Abstract: An auto bleed valve and method of bleeding a hydraulic system of an aircraft is accomplished by illuminating a plenum of a bleed valve using an LED oriented to illuminate a phototransistor when air is present in the plenum. A comparator circuit is used on an output of the phototransistor such that a predetermined voltage output corresponds to air detected in the plenum. An integrating circuit and a second comparator in series with the first comparator circuit is used to determine when a predetermined time period is met in which air is continuously detected in the plenum. Thereafter an air bleed solenoid can be used to vent the air upon a signal from the aircraft computer logic system.

Abstract: An auto bleed valve and method of bleeding a hydraulic system of an aircraft is accomplished by illuminating a plenum of a bleed valve using an LED oriented to illuminate a phototransistor when air is present in the plenum. A comparator circuit is used on an output of the phototransistor such that a predetermined voltage output corresponds to air detected in the plenum. An integrating circuit and a second comparator in series with the first comparator circuit is used to determine when a predetermined time period is met in which air is continuously detected in the plenum. Thereafter an air bleed solenoid can be used to vent the air upon a signal from the aircraft computer logic system.

Abstract: Composite cylinder assembly includes a removable liner assembly consisting of a liner member having circumferential hoop stress windings wrapped thereabout. The ends of the liner assembly freely float on cylindrical end portions on the inner ends of end glands at opposite ends of the cylinder for sliding sealed engagement with ring seals contained in external grooves in such cylindrical end portions. Surrounding the removable liner assembly in radially spaced relation therefrom is a composite outer wall portion having opposite ends threadedly connected to the end glands radially outwardly of the removable liner assembly, whereby disconnecting the ends of the outer wall portion from the end glands will permit removal of the liner assembly as well as the liner seals and outer wall portion for refurbishment and/or replacement as desired.

Abstract: Fluid actuator includes a piston rod comprised of a wound filamentary composite structure to provide an extremely light weight, relatively low cost, envelope efficient design. Attached to the piston rod are one or more non-integral piston heads which are preloaded against one or more ramp surfaces on the exterior of said piston rod. A pair of oppositely facing ramp surfaces may be formed on the piston rod by interspersing filler means between the piston rod fiber layers. Another ramp area may be formed by providing an external groove in the piston rod which is engaged by longitudinally split support shoes that provide an attachment surface for a detachable piston head. An internal ramp may also be provided on the inner diameter of the piston rod adjacent the axial outer end thereof for mating engagement by a conically ramped exterior surface on an internal metal stud used to attach a rod end assembly to the axial outer end of the piston rod.

Abstract: A dual tandem composite cylinder composite cylinder assembly including a pair of composite cylinder barrels in series, and a center dam connection between adjacent ends of the cylinder barrels formed by providing an interference between external ramps on the adjacent ends of the cylinder barrels and correspondingly sloping internal ramps on respective clamping rings and/or split spacers between the clamping rings and external ramps for clamping the external ramps against a center dam between the adjacent ends of the cylinder barrels. The clamping rings may be connected together by means of a plurality of bolts which, when pretensioned, force the clamping rings toward each other to cause a compression load to be applied at the ramp surfaces. Alternatively, a tensioning nut having internal threads of opposite hand in opposite ends of the nut in threaded engagement with the clamping rings may be used in place of the bolts to move the clamping rings toward each other.

Abstract: Piston rod assembly includes a piston head and rod which are formed separately and subsequently jointed together by injecting adhesive through a porting passage in the piston head into an annular space formed by an internal groove in the piston head and an external surface of the rod to provide a bonded joint therebetween. The piston head includes a radially enlarged center dam portion and a pair of reduced diameter end portions extending coaxially from opposite sides of the center dam portion. The internal groove extends axially beyond opposite sides of the center dam portion for a substantial portion of the length of the reduced diameter end portions. The reduced diameter end portions are externally tapered radially inwardly from opposite sides of the enlarged center dam portion toward opposite ends of the reduced diameter end portions to provide a gradual build-up of stiffness in the piston head from the opposite ends of the bonded joint toward the middle.

Abstract: A composite pressure vessel includes retaining rings at opposite ends of a side wall structure having circumferentially spaced oppositely facing tabs thereon about which longitudinal tension windings are progressively wrapped back and forth in a continuous manner around the circumference of the vessel. Between the tabs at opposite ends of the vessel are oppositely tapered ramp surfaces providing a transition for the longitudinal tension windings from a first diameter axially inwardly of the retaining rings to a second, smaller diameter adjacent the axial outer ends of the tabs, which places the retaining rings in compression in a circumferential direction. Each of the retaining rings has a generally cylindrical support surface adjacent the axial outer ends of the tabs for supporting the generally circumferential extending portions of the longitudinal tension windings thereon. The tabs have sides which taper toward each other in the direction of the axial outer ends of the tabs.

Abstract: A composite pressure vessel including a fluid port extending through the composite sidewall structure formed by providing a radial hole through the sidewall structure for receipt of an externally removable porting plug. The porting plug is retained within the radial hole by threaded engagement in an internally threaded grommet which may either be incorporated into the composite windings of the sidewall structure or held in place against the exterior surface of the sidewall structure by local composite windings. At the inner end of the porting plug is a seal groove containing a ring seal which is sized to form a fluid-tight seal around a porting hole in a liner member in the interior of the sidewall structure to prevent fluid leakage between the porting plug and liner member.

Abstract: Dual tandem composite cylinder assembly includes a cylinder having circumferential or hoop stress windings surrounding a pair of hydraulic chambers in series to react the circumferential loads and prevent diametrical expansion of the hydraulic chambers. Longitudinal tension windings extend over substantially the entire length of the cylinder outwardly of the circumferential windings to react the axial loads which the cylinder must contain. Compressive cylinder composite windings are also provided for carrying compressive loads generated within the cylinder. The hydraulic chambers are desirably lined with removable liner members to facilitate changing of seals and refurbishment of the cylinder.

Abstract: Fluid actuator includes a composite cylinder having circumferential hoop stress windings wrapped about a liner member forming the piston chamber wall, and longitudinal tension windings extending from the outboard end of the cylinder along one side thereof and around the inboard end of the cylinder to the other side and back to the outboard end where they are secured to the cylinder. A compression column of composite material may be provided between a cylinder end wall and a permanent structure mount at the inboard end of the cylinder to extend the length of the cylinder to accommodate a tail stock on the piston of a pressure balanced actuator.

Abstract: Clevis connection includes a clevis bushing having a bushing sleeve, with a shoulder at one end having a tapered inner diameter, and a longitudinally extending slot through the shoulder and a portion of the length of the bushing sleeve. The bushing is inserted through aligned holes in the clevis arms and connecting lug. Then a tapered expander collet is inserted into the tapered inner diameter of the bushing shoulder and a bolt is inserted through the collet and bushing so that the bolt head loads through the collect which expands the bushing to cause pre-stress on the surrounding lug and a pre-load clamping of the connecting lug to one of the clevis arms, and cause pre-stress on the other clevis arm.