ELECTRICAL MONITOR FOR FIRE EXTINGUISHER

• US 3,664,430 A
• Filed: 10/06/1970
• Issued: 05/23/1972
• Est. Priority Date: 10/06/1970
• Status: Expired due to Term

• Current Assignee: Abdul N. Sitabkhan
• Original Assignee: Abdul N. Sitabkhan
• Inventors: Sitabkhan, Abdul N.
• Primary Examiner(s): Wood, Jr., M. Henson
• Assistant Examiner(s): Grant, Edwin D.
• Application Number:
  US05/078,440
• Time in Patent Office: 595 Days
• Field of Search: 169/23,42,2,26 340/227.1 116/5,106
• US Class Current: 169/23
• CPC Class Codes: A62C 37/50 Testing or indicating devices for determining the state of readiness of the equipment

Abstract

Covers a fire extinguisher for use on aircraft. The fire extinguisher includes a container equipped with mechanism for signalling the pilot in the cockpit in the event that the fire extinguishing fluid has been discharged through the safety relief valve of the container. The fire extinguisher is equipped with a thermally responsive material, which is positioned on or adjacent to the surface of the container and is electrically conductive. The material melts when its temperature reaches a predetermined value. The material is wired to the cockpit of the aircraft and the circuitry includes an indicating device, such as a lamp, to indicate instantly to the pilot that the fire extinguisher has been discharged and that, therefore, the fire extinguisher is not suitable for extinguishing a fire.

Claims

1. The combination of a sealed container housing a fire extinguishing fluid, a thermally responsive, electrically conductive material positioned at or adjacent to the periphery of the container, said material being responsive to the ambient temperature and being melted upon reaching a predetermined temperature to release the fire extinguishing fluid, and indicating means electrically connected to said material to promptly respond to the melting of said material.

2. The combination of claim 1 in which the thermally responsive material is conductively connected to the indicating means over a continuous circuit which is opened upon the melting of said material.

3. The combination of claim 1 which includes a visual indicator electrically connected to the thermally responsive material and electrically disconnected from said material when the material is melted.

4. The combination of a sealed container housing a fire extinguishing fluid, a thermally responsive, electrically conductive material positioned at or adjacent to the periphery of the container, said material, when melted, releasing said fluid, a transistor having base, emitter and collector electrodes, said material being conductively connected between the base and emitter electrodes, a source or voltage, an indicator connected in series between the collector electrode and the source of voltage, and a resistor connected between the base electrode and the terminal common to the indicator and the source of voltage, the indicator monitoring the electrical continuity of said material, whereby the status of the fluid within the housing is observable.

5. The combination of claim 4 in which the thermally responsive material will be melted either in response to a rise in the pressure within the sealed container to a predetermined value or a rise in the ambient temperature to a different predetermined value.

6. Apparatus for continually monitoring the condition of a fire extinguisher having a container housing a fire extinguishing fluid, comprising a safety valve on the surface of the container, a thermally responsive, electrically conductive material inserted in said safety valve, and an indicating mechanism wired to two separated points of said material so that said material provides continuity in the circuit to the indicating mechanism, whereby said mechanism will indicate the continuity of said material, said material having a melting point at which the fire extinguishing fluid will be discharged from the container through said safety valve.

7. Apparatus according to claim 6 in which the thermally responsive material will melt at a temperature which corresponds to a maximum allowable pressure within the container.

8. The combination of a sealed container using a fire extinguishing fluid, a safety valve positioned adjacent to the surface of said container, a conductive material positioned in said safety valve, said material being normally continuous electrically but being severed and rendered discontinuous in response to pressure within the container exceeding a predetermined value or when the ambient temperature exceeds a predetermined value, and electrical circuitry connected in series with said material and indicating the severance of said material, the fire extinguishing fluid being released from said container upon the severance of said material.

9. The combination of claim 8 in which the conductive material is in the form of a thermally responsive, electrically conductive substance which is severed upon the ambient tempera-ture reaching a predetermined value.

10. The combination of claim 8 in which the conductive material is in the form of a conductive tape which is severed in response to an abnormal pressure within the container.

11. The combination of a sealed container housing a fire extinguishing fluid, a safety valve adjacent to the surface of said container, a pressure sensitive disc made of conductive material and positioned within said safety valve, and an electrical cirCuit connected to said disc so that said disc forms a serial element of said circuit, said disc being punctured in response to a rise in the pressure of said container above a predetermined value, so that the fire extinguishing fluid may be discharged through the opening provided by said punctured disc, whereby the electrical circuit will continuously monitor the condition of the fire extinguishing fluid within said container.