Abstract: The instant invention provide a helicopter blade and the like stand-off and folding device that permits a helicopter blades to be folded up to positions close to the tail of the aircraft during inclement weather, storage, transport, or maintenance, etcetera. During a fold or unfold a one-to-one correspondence between the blades and the main rotor head is maintained and critical adjustments of the rotor blade assembly are not disturbed.

Abstract: A helicopter rotor control system (13) including a stop azimuth controller (32) for establishing the value of a deceleration command (15') to a deceleration controller (23), a transition azimuth predictor (41) and a position reference generator (55), which are effective during the last revolution of said rotor (14) to establish a correction indication (38) to adjust the deceleration command (15') to ensure that one of the rotor blades (27) stops at a predetermined angular position.

Abstract: A filament wound fiber reinforced resin matrix composite structure. The structure is particularly adapted for use as a torque drive diaphragm in a rotary wing aircraft hub. The structure comprises a substantially flat diaphragm and a rim. The diaphragm has a central hole therethrough for receiving a shaft and the rim has an inward turning flange for attachment. The diaphragm has an attachment means surrounding the central hole. An alternative embodiment of the structure is a hollow disc having first and second substantially flat diaphragm sides with a rim. The sides have concentric central holes therethrough and attachment means surrounding the holes. The structure comprises a resin matrix, fibers wound substantially tangentially to the central hole with sufficient tension in a multiple circuit pattern to form the structure, and fibers wound with sufficient tension in an essentially circumferential manner to reinforce the rim of the structure.

Abstract: A filament wound fiber reinforced resin matrix composite structure. The structure is particularly adapted for use as a torque drive diaphragm in a rotary wing aircraft hub. The structure comprises a substantially flat diaphragm, a rim, rim reinforcement fibers and at least one fiber reinforcement ring. The diaphragm has a central attachment means for receiving a shaft and the rim has an attachment means. An alternative embodiment of the structure is a hollow disc having first and second substantially flat diaphragm sides with a connecting rim, rim reinforcement fibers and at least one fiber reinforcing ring for each diaphragm side. The sides have centrally located attachment means.

Abstract: Folded helicopter blades are secured against undesirable motion by a device that attaches to a receptacle in the underside of each blade. The device comprises a pin for engaging the receptacle, a spherical bearing disposed about the pin, an annular housing disposed about the bearing and including two diametrically opposed recesses therein, a primary strut attached at one end to the fuselage and at the other end to a clevis-type yoke, wherein the yoke ends are pivotally attached to the housing within the recesses, a secondary strut attached at one end to the fuselage and attached at the other end to the primary strut near the yoke. This arrangement forms a three bar linkage.

Abstract: A helicopter rotor having a rotor hub and a plurality of rotor blades includes for each blade a blade fold mechanism comprising a reversible rotary power source and a rack and pinion mechanism adapted to operate one or more lock pins and to fold the blades between an operational spread position and a folded position. Two embodiments of the invention are described and illustrated.

Abstract: A helicopter rotor includes a powered blade fold mechanism adapted to move a rotor blade between a spread operational position and a folded position and at least one lock pin (17) to lock the blade in its spread position. The mechanism includes a rotary power source (21) and a mechanical linkage (23, 25) having an over-center position and adapted so that energization of the power source in one direction moves the linkage through the over-center position to withdraw the lock pin and fold the blade, and energization in the other direction moves the blade to the spread position and re-inserts the lock pin automatically as the linkage moves back through its over-center position. Lock means may be provided to lock the blade in pitch and, in one embodiment particularly adapted for use in an articulated rotor, the lock means includes pitch, flap and lag locks.

Abstract: The blade angle of the blades of a rotary wing aircraft is adjusted by a control rod (5) inside the hollow rotor head operating a control shaft (8) extending radially out of the rotor head in axial alignment with the blade angle adjustment axis. The adjustment movement of the shaft (8) is transmitted to the respective blade (3.3) by a yoke (11, 12) and a torsion-stiff sleeve (7) which bridge the blade root (3.1) and the torsion yielding blade neck (3.2) respectively. The blade root (3.1) is connected to the rotor hub (1) by a forked member (2) through which a portion (11) of the yoke extends for connection to the control shaft.

Abstract: The foldable rotor blades (12) of a helicopter are automatically adjusted to pitch angles where they can be locked as a prerequisite to folding, by commands generated (98, 112) to cause trim actuators (39-41) to drive swash plate servos (17-19) to the correct positions, initially (98) in response to stored trim references (120) and eventually (112) in response to the difference (109) between stored swash plate servo positions (120) and current servo positions (20-22). A claimed embodiment uses values of servo positions (20-22), just before unlocking the blades upon re-spreading them, to store, in nonvolatile memory (138), deviations (131) from nominal positions stored in read only memory, and generates (159) trim references in a subsequent folding operation in response to integrated values (166) to reduce actual position errors (162) toward zero from desired positions indicated by the stored deviations (148).

Abstract: The foldable rotor blades (12) of a helicopter are automatically adjusted to pitch angles where they can be locked as a prerequisite to folding by commands generated (98, 112) to cause trim actuators (39-41) to drive swash plate servos (17-19) to the correct positions, initially (98) in response to stored trim references (120) and eventually (112) in response to the difference (109) between stored swash plate servo positions (120) and current servo positions (20-22).

