Abstract: A valve modulation method and a system utilizing the method is provided. In a hydronic heating system having primary and secondary loops, a simple two-position valve is powered on an intermittent duty cycle to regulate the amount of flow of boiler water from the primary loop to a radiation system in the secondary loop. The actuator of the valve is pre-powered so that it is fully responsive to this intermittent duty cycle. By only supplying power to the actuator of the valve intermittently, the piston of the valve remains in a partially open position, and allows some flow to pass from the primary loop to the secondary loop. The position of the valve remains constant, owing to the duty cycle being shorter than the response time of the valve. By pre-powering the valve, the lag time it takes for the valve to become responsive to changes in the duty cycle is significantly reduced or eliminated. In this fashion, the temperature of the water in the secondary loop may be controlled.

Abstract: A two-way variable-section control valve for a refrigeration circuit, having a movable member for choking a refrigerant passage interposed between the inlet and outlet of the valve; the position of the movable member is controlled by a wax actuator having a bulb fitted with an electric resistor supplied by a control circuit; and the bulb is immersed in and cooled rapidly by the refrigerant when the heat supplied by the resistor is reduced, thus ensuring rapid response.

Abstract: A compact, quiet, electrically actuatable multiple-way valve, in particular for coolant circulation in an internal combustion engine, includes an inlet duct and at least two outlet ducts branching off from a collecting chamber, each outlet duct being respectively closable by a locking part. Each locking part is connected with an electrically triggerable actuating member which includes a temperature-sensitive, electrically heatable extensible material element.

Abstract: A process for controlling a refrigeration system, as well as the refrigeration system and a new expansion valve for the refrigeration system. An electronic regulator is used to operate a sensor system having a device for applying heat power to the sensor system in direct dependence on sensed superheat of the refrigerant leaving the evaporator. By locating the sensing system in communication with liquid refrigerant upstream of the evaporator, heat transfer to the liquid refrigerant is utilized for operation of the sensor system rather than heat transfer to the superheat, resulting in a far more stable and efficient refrigeration control.

Abstract: Apparatus, positioned at an inlet port to a pump, for shielding the pump from a process chamber of a semiconductor wafer processing system, where the apparatus has a controllably variable effective throughput area, and method for electrically controlling the size of the effective throughput area. Specifically, the apparatus is a controllable restrictor shield supported by an actuator, having a first effective throughput area and a second effective throughput area, where the first effective throughput area is typically less than the second effective throughput area. The size of the effective throughput area is directly responsive to an electric signal that controls the actuator.

Abstract: A thermostatic control valve has an expansion composition held in a cavity thereof. The composition contains electrical conductor particles dispersed throughout an electrical isolator. The particles conduct electrical current through the isolator when the electrical isolator has a volumetric size that is less than a predetermined expanded volume. When the isolator expands to the predetermined expanded volume, the distance between the particles is increased to the extend that the electrical current cannot be conducted.

Abstract: A thermal expansion valve unit comprises a closed vapor system, which includes a temperature sensing chamber in thermal communication with a source such as a two phase refrigerant, and a pressure chamber with a deformable member, the position of which controls the size of an expansion orifice. A line confining a selected vapor, which optionally may be a refrigerant, communicates between the interiors of the temperature sensing chamber and the pressure chamber. A heater, separately controllable, is thermally coupled to the temperature sensing chamber such that the selected refrigerant may be independently heated to change the pressure in the chamber. A thickness of insulating material is disposed between the temperature sensing chamber and the source to limit thermal energy loss to refrigerated elements in the system.

Abstract: For a thermostatic valve in the coolant circulation system of an internal-combustion engine having an expansion material element penetrating the main valve for the cold-side stationary support and the hot-side driving connection with the valve disk of the main valve, it is provided for increasing the response characteristic of the thermostatic valve to act upon the expansion material element in the cold-side end section in addition by a hot coolant and/or to provide a metal film resistor as an electric heating device placed in the expansion material.

Abstract: A thermostatic valve has a multi-part valve housing which forms a mixing or distributing chamber which is provided with engine connections for an engine inlet, an engine outlet and a radiator connection. An electrically heatable thermostatic working element is situated in the mixing or distributing chamber, having a housing which is arranged in a stationary manner and to which electric connecting lines are guided from the outside. The thermostatic working element has an extendable working piston which is provided with at least one valve member for adjusting flow cross-sections for flows between the engine inlet, the engine outlet and the radiator connection. The housing of the thermostatic working element is arranged completely in the mixing or distributing chamber. The housing of the thermostatic working element is held on a support of the valve housing which is situated in the mixing or distributing chamber and through which the electric connecting lines are guided to the housing of the working element.

