Abstract: An air extractor assembly for an automotive vehicle is disclosed which has first and second air extractor valves mounted in a body panel. The first air extractor valve opens when pressure within the passenger compartment at a first pressure differential and the second air extractor valve opens at a second higher pressure differential. The second flap has a weight, which by virtue of gravity, resists opening. The weight can be a magnetic strip that is attracted to a ferrometallic and/or magnetic strip applied around the second aperture. By providing air extractor valves which open at different pressure differences, only the first air extractor valve opens when the pressure difference is in a lower range thereby limiting noise transmission into the passenger compartment. When a car door is shut and/or the climate control system is operating at maximum, the pressure difference is greater causing both extractor valves to open.

Abstract: A pressure relief valve includes a housing and vane that is movable to one of an open position and a closed position. A linear actuator mechanically couples between the movable vane and the housing. The linear actuator is a wire device fabricated from a shape memory alloy. An actuable latching system is configured to retain the movable vane in one of the open position and the closed position for an indeterminate time period.

Abstract: An active pressure relief valve adapted for selectively regulating a condition within an interior compartment generally includes a housing fluidly coupling the compartment to an external environment and defining an opening, an actuator including an active material element operable to effect movement of a flap relative to the opening, a load limit protector coupled to and configured to present a secondary output path for the element, when the flap is unable to move, and/or a latching mechanism coupled to, and configured to engage the flap, so as to retain the flap in a modified condition.

Abstract: Testing of an aircraft pressure control system may be performed without use of an altitude chamber. Aircraft cabin configuration date may be modeled and used, along with high resolution positional feedback from a simulated valve, to produce a high resolution electrical signal that may represent a simulated cabin pressure. A voltage-to-pressure transducer may convert the electrical signal to a pneumatic signal. The pneumatic signal may be employed to operate a cabin-pressure controller under test. The controller may operate an outflow valve actuator and an attached potentiometer. The potentiometer may produce a feedback signal and closed-loop testing of the aircraft pressure control system may thus be performed. The outflow valve actuator may be operated without being attached to an outflow valve because a simulated aerodynamic load may be applied to the actuator.

Abstract: An HVAC system for work vehicle having an operator compartment for an operator is disclosed. The HVAC system includes a pressurizer blower and an air-conditioning system coupled to an electronic circuit. The electronic circuit is configured to reduce the output of the pressurizer blower when the operator selects a high output from the air-conditioning system. The HVAC system is also configured to provide defog operation in both a manual mode and an automatic mode of operation. The HVAC system is configured to reset the defog operation when the vehicle ignition is turned off or turned back on. The HVAC system is also configured not to reset the defog operation when the operator switches rapidly between the automatic mode and the manual mode of operation.

Abstract: Methods and systems for providing a depressurization alert. An example method includes receiving a cabin depressurization discrete signal, determining if the cabin depressurization discrete signal is valid, and issuing a cabin depressurization alert, if the cabin depressurization discrete signal was determined to be valid. In accordance with further aspects of the invention, a time delay is executed before the receiving, determining, and issuing steps are repeated. The cabin depressurization discrete signal is determined not valid if uncorrected pressure is not greater than a predefined altitude. The uncorrected pressure is a raw pressure value produced by a Pitot-Static system. Also, the cabin depressurization discrete signal is determined not valid if the aircraft's altitude above an intended runway is not greater than a first predefined value.

Abstract: A cabin pressure control system (CPCS) software control logic modification may boost the voltage applied to a motor when conditions are sensed indicating a combination of larger than normal cabin pressure and cabin rate error conditions. The motor may be part of an open-loop system for operating a butterfly valve that may regulate outflow from the aircraft cabin. The larger than normal cabin pressure and cabin rate error conditions may be an indication that the outflow valve is not responding in a normal manner, potentially caused by excessive loading to the motor or motor degradation. By boosting the motor voltage during excessive load conditions or with a degraded motor, CPCS performance and robustness may be improved.

