An automatically activated fire extinguishing device for a stove. The device is installable in a hood over the stove and has a compact design which substantially hides portions of the device from normal viewing. The invention also includes an automatic stove shut-off which shuts off the electricity or gas to the stove in the event of a fire.

Fire extinguisher installation

A fire extinguishing system for suppressing fires on cook stoves, fryers or other heating or heated devices with fire suppressant dispensed through nozzles is powered by batteries which provide current for both a detection circuit including a pair of heat sensors and control circuitry and current for a gas or electric house current shut-off. The appliance shut-off device is operated by the standard hardwired interconnect cable that provides a signal between the control board and shutoff device or by an optional sonic receiver assembly that is acoustically tuned to detect an audible alarm emitted by a signal from the main control board. Preferably, the heat sensors are diodes, but in alternative embodiments may be thermistors or active temperature sensors. Mounting of heat sensors and nozzles are facilitated by tees and 90 degree elbows. While the standard interconnect cable is usually used between the control circuitry and shutoff device, a wireless link, such as the sonic receiver assembly, may also be used with the shutoff device.

Fire extinguishing systems and methods

An automatic fire suppression unit and method for use in various fire exposures where the area in which a fire can occur is limited, manually operated portable extinguishment is either impractical or not recommended, the ability to provide additional suppression in the event of re-ignition is crucial to fire safety, or the ability to limit environmental impact of the fire suppressant is desired. The system includes a tank containing a suitable fire extinguishing agent and equipped with a temperature activated valve to discharge the extinguishing agent when a thermocouple or metallic alloy element responds to a high temperature condition and opens the valve. When the fire has been suppressed and a high temperature condition no longer exists, the valve automatically closes and stops the discharge of suppressant. Position indication contacts within the valve are utilized to activate appropriate alarms and to remove electrical or gas supply if necessary.

Automatic fire suppression apparatus and method

A fire suppression system for use with a cookstove or range operates in several modes or stages to warn of, prevent, and extinguish stovetop fires. The system includes a pressurized supply of fire retardant (52) connected to a nozzle (62). A fusible link (34) releases the fire retardant through the nozzle (62). Several sensors (38) are attached to the circuit so that increasing ambient temperature can be monitored. The supply of fire retardant is provided with a low pressure sensor which may be overridden. On sensing a first temperature increase, a fan (42) is switched on. At a second temperature, an alarm is activated. At a third temperature, the stove is shut down. The fusible link (34) is to melt at a temperature higher than the third temperature so that provisional measures may be activated prior to dispensing the fire retardant. Methods related to the fire suppression system are also disclosed.

Fire suppression system and method for its use

A range hood positioned above a cooking range employs a continuous heat sensor system which includes twisted wires which are separated from one another by an insulator which is formed of a material which melts at a predetermined temperature The wires carry a supervisory current which is monitored continuously When the magnitude of the current is increased, such as by the creation of a short-circuit condition as would be caused by the presence of a fire, an actuation signal is issued to an actuator, which may include an explosive squib The explosive squib releases a tension wire which holds a discharge valve in a closed position, permitting a fire suppressant fluid to be discharged from a supply tank Monitor circuitry ensures that open-circuit or short-circuit faults do not disable the functioning of the actuation system Multi-condition fault indicators alert the user visually and audibly of system faults

Wire-sensored fire extinguisher with fault-monitoring control system

An automatic fire extinguishing system for ranges having top burners, including a hood, mountable over the range, tanks containing fire extinguishing fluids remotely located from the hood, solenoid operated valves connected in circuit with heat sensors and power lines to discharge fluid from the tanks when the heat sensors are operated. The range may have electric or gas burners. A solenoid operated switch or solenoid operated valve is connected in circuit with the heat sensors to open the power line to the electrical burners or to open the gas main to the gas burners when the heat sensors operate. An automatically operated exhaust fan and audible alarms are also provided. The system includes manually operable set and reset switch means.

James W. Walden

Papers

Fire extinguishing system