Abstract: A servo device for regulating a refrigerant into a compressor comprises a low pressure regulator, a high pressure regulator, and a solenoid valve. The low pressure regulator is connected to an inlet of the compressor and the high pressure regulator is connected to an outlet of the compressor. The solenoid valve is communicating with the low pressure regulator and the high pressure regulator respectively. The low pressure regulator further comprises a cylindrical plunger and a spring. The plunger is located in the low pressure regulator and the spring is located at lower end of the plunger to bias against the plunger. The plunger is pushed to move upward intermittently by a refrigerant coming from the high pressure regulator via the solenoid valve so that the refrigerant entering the compressor is hindered by the plunger to correspond with a state of optimal cooling in an air conditioning system or in a mechanical refrigeration system.

Abstract: A refrigerant flow switching device for alternatively conveying flow of refrigerant from either a high presure or a low pressure evaporator to a compressor of a refrigeration system and a refrigerator using such a refrigeration system. The device utilizes the pressure difference between the higher pressure refrigerant from the high pressure evaporator and the lower pressure refrigerant from the low pressure evaporator or atmospheric pressure to open and close a first flow controller of the device positioned in a conduit leading from the high pressure evaporator to the compressor. The device further comprises a second flow controller, such as a check valve positioned in a conduit leading the low pressure evaporator to the compressor, which stays open only when the first flow controller is closed.

Abstract: In a pneumatic variable air volume controller, a linear relationship is achieved between the actual air velocity in a duct carrying conditioned air to a defined area and a pneumatic pressure signal representing the temperature in that area; and this linear relationship is used to vary the volume of air flowing in the duct. This is achieved by comparing a pneumatic pressure control signal which is a linear representation of the velocity pressure in the duct to a pneumatic pressure control signal which varies as the square of a thermostat pneumatic pressure signal which itself varies in a linear manner with respect to the temperature in the controlled area.

Abstract: In a refrigeration system there is provided a main valve that has its inlet port fluidly connected to an evaporator while its outlet port is fluidly connected to the suction port of a motor-compressor. The closing of the main valve is controlled by an auxiliary valve, the auxiliary valve being connected in an auxiliary line that at one end opens to the gas port of a condenser or to a line between the condenser and the motor compressor. The auxiliary valve is connected in the auxiliary line in series with a fixed throttle and is downstream of the throttle. The closure member of the auxiliary valve opens on an increase in the evaporator pressure. A check valve, for example a two way magnetic valve, is connected between the auxiliary valve and the suction port.

Abstract: Line valve apparatus for shower anti-scald and other uses comprising a housing (10) valving member (14) and a coil spring pilot valve (20) formed of a shape memory effect alloy and arranged for a first closed loop fluid blocking configuration to prevent, and second open spiral loop configuration(s) to enable, coil expanding valving member movement under the combined force of line back pressure and the coil expanding forces per se as a rising fluid temperature puts the alloy through a martensitic to austentitic transformation.

Abstract: A system for controlling the amount of natural supply gas delivered from a natural gas supply source to a natural gas burner adapted to continually heat a process fluid in a vessel and for enabling the gas burned to continuously automatically maintain the temperature of the process fluid within a predetermined minimum range of temperatures above and below a preset nominal temperature. The system comprises a gas operated flow regulator device associated with a supply gas line connected to the gas burner for regulating the amount of gas delivered to the gas burner in accordance with pressure of regulator control gas delivered to the flow regulator device through a control gas line, gas pressure control apparatus associated with the control gas line for varying the pressure of the control gas delivered to the flow regulator device; and a linearly movable temperature sensing device operable by process fluid temperature and connected to the gas pressure control apparatus to vary the control gas pressure.

Abstract: In a self-powered diffuser for a variable volume air distribution system, an installation for the control components which facilitate adjustment, modification and system start up. A Tee fitting located in the control compartment feeds through the bulkhead and into the diffuser to sense the flow rate of air in the diffuser. One leg of the Tee fitting is available to receive a tube in order to permit servicemen to actually measure the flow rate from below the ceiling. The maximum flow rate is adjustable from below the ceiling and is carried out by an adjustment mechanism having enhanced stability and reliability. A thermostat in the control compartment can be installed, serviced and replaced if necessary from below the ceiling.