Abstract: An electrically heatable thermostatic valve for a coolant circulating system of an internal-combustion engine in which the housing of a thermostatic working element is arranged in a stationary manner and is provided with feed lines for a heating element. The valve elements of a main valve and of a bypass valve are arranged on the working piston of the working element, the valve element of the main valve being designed such that the housing of the thermostatic working element is situated in the cold coolant flow when the main valve is closed.

Abstract: A valve construction and method of assembling the same are provided, the valve construction having a deflector unit for directing fluid flow from the inlet of the housing means of the valve construction away from an operating part of a bimetallic lever means of the valve construction that controls a valve seat means thereof, the deflector unit having a part engaging one of a top and bottom edge of a screen at the inlet of the housing means so as to hold another part of the deflector unit in a cantilevered manner in the internal chamber of the housing.

Abstract: The invention relates to a cooling machine having a cooling cycle in which coolant circulates, which cooling cycle comprises:1) an evaporator:2) a compressor;3) a condenser;4) a thermostatic expansion valve whereof a bulb is connected to a coolant outlet of the evaporator; and integrating control circuit for the thermostatic expansion valve, comprising:a liquid-sensitive sensor placed in the cooling cycle for direct contact with coolant and connected via a voltage source to a heating element with which the bulb can be heated,and to a thermostatic expansion valve therefor.

Abstract: The invention relates to a control device for a system for regulating the ntilation of a controlled-atmosphere room. The system has at least one sensor located in the room to pick up desired information such as temperature, humidity, carbon dioxide level, or other similar levels, or occupancy or nonoccupancy of the room. A valve, of the deformable bladder type, is located in the ventilation duct of the room and the system is controlled by the control pressure of the valve as a function of information picked up by the sensor.

Abstract: A control device, refrigerator system utilizing the control device and methods of making the same are provided, the control device comprising a housing having a valve seat and having an inlet and an outlet interconnected together by the valve seat, a movable valve member carried by the housing and being adapted to open and close the valve seat by being respectively moved to an open position thereof and a closed position thereof, and a shape memory unit carried by the housing and being operatively interconnected to the valve member to move the valve member to one of the positions thereof by the unit sensing a temperature above a first temperature and to move the valve member to the other of the positions thereof by the unit sensing a temperature below a second temperature, the shape memory unit comprising a shape memory wire having opposed ends interconnected to the housing and having an intermediate portion thereof operatively interconnected to said valve member.

Abstract: A valve construction and method of making the same are provided, the valve construction comprising a housing provided with a chamber therein and with an inlet leading to the chamber and outlet leading from the chamber, a valve seat carried by the housing and leading to the outlet, a movable bimetallic lever carried by the housing and having an operating bimetallic part, a heater wire disposed in coiled relation about the operating part to heat the same when an electrical current flows through the heater wire, and a valve member carried by the bimetallic lever for opening and closing the valve seat under the control of the operating part of the bimetallic lever, the operating part of the bimetallic lever having a fastening unit operatively interconnected to the heater wire to tend to hold the heater wire in the coiled relation on the operating part of the bimetallic lever, the heater wire comprising a length of the wire doubled upon itself to define a looped end and pair of free ends adjacent each other with t

Abstract: A valve construction and method of making the same are provided, the valve construction comprising a housing provided with a chamber therein and with an inlet leading to the chamber and outlet leading from the chamber, a valve seat carried by the housing and leading to the outlet, a movable bimetallic lever carried by the housing and having an operating bimetallic part, a heater wire disposed in coiled relation about the operating part to heat the same when an electrical current flows through the heater wire, and a valve member carried by the bimetallic lever for opening and closing the valve seat under the control of the operating part of the bimetallic lever, the operating part of the bimetallic lever having a fastening unit operatively interconnected to the heater wire to tend to hold the heater wire in the coiled relation on the operating part of the bimetallic lever, the heater wire comprising a length of the wire doubled upon itself to define a looped end and pair of free ends adjacent each other with t

Abstract: The regulating valve has a heat responsive extension element which is prestressed and which extends crosswise of the gas line. The extension element biases the valve body into sealing engagement with the valve seat to maintain the valve in a normally closed position. Due to the slight deflection of the extension element, the thermal length variation of the extension element is transformed into an approximately 100-fold stroke of the valve body relative to the valve seat. The control accuracy of the valve is considerably increased.

