switch arm and said second selectively positionable switch arm movable in response to said coil to move both of said first and second selectively positionable switch arms from said first position to said second position and upon the cut off of current to said coil to allow both of said first and second selectively positionable switch arms to return from said second position to said normal first position.

6. The combination of claim 5 wherein said actuating electrical element comprises a thyristor having a gate element and an anode element, said gate element connected to said resistor at its end remote from said diode and said anode element connected to said coil.

7. The combination of claim 5 further comprising latch means manually operable to move said plunger to cause both of said first and said second selectively positionable switch arms to move from their normal first position to said second position.

8. The combination of claim 7 wherein said latch means comprises a reset button.

9. The combination of claim 5 wherein said actuating electrical element comprises a transistor having a base element and a collector element, said base element connected to said resistor at its end remote from said diode and said collector element connected to said coil.