Abstract: This invention provides a water heater including a water storage tank, a flue, a jacket around the tank and the flue and having a top end, a top cover which extends over the tank and the flue and which closes the jacket top end, and a flue collector within the top cover and having an exhaust opening within the top cover and in communication with the flue. The water heater further includes a flue damper mechanism comprising a damper disk pivotally mounted within the flue collector exhaust opening so that the disk can pivot between a closed position closing the exhaust opening and an open position opening the exhaust opening, and drive means for pivoting the damper disk. The drive means comprises a damper actuator exterior of the top cover, a mounting tube secured to the flue collector and secured to the damper actuator, and a damper shaft within the mounting tube and extending between the damper actuator and the damper disk.

Abstract: A combination damper and chimney cap apparatus is provided to ventilate a fireplace and a flue connected thereto to provide a draft through the flue. The apparatus includes a platform constructed and arranged to be removably mounted to the flue and formed with an aperture extending therethrough in communication with the flue. An element senses temperature-smoke at the flue and at an area external to a fireplace connected to the flue to provide a signal in response to the temperature-smoke. A ventilation fan is connected to the a support to provide a draft sufficient to exhaust the smoke from the fireplace and the flue and to cool a electronic motor for the apparatus.

Abstract: An oven, particularly with an apparatus for pyrolytic self cleaning, includes an oven wall having an exhaust opening formed therein through which exhaust produced during oven operation can flow out to the outside. A throttle automatically adjusts an exhaust flow cross section of the exhaust opening or of a flow conduit adjoining the exhaust opening.

Abstract: A stack damper control apparatus for positioning a stack damper and controlling a fuel source in response to closing of a temperature sensitive switch. Limit switches comprising drop cams are coupled to the drive shaft of the damper. In response to a call for heat, a motor turns the damper, coupling a source of energy to a fuel source when the damper is open and the limit switches transfer. A relay coil is energized to hold open a switch providing a parallel energization path for the motor. When the call for heat has been met and the temperature sensitive switch opens, the relay de-energizes closing the parallel energizing path and allowing the motor to close the damper. Provision is made for a safety interlock to ensure the fuel source is not activated when the damper is closed. Provision is also made for interface to a blocked vent shutoff system.

Abstract: A flue gas closure system for a furnace which includes a burner and a heat exchanger through which flue gas flows. The system includes a closure member which in an open position permits the flow of flue gas through the heat exchanger and in a closed position prevents the flow of air through the heat exchanger and means for causing said closure member to be in an open position when the burners are on and to be in a closed position when the burners are off. The closure member includes a closure plate which is slidably connected to the heat exchanger. An actuator is connected to said closure member for moving said closure member to at least one of the open and closed positions.

Abstract: A furnace comprises a housing, a fan or blower for moving air through housing, a burner in the housing, fuel supply means operatively connected to the burner, a heat exchanger in the housing a combustion chamber, the burner cooperating with said combustion chamber, an enclosure enclosing the heat exchanger and burner, said enclosure having an opening therein, and a damper operable to control the flow of air through said opening to the heat exchanger. The damper comprises a plate member pivotally mounted in the housing for opening and closing said opening. Preferably a drive motor opens the plate member and a spring biases the plate member closed. The damper is closed when the burner is off and is open when the burner is on. There is a circuit associated with the fuel supply means which is responsive to a predetermined open position of the plate member for permitting the flow of fuel through the fuel supply means when the plate member is open to said predetermined open position.

Abstract: A remotely controlled, reversible drive motor is mounted on an extension of the upper end of a chimney below a protective housing enclosing a spiral cam drive mechanism converting rotational movement of the motor into vertical linear motion of a cap laterally spaced from the housing in axial alignment with the chimney extension. Guided movement is thereby imparted to the cap between a closed chimney sealing and open positions.

Abstract: A method of and apparatus for automatic flue damper control of a solid fuel burning stove has a driveshaft connected to the damper, a plurality of cams on the driveshaft, a plurality of thermoswitches on the chimney pipe, a plurality of selection switches operated by the cams, and an electric motor controlled by the thermoswitches and the selector switches for moving the damper to open, partial and closed positions in response to low, rising, and too high temperatures respectively.

