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: A vent assembly adapted for venting into the atmosphere hot burner exhaust gases from the flue exhaust port of a heating appliance within an enclosure, such assembly including an exhaust duct and a relief duct. The exhaust duct is connected at one end to said flue exhaust port and is opened at its other end to the ambient atmosphere outside of the enclosure. A selectively responsive closure device, such as a thermally controlled damper, is disposed within the exhaust duct. The relief duct is connected to the exhaust duct at a point along the flow of exhaust gases upstream of the closure device and has a relief aperture disposed at a height between that of the exhaust port and that of the burner.

Abstract: A draft control plate, which automatically opens or closes to provide efficient draft conditions in a furnace, is provided with both horizontal and vertical counterbalance devices which respectively permit adjustment of the initial position of the plate and the sensitivity of its movements. Initially, the plate is partially open where it remains while the furnace is operating under normal conditions. It is then capable of opening or closing in response to changes in the pressure differential across it. Preferably, the plate is horizontally mounted in an auxiliary flue channel which is adjacent to and in connection with the main flue of the furnace.

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: For a single blade damper, an improved damper operator including a bimetallic element, one end of which is attached to the frame of the damper, and the other end of which is pivotally associated with a bracket connected to the damper blade.

Abstract: An energy-saving closure system is provided for use in preventing needless energy loss. The system employs a pivotal closure adapted to alternately move between the fully open and fully closed portion in a conduit for conveying gases relative to a combustion zone. The closure requires pressure diffentials only for being urged into the open and closed positions such as normally occur in the heating cycle. No energy-consuming, auxiliary apparatus is needed.

Abstract: A draft control plate, which automatically opens or closes to provide efficient draft conditions in a furnace, is provided with both horizontal and vertical counterbalance devices which respectively permit adjustment of the initial position of the plate and the sensitivity of its movements. Initially, the plate is partially open where it remains while the furnace is operating under normal conditions. It is then capable of opening or closing in response to changes in the pressure differential across it. Preferably, the plate is horizontally mounted in an auxiliary flue channel which is adjacent to and in connection with the main flue of the furnace.

Abstract: There is disclosed a damper for controlling the flow of high temperature gases to respective hearth chambers of a multiple hearth furnace, for example, the damper being formed of temperature resistant ceramic plate having an air cooled shaft extending diametrically therethrough and insulated from the plate by a heat resistant ceramic fiber material.

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: This invention is concerned with a removable filter to prevent the buildup of Creosote in chimneys which become vulnerable to fires.A hollow enclosure means that is adapted to connect between the chimney and the fire source has within it a support for mounting a filter. The filter is made of a special metal, is knitted with small openings therein permitting the flow of smoke but at the same time to reduce the particles into a minute white ash. The filter acts as a continuous burn reactor. A door is provided whereby the filter can be easily removed from the hollow enclosure and cleaned so that it can be used for an indefinite period without replacement.

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 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: A flue restrictor for installation in the flue piping of a heating system to reduce its effective cross sectional area comprises sheet metal inlet and outlet sections having flanges secured together in a joint that has a guideway in it for a sheet metal gate valve that may be transversely positioned to produce the desired cross-sectional area and riveted in place to provide a substantially tamper-proof assembly.

Abstract: A combination powered flue products exhaust and preheated combustion air supply assembly is provided for use in association with a heating furnace so that flue exhaust products are given a positive exhaust to the outside while a balanced pre-heated combustion air supply is simultaneously and positively pulled inside. A compartmented main housing is provided having flue products exhaust and combustion air compartments. A flue products exhaust fan is provided in the flue products exhaust compartment and a simultaneously activated and driven combustion air intake fan is provided in the combustion air compartment. An outside air intake pipe is connected to the main housing so as to deliver combustion air to the combustion air compartment for delivery to the furnace area upon selective activation of the combustion air intake fan.

Abstract: A fuel economizer, for mounting in a flue pipe between a furnace and a chimney, having a lateral vane overlying a cutout in the flue pipe and carrying a baffle plate in between ends thereof mounted transversely to the flue pipe to obstruct a portion of the passageway therein. A housing overlies the vane. Hinge and weight means are attached to the vane and baffle plate to permit opening of the baffle plate, in response to gas pressure exerted on an interior surface of the vane, and closing down thereof, to maximize efficiency of the furnace by providing a properly sized flue outlet during different phases of use of the furnace.

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: A damper construction, comprises, a central hollow tubular pipe pivot portion having an axially extending interior pipe coolant flow passage therethrough and a substantially cylindrical flat plate portion connected to the pipe pivot portion. The pipe pivot portion is mounted for rotation in a bearing formed at diametrically opposite sides of a tubular conduit made up of walls formed by longitudinal pipes arranged side-by-side in a circular pattern and welded together. The bearing includes a hollow portion and it is furnished with coolant which is circulated through the pipes of the conduit.

Abstract: A damper assembly for association with the draft hood of a fuel fired heating appliance to control flow of exhaust gases through both the flue tube and the vent pipe. The assembly comprises a pair of damper members shaped to conform to the cross-section of the inlets and outlets of the draft hood. The damper members are spaced apart a distance equal to the distance between the inlet and outlet and carried from a single mounting shaft which extends transversely into the draft hood generally midway between the inlet and outlet openings. Suitable power means are provided to rotate the damper members from a first position in which they are in alignment with the inlet and outlet openings to a second position wherein they are out of alignment and permit free flow of exhaust gases.