Abstract: A telescopic hydraulic shock absorber with controlled damping comprising a cylinder (1), within which a piston (6) connected to the end of a rod (7) can reciprocate, the piston having at least one restricted passage (12) interacting with an elastic flap (13), an additional passage (16, 17) capable of being closed to a greater or lesser extent by a remote-controlled shut-off (18), to allow the hydraulic fluid to pass from one side of the piston to the other during the movement of the latter within the cylinder, wherein the movement of the shut-off (18) is controlled via an actuating member (21) comprising an active element comprised of a metallic memorizing material capable of changing its size at a predetermined conversion temperature.

Abstract: The present invention is a valve and valve housing designed for controlling the flow of water into washing machines comprising a molded plastic housing (1) with an inlet coupling (2) connecting the valve to the water supply, and an outlet coupling (3) connecting the valve to the washing machine; a poppet valve (4) located between said water inlet and outlet couplings normally remains closed with respect to its seat (5); the stem (4a) of said poppet valve (4) is associated with a leaf spring (8), and actuated by a piston (7) projecting from a casing (6) containing a wax with high thermal dilative properties; said casing (6) is in contact with one or more thermistors (9) (PTC) electrically powered through terminals (10) connected to the washing machine's timer, and having the purpose of opening the valve when the thermistor(s) is/are energized causing the wax contained in the casing (6) to expand inducing the axial movement of the piston (7), the leaf spring (8), and the poppet (4) of the valve, which retracts

Abstract: A compact linear operator is provided for a gas valve. The operator may be of modular form for operative combination with combination gas controls of existing design, as by threaded engagement with an existing threaded bore in the control. The operator is suited for directly controlling displacement of a valve or more typically, for controlling displacement of the seat for the regulating spring associated with a servo pressure regulating diaphragm/valve arrangement. The operator includes a controllably heated bimetallic actuator, and a plunger directly or indirectly driven linearly by deflection of the actuator. To enhance compactness of the operator, a displacement-amplifying lever is interposed between the actuator and the plunger. Stops are included for establishing "high fire" and "low fire" limits for the regulated gas pressure.

Abstract: A power driven valve actuator includes a thermostatic device which is movably supported in a housing to accommodate overtravel of a thrust member against the stem of the valve resulting from excess expansion of a thermostatic element enclosed in the thermostatic device and heated by a heating device. Movement of the thermostatic device trips a dust-tight switch to interrupt power to the heating device, and a spring engaging the thermostatic device returns the thermostatic device to a starting position, so that whenever heat is called for by the thermostat, the thermostatic device cycles in a reciprocating motion within the housing after the valve has been fully opened. The heating device comprises an electric resistance heating element placed in contact with a thermal enclosure of the thermostatic element and covered by an insulating material.

Abstract: A capsule of a thermic control device contains a substance which expands when heated by an electrical resistor to displace a piston. Devices are disclosed wherein the capsule is disposed transversely in a pipe which carries a circulating fluid, and the front and rear ends of the capsule are sealingly affixed in opposed openings in the wall of the pipe. In one such embodiment, the pipe has two fluid channels; the capsule lies in one channel; and, the piston actuates a valve which is disposed in the other channel.

Abstract: A thermostat member (10) disposed within a coolant flow passage (12) of an engine comprises a valve (32,34,36,40,42) movable between first and second positions for opening and closing the flow passage (12) and when in the first condition prohibiting coolant to flow from the engine and when in the second condition permitting the coolant to flow to a heat exchanger. A thermally responsive element (22) contained within a housing portion (16), and coupled to the valve. The element expandable in volume, when exposed to a predetermined temperature so as to urge the valve into the first position to terminate flow therethrough and a heater (50) for increasing the temperature of the element above the temperature of the coolant, to cause the element to urge the valve into the second cindition.

Abstract: A valve construction and method of making the same are provided, the valve construction comprising a housing, a valve seat carried by the housing, a movable lever carried by the housing and having an opening passing through opposed sides thereof, a valve member for opening and closing the valve seat and having a stem projecting through the opening of the lever whereby the valve member is carried by the lever, and a tubular member disposed in the opening of the lever and telescopically receiving the stem of the valve member therein whereby the tubular member spaces the stem from the lever at the opening thereof.

Abstract: A zone valve of the type using a heat motor includes a biasing spring that operates on a lever, the lever operating on a valve. The spring includes arms that slidingly engage the lever. The arms each include a bent portion adjacent the point of contact with the lever. By providing the bent portion on each arm, the effective biasing force produced on the lever is decreased when the lever is in a raised position.