Abstract: A fluid current motor having at least one vane mounted on a support for being moved by a fluid current. Flappers are pivotally mounted on the vane for orbital movement and are stopped from movement when moving with the fluid current and swing parallel to the direction of flow of the fluid current when moving against the fluid current. A governor system is further provided to regulate the speed of operation of the vane assembly, and to essentially shut off the motor in excessively strong fluid currents, thereby preventing damage to the fluid current motor. Electricity can be generated directly by the movement of the vane through use of a linear induction system.

Abstract: A variable pitch marine propeller having a plurality of circumferentially spaced apart blades mounted on axles at the root portion of the blades in a hub to permit independent movement of each of the blades about an axis of rotation substantially parallel to the axis of the hub between a first nested position adjacent the hub and a second extended position. Each of the blades includes leading and trailing striking surfaces or root segments on the root portion of the blades which are hub engageable upon initial rotation of the blade in either direction. Intermediate the leading and trailing segments of the blades are positioned cushioning means which may be mounted in either the hub or the blade root segments for inhibiting the shock of engagement of the blades and the hub upon initial start up of rotation of the hub or upon a sudden reversal of rotation of the hub.

Abstract: In a fully articulated helicopter rotor head, utilizing an elastomeric bearing to support each rotor blade and react centrifugal flight loads, a blade restraint, effective in three axes is provided for use during blade folding for aircraft stowage purposes. The restraint allows the blade to be folded through a predetermined fold plane, and held there while preventing or minimizing deflection of the elastomeric bearing.

Abstract: The invention relates to equipment which makes it possible to fold the blades of a rotor, in particular of the type comprising a star-shaped hub with arms flexible in the direction perpendicular to the plane of the star-shaped hub.This equipment comprises a housing which is detachably mounted on the rigid central part of the rotor hub. This housing carries elongate supports at the side. The free end of each support is detachably joined to the upper part of the folding shaft of the corresponding blade. This folding shaft can consist of a spindle replacing a link shaft between the foot of the blade and the corresponding arm of the hub.

Abstract: An apparatus is disclosed for folding a helicopter rotor blade (16) for storage. The blade (16) is secured to a grip (12) by blade bolts (18, 20) which are locked in place by a latch plate (22). Each bolt (18, 20) has an annular groove (30, 31) in which is mated a corresponding aperture (42, 46) in the latch plate (22). To fold the blade (16) the latch plate (22) is translated against the tension of spring (24) to expose a blade bolt (18) to an enlarged aperture (40). This bolt (18) can then be removed to permit pivoting of the blade (16) about the remaining bolt (20). To further secure the latch plate (22), a cap (54) is provided to lock the latch plate (22) to the blade bolt (18).

Abstract: An adjustable centrifugal impeller including a hub, a plurality of elongated vanes located circumferentially on the hub with each of the vanes having inner and outer portions, an annular ring mounted for circumferential sliding movement on the hub, first fasteners extending directly between the inner portions of the vanes and the annular ring for fastening the inner portions of the vanes directly to the hub, and second fasteners extending directly between each of the outer portions of the vanes and the hub for fastening the outer portions directly to the hub, and a plurality of locations on the vanes for receiving the second fasteners to thereby adjust the positions of the vanes on the hub, each of the vanes having a flat face which bears against flat faces of the annular ring and the hub to provide a rigid connection therewith through full face-to-face contact of the overlapping parts.

Abstract: A turbine wheel on a horizontal axis is coaxially mounted within a primary nozzle, for support in a fluid current below a platform carrying electrical power generation equipment. The turbine wheel and primary nozzle are submerged and oriented to enable flow of a portion of fluid current through the nozzle and past the turbine wheel.The turbine wheel comprises a shroud-ring rim, a set of blades extending inwardly toward the axis, the blades being mounted at their outer ends on the inside of the rim, and at their inner ends on the outside of an axial hub. Each blade has its longitudinal tensile elements shaped in the form of part of a relaxed catenary, extending from rim to hub, with sufficient bow in the direction of force of fluid current on the blade to provide a practical wheel of reasonable cost. Struts and strut vanes supporting hub elements within the nozzle may also be of relaxed catenary configuration.

Abstract: This invention provides a rotor hub for a rotary wing aircraft in which elastomeric bearing means are utilized to transmit centrifugal loads and blade pitch, flap and lead lag movements, and in which the blades are foldable about a pivot located outboard of the elastomeric bearing means between extended and folded positions. Locking means are provided to ensure that no deflection of the elastomeric bearing means occurs during the folding operation.

Abstract: A centrifugal blower is disclosed wherein the impeller blades are made of a pliable, flexible, uniformly apertured sheeting made, for example, of plastic, affixed by a flexible support system, to a central rotatable shaft, so that as the rotatable shaft is driven, the apertured plastic sheet is moved centrifugally outwardly with the solid portions thereof assuming the shape of impeller blades. The impeller blades and support system therefor are made completely of thin, flexible, pliable, material, such as plastic, and the blades may assume forward curved, radial, or backward inclined configurations, during blower operation. The impeller blades cause air movement and, in turn, cause a scroll-shaped housing surrounding the impeller blades, also preferably made of plastic sheeting, to immediately inflate, directing the air to the desired location via ducts and the like, for heating, or cooling, or air conditioning or other purposes.