Abstract: A blanking cover for a pipe comprises a plate able to close the pipe by tilting or rocking under the action of gravity, about a pivot pin to which it is fixed. A part is fixed to the pin, and an electromagnet able to retract the part and fixed to another part rotates on the pin and a jack is provided for actuating the other part. When excited, by attracting the part, the electromagnet makes it possible to keep the pipe open. Its deexcitation leads to the tilting of the plate and consequently to the closing of the pipe. If a tilting or rocking problem occurs, the action of the jack on the other part brings about the tilting by displacing the part. In order to reopen the pipe, the jack is actuated so as to press the excited electromagnet against the part and is then actuated in the opposite direction.

Abstract: A hot air circulating oven in which separate shape memory alloy springs are employed as a drive means to open and close a damper for the oven.

Abstract: A damper control is employed in the exhaust duct of a bakery oven to maintain constant air mass flow through the duct during a baking cycle to ensure even baking conditions. The damper control can include a pitot tube from which velocity pressure can be derived, and a pneumatic or electronic control loop to move an exhaust damper in the exhaust duct as necessary to keep the velocity pressure constant.

Abstract: A thermal shock chamber comprising a test area, a high-temperature air conditioning unit having a gas outlet and a gas inlet adjacent to the test area, an outside air supplying unit having an air outlet and an air inlet adjacent to the test area, a low-temperature air conditioning unit having a gas outlet and a gas inlet adjacent to the test area, a first damper assembly for opening the outlet and the inlet of one of the high-temperature air conditioning unit and the outside air supplying unit and closing the outlet and the inlet of the other unit at the same time, and a second damper assembly for opening the outlet and the inlet of one of the low-temperature air conditioning unit and the outside air supplying unit and closing the outlet and the inlet of the other unit at the same time.

Abstract: A control system is provided for controlling a flue damper in a furnace flue. The control system includes a voltage source, a thermostat, a gas valve, and means for moving the flue damper between a closed position and an open position. The moving means includes a timer driven by a motor with a specially wound coil assembly including a first winding and a second winding. The coil assembly further includes a first terminal, a second terminal and a center tap terminal. The control system manipulates the flue damper and heating system during three stages of operation. The flue damper is closed and the furnace is off at the beginning of stage one. The control system opens the flue and turns on the furnace during stage one. The flue damper remains open during stage two. The control system turns off the furnace and closes the flue damper during stage three.

Abstract: A solenoid operated exhaust damper having a housing designed for installation as a segment of an exhaust air duct and upper and lower adaptor sleeves for connecting the housing to exhaust ducting of conforming size and shape. Inside the housing, attached to mounting means is a solenoid having an energized and deenergized position for its solenoid shaft. Included is a plunger, disposed within said housing, and plunger seating means, attached to the housing, for forming an air-tight seal with the plunger when the solenoid is deenergized. A coiled spring is installed in compressive engagement with both the mounting means and the plunger and adapted for pressing the plunger against the plunger seat when the solenoid is deenergized. A control rod connects the plunger to the solenoid shaft and is adapted to pull the plunger away from the plunger seat when the solenoid is energized.

Abstract: A control system for controlling movement of damper blades in a damper housing being open and closed positions consists of a support member having a driving link movable thereon and moved through a drive means. The driving link is biased to a closed position by a spring and is moved to an open position through the drive means, which is disengaged from the driving link through a power-operated member. The drive motor and the power-operated member connected to a power source through an electric circuit which incorporates switches and sensors that will automatically cause the damper blades to close under preselected conditions and a manual-override for remote-control and for manually overriding the temperature-sensing mechanism when desired.