Abstract: A zone valve is described in which the frame for the operator unit is assembled without separate fasteners. Tongue and groove on the frame pieces fit together in an interlocking manner to provide a rigid frame construction. The assembly of the frame, hinges the parts against each other so that they snap together and are rigidly retained together by the inherent spring force of the members.

Abstract: A gas valve of the type having a movable resilient poppet attached to the free end of an electrically heated cantilever bi-metal arm. The poppet is preloaded by the arm to the closed position against a valve seat by the bi-metal arm and is lifted by warping the bi-metal arm with a predetermined electrical current. The poppet has a necked position received through an aperture near the free end of the arm. An annular bead ring is formed on the poppet and surrounds the neck. The annular bead is resiliently contacted by the surface of the arm in the preloaded condition.

Abstract: The invention relates to a valve assembly. A closure member for the valve unit is controlled directly or indirectly by a movable wall of an expansible chamber filled with a refrigerant medium having vapor and liquid phases. The pressure exerted by the vapor phase of the medium provides a bias which is directly related to the temperature of the liquid phase. A heat transfer element such as a heating resistor in the liquid phase is heated or allowed to cool in a controlled manner by an external control unit. A temperature responsive sensor element in the liquid phase of the medium is part of a feedback system for the control unit which allows a selected temperature to be maintained in the chamber which results in a desired constant pressure to be maintained in the chamber. A pilot valve unit is disposed between the valve closure member and the movable wall. An expansible chamber behind the closure member houses a spring for biasing in a valve closing direction.

Abstract: The invention relates to a valve assembly. A closure member for the valve unit is controlled directly or indirectly by a movable wall of an expansible chamber filled with a refrigerant medium having vapor and liquid phases. The pressure exerted by the vapor phase of the medium provides a bias which is directly related to the temperature of the liquid phase. A heat transfer element such as a heating resistor in the liquid phase is heated or allowed to cool in a controlled manner by an external control unit. A temperature responsive sensor element in the liquid phase of the medium is part of a feedback system for the control unit which allows a selected temperature to be maintained in the chamber which results in a desired constant pressure to be maintained in the chamber. A pilot valve unit is disposed between the valve closure member and the movable wall. An expansible chamber behind the closure member houses a spring for biasing in a valve closing direction.

Abstract: Combustion apparatus having a vent with a damper actuated by an element comprised of a material having a shape memory effect. The element is heated and cooled above and below the deformation temperature for causing the element to deform between its different shapes for changing the position of the damper within the vent. Control means is provided in one embodiment for heating the shape memory element so that it deforms for moving the damper closed during a shutdown mode of the combustion apparatus, and in another embodiment the shape memory element is heated so that it deforms to a shape for holding the damper open during the heating mode of the apparatus.

Abstract: A pilot controlled, diaphragm actuated valve having simplified construction is provided which is capable of maintaining a variety of valve operating positions. In the preferred embodiment, the valve pin is controlled precisely with respect to the pilot opening in the diaphragm to permit modulation of the diaphragm position. Control of the valve pin is maintained through the use of a power assembly which positions the valve pin in accordance with some sensed system variable. The valve includes structure for reducing instability of the valve over the valve operating range.

Abstract: A control system for central heating is disclosed which varies the flow rate of the heating medium as a function of remotely sensed outdoor temperature. A power transistor, which is part of the electronic control circuit, also functions as a heat source for a measuring bulb which controls the position of a flow rate control valve.

Abstract: The invention relates to a valve assembly. A closure member for the valve unit is controlled directly or indirectly by a movable wall of an expansible chamber filled with a refrigerant medium having vapor and liquid phases. The pressure exerted by the vapor phase of the medium provides a bias which is directly related to the temperature of the liquid phase. A heat transfer element such as a heating resistor in the liquid phase is heated or allowed to cool in a controlled manner by an external control unit. A temperature responsive sensor element in the liquid phase of the medium is part of a feedback system for the control unit which allows a selected temperature to be maintained in the chamber which results in a desired constant pressure to be maintained in the chamber. A pilot valve unit is disposed between the valve closure member and the movable wall. An expansible chamber behind the closure member houses a spring for biasing in a valve closing direction.

