Abstract: A propeller for aircraft has a tip-to-tip flex-beam spar and torsionally stiff hollow blades bonded to the spar throughout an outer portion of the blades. The spar has two end caps which are separated from each other at the hub and converge in the outer portion. The blades have an inner region which is not bonded to the spar, allowing an inner portion of the spar to twist during pitch changes. A counterweight is mounted to an arm extending from an inner end cuff of each blade. The counterweight is located out of the plane of rotation. The counterweight is also located on a side of a line opposite from the trailing edge, the line passing through the pivot axis perpendicular to the plane of rotation.

Abstract: A variable-pitch propeller, especially for a sport board, has angularly displaceable blade support plates which can be rotated about respective radial axes. The plates are provided with radially inwardly directed claws which engage in circumferential grooves of bases of the blades. The latter can have radial projections reaching beneath the claws. The resulting bayonet connection simplifies mounting and dismounting of the propeller blades even under water.

Abstract: A rotor blade for a bearingless rotor of a helicopter includes a lift-generating airfoil blade, a flexbeam connecting the airfoil blade to a rotor head, and a control sleeve enclosing the flexbeam. The junction between the flexbeam and the airfoil blade is a separable junction (J) to allow the airfoil blade to be folded in a simple manner while maintaining a high lead-lag stiffness and reduced structural height of the junction (J). The junction (J) is formed by two connection arms (5.1, 5.2) arranged side-by-side in the lead-lag plane (E.sub.R) of the rotor blade (R). Preferably, the two connection arms extend from the inboard end of the airfoil blade (3) and receive the head (1.1) of the flexbeam (1) therebetween lying in the lead-lag plane (E.sub.R). A connecting fixture (6) connects the connection arms (5.1, 5.2) to the flexbeam head (1.1) using fasteners such as bolts (V.sub.1, V.sub.2) that are spaced laterally from each other at a spacing distance of at least 1.

Abstract: Each blade of the rotor has a rigid root oversleeve connected to a torsionable and flexible root strip by two laminated, spherical support half bearings, fixed by their outer frame with double rigid horns the lateral ends of which facing each other on each side of the strip and half bearings are clamped towards each other and against struts so as to allow a significant, calibrated pre-compression of the half bearings. The double horns and/or struts are fixed axially to the oversleeves by fixing elements distinct from the compression means of the double horns on the struts and perpendicular to these compression horns on the struts and perpendicular to these compression elements. One of the struts, possibly in a single piece with one double horn, is also in a single piece with a pitch lever.

Abstract: An actuation system which includes apparatus for transferring control signals for varying the blade pitch from a non-rotating member to a rotating member of a gas turbine engine is described. In one embodiment, the engine includes a main disk containing a row of blades, and the disk is coupled to a main shaft which rotates about the engine axis. An actuating disk, or cone, rotates with the main disk, and the torque required to rotate the actuating cone is transmitted through ball splines attached to the main shaft. The ball splines allow transmission of torque between the disk and the cone and at the same time enable the disk and the cone to move axially relative to each other without binding. The actuating cone is supported at one end by the ball splines and at its other end by ball thrust bearings. The ball thrust bearings are pre-loaded to enable the bearings to withstand axial loads in opposite directions.

Abstract: A propulsion blade retraction and pitch control apparatus includes a hollow primary drive shaft, a pitch control gear assembly mounted, within a propeller hub, to the primary drive shaft, a radially spaced array of pitch control stub shafts mounted to, in co-operation with, the pitch control gear assembly, so as to be selectively rotatable about corresponding pitch control shaft longitudinal axes upon selective actuation of the pitch control gear assembly, propulsion blades pivotally mounted to the pitch control stub shafts at ends of the pitch control stub shafts radially distal from the pitch control gear assembly, one or two coaxial nested pitch control drive shafts, rotatably co-axially journalled so as to be nested within, and co-axial to, the hollow primary drive shaft, said pitch control drive shaft or shafts selectively rotatable to actuate the pitch control gear assembly.