Abstract: A regulating valve having a fail-safe action which is suitable for controlling the flow of either a heating or cooling medium in response to a sensed condition is disclosed. The flow of heating or cooling medium is responsive to changes in temperature at a selected location, which changes are sensed by thermal element. The fail-safe action of the regulating valve either permits or prevents flow of the heating or cooling medium upon failure of the thermal element.

Abstract: A low pressure pneumatic pressure regulator having particular application to the control circuits of system powered air distribution systems. A diaphragm separates a control chamber located above the diaphragm from an underlying output. The chambers communicate through a fixed orifice. A vent line extending from the control chamber includes an adjustable orifice which may be thermostatically controlled. An output line extending from the output chamber leads to the load controlled by the regulator. Power to operate the regulator can be supplied from the load or from a separate pressure source which connects with the output chamber through a supply port. An exhaust port which bleeds pressure from the output chamber when open is closed by the diaphragm unless the pressure differential between the chambers overcomes the diaphragm weight and possibly the added force applied by an optional spring.

Abstract: An apparatus for controlling the opening and closing operation of a liquid flow valve dispensing fluid fed thereto from a reservoir, using the inherent gas pressure from the reservoir, comprising in combination (a) an actuator means operably connected to the flow valve for opening and closing the same; and (b) control means for controlling the operation of the actuator means, the control means comprising circuitry having pneumatic linear timer means and pneumatic control valve means operably connected one to another and to the actuator means. Also disclosed is a method of controlling the opening and/or closing operation of a liquid flow valve dispensing liquid fed thereto from a reservoir, using the inherent gas pressure from the reservoir.

Abstract: A refrigeration system for use in an automotive air conditioning system has a vane type variable displacement refrigerant compressor drivingly connectable by an electromagnetic clutch to an automotive engine, a refrigerant evaporator through which air is caused to flow by a blower, and a pressure check valve which prevents the refrigerant pressure in the evaporator from lowering under the predetermined pressure, so that frost or icing is not formed on the evaporator fins. The compressor is provided with one or two unloading ports for releasing the refrigerant being compressed and with a valve member or members associated with the unloading port. The refrigerator temperature and the pressure of the refrigerant in the conduit between a throttling valve and the compressor are detected. A signal is emitted to an electric circuit for actuating the valve member or members so that the unloading port is selectively opened to vary the compressor displacement to provide a multi-stage compressor displacement control.

Abstract: A refrigeration apparatus comprising a compressor, a condenser, a pressure-reducing device and an evaporator connected sequentially in a loop. The loop includes a check valve placed between the outlet of said evaporator and the intake port of said compressor to prevent a refrigerant from flowing from the compressor side to the evaporator side; a pressure signal transmission pipe whose one end is connected to the outlet of said check valve to apply a pressure corresponding to the refrigerant pressure at the outlet side of said check valve and, a fluid control valve communicated with the other end of said pressure signal transmission pipe to control the refrigerant flowing to the inlet side of device in response to the refrigerant pressure in the other end of said pipe.

Abstract: A stabilizer for a ventilation duct includes a sensor, sensitive to a variable parameter such as temperature, which affects the flow of air in the duct. The sensor includes an opening in a return flow conduit communicating with a deformable chamber contained within a section of the duct. As the parameter changes, pressure at the opening changes thereby affecting the volume of the chamber and likewise the volume of the section of the duct in which the chamber is located.

Abstract: A system for controlling the amount of natural supply gas delivered from a natural gas supply source to a natural gas burner adapted to continually heat a process fluid in a vessel and for enabling the gas burner to continuously automatically maintain the temperature of the process fluid within a predetermined minimum range of temperatures above and below a preset nominal temperature. The system comprises a gas operated flow regulator device associated with a supply gas line connected to the gas burner for regulating the amount of gas delivered to the gas burner in accordance with pressure of regulator control gas delivered to the flow regulator device through a control gas line, gas pressure control apparatus associated with the control gas line for varying the pressure of the control gas delivered to the flow regulator device; and a linearly movable temperature sensing device operable by process fluid temperature and connected to the gas pressure control apparatus to vary the control gas pressure.

