Abstract: A butterfly valve comprises a butterfly vane including a radial notch. A seal groove is situated in the vane and a seal including tabs is disposed within the seal groove wherein the tabs are adapted to fit within the notch. The tabs are designed to bear against the sides of the notch. The notch is located on the high pressure side of the butterfly vane and in a position such that the butterfly housing limits the radial motion of the tabs when the valve is in the open position.

Abstract: A system for changing pitch in aircraft propfans is disclosed, in which a motor, located at a stationary position, changes pitch of the blades by of a gear train. Three features of the system are that a feather brake can override the motor and drive the blades toward feather; a unison brake can prevent pitch from undergoing excursions toward fine pitch when propeller speed exceeds a limit; and the motor is non-rotating in the absence of pitch change. A pair of such systems can be used in a counterrotating propfan system, in order to independently change pitch of the propfans.

Abstract: The invention concerns a system for controlling an aircraft propeller. A hydraulic motor controls pitch of the propeller blades. The propeller blades are characterized by the absence of feather-inducing counterweights. An overspeed governor senses when propeller speed exceeds a limit, and, in response, assumes control of the hydraulic motor and drives the blades toward a coarsened pitch position, which reduces the propeller speed. In another form of the invention, a mechanical brake can override the hydraulic motor and mechanically retard a rotating gear, which causes the propeller blades to move toward a coarsened pitch.

Abstract: The invention concerns a pitch change mechanism for an aircraft propeller in which a common ring gear (51) changes pitch of all propeller blades on a given rotor simultaneously. Motion of the ring gear (51) is induced by a planet (40)-and-carrier (101) system driven by a pinion (110). Acceleration of the pinion causes a change toward flat pitch. Deceleration of the pinion causes change toward feathered pitch. If the motor driving the pinion fails, a large deceleration occurs, driving the blades to a safe, feathered position.

Abstract: This invention relates to an actuating mechanism for a pump inlet closure valve and includes in combination a pump housing which projects into a fuel tank and has an opening to allow passage of fuel from the tank into the pump housing. A pump inlet closure valve sleeve is positioned within the pump housing and is mounted for movement in a predetermined path. A pump is positioned within the valve sleeve. A fixed pump housing seal is located in the path of the valve sleeve as well as within and between the pump and the housing. A valve actuating mechanism includes a handle which is pivotally secured to the pump housing and slideably moveable in a direction parallel to the path of the valve sleeve. The handle is mechanically coupled to the valve sleeve whereby initial manual movement of the handle causes the valve sleeve to move into a position blocking the opening to the fuel tank.