Abstract: A Kaplan turbine or similar hydraulic machine has a hub body (1) fixed to the turbine shaft with radial blades attached to the hub body. The blades are fitted with oil lubricated bearings in the hub body. A sealing arrangement for the oil system has first (60) and second (61) circumferential sealing members with a circumferential space (65) between the first and second sealing members (60, 61). High pressure water from a water source is directed into the circumferential space (65) via a connecting channel (64) to block the lubricating oil from leaking into the working fluid.

Abstract: A variable-pitch marine propeller system has a propeller unit for mounting on a drive shaft, and a power unit including a stationary annular hydraulic cylinder for operating the propeller unit, a hydraulic remote control unit being fluid-coupled to the power unit. An annular piston of the hydraulic cylinder is coupled to a ring-shaped actuator yoke by a roller thrust bearing, the actuator yoke axially displacing a mating yoke of the propeller unit with which the actuator yoke is allowed to rotate. The piston operates in a sealed environment for the exclusion of water from the separately sealed surfaces of the cylinder itself. In one configuration, the propeller unit is replaceable without disturbing the sealed environment of the annular piston. The control unit includes a hydraulic control cylinder that is operated by a rotatably mounted barrel that engages a threaded piston rod. Alternatively, the control cylinder is actuated by a lever having biasing springs and an adjustable brake.

Abstract: A cyclic and collective control system is provided for controlling rotor pitch in a rotary wing aircraft. The rotor blades are pivotally mounted on a hollow, spinning shaft. An angularly and vertically displaceable control shaft is mounted with the spinning shaft and carries a rotatable control hub at its end. The control hub is coupled through pitch link rods to the rotor blades. When the control shaft is displaced vertically within the spinning shaft, the rotor blade pitch is changed collectively. When the control shaft is displaced angularly relative to the spinning shaft, the rotational plane of the control hub becomes skewed relative to the rotor axis. This has the effect of changing the pitch of the rotor blades in accordance with their rotational position around the rotor axis and has the further effect of providing cyclic control.

Abstract: A hingeless rotor including a rotor mast driven in rotation about an axis of the rotor, a hub secured in terms of rotation to the mast, and at least two blades, each of which is, firstly, joined to the hub by a root attachment part comprising at least one arm which can twist about a longitudinal pitch-change axis of the blade and, secondly, equipped with a cuff which is rigid in torsion, surrounding the at least one twistable arm, and the radially external part of the cuff, with respect to the rotor axis is secured in terms of torsion to the blade and to the twistable arm about the pitch-change axis, while the radially internal part of the cuff surrounds, without contact, the at least one twistable arm and exhibits a pitch lever projecting towards the outside of the cuff and joined to a pitch-control rod, wherein, for each blade, an intermediate pitch-control ring which is rigid in terms of torsion about the corresponding pitch-change axis, and which surrounds the corresponding at least one twistable arm is a

Abstract: A mounting arrangement (60) for coupling a control rod (38) to a stationary swashplate member (32) of a helicopter swashplate assembly (30) wherein the mounting arrangement (60) is characterized by a specially configured stationary swashplate member (32) and a trunnion fitting (62) for mounting in combination therewith. More specifically, the stationary swashplate member (32) includes a horizontal web (74) disposed between an inner ring segment (72.sub.IR) and an outer ring segment (72.sub.OR), wherein the horizontal web (74) includes an aperture (78) and defines a mounting surface (74.sub.S). The trunnion fitting (62) includes a base (64) defining a mounting surface (64.sub.S) and a pair of mounting ears (66) having aligned apertures (66.sub.O). The mounting surface (64.sub.S) of the trunnion fitting (62) engages the mounting surface (74.sub.S) of the horizontal web (74) such that the mounting ears (66) are disposed through the aperture (78) of the horizontal web (74).

Abstract: A pitch link having an adjustable length is constructed as a diamond-shaped frame by coupling and fixing four flexible beams at end portions thereof. Spherical bearings are provided on opposite ends of the structure. A turnbuckle shaft is screwed into vertices of the structure and turned to the length of the pitch link. The turnbuckle shaft can be rotated by a detachable motor.