Abstract: A damper assembly for use in gas-conducting conduits including a damper blade with a cavity therein for receiving a fluid and a plurality of outlet ports in flow communication with the cavity to provide means for providing a pressurized fluid seal around the damper blade when in a closed position.

Abstract: A heating wall for coke ovens with horizontal coking chambers comprises vertical heating flues arranged in pairs, every pair of adjoining heating flues being separated by a partition formed with a flow port in the upper portion. Lateral sides of the flow port are provided with vertical slot-like guides which accommodate projections of a slide gate. The guides are formed in their upper portion with stepped recesses the vertical extent of which exceeds the length of the slide gate projections. The slide gate center of gravity is shifted with respect to the longitudinal axis of its projections in the direction opposite to the stepped recesses. The slide gate is provided with means for introducing a hook and vertically moving the slide gate into its uppermost and lowermost position in the flow port. As a result, the flow port vertical position is changed substantially without changing the clear opening of the flow port.

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 ventilated poppet damper assembly for use in a gas conveying conduit to selectively allow and prevent the flow of gas through the conduit has a movable pair of spaced apart damper plates which define a transverse chamber when in the closed position. The transverse chamber is vented to insure that there is no leakage of conveyed gas past the closed damper plates.

Abstract: Method and apparatus for the heat treatment of volatile containing materials in a rotary hearth type furnace wherein the flue gases emanating from the calciner are employed to create either a positive or negative pressure within the calciner hearth as well as the soaking pit area of the said calciner.

Abstract: A control arrangement for a heating system including a furnace having a fuel-fired burner apparatus and a vent stack with a motor driven damper plate for opening and closing the stack, includes an interlock switch which provides a safety interlock between fuel supply valves of the system and first and second limit switches which control the energization of a drive motor for the damper plate and effect energization of the fuel supply valves of the system, permitting the fuel valves to operate only when the damper plate is in the open position and preventing energization of the fuel valves in the event of a malfunction of either of the limit switches. The interlock switch also permits recycling of the system in the event of a momentary power interruption. The control arrangement may include a stack mounted heat sensor switch which interrupts the energizing path for the fuel supply valves in the absence of heat from the main burner within a predetermined interval of time.

Abstract: A control arrangement for a heating system including a furnace having a fuel-fired burner apparatus and a vent stack with a motor driven damper plate pivotally mounted within the stack, includes a stack damper control circuit including first and second limit switches which permit energization of a drive motor in response to a request for heat, premitting the damper plate to be driven to an open position, and for energizing an interlock switch which prepares an energizing path for fuel supply valves of the system, the first limit switch being operated when the damper plate approaches the open position to complete the energizing path for the fuel supply valves prepared by the interlock switch, and the second limit switch deenergizing the motor when the damper plate is driven to the fully open position. The motor is reenergized at the end of the heating cycle to drive the damper plate to the closed position, and the second limit switch deenergizes the motor when the damper plate reaches the closed position.

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: A damper assembly for high temperature or corrosive gases including a flow through housing with a damper blade disposed therein, the damper blade including a metallic plate member attached to a transversely extending support member which extends through openings in the side walls of the housing. The plate member includes means for receiving refractory thereon wherein the refractory substantially covers the plate member and is divided into a plurality of preselected sections, each section being separated by a material having a relatively low disintegrating temperature whereby upon initial heating of the damper assembly to temperatures higher than the disintegrating temperature of the relatively low disintegrating material, the said material disintegrates thereby leaving spacing in the refractory for expansion and contraction over a wide range of temperatures.

Abstract: A stack damper control arrangement for use in a heating system including a furnace having a fuel-fired burner apparatus and a vent stack for conducting combustion products away from the burner apparatus and a damper plate pivotally mounted within the stack and movable between a fully open and a fully closed position, includes a reversible drive motor which is energizable in response to a request for heat to drive the damper plate to the open position, a first limit switch operated when the damper plate reaches the open position to effect the deenergization of the motor, the motor being reenergized at the end of the heating cycle to drive the damper plate to the closed position, and a second limit switch operated when the damper plate reaches the closed position to effect the deenergization of the motor.

Abstract: A damper for controlling the passage of combustion gases through a conduit in a furnace. The damper is a mass of formed refractory material shiftable through an opening in the side of the conduit between an operative position extending into the conduit and inoperative position spaced laterally of the conduit. The damper is mounted on an elongate hollow beam which has a coolant fluid flow passage extending therethrough and apertures through which coolant fluid may pass to cool the exterior of the damper and support. A housing extends laterally of the conduit and has side and end walls positioned to receive and enclose portions of the damper and damper support retracted from the conduit. The damper support is enclosed and shielded by the housing walls throughout operation of the apparatus. A coolant fluid supply is operable to inject coolant fluid under pressure into the damper support so that such fluid may flow outwardly therefrom to cool the damper support and surfaces of the damper.

Abstract: The device is a baffle array that is housed in a section of pipe that coupled from an oil burner to a chimney. The baffle array, when closed, blocks about 70 percent of the pipe cross-sectional area and opens upon the occurrence of a small explosion when the oil burner starts to permit this explosive puff to pass to the chimney. The baffle array includes three baffle plates, each pivoting at its top end and all interconnected at the bottom end.

Abstract: An improved automatic draft regulator having significantly fewer parts than previous such devices, and comprising a frame adapted to fit into the flue pipe of a furnace, a gate pivotally mounted in the frame, and adjustable weight means pivotally connected to the gate and extending through it.

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.