Abstract: A combined microwave and electric heater oven includes a fan system for cooling a magnetron, and a damper for selectively introducing a forced air flow generated by the fan system into an oven cavity. A damper cam is secured to a drive shaft of a damper motor, and a damper link is disposed between the damper cam and the damper to drive the damper. A microswitch is disposed near the damper cam so that the microswitch develops a first detection signal when the damper is tightly closed. In response to the first detection signal, the rotation of the damper motor is terminated to hold the damper in the tightly closed state. The microswitch develops a second detection signal when the damper is placed in the full-open state. In response to the second detection signal, the rotation of the damper motor is terminated to hold the damper in the full-open state.

Abstract: An automatic vent damper control mechanism for use on furnaces or the like having a spring loaded open position and an electric motor which drives it to a closed position, against the spring bias, via a gear train. A unique over-travel mechanism is provided which prevents damage to the gear train from occurring when the damper reaches the end of its travel towards its open condition.

Abstract: The present invention is concerned with an improved automatic, direction drive damper device constructed for installation over the terminal openings of furnace duct boots residing within room registers, said device being used as a part of a forced air heating/cooling system for the purpose of controlling and regulating the flow of the heating/cooling medium passing into individual rooms from furnace duct. Direct drive damper means include damper housing with rotatable damper plate, said plate having an integral shaft attached directly and removably to drive shaft of motor means, said damper plate being rotatable between open and closed positions by direct drive motor means when said motor means respond to commands of room thermostat.

Abstract: A damper device insertable into a slotted duct or flue without cutting completely through the duct, including a sleeve conforming to the duct cross-section and adapted for insertion through the slot to nest within the un-cut duct portion. A damper plate with stiffener ribs is rotatably mounted within the sleeve. An apertured cover plate slightly larger than the duct slot size is located to overlap the slot for mounting the damper device to the duct, and a spacer plate may be placed intermediate and rigidly attached to the cover plate and the sleeve for reinforcing the support at one end of a damper shaft. The damper shaft may be rotated manually or by means of a motor mounted by a bracket to the cover plate.

Abstract: The present invention relates to a self-checking safety switch control circuit for a power combustion system. The circuit comprises a safety switch, a combustion blower relay, a thermal pilot switch, and a fuel supply system. The safety switch operates to detect flow through the combustion system. The safety switch either operates the pilot switch directly or operates the fuel supply system directly to shut down the system if no flow through the combustion system is detected. The circuit has a self-checking feature because combustion cannot be initiated in a subsequent cycle of the system if the safety switch remains in the proven condition from the previous combustion cycle.

Abstract: A control system for an automatic damper in a heat generation system. The damper is provided with a spring biasing arrangement to open the damper when the plant is generating heat to permit unobstructed discharge of the products of heat generation. A motor maintains the damper closed when no heat is being generated. Provision is made for disabling the control system permitting the damper to be opened by the spring and the heat generator to function normally when a malfunction occurs in a switch which normally performs in a safety capacity. Included in this arrangement is a fuse in a circuit which opens the circuit when the switch fails as the result of a short circuit or welding of the contacts. The circuit includes means for preventing short circuiting during normal operation.

Abstract: In the event of a malfunction of the unit, the damper plate may be moved to and locked in the open position, to permit the furnace to operate. With the plate locked, the motor would normally run continuously, even when the furnace was not operating. This is because the closed position of the plate, necessary to turn off the motor, cannot be reached. A slip clutch, located between the motor shaft and the plate, has parts which slip relative to each other when the motor is running but the plate is locked. The contours and biasing of the parts causes one part to move a limited distance, in a direction opposite to normal. The motor is stopped in response to this oppositely directed movement.A bent portion of the plate positioning shaft is freely received in a recess elongated in and laterally spaced from the motor shaft for self-alignment and to permit the oppositely directed movement necessary to stop the motor.

Abstract: A controlled air intake apparatus for a furnace includes a substantially flat cover plate attached to and placed over the updraft opening of the flue and a generally rectangular housing attached over the air intake opening adjacent the burner region. The housing includes a first open side and opposite thereto a side including a plurality of apertures. The remaining sides of the housing are enclosed. The first plurality of apertures are disposed into two rows and the housing further includes a cover plate with a similar arrangement of apertures. The cover plate is slidably received by the housing and is movable by means of a solenoid between an aperture-closed orientation and an aperture-open orientation.