Abstract: A regulator valve having a balanced port construction is provided with a balanced piston design, the piston being operated under positive control in all valve positions. The piston regulates fluid flow through the valve. The piston is operatively connected to a heat motor, and the electrical energy input to the heat motor is used to adjust piston position. Because of the balanced piston design, valve operation is dependent solely upon electrical energy input to the heat motor, and precise control of a refrigeration system, for example, may be maintained.

Abstract: A pressure transducer is disclosed which produces a variable fluid pressure level in correspondence with the level of a varying electrical signal. The particular application of the pressure transducer disclosed is for a vacuum modulator for producing a variable level vacuum pressure for operating an actuator utilized to position a blend air door in an automatic temperature control system for automotive passenger compartments. The pressure variation is accomplished by controlled communication of either a low pressure or a high pressure source with an interior chamber of the transducer housing, such controlled communication being produced by a pair of heated bimetal actuator devices, each including a bimetal arm which is normally biased to seal the respective inlet port associated with each of the low pressure and high pressure sources.

Abstract: A closed loop control circuit for regulating the response of an automatic temperature control system is disclosed. The temperature control system provides automatic regulation of the temperature for the passenger compartment of a vehicle by positioning a blend air door in response to three control parameters. Two of the control parameters, the actual temperature of the passenger compartment and the desired temperature of the passenger compartment, are serially combined in one leg of a bridge circuit and compared against another leg of the bridge presenting the third control parameter, the position of the blend door. An unbalanced condition in the bridge circuit is corrected by the repositioning of the blend door until the error between the two legs is nulled. Repositioning is accomplished by a pair of differential amplifiers which detect the sense of the error and thereafter provide an interrupter control function to a vacuum modulator.

Abstract: An improved flue damper for isolating furnace from chimney-flue when burner is not operating includes in preferred embodiment a damper plate pivotally mounted within a flue section on a control rod extending through the flue section to bearing support in a bracket spaced from the flue section by a frame affixed to the flue section exterior; a bimetallic strip spiral having inner end affixed on the control rod and outer end detachably looped over a stud extending from the frame rotates the control rod under thermal actuation provided by an electric heating element adjacent the bimetallic strip spiral; a damper control strip on the end of the control rod adjustably affixes a switch plate rotatable therewith and bearing a first mercury switch controlling the heating element circuit and a second mercury switch controlling the furnace burner circuit; stop structure on the bracket limits rotation of the damper control strip and control rod.

Abstract: A vacuum metering valve comprises a housing having an inlet and a discharge space from the inlet with a flow passage between the inlet and outlet having a valve seat with a valve member which is mounted in the housing for movement toward and away from the seat. The construction includes mechanical means for adjusting the position of the valve member in relation to the seat and in addition temperature control means are provided for varying the position in reference to the seat in accordance with temperature variations. Temperature variations are produced by suitable means for heating and cooling an auxiliary member which is disposed for example between a mechanical adjustment device and the valve member.

Abstract: An expansion valve for a refrigeration system, and in particular, for a reversible flow or heat pump application is provided in which the valve is electrically operated by a heat motor mounted to a valve body. The valve includes a valve stem operatively connected to the heat motor. The valve stem position, and consequently, valve operation, is controlled by heat motor operation. Because of the reverse flow nature of the fluid flow in the system described, means for protecting the heat motor from fluid leakage is necessary, if the valve is to function properly. The valve of this invention includes bleed or drain means positioned to drain fluid from the heat motor, and seal means on the valve stem of the valve to reduce flow leakage along the stem.

Abstract: An electric vacuum valve comprising a body including a chamber having a first passage adapted to be connected to a source of vacuum, a valve seat in the chamber, a bi-metallic disc associated with the valve seat and operable to close the first passage and a second passage to the exterior of said body. A PTC disc is positioned in the chamber adjacent the bi-metallic disc and includes a first terminal connected to one side thereof and extending exteriorly of the body and a second terminal connected to the other side thereof and extending externally of the body such that heat from the PTC disc functions to radiate toward the bi-metallic disc when power is applied to said terminals to cause the bi-metallic disc to seat against the valve seat and when power is terminated, the bi-metallic disc cools and moves away from the valve seat.

Abstract: An electric-thermal switch valve has a body with a first port and at least one second port with a temperature operated valve means including a valve seat and a bimetal element, responsive to temperature, positioned to cooperate with the valve seat to control flow between the first port and the second port. An electrical heating means, including a semi-conductor, having a positive temperature coefficient of resistance, positioned in the body, is used to heat the bimetal element when energized whereby switching of the bimetal element at a predetermined temperature, will occur as the combined effect of heat sensed by the body and the heat generated by the electrical heating means.