Abstract: A system for supplying conditioned air through a duct to an area to be treated by the conditioned air, the system having an area thermostat that tends to maintain the temperature of the area at a selected set point temperature of the thermostat. The thermostat provides a signal in relation to the temperature sensed by the thermostat. A damper unit is provided for controlling the flow of air from the duct to the area. A controller that is non-readily accessible in the area and is remote from the thermostat directs a signal to the damper unit to operate the same in relation to the value of the signal of the thermostat and in relation to the air pressure in the duct to compensate for pressure changes originating elsewhere in the system whereby the controller tends to maintain the air flow to the area at the rate called for by the signal of the thermostat regardless of the air pressure in the duct.

Abstract: An automatic air-fuel ratio control apparatus for use in a combustion system of a type in which combustion air is preheated, which is so arranged that a push rod depresses one end portion of a rocking lever in accordance with temperature of preheated combustion air and consequently the other end portion of the rocking lever depresses a valve member to correct pressure of working fluid for controlling a flow of fuel so as to obtain best air-fuel ratio, and further that a bearing member for pivotally supporting the rocking lever can be diagonally shifted to change the air-fuel ratio.

Abstract: A refrigeration system provided with a rotary compressor, a refrigeration pipe line system connected with the compressor and having a gas-liquid separator for separating an injection pressure gas refrigerant, and a gas injection channel extending from a gas zone of the separator and having an open-close valve. The compressor is provided at its cylinder block with an injection pressure port opening to a pumping chamber and with a valve chamber communicating with the port. A by-pass passage channel communicating with the suction port side of the chamber extends from the valve chamber, and a control valve having a communication aperture and a spring, are housed within the valve chamber, the injection channel is connected with a back chamber of the control valve within the valve chamber, so that the open-close valve may be operated to control a capacity of the refrigeration system.

Abstract: A pneumatic control circuit for controlling the discharge of conditioned air from an air distribution system. The circuit is arranged to apply the supply pressure to an inflatable bladder which controls the discharge of conditioned air from a ventilation duct. A diaphragm controls the bleeding of air from the bladder under the influence of the supply pressure, a thermostat, a velocity sensor at the duct outlet and a plurality of selectively sized orifices. The velocity sensor compensates automatically for variations in the main supply pressure so that the control function of the circuit is independent of the supply pressure.

Abstract: In a central air conditioning system where airflow is regulated by bellows inflation which is controlled by a bleed-type thermostat, a second bleed which is controlled by a regulator is provided to insure a minimum flow for ventilation independent of cooling demand.

Abstract: In a central air conditioning system wherein air flow is regulated by bellows inflation which is controlled by a bleed-type thermostat, simultaneous heating and cooling in a zone is prevented by disabling the bleed-type thermostat when the heating system is activated.

Abstract: A variable air flow volume conditioned air distribution system of the kind having an air flow duct for supplying conditioned air to a room and a valve in the duct for regulating the volume of air flowing through the duct has a controller which senses the flow velocity in the duct and the room temperature in the room.The controller combines a temperature signal with a flow velocity signal through a velocity spring. A temperature change resets the flow velocity set point and produces a corresponding change in the volume flow through the duct.The controller includes an adjustable bias for the velocity spring for varying the rate of the velocity spring from a low spring rate for control at a low maximum permitted flow velocity in the duct to a higher spring rate for control at a higher permitted maximum flow velocity flow in the duct and vice versa.

Abstract: A refrigeration system is disclosed having a compressor, a condenser, an evaporator, a refrigerant expansion device, a control for cycling the compressor on and off according to a sensed condition, and a refrigerant flow controlling valve. The flow controlling valve blocks the flow of refrigerant between the condenser and the evaporator when the compressor is cycled off and enables refrigerant flow between the condenser and the evaporator when the compressor is cycled on. The flow control valve includes a refrigerant pressure responsive member movable to condition the valve to block refrigerant flow in response to changes in refrigerant pressure caused by the compressor cycling off and movable to condition the valve to enable refrigerant flow in response to changes in refrigerant pressure caused by the compressor cycling on.