Abstract: For use in a ventilation flue or the like, a damper positioning mechanism comprising a yieldable means biasing said damper toward a first position, motive means for opposing the bias of said yieldable means to drive said damper to a second position and thermally responsive means modulating the return of said damper from said second position to said first position, said thermally responsive means being strong in relation to said yieldable means. In one embodiment the thermally responsive means resists closure of said damper until exposed to a sufficiently low temperature. In another embodiment the thermally responsive means resists opening of said damper until exposed to a sufficiently high temperature.

Abstract: A damper assembly for solar heating systems and the like includes a damper blade pivotably mounted to a peripheral main frame. The damper blade is surrounded by a peripheral flexible sealing element which extends inwardly from the surrounding frame and which is inclined in a direction against the direction of closing damper blade movement. As the damper moves toward a closed position, its sides progressively engage the side portions of the sealing element, with the latter providing a seal with the peripheral face of the blade. The ends of the blade engage the sealing element prior to the blade finally reaching its ultimate closed position, with the sealing being complete at the moment of engagement and throughout the final range of blade movement. The peripheral sealing element is mounted to a subframe which is adjustable on the main frame to thereby sealingly accommodate a warped damper blade.

Abstract: A controlled air intake apparatus for a furnace includes a substantially flat cover plate attached to and placed over the updraft opening of the flue and a generally rectangular housing attached over the air intake opening adjacent the burner region. The housing includes a first open side and opposite thereto a side including a plurality of apertures. The remaining sides of the housing are enclosed. The first plurality of apertures are disposed into two rows and the housing further includes a cover plate with a similar arrangement of apertures. The cover plate is slidably received by the housing and is movable by means of a solenoid between an aperture-closed orientation and an aperture-open orientation.

Abstract: This device provides a means of automatically detecting smoke in a room, through an ionization chamber, prior to it being noticed by humans. It consists primarily of an automatic control unit, which through a small servomotor will open the fireplace damper in step fashion, or close it to conserve heat. It further includes a manual over-ride switch for use when desired.

Abstract: A stack damper valve comprising a pair of semicircular steel discs typically joined by a removable piano-type hinge. Each of the discs pivot upwardly in the direction of flow from a closed to an open position and vice versa. In the closed position the discs seat in a metal-to-metal relationship against a circular truncated steel seat which is secured such as by welding to the inner surface of the steel stack in which the valve is mounted.

Abstract: A device for generating an electric output signal in response to the positioning of a mechanical member. The mechanical member carries an optical fibre, and the optical fibre coacts with one of several, preferably two, phototransistors in response to the setting position of the mechanical member. The phototransistors are connected to an amplifier generating the electric output signal corresponding to the member's position.The device may be used in control equipment for controlling the draught in a boiler, preferably an oil-fired boiler.

Abstract: In a flue damper control system, a thermistor 64 responsive to flue temperatures upstream of the damper 12 is incorporated in a trigger circuit for a triac 52 which controls energization and deenergization of the damper motor 17, the damper motor being fully energized only when the flue temperature is below a predetermined value and there is no demand for heat by the thermostat 36.

Abstract: An automatic vent damper control mechanism for use on furnaces or the like having a spring loaded open position and an electric motor which drives it to a closed position, against the spring bias, via a gear train. A unique over-travel mechanism is provided which prevents damage to the gear train from occurring when the damper reaches the end of its travel towards its open condition.

Abstract: A chimney cap for closing and venting, selectively, the upper end of the chimney is manually controlled by means of chains or the like from a combustion area, particularly a fireplace, through counterweights and pulleys. Automatic control is determined by a smoke, heat, or incipient fire detector that will operate a hold relay to produce a signal split between a reset timer and double-throw, double-pull switch that is in turn operated by the position of the cap to operate a reversible motor for movement of the cap to its upper vented position upon the detection of combustion products within the chimney. Movement of the cap to its upper position will shield the detector and other electronics from combustion products, and after a timed period, the reset timer will actuate the motor to move the cap to its closed position where it will remain unless the detector again detects the presence of combustion products.