Abstract: The device comprises, in addition to the conventional non-rotating plate and rotating plate of a swashplates device, a secondary rotating plate which can move in translation with the non-rotating plate but which cannot be inclined, and, for each blade, an articulated link with two levers which are articulated together and the first of which is articulated to the secondary rotating plate. The second lever is also articulated to the pitch rod controlling the corresponding pitch lever, and it is moreover articulated to a stationary point of the rotating plate. The inclinations of the plates give rise to angular manoeuvres of the levers of each link in order to actuate the pitch rod and control the pitch of the corresponding blade.

Abstract: The device for controlling the pitch of the blades of a rotor using a mechanism having swashplates includes an auxiliary plate mounted on the non-rotating plate of the mechanism and which is secured in terms of rotation to the rotating plate of this mechanism and, for each blade, an articulated link in series with the corresponding pitch rod to which it is articulated, and including at least one arm articulated to the rotating plate, each articulated link being controlled by a lever articulated to it and to the auxiliary plate which is off-centered to the desired value so that each of the control levers controls the itch of the corresponding blade by applying a bicyclic component to it, the amplitude and phase of which component depend on the eccentricity of the auxiliary plate as defined with respect to the non-rotating plate.

Abstract: In the rotor, the pitch lever of each blade is connected to the tab of the pitch control spider by a ball joint mounted on a wrist pin and received with clearance in an oblong opening in a ring. The axially offset bearing surfaces of the cuff of the blade are mounted with a radial clearance in the bearings of the hub on which they swivel about the pitch axis of the blade. These radial clearances enable contacts of the ball joint against the edge of the opening on the side of the ends of its minor axis, but prevent these contacts on the side of the ends of the major axis of the oblong opening.

Abstract: A pitch link having an adjustable length is constructed as a diamond-shaped frame by coupling and fixing four flexible beams same in length and rigidity each at end portions thereof. Spherical bearings are provided on opposite ends with the longer diagonal line as an axis of the pitch link. A turnbuckle shaft is screwed into vertex portions on the shorter diagonal line, which is turned so as to adjust a length of the shorter diagonal line, thereby adjusting a length of the pitch link. The turnbuckle shaft is rotated by a detachable motor. Vibrations of a body and the rotational position of a rotor are detected by a vibrosensor and a phase detector respectively while an aircraft equipped with the pitch link is flying, an amount for adjusting the pitch link is calculated by a vibration analyzer from the electrical signals, and the motor is driven through a FM data transmitter/receiver to adjust the pitch link.

Abstract: A tail rotor for a rotary wing aircraft is located in a laterally directed duct located at the end of a tail cone extending rearward from the aircraft cabin and at the base of an empennage extending upward from the duct. The rotor includes a rotor shaft driveably connected to a power source, a rotor hub connected to the rotor shaft, a rotating control shaft, a stationary control shaft, and an actuator connected to the stationary control shaft for moving the rotating control shaft axially. The rotor hub includes rotor arms each supporting a pitch shaft-blade spar assembly for pivotable movement about a pitch axis. A pitch beam supports flexures, each connected to a pitch arm offset laterally from the associated pitch axis. The flexures driveably connect the pitch arms to the pitch beam and transmit pitch control motion to the blades as the pitch beam moves along the rotor axis. Pitch bearings, on which the pitch shafts turn about the pitch axes, are supported on a rotor hub shell fixed to the rotor hub.

Abstract: The blade has its lower-surface and upper-surface skins of its shell, its front and rear filling bodies and its spar made of a composite material having the same thermoplastic matrix, preferably made of PEEK, reinforced preferably with carbon fibres. The spar is extended outside the shell by an integrated rooting part with linkage attachment, in a loop or laminate, in the same thermoplastic composite. The method consists in assembling, by melting, under pressure, all the thermoplastic composite components of the blade, in a single step after manufacturing these components in the form of prefabricated elementary pieces.

Abstract: The blade has its lower-surface and upper-surface skins of its shell, its front and rear filling bodies and its spar made of a composite material having the same thermoplastic matrix, preferably made of PEEK, reinforced preferably with carbon fibres. The spar is extended outside the shell by an integrated rooting part with linkage attachment, in a loop or laminate, in the same thermoplastic composite. The method consists in assembling the spar with the skins, after manufacturing these components in the form of prefabricated elementary pieces, by injecting under pressure a fluidized thermoplastic composite with short reinforcing fibres moulding the filling bodies.