Abstract: Pressurized control signal apparatus is disclosed, which being supplied with air from a source of variable pressure, is operative to produce a control signal essentially independent of variations in the supply pressure. In one aspect of the invention, the control signal is amplified in volume of flow; in another, it is generated in response to temperature. The apparatus is specifically adapted to effect regulation of air flow in a variable air volume (VAV) temperature conditioning system in response to temperature in a conditioned zone, wherein the supply air for the apparatus is derived from a temperature conditioned air distribution duct of the VAV system.

Abstract: An air distribution unit for discharging conditioned air into an area to be conditioned and having a plenum chamber for receiving conditioned air and an outlet in communication with the plenum chamber and with the area being conditioned. A damper is employed to regulate the flow of conditioned air from the plenum chamber to the outlet with the damper being responsive to a thermostat to regulate the quantity of air discharged into the area in accordance with the temperature requirements thereof. The distribution unit includes an override control to maintain the flow of air through the damper at a constant predetermined rate irrespective of the temperature requirements in the area, the override control becoming operable when the damper has initially discontinued flow of conditioned air into the area in response to sensed temperature.

Abstract: An air flow velocity controller in a variable air volume control system interlocks a room temperature signal from a thermostat with the velocity set point so that the velocity controller maintains a constantly regulated amount of air into a room in proportion to the room's thermostat demands and independent of variations in the static pressure in the duct.The controller includes a maximum lift cam and a movable spring fulcrum which are both mounted in a common cam housing to permit the maximum velocity setting to be adjusted for varying room requirements while maintaining a constant spring range regardless of the maximum velocity setting.The controller is constructed to provide automatic compensation for control offset produced by changes in the static air pressure in the duct.The controller includes the ability to control the air flow at a minimum velocity so that the air can be economically reheated or a minimum volume of air flow can be maintained for ventilation requirements.

Abstract: Apparatus to override the primary pneumatic circuitry of an air distribution system during warm up cycles. Means are provided for nullifying the pressure signal, indicative of ambient temperature, to which the flow controller responds. In the preferred embodiment, the override means comprises a bimetallic helical element which operates to bleed the pneumatic thermostat's air supply, thereby reducing the temperature indicative signal to zero.

Abstract: A manifold gas valve for controlling gas flow to a burner has a diaphragm operated main valve, an electrically operated control valve, and means to delay the application of gas pressure to the main valve operating diaphragm to effect a delayed opening of the main valve. Opening of the control valve permits an immediate flow of gas to the main burner and simultaneously admits the application of gas pressure to effect a delayed opening of the main valve. The immediate flow of gas to the burner, which occurs upon opening of the control valve, is sufficient to effect reliable and timely ignition and support combustion.

Abstract: A variable flow, modular-type terminal unit for conditioning rooms in a centralized conditioning system is provided with means for controlling the conditioned air flow arranged within the outlet diffuser in order to vary the cross-section area of the outlet ports, being operated by a thermostatic device. The thermostatic device, directly fed with conditioned air operates such controlling means through a control lever, a control rod displaceable in the direction of its length and a triangular lever hinged at one vertex for rotation in a plane parallel to that where the control lever is pivotedly mounted. The operating member of the thermostatic device engages the control lever through the end of a threaded rod adjustable for setting the operation temperature. Other two adjusting screws are provided for hand control of the maximum and minimum cross-section opening of the diffuser outlet ports, by limiting the control lever rotation in two opposite directions.

Abstract: A control system for a refrigeration unit incorporating a pressurized liquid gas reservoir is disclosed. The control system is self-contained and suitable for use in the transportation of food in containers. The improvement of the present system is that it avoids overshoot problems in feeding liquid gas coolant to the container. The system includes a gas line from a liquified gas reservoir, a first gas pressure actuated three-way valve, a second gas pressure three-way valve, a first restricting means which provides a time delay for switching the second three-way valve from being connected to the gas line to vent and a second restricting means which provides a second time delay for switching the second three-way valve from vent to the gas line. A temperature sensing control is also incorporated in another embodiment of the invention.