Abstract: A fuel control system for a main burner having a dual rate pilot burner and a control device for providing a standby flame flow of fuel to the pilot burner when the output temperature effect of the main burner is above the temperature setting of the control device and for providing a large heater flame flow of fuel to the pilot burner when the output temperature effect of the main burner is below the temperature setting of the control device so that only the heater flame will cause a main flow of fuel to the main burner for a heating operation thereof. A diverter valve is provided for diverting the heater flame flow of fuel from the dual rate pilot burner to another pilot burner so that the main flow of fuel to the main burner will cease even though the output temperature effect of the main burner is below the temperature setting of the control device, the diverter valve being controlled by a timer or the like to provide a "cook and hold" feature of the system.

Abstract: A control circuit for a gas appliance includes ignition and hold circuits, the former providing for series energization of the heater of a thermal fuel valve and an electric igniter positioned proximate the appliance burner port area for ignition of the gas fuel and air mixture exiting the same and the latter providing for direct energization of only the igniter to hold or to maintain the appliance at a warm temperature. Moreover, the fuel valve includes an exterior selector mechanism for facile calibration and/or other adjustment for effective valve operation with either of two different gases at respectively different pressures, such as, for example, natural gas and bottled gas.

Abstract: An electrically operated valve having a valve body in which a valve member is mounted for movement to an open or closed position, an operating assembly being removably mounted on the body and including a heat motor that is offset with respect to the axis of the valve member and that is operable to effect movement of the valve member against the action of a control spring as also mounted in the operating assembly, the heat motor having a thermal switch mounted directly thereon for controlling current to the heating element thereof and thereby protecting the heat motor for increased life thereof.

Abstract: A fluid flow regulating or shut-off valve of the kind having a bimetallic element which regulates or opens and closes a flow passage through the valve in dependence upon temperature is provided with at least one electrically heatable PTC-element which is in thermal contact with the bimetallic element. Heating of the PTC-element by control of the supply of electricity to it thus controls the operation of the valve. The bimetallic element is preferably in the form of a snap-acting bending bimetallic plate which is heated by radiation from the PTC-element and which itself forms the valve closure member. With the bimetallic plate snapped in one direction, a passage through the valve is opened, but when the plate snaps in the other direction, it bears against a sealing ring surrounding a valve opening within the valve to close and seal the opening and thus shut the valve.

Abstract: An explosion resistant gas valve in which a valve actuating mechanism in the form of a bimetallic strip is operated by an electric heat motor. An explosion containment structure is provided about the electric heat motor to isolate it from the path of gas flow. A plurality of pressure relief apertures extend through the sides of the containment structure.

Abstract: The invention relates to a regulating drive for a thermostatically controlled feed member, especially the shaft of a heating valve, having a pivotable, spring-loaded actuating lever carrying a control element, preferably an expansion-material element, the operating member of the said control element being stationary and the mobile element being supported on the actuating lever, characterized in that the control element is mounted pivotably on the actuating lever.

Abstract: An electrofluid converter converts electrical energy into fluid energy by ntrolling the linear expansion of a wire that is used as a fluid control valve. Thermal linear expansion of the wire is brought about by passing an electric current through the wire thereby increasing or decreasing the portion of the wire within the fluid flow path. The converter can be used in applications that require converting electrical proportional or digital signals into corresponding fluid signals. The converter signal may be used to control fluid amplifiers or other fluid sensors.

Abstract: An apparatus for adjustably controlling the flow of air in an air conditioning system and comprising a regulator having flow control means movable in response to fluctuations in the pressure of the air supplied to the regulator for maintaining the flow of air passing through the regulator at a substantially constant rate and having flow adjustment means cooperating with the flow control means for permitting varying the flow rate maintained by the flow control means.

Abstract: A mixing valve for mixing airstreams in an air distributing system including a housing having first and second air inlet passages therein for receiving respective airstreams of different characteristics, valve means cooperating with the first and second inlet passages for adjustably selecting the proportion of air received through the respective passages so as to obtain a mixture of the two airstreams from the mixing valve, and an actuator cooperating with the valve means for effecting adjustment of the same to obtain a desired mixture of the different airstreams from the mixing valve. The actuator includes a thermal motor having an axially movable shaft extending therefrom, a heater cooperating with the thermal motor for applying heat thereto to effect movement of the motor shaft toward an extended axial position, and linkage operably interconnecting the thermal motor and the valve means and being movable in response to axial movement of the motor shaft for effecting adjustment of the valve means.