Abstract: An automatic damper means and controls, which provide an exceedingly safe automatic damper for the exhaust duct-work of an associated gas furnace or the like, by automatic control of the damper, and automatic control of the gas supply, with redundancy features for providing exceedingly safe operation.

Abstract: An automatic vent damper for combustion devices such as furnaces which closes the combustion chamber exhaust vent when the furnace burner is off to conserve heat and prevent backdrafts. A damper blade pivotally mounted in the exhaust vent is closed by an electrically-operated damper motor operating against a torsional spring urging the damper plate into the open position, the damper motor being energized whenever burner operation is not in demand by the automatic controls. When the controls call for burner operation, the motor is deenergized and the damper blade moves to the open position under the influence of the torsional spring. A limit switch senses the damper blade achieving the open position and enables burner operation.

Abstract: A conventional forced air furnace is provided with a source of outside air for use in combustion. The amount of outside air admitted to the furnace and the amount of heated air lost through the chimney are regulated by simultaneously operable dampers synchronized with the operation of the furnace. Alternate power circuits and an alarm system for the dampers are provided.

Abstract: A gas-fueled oven having energy saving capabilities provided by a thermostatically controlled gas supply valve which supplies fuel to the gas burner at cycled intervals, and a flue restricter which is operatively connected with the thermostat to move into closing relation to the oven exhaust flue when the burner is cycled off, thereby retaining within the oven cavity an amount of heat which would normally be allowed to escape through the flue if the flue restricter was not utilized.

Abstract: A flue throttle to control the amount of flue gas or heated air going out the flue from a heating system, by throttling the flue to the minimum amount required while the heat source is on and to change to a further reduced or a complete throttling of the flue when the burner or heat source is off. The heat source referred to throughout this application is from the combustion of fuel through an electric motor driven burner.

Abstract: For a vent or flue damper of the type in which the damper is closed by an electrically energized actuator when the furnace is off and the actuator has first biasing means to open the damper when the actuator is deenergized, a second biasing means such as a torsion spring, independent of the first biasing means, is associated directly with the damper shaft and is adapted to always move the damper to an open position in the absence of the actuator.

Abstract: An automatic flue damper positioned respectively to open and closed positions by means of motive apparatus, such as a solenoid motor, is provided with mechanical means for automatically latching the damper in its open position.

Abstract: For an automatic flue damper assembly of the type in which the motor of a clockwork mechanism is energized to hold the damper closed and the mechanism is mechanically biased to move the damper to an open position in the absence of motor energization, a stopping or braking arrangement is provided which applies DC to the motor for dynamic braking as the damper closely approaches its open position. Additionally, the remote possibility of a damper hang-up at an intermediate position resulting from a residual magnetic locking torque is substantially eliminated through the provision of an AC trickle circuit connected to the motor.

Abstract: Apparatus and a method for assuring safe retrofit installation of a flue damper in a hot air furnace. The flue damper is electrically connected to the original furnace control circuit by engaging a flue damper connector with a portion of a printed circuit board containing part of the furnace control circuit. The physical configuration of the adapter and the printed circuit board require removal of a jumper conductor within the printed circuit board prior to connection of the adapter thereby assuring that the flue damper is correctly installed so that it will be in the open position before the furnace may be ignited.

Abstract: An improvement in space heating furnaces fueled by gas or liquid for saving heat ordinarily lost through the draft system of such a furnace, comprises a means of automatically closing the air inlet to the combustion chamber as well as the air inlet to the diverter air opening at the flue immediately after cessation of the main burner flame, and also for opening both of the air inlets immediately prior to the ignition of the main burners.

Abstract: A gas furnace employs an exhaust flue damper driven by an electric motor equipped with position indicating switches. A gas flow detector switch supported in the gas line has a vertical passage and a valve member gravity biased into a rest position in which it blocks gas flow through the passage. Fuel flow through the line creates a differential pressure on the valve, raising it above the rest position. Circuitry interconnecting the damper drive and position indicating switches and the gas flow switch with the furnace thermostat and the gas line control valve, positions the damper in a closed position when there is no gas flow to the furnace and in an open position otherwise and prevents energization of the gas flow valve when the damper is closed.