Abstract: A butterfly damper, controlling volume air flow through a duct, is biased toward a closed position at least partially by aerodynamic pressure and is moved against its bias by a small pneumatic actuator in response to a sensed condition. The position of the damper is stabilized by a feedback and oscillations are damped.

Abstract: A damper and control unit for controlling air flow through a conduit comprises a movable damper having a ball-joint connection with the end of an actuating rod. The actuating rod has first and second angularly related portions and the first portion serves as a pivot element for a movable actuating plate, the second portion mounting the damper. The movable or swingable plate is arranged above an expandible and contractable actuating bellows and has a stop chain associated therewith for limiting downward swinging movement thereof in the direction of bellows contraction. The bellows has a supply line leading to the conduit upstream of the damper and a control unit is interposed in the line for determining bellows pressure. Conduit pressure and/or temperature signals are supplied to the control for bellows and damper operation as a function thereof. A seat associated with the damper is uniformly and tightly engaged whereby to seal the conduit due to the floating or ball-joint damper connection with its actuator.

Abstract: An inlet plenum extends into a control box and opens into the interior of the control box. Conditioned air is introduced into the box through the inlet plenum and flows from the box, to an area being serviced, through an outlet spaced from the plenum opening in the box. A damper is positioned at the plenum opening and it and the plenum at the opening having conforming shapes, i.e., segments of a circle. The damper closes over the discharge opening and, to vary the volume of air flowing through the box, pivots away from the opening about an axis offset from the center of the arc of the damper and the plenum opening. When the damper is closed on the plenum opening, the centers of the arcuate plenum opening and the damper are coincident and, relative to a central plane parallel to air flow through the plenum, are offset from that plane so that the damper is moved away from the plenum opening by air flow.

Abstract: An improved pneumatic thermostat is provided which is capable of generating from a variable pressure air supply a pressurized air signal indicative of ambient temperature. The thermostat is used in conjunction with an air flow regulator in an air distribution system and utilizes as an air supply a portion of the air flow being distributed. The thermostat utilizes a pressure reducing valve which is referenced to pressure downstream from the air flow regulator, a flapper and nozzle pneumatic mechanism activated by a bi-metallic lever, and a self-aspirating arrangement which insures the bi-metallic lever is continuously sensing the true ambient temperature.

Abstract: A heat exchange system having a source of heat exchange output fluid for effecting a heat exchange function and having a source of return fluid resulting from the output fluid providing its heat exchange function. A thermally operated element controls the amount of flow of the output fluid from the source in relation to the temperature of the thermally operated element. A sensing device senses the temperature effect of the heat exchange function in relation to a predetermined temperature that the heat exchange system is to provide, the sensing device directing one of the output fluid and the return fluid to the thermally operated element to cause the same to change the amount of flow of the output fluid when the temperature effect deviates from the predetermined temperature by a certain amount whereby the thermally responsive element is subject to a relatively wide swing in temperature for large control movement thereof in relation to a relatively narrow swing in temperature at the sensing device.

Abstract: Three embodiments of an air distributor apparatus are shown which utilizes a balanced type air flow control valve of cylindrical configuration co-operatively associated with a cylindrical sleeve having circumferentially spaced openings closed by the valve. A diaphragm powered valve actuator is disposed within the sleeve which is installed at the air inlet of an air distributor plenum. Several control schemes are disclosed.

Abstract: Air flow volume in a delivery duct is sensed in the form of changes in duct pressure and the sensed pressure is fed back to a diaphragm assembly which is part of a thermostatic control located in the room to which hot or cold air is being delivered. Dependent upon the sensed pressure, the diaphragm assembly throttles a bleed opening in the supply line of a pneumatic actuator, which actuator determines the position of a damper in the duct to thereby control the volume of air flow in the duct. A bellows is also part of the thermostatic control and senses room temperature to establish a spring force on the diaphragm assembly and against which the sensed pressure must act. The bellows is adjustable to afford room temperature selection. The bellows and a compression spring act on a master lever, the compression spring reacts against the bellows force.