The present invention relates to Tetracyclic Heterocycle Compounds of Formula ##STR00001##
and pharmaceutically acceptable salts or prodrug thereof, wherein A, X, R.sup.1, R.sup.2, R.sup.3 and Ware as defined herein. The present invention also relates to compositions comprising at least one Tetracyclic Heterocycle Compound, and methods of using the Tetracyclic Heterocycle Compounds for treating or preventing HIV infection in a subject.

A rotor assembly comprises a rotor hub and rotor-blade assemblies. The rotor hub comprises rotor-blade supports. Each rotor-blade assembly is coupled to a respective one of the rotor-blade supports and comprises a flap axle, a hub connector, a rotor blade, and a torsion strap. The flap axle extends through a respective one of the rotor-blade supports and has a central flap-axle axis. The hub connector is pivotable relative to a rotor-blade support about the central flap-axle axis and defines a central hub-connector axis. The rotor blade is coupled to and is pivotable relative to the hub connector, and, together with the hub connector, is pivotable relative to a respective one of the rotor-blade supports about the central flap-axle axis. The torsion strap has a first end, coupled to the rotor blade, and a second end, through which the flap axle passes.

A rotor assembly comprises a rotor hub and rotor-blade assemblies. The rotor hub comprises rotor-blade supports. Each rotor-blade assembly is coupled to a respective one of the rotor-blade supports and comprises a flap axle, a hub connector, a rotor blade, and a torsion strap. The flap axle extends through a respective one of the rotor-blade supports and has a central flap-axle axis. The hub connector is pivotable relative to a rotor-blade support about the central flap-axle axis and defines a central hub-connector axis. The rotor blade is coupled to and is pivotable relative to the hub connector, and, together with the hub connector, is pivotable relative to a respective one of the rotor-blade supports about the central flap-axle axis. The torsion strap has a first end, coupled to the rotor blade, and a second end, through which the flap axle passes.

There is disclosed in one example a mechanical assembly, including: a parent part including a parent part lug; a bushing to pass through the lug, the bushing comprising a central inner diameter, and respective left and right relief zones having a second inner diameter different from the central inner diameter; and a through-pin to pass through the bushing.

There is disclosed in one example a mechanical assembly, including: a parent part including a parent part lug; a bushing to pass through the lug, the bushing comprising a central inner diameter, and respective left and right relief zones having a second inner diameter different from the central inner diameter; and a through-pin to pass through the bushing.

A propeller provided with interchangeable blades, and to a method of mounting such interchangeable blades on the propeller. The propeller comprises a hub, fastening fittings, rotation guide devices for guiding the fastening fittings in rotation relative to the hub, locking parts, and blades. The fastening fittings are configured to be assembled into the hub from the inside of the hub, and the locking parts lock respective ones of the fastening fittings onto the hub. The blades are fastened to respective ones of the fastening fittings outside the hub and can thus easily be replaced with other blades without removing the propeller.

A rotor blade retention assembly is configured to connect a rotor blade to a central hub comprising a hub arm coupled to and extending radially outward from a hub bowl. The hub arm includes a hub arm lug. The rotor blade retention assembly includes a tension-torsion strap with an inboard end and an outboard end, the inboard end including an inboard pin hole and the outboard end including an outboard pin hole. The rotor blade retention assembly further includes an inboard blade pin and an outboard blade pin. The inboard blade pin is configured to extend through the hub arm lug and the inboard pin hole and to couple the inboard end of the tension-torsion strap to the hub arm. The outboard blade pin is configured to extend through a blade lug of a rotor blade and the outboard pin hole and to couple the outboard end of the tension-torsion strap to the rotor blade.

A rotor blade retention assembly is configured to connect a rotor blade to a central hub comprising a hub arm coupled to and extending radially outward from a hub bowl. The hub arm includes a hub arm lug. The rotor blade retention assembly includes a tension-torsion strap with an inboard end and an outboard end, the inboard end including an inboard pin hole and the outboard end including an outboard pin hole. The rotor blade retention assembly further includes an inboard blade pin and an outboard blade pin. The inboard blade pin is configured to extend through the hub arm lug and the inboard pin hole and to couple the inboard end of the tension-torsion strap to the hub arm. The outboard blade pin is configured to extend through a blade lug of a rotor blade and the outboard pin hole and to couple the outboard end of the tension-torsion strap to the rotor blade.

A rotor assembly includes a pitch spider, rotor blade assemblies, and pitch horn joints. The pitch spider has a body and pitch spider legs extending from the body. Each blade rotor assembly includes a rotor blade, a pitch adapter joined to the rotor blade and connecting the rotor blade to the rotor hub, and a pitch horn. Each pitch horn joint joins one of the rotor blade assemblies to a corresponding pitch spider leg. Each pitch horn joint includes a pitch horn joint bolt extending from the pitch horn of the rotor blade assembly to the pitch spider leg along a pitch horn joint axis, the pitch horn joint bolt fixed to the pitch horn; a spherical bearing having an inner ring and an outer ring; and a slider sleeve coupled to the spherical bearing, the slider sleeve enabling the pitch horn to translate along the pitch horn joint axis.

A rotor system includes a drive hub, a set of rotor blades extending radially from the drive hub, and a set of tension-torsion straps connecting the rotor blades to the drive hub. The drive hub has a rotor mast opening extending along a mast axis. The rotor system is configured to rotate about the mast axis. The drive hub further has a set of mounting slots for mounting the tension-torsion straps. The mounting slots are arranged along a circle around the drive hub, each mounting slot extending through the drive hub along a respective mounting axis. The mounting axis of each of the mounting slots is biased relative to the mast axis. The tension-torsion straps are mounted to the drive hub at their corresponding mounting slots.