Abstract: A drive system for a variable diameter rotor system that includes a plurality of rotor blade assemblies with inner and outer blade segments. The outer blade segment being telescopically mounted to the inner blade segment. The drive system engaging a jackscrew for telescoping the outer blade segment with respect to the inner blade segment. The drive system includes a rotor hub that is pivotally mounted to the upper end of a main rotor shaft about a pivot point. A gimbaled bearing is disposed between and attached to the main rotor shaft and the rotor hub. The gimbaled bearing permits the rotor hub to pivot about the pivot point. A blade actuation shaft is concentrically disposed within the main rotor shaft. The blade actuation shaft has a constant velocity joint pivotally attached to its upper end about the pivot point. A planetary gearset engages the blade actuation shaft with the jackscrew.

Abstract: A rotor blade actuation system is disclosed for controlling extension and retraction of an outboard blade section of a rotor blade by varying the speed and direction of rotation between a main rotor shaft and a blade actuation shaft. The rotor blade actuation system includes a drive gear on the main rotor shaft and a blade actuation drive gear on the blade actuation drive shaft. A primary drive unit is engaged with and transmits rotary motion from the main rotor shaft to the blade actuation shaft. The primary drive unit includes an input gear engaged with the drive gear. A primary drive is engaged with the drive gear through an input gear and a master clutch. An output drive is engaged with the blade actuation drive gear. A forward clutch controls engagement of a forward planetary gearset with the primary drive and the output drive. The engagement of the forward planetary gearset causes the blade actuation shaft to rotate in the same direction as the rotation of the main rotor shaft.

Abstract: A retractable helicopter rotor in which the rotor and its blades, the swashplate and the pitch change rods are retracted and extended as a unit during the helicopter rotor retraction/extension mode of operation, wherein the connection between the rotor support system and the fuselage constitutes a single interface between overlapping circumferentially extending flanges of each, and with the bolts joining those flanges being loaded in compression.

Abstract: A locking control system and an overtravel safety top system are presented for a variable length rotor blade system. The lock system has linkage and pawl apparatus operated by a pilot actuated lock shaft to lock and unlock the blade adjustment system. A traveling nut on the lock shaft actuates the lock linkage, either directly or through the lock shaft to lock the blade adjustment system to prevent overretraction or overextension in the event of malfunction of the extension control system.