Abstract: A battery pack cooling and body pressure relief system for a vehicle having a passenger cabin is disclosed. The system may include an intake air flow duct connected between the passenger cabin and the battery pack, and an air flow duct connected between the exhaust air outlet and the body pressure relief valve. The system may include a one-way cabin pressure relief vent connected to the air flow duct and configured to selectively allow for air flow into the air flow duct, and may include a duct pressure relief vent connected to the air flow duct and configured to selectively allow for air flow out of the air flow duct into the vehicle.

Abstract: One or more valves may be employed in a pressure relief vent of a vehicle. The valves may have asymmetrical closing characteristics of differing pressuring inducing closing characteristics or both in order to reduce the peak noise generated as the valves are closing.

Abstract: A cabin for a work vehicle, comprising: a ceiling portion; an air conditioner provided to the work vehicle; an air distribution duct provided to the ceiling portion for communicating conditioned air from the air conditioner to the cabin; an air guide projecting into the air distribution duct at an intermediate portion of the duct and forming an inlet opening in a lateral face of a projecting portion of the air guide; and an outlet portion extending to outside the duct and having an opening for introducing the conditioned air from the inlet opening into the cabin. The air guide is pivotable between a use condition and a non-use condition where the inlet opening is oriented differently from an orientation of the inlet opening when the air guide is in the use condition.

Abstract: An aircraft pneumatic cabin pressure control system that is adapted to prevent the difference between cabin pressure and atmospheric pressure from exceeding a threshold value wherein the threshold value varies in relation to aircraft altitude. In some instances the control system includes at least one outflow valve adapted to prevent the difference between cabin pressure and atmospheric pressure from exceeding a threshold value, and the control system is adapted to override the outflow valve at predetermined altitudes. The control system may implement a method for controlling the cabin pressure of an aircraft using a pneumatic cabin pressure control system that includes an outflow valve comprising at least two pressure input ports, the method comprising coupling an isolation valve to an input port of the outflow control valve and utilizing the interrupt valve to isolate the outflow valve input port to which the isolation valve is coupled from pressure changes.

Abstract: A method and apparatus for providing a cab pressure drop warning to an off-road machine operator and instructions for increasing the cab pressure and for providing incentive to correct the pressure drop, the method including comparing ambient and cab pressures and threshold pressure (i.e., the ambient plus a differential value), causing a vehicle operation disruption for at least a short period during which the operator may elect to remedy the cab pressure drop.

Abstract: The present invention relates to a system for venting interior cores of composite structures. Generally, the venting system includes a mounting assembly and a venting medium. The mounting assembly generally interconnects the venting system to the composite structure generally with respect to a first air hole of the composite structure. The venting medium may have a perimeter region and an airflow region disposed inwardly of the perimeter region. In one aspect, this airflow region of the venting medium may be free from direct contact with any other portion of the venting system. In another aspect, the venting medium may be made of a fluorocarbon polymer/copolymer. Upon implementation of the present invention, airflow that is generally directed through the first air hole and that passes between the core of the composite structure and an exterior environment (e.g., a payload compartment) generally passes through the venting medium of the venting system.

Abstract: A method and apparatus for providing a cab pressure drop warning to an off-road machine operator and instructions for increasing the cab pressure and for providing incentive to correct the pressure drop, the method including comparing ambient and cab pressures and threshold pressure (i.e., the ambient plus a differential value), causing a vehicle operation disruption for at least a short period during which the operator may elect to remedy the cab pressure drop.

Abstract: A device for providing a plurality of indications of a select pressure, said device including: an electronic interface having an input and an output; a resistive structure adapted to measure the select pressure and being electrically coupled to the input of the electronic interface; a first output for providing a signal indicative of the select pressure, the first output being electrically coupled to the output of the electronic interface; and, a comparator coupled to the output of the electronic interface and being adapted to provide a signal indicative of whether the select pressure is greater than a predetermined threshold.

Abstract: A fan causes a flow of cold air and warm air into the internal space of the passenger compartment of a vehicle. Air extraction channels connected to corresponding extraction vents are distributed at different locations in the passenger compartment. Controllable flaps selectively apportion and control the distribution of the extracted airflow between the different extraction channels.