Abstract: The pitch change mechanism for a variable pitch propeller blade or Advanced Ducted Propulsor (ADP) interconnecting the pitch change actuator and the propeller blades of the type that includes a trunnion attached to the root of the propeller blade, the connecting mechanism includes in one embodiment a translating ball screw nut interconnecting the trunnion through a yoke and a cooperating sliding pin and arm connector. In another embodiment where a hydraulic piston is included in the pitch change actuator the cylindrical housing supports a plurality of circumferentially spaced pins that are in sliding relationship with a rod attached to the trunnion. The trunnions in both embodiments are extended to make the interconnections. Means are provided to prevent the blades from binding up during pitch change movements. This invention eliminates the heretofore utilized sliding anti-rotation spline and the multiple linkage connectors.

Abstract: One embodiment of a main rotor pitch control rod subassembly includes an upper rod end segment having a bearing subassembly, a lower rod end segment having a bearing subassembly, an eccentric bushing disposed in rotatable combination with the upper rod end segment bearing subassembly for varying the axial length of the pitch control rod subassembly, a composite central body structure interposed between the upper and lower end segments, a composite strap member wrapped around and secured in combination with the lower end segment bearing subassembly, the composite central body structure, and the upper end segment bearing subassembly, eccentric bushing combination, a composite overwrap overlayed in combination with the composite strap member, a locking key member and a clamp-up bolt for clamping the composite strap member in tensioned combination with the locking key member, and a locking bolt.

Abstract: A tail rotor for a rotary wing aircraft is located in a laterally directed duct located at the end of a tail cone extending rearward from the aircraft cabin and at the base of an empennage extending upward from the duct. The rotor includes a rotor shaft driveably connected to a power source, a rotor hub connected to the rotor shaft, a rotating control shaft, a stationary control shaft, and an actuator connected to the stationary control shaft for moving the rotating control shaft axially. The rotor hub includes rotor arms each supporting a pitch shaft for pivotable movement about a pitch axis. Each pitch shaft is adapted to support a rotor blade so that its angle of attack changes with movement of the pitch shafts. A pitch beam, located adjacent the rotor hub, supports flexure members, each connected to a pitch shaft eccentric of its pitch axis.

Abstract: A self-actuating variable pitch marine propeller which incorporates two or more blades which are rotatably connected to a central hub; the blades rotate relative to the hub center about the shank axis. In operation, the blades are biassed towards the lower pitch, both by mechanical means, such as a spring, and optionally also by hydrodynamic load means. As the propeller rotational speed increases, centrifugal forces act to move the blades towards the higher pitch position. In one alternative mode the hydrodynamic load also acts towards the higher pitch position. There is further provided a holding mechanism to retain or hold the blades at least preferably in the lower pitch position, the holding mechanism being so designed that at a sharply defined combination of parameters, including rotational speed and optimally hydrodynamic load acting on the blades, the holding mechanism is caused to be released and the blades permitted to move to a second higher pitch position.

Abstract: A ducted fan-type tail rotor of a rotor craft in which the tail rotor is surrounded by a tubular duct is provided which includes at least six rotor blades, and pitch horns, each mounted to the respective rotor blades. Each pitch horn is swingable to change a pitch angle of the rotor blade. Some of the pitch horns, the number of which is about a half of the total number of the pitch horns, are mounted to a first type of the rotor blades at a mounting angle larger than a reference mounting angle required to obtain a predetermined thrust, and the remainder of the pitch horns are mounted to a second type of the rotor blades at a mounting angle smaller than the reference mounting angle.

Abstract: An autogyro aircraft has freewheeling rotor blades that provide lift. A separate pusher propeller provides forward thrust. The rotor system (20) has a collective arm (30) as a control for selectively setting and maintaining a tension force on a collective cable to regulate the rotor blade angle of attack or pitch angle between a no-lift attitude and a positive lift angle. The collective arm (30) sets a tension on collective cable against a coil spring biasing. The collective arm is connected to pivot or tilt a pitch change horn assembly and, in turn, connected rotor blades. The collective arm can be selectively set and maintained and released and reset both on the ground and in flight.