Abstract: A flue damper control includes a flue pipe, a damper in the flue pipe and an electro-mechanical control for opening and closing the damper according to thermostatically controlled conditions. The damper control is provided with an adjustment means to adjust the "full" open and "full" closed positions of the damper vane.

Abstract: In the present invention, an automatic flue damper located in the vent stack of a household furnace or other apparatus requiring venting is interfaced with a thermostatic control and a fuel supply valve associated with the apparatus so as to maintain a vent passage to the atmosphere normally open during times when combustion is occurring in the apparatus and to close the vent passage at an appropriate time following the termination of combustion in the apparatus. The normally open vent condition is maintained by a damper positioning spring. Vent closure following combustion is accomplished by means of a direct current solenoid. Further included in the interfacing circuitry are a temperature sensing device effective to disable the solenoid, thus opening the vent, upon the appearance of unsafe stack temperatures and a pressure sensor which also disables the solenoid to open the vent stack upon the occurrence of an inappropriate discharge of fuel to the combustion chamber.

Abstract: In a fuel-burning device having a combustion chamber, a burner with a control, an exhaust stack connected to said chamber, an air diverter in said stack and a thermostat connected to said burner control; the improvement which comprises a damper section in the stack downstream of the diverter. The damper is disposed within and journalled upon bearings attached to the damper section. A motor on the damper section has an output shaft connected to the damper and includes a rotary switch on said shaft. An electrical circuit includes a relay switch interconnecting the thermostat, burner control, motor and rotary switch. The motor output shaft is intermittently rotatable through successive arcs of 90.degree., through 360.degree., whereby the damper normally closes the stack preventing escape of room air therethrough when the burner is not operating. The thermostat, when calling for heat, closes the circuit to the motor rotating the damper 90.degree. to open position and successively energizing the burner.

Abstract: An automatic boiler damper comprising a solenoid valve secured to the pivot axis of a damper included within a stack utilized to vent a heating system. The solenoid is electrically operated upon the closing of a thermostat secured to the stack at a point immediately over the damper location. The damper is provided with a vent hole which enables the thermostat to detect the presence of heated stack gases in sufficient quantity and temperature flowing upwardly from the damper in the closed position, so as to enable the solenoid to open the damper and vent the stack gases through the stack. Heat is conserved thereby and cold drafts are not permitted to enter the stack as a downdraft.

Abstract: An improvement in a system comprising a heat stack, a damper having a vane in said heat stack, actuating means for opening and closing said damper, the actuating means being electrically connected to and responsive to a thermostat in an electrical circuit containing the heating means for generating heat, the by-products from which pass through the heat stack, the improvement residing in that the actuating means comprises an electric motor which is spring biasedly connected to the vane, the electric motor being in a normally "On" position having current passing therethrough and holding said vane against the action of said spring in a closed position. Means are provided to deactivate the motor and allow the spring to return the vane so that the stack is in an open position.

Abstract: In the present invention, an automatic flue damper located in the vent stack of a household furnace or other apparatus requiring venting is interfaced with a thermostatic control and a fuel supply valve associated with the apparatus so as to maintain a vent passage to the atmosphere normally open during times when combustion is occurring in the apparatus and to close the vent passage at an appropriate time following the termination of combustion in the apparatus. The normally open vent condition is maintained by a damper positioning spring. Vent closure following combustion is accomplished by means of a direct current solenoid. Further included in the interfacing circuitry are a temperature sensing device effective to disable the solenoid, thus opening the vent, upon the appearance of unsafe stack temperatures and a pressure sensor which also disables the solenoid to open the vent stack upon the occurrence of an inappropriate discharge of fuel to the combustion chamber.

Abstract: An automatic damper means and controls, which provide an exceedingly safe automatic damper for the exhaust duct-work of an associated gas furnace or the like, by automatic control of the damper, and automatic control of the gas supply, with redundancy features for providing exceedingly safe operation.