Abstract: An air conditioning system and method are provided for use in an aircraft having a pressurized area and an unpressurized area. The air conditioning system includes an air conditioning pack located in the unpressurized area of the aircraft that conditions fresh air. The air conditioning system also includes a first air duct for directing a flow of recirculation air from the pressurized area, through a pressure bulkhead, and into the unpressurized area. A mixer is also provided and advantageously positioned in the unpressurized area for mixing the conditioned air from the air conditioning pack and the recirculation air from the pressurized area. Advantageously, the mixer obviates the need for a mix manifold and saves valuable space for passengers, cargo, and other aircraft equipment. The air conditioning system also includes a second air duct that directs the mixture of conditioned air and recirculation air from the mixer to the pressurized area of the aircraft.

Abstract: A closure mechanism and seating controls in combination with use with a hyperbaric chamber are described. The closure mechanism in combination with a hyperbaric chamber includes a door opening, a chamber door with dimensions larger than the door opening, a ring of sealing material secured to either the outer surface of the door or the inner surface of the chamber, a means for positioning the door adjacent the door opening and a means for pressurizing the chamber to effect a seal. The closure mechanism also includes an upper rail and pivoting carriers that may slide along the rail and a lower track mounted adjacent the floor and door guides that may slide within the track. The carriers and door guides are mounted to the interior surface of the door. The door and chamber walls may be flat, or curved in one or more planes.

Abstract: The present invention relates to a pressure regulation system for maintaining the air pressure within a defined space at a substantially constant level. The pressure regulation system comprises a housing and a flexible diaphragm within the housing which divides the housing into first and second chambers. The first chamber contains air at a desired or reference pressure. The second chamber communicates with the defined space and contains air at the same pressure as that in the defined space. The system further includes a laser system for detecting movement of the diaphragm due to pressure imbalance between the first and second chambers and a system for introducing air into or withdrawing air from the defined space when a pressure imbalance is detected. The pressure regulation system of the present invention has particular utility in aircraft systems for maintaining substantially constant pressure in the passenger cabin.

Abstract: An air-flow management system for controlling the supply air to a motor vehicle passenger compartment is disclosed. The air-flow management system includes a reversible heat pump system for transferring heat energy between an outside environment and a refrigerant. Air from the outside environment, fresh air, and from the passenger compartment, recirculated air, is forced through the air-flow structure by a blower resulting in the transfer of heat energy between the refrigerant and the passenger compartment. A recirculation door provides a means for controlling the mixture of fresh air to recirculated air that flows through the air-flow structure. The position of the recirculation door is selectable by a controller to prevent fogging during the transition from cooling mode to heating mode, minimize the energy expended conditioning the passenger compartment air, and prevent the backflow of unconditioned outside air from the fresh air duct into the recirculation duct.

Abstract: A regulating apparatus and a regulating method for regulating the internal pressure P.sub.i of a ventilated, closed volume subjected to variations in external pressure P.sub.e, the apparatus including at least two compensation circuits enabling the intake air flow rate q.sub.1 and the extraction air flow rate q.sub.2 to be adjusted in real time so that the difference between these two flow rates algebraically compensates for the leakage flow rate q.sub.f, and maintains the internal pressure P.sub.i inside the volume at a constant level.

Abstract: An apparatus for preventing sudden changes of pressure in an air conditioned or ventilated vehicle, the vehicle comprising: an inlet orifice (3) for outside air and an outlet orifice (5) for inside air, the inlet orifice being connected to an intake duct (2) directing the air taken in to an air conditioning or ventilation system, the outlet orifice being connected to an exhaust duct (4) exhausting the inside air to the outside; shutter means (6, 7) for the intake and exhaust ducts (2, 4); a control member (14) receiving signals from the detector; and detector means (16, 17) for detecting the pressure outside the vehicle Po and the pressure inside the vehicle Pi and delivering signals representative of the pressure wave.

