Positive opening damper for combustion appliance
OwnerClifford L. Hoymeinventor
Life of this patent
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Abstract
A normally energized motor maintains a counterbalanced damper closed to block air inflow in a non-combustion condition of an appliance. Deenergization of the motor by thermostat control releases a rotor for displacement through a limited angular stroke. Through a lost-motion linkage connection the damper is displaced, in lagging relation to the rotor to the open position. The open position of the damper is detected by a sensor to open a fuel valve in the appliance.
Claims17
In combination with a control system for a combustion appliance including a fuel valve, a duct and a damper element movable between open and closed positions relative to the duct, the improvement comprising pivot means movably mounted on the duct for pivotally suspending the damper element, a motor, lost-motion transmitting means operatively connected to the motor and driven thereby through an operating stroke for movement of the damper element toward the open position in lagging relation to movement of the motor, and means engageable with the lost motion transmitting means for yieldably displacing said damper element to the open position in delayed response to movement of the motor and the lost motion transmitting means through said operating stroke thereof.
In combination with a control system for a combustion appliance including a fuel valve, an air supply duct having an open end, a damper pivotally displaceable between open and closed positions relative to the open end of the duct, electrically energized operating means for effecting displacement of the damper between said open and closed positions, and thermostatically controlled relay means for deenergizing the operating means, the improvement comprising yieldable transmitting means operatively connecting the operating means to the damper for displacement thereof to the open position in delayed response to deenergization of the operating means through the relay means, and sensing means responsive to detection of the damper in the open position during said deenergization of the operating means for opening the fuel valve.
In combination with a combustion air supply duct including an outlet end, a mount carried by one side of said outlet end, pivot means defining a pivot axis disposed outwardly of and adjacent said one side of said outlet end and swingably supported from said mount for lateral shifting outwardly away from and back toward said one end, a damper plate, said damper plate including an outwardly projecting lever arm from one end of which said damper plate is supported, a portion of said lever arm intermediate its opposite ends being supported for swinging oscillation about said axis with said lever arm disposed transverse to said axis and said damper plate being swingable with said lever arm into and out of position extending across and closing said outlet end, and a thermostat electrical circuit controllable motor operatively connected with the other end of said lever arm by lost motion connecting means for swinging said other end in an upstream direction relative to said outlet end responsive to actuation of said motor, said connecting means operatively connecting said motor to said other end of said lever arm by a lost motion connection therewith wherein full movement of the lever arm to the damper plate open position may lag relative to full actuation of said motor to open said damper plate, said connecting means including a rotor connected to the motor and having a slot formed therein, a link pivotally connected to the damper plate and having an end portion slidably mounted in the rotor slot, said slot and end portion of the link constituting said lost motion connection, and spring means engaging the end portion of the link within the rotor slot for yieldably biasing said lever arm to a position with said damper plate in the open position responsive to full actuation of said motor.
Dependencies are inferred from the claim text.