The invention is in the field of chimney and furnace dampers, specifically safety switches for the operation of gas fueled fireplaces and furnaces.
Home fireplaces and furnaces require an exhaust for smoke or fumes created by combustion. The most common exhaust for such smoke or fumes is a chimney or exhaust vent, providing a direct conduit from the fireplace or furnace to the exterior of the building.
To prevent entry of objects from outside of the building, most chimneys and exhaust vents include dampers to close off access to the chimney or exhaust vent. Such dampers may be mounted within the chimney or exhaust vent or as a cap at the end of the chimney or exhaust vent. For home installations, where chimneys are located at or near a roof, the damper is often affixed at the top of the chimney.
When the furnace or fireplace is in operation, smoke and fumes from the combustion need to exit the building through the chimney or exhaust vent, and the damper must be open for the safe operation of the furnace or fireplace. If smoke and fumes remain within the home a health and safety hazard exists. It is known in the field that ensuring that a damper is open is a key safety feature for any chimney.
Fireplaces and furnaces operated using gas instead of wood for combustion present a clean and consistent flame, with less smoke than wood fires. Gas operated fireplaces in homes are desirable for their ease of use. However, there is a significant health risk in having gas flowing openly within a home. Among the dangers are carbon monoxide and gas poisoning, as well as smoke inhalation or fire. To protect against these dangers, regulations for gas operated fireplaces require dampers to be disabled or fixed in an open position.
Open dampers allow external air and objects to enter a house through the chimney, often with undesired effects. For example, because chimneys are located near the roof of a home, small animals may enter the home through the open damper and chimney.
Therefore, a safe solution is needed to allow a damper to be closed when a gas operated fireplace or furnace is inactive, and conversely, to prevent the operation of a gas operated fireplace or furnace when the damper is closed.
The present invention is a safety switch that prevents the flow of gas in a gas operated fireplace when a damper is in a closed position, and only allows the gas flow when the damper is in an open position. The safety switch is mechanically connected to the damper and electrically connected to a gas line valve. When the damper is in an open position, the safety switch allows the gas to flow, or conversely, when the damper is in a closed position, the safety switch prevents the gas from flowing.
The attached photographs show the invention with a chain connecting to the damper and wires which lead to the gas line valve.
The invention preferably consists of a switch 200 connected to a gas line valve 500 or other control mechanism for controlling the flow of gas or fuel to a fireplace or furnace. The switch 200 is activated by a mechanical connection to damper 110, preferably through the movement of the mechanical connection.
In
As shown in
Switch 200 may be a magnetic reed switch, as is known in the art.
Electrical leads 325 extend from switch 200 to gas valve 500, as shown in
When activating magnet 60 causes magnetic switch element 320 to move to an activating position with respect to switch contact 310, an electrical signal is sent through electrical leads 325 to gas valve 500. Gas valve 500 then opens to allow a flow of gas between gas supply 570 and combustion device 550. In a preferred embodiment, activating magnet 60 is proximate to magnetic switch element 320 and the magnetic field forces magnetic switch element 320 into contact with switch contact 310 for a closed electrical circuit with gas valve 500. In this preferred embodiment, activating magnet 60 is only proximate to magnetic switch element 320 when damper 110 is in an open position.
Activating magnet 60 is preferably part of or attached to an elongated drive mechanism that directs the opening and closing of the chimney damper. The elongated drive mechanism may be a chain, cable or rod, moving in a bilateral manner within or along the chimney as is known in the art. Preferably, activating magnet 60 may be attached to an existing damper control system.
Existing damper control systems are often chains that extend from the damper down into a fireplace, as shown in
The movement of the mechanical connection to the damper also serves to activate switch 200, opening or closing the switch 200, thereby completing the electrical circuit connected to the gas line valve 500.
Where switch 200 is placed within the chimney, switch 200 is preferably made of a thermal resistant material to prevent damage due to heat from the fireplace in use.
Switch 200 may also activate a light, sound, indicator or alarm, advising of the position of the damper 110 and whether it is safe to use the fireplace.
While the preferred embodiment depicts implementation of the invention in a home fireplace and chimney, the invention may also be used with a gas furnace in a home or commercial building.
While certain novel features of the present invention have been shown and described, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing from the spirit of the invention.
Number | Date | Country | |
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62203962 | Aug 2015 | US |