Abstract: In a tunnel control system for traction vehicles, the normal deration function is suppressed to delay deration in a tunnel. The traction vehicle is provided with a controller having a normal operation mode and a tunnel operation mode. A tunnel indicator connected to the controller provides an indication of when the vehicle is approaching a tunnel and causes the controller to switch into the tunnel operation mode. In this mode, the controller increases cooling to reduce the temperature of the vehicle's prime mover and the control electronics prior to entering the tunnel. As the traction vehicle enters the tunnel, the controller monitors the engine oil temperature and the ambient air temperature. If the ambient air temperature exceeds a predetermined value, then the cooling of the control electronics is discontinued. If the oil temperature exceeds a threshold (which is about 10.degree. C. higher than the normal deration threshold), then power to the prime mover is derated.

Abstract: A process and apparatus for regulating the quantity of fresh air in high-speed trains by means of pressure-wave valves. A signal for adjusting a drive unit is determined from the passenger count and outside temperature. This drive unit causes a stop fork to move into a flap stop position of the valve in the "open" operating mode so that the required amount of fresh air can be supplied. The process according to the invention results in a considerable saving on energy, since only the absolutely necessary amount of fresh air need be heated or cooled and the period of time in which ventilation can be used rather than cooling is lengthened.

Abstract: A rolling stock ventilator including an air supply fan, an exhaust fan an inverter for changing air feed characteristics of the air supply fan and the exhaust fan. Flow path resistance changers, a tunnel detector to detect the presence of a tunnel, and a car internal pressure detector are also provided. A controller provides signals to the inverters and the flow path resistance changers with the signals representing a control command to change the operation frequency of the air supply fan and the exhaust fan in accordance with the result of a detection by the tunnel detector and the car internal pressure detector and also provides a control command to change the air feed resistance of the flow path resistance changers.

Abstract: Air conditioning (AC) system for motor vehicles comprising two fans connected in a series circuit whereby the first fan provides only a part of the air required for admission into the passenger compartment, and the remaining contribution to the desired quantity of air is provided by the second fan. Under normal operating conditions, where all openings such as windows, doors and sunroof (if any) are closed, both fans are independently regulated by a main controller device in such a manner that the air on the passenger compartment experiences a slight overpressure in order to permit the rapid entry and exit of air flow through the passenger compartment and a uniform air circulation therein. A manometer is included in the AC system to provide air pressure differential data (between the passenger compartment and the outside) to the main controller.

Abstract: The invention relates to a device for eliminating sudden changes of pressure in a ventilated or air-conditioned vehicle, the device comprising: a detector for detecting changes in the pressure outside the vehicle and delivering signals representative of said changes; closure means for closing an outside air suction duct and an inside air rejection duct; a control unit receiving the signals from the detector and controlling closure of the ducts above a first determined rate of change in outside pressure, said unit also controlling re-opening of the ducts after said change in outside pressure has fallen below a second determined rate; and means for balancing the inside pressure and the outside pressure by a controlled flow of air between the outside and the inside of the vehicle, said means constraining the pressure inside the vehicle to change as a function of time at less than a set rate.

Abstract: An improved air conditioning system is provided for an aircraft, particularly with respect to providing an enhanced supply of fresh air to the aircraft cabin or cockpit. The system includes a dual inlet turbine driven at least in part by pressurized bleed air from an aircraft engine, wherein the turbine expands and cools the air preparatory to supply thereof as conditioned air to the aircraft cabin. During relatively low altitude operation, the bleed air flow is supplemented by compressed fresh air discharged from a turbine-driven compressor and supplied to the dual inlet turbine. At relatively higher altitude operation, this fresh air flow is bypassed around the turbine for addition to the bleed air flow at a downstream side of the turbine, and the entire nozzle area of the turbine is opened to the bleed air flow.

Abstract: An automobile air conditioning system supplies conditioned air to the passenger compartment of an automobile. The air conditioning system includes an evaporator for cooling the incoming flow of air and a heater core for heating the incoming air from said evaporator to a predetermined temperature. The air conditioning system also includes front and rear vent units for expelling conditioned air, and a control unit which includes a single mode selector for expelling heated air out the front vent unit and a dual mode selector for expelling heated air out both the front and rear vent units. A bypass for directly leading air from the cooling unit to the front vent unit is provided for the air conditioning system. The control unit opens the bypass when the single mode and maximum cooling mode are selected, and closes the bypass when the dual mode is selected.