Abstract: A rotor for a rotary wing aircraft includes a rotor shaft driveably connected to a power source, a rotor hub connected to the rotor shaft, rotor arms inclined with respect to a plane perpendicular to the rotor axis and pitch shafts supported on each rotor arm. The rotor arms each support a pitch shaft for pivotable movement about a pitch axis. A pitch beam carries flexures, each connected to a pitch arm at a location offset laterally from the associated pitch axis. The flexures driveably connect the pitch arms to the pitch beam and transmit pitch control motion to the blades as the pitch beam moves along the rotor axis. Each flexure is intentionally displaced by bending radially during installation in a direction that reduces forces among components of the flexure bearings developed during operation.

Abstract: A variable-pitch multi-blade rotor for use as the anti-torque rear rotor of a rotating wing aircraft has a rotor with a central shaft rotated about a central axis, a hub constrained to rotate with the central shaft about the central axis, blades distributed around the central axis with each blade being connected to the central shaft by a twistable element, a pitch control disk for the blades which is constrained to rotate with the central shaft but free to slide axially relative to the central shaft, and a member for controlling the sliding of the pitch control disk along the central shaft. Each blade root is secured to a transverse thrust and pitch control lever forming a yoke having one end hinged to the hub and another end hinged to the pitch control disk.

Abstract: Mechanism for controlling pitch changes in helicopter blades, related to the helicopter mast and connected to a lever assembly mounted into the structure, having a pair of command arms, the assembly comprising first and second bars, related by rocker arms, for selective transmission of cyclic and collective pitches.

Abstract: A rotor blade control mechanism includes a transmission driving a hollow rotating drive shaft, extending through the transmission. A rotor head is attached to a top end of the drive shaft and includes rotor blade shafts of variable pitch and having control arm and lengths for cyclic and collective variation of the rotor blade shafts. A control regulates the rotor head control and lengths and includes at least a pair of rods extending through the hollow drive shaft with upper ends operably connected to the rotor head control arm and links and lower ends terminating substantially at a drive shaft bottom end. The control includes a fork with spaced fingers at the drive shaft bottom end and a yoke with spaced arms positioned in opposed relation to the fork. The yoke has a mounting block extending between the arms with the control rod lower ends swingably connected to the mounting block. A swing pin extends perpendicular to the yoke, through the mounting block, and is retained in the fork by the spaced fingers.

Abstract: A hollow hub has around its exterior a plurality of apertures for individually receiving a respective cylindrical inner end portion of one of a plurality of axially rotatable propeller blades. Additionally, the hub has around its exterior a plurality of arcuate recesses for (a) individually receiving an inner portion of one of the respective propeller blades when the cylindrical inner end portion of that blade is received in one of the apertures, and (b) accommodating arcuate movement of the blade inner portion upon axial rotation of the cylindrical inner end portion of the blade.

Abstract: The invention relates to a regulating device for maintaining constant the rotary speed in turbines of the type comprising a turbine hub and a number of turbine blades which are axially, but rotatably connected to the hub and have such a shape and are so aranged that each turbine blade in a flowing medium and by the action thereof is acted on by a torque about its longitudinal axis against the action of a spring device and acts on the turbine hub by a torque acting about the axis of rotation of the turbine.

Abstract: A blade pitch control system for a rotary wing aircraft which incorporates a mast and rotor which is pivotally adapted for movement of the mast between a generally horizontal stored position and a vertical position for operation in a helicopter mode. The pitch control system incorporates a motion amplification mechanism such as a star gear arrangement connected to the pitch horn to amplify control motions which are transmitted to the pitch horns through a push-pull control tube generally parallel to the folding axis of the rotor blade. In another embodiment, the push-pull tube inputs parallel to the mast axis. A locking mechanism retains the blades so pitch changes cannot be made during a predetermined portion of the blade coning cycle.

Abstract: A calibration device for a pitch change link (10) for a helicopter rotor grip where the link (10) includes a bearing (12) and includes a plurality of sequential reference numbers (22) equally spaced apart and concentrically disposed around the link (10). An indexing device (30) is mounted to the bearing (12) and is disposed adjacent to the plurality of sequential reference numbers (22) for locating one of the plurality of reference numbers (22) representing the length of the link (10). The indexing device (30) includes a window (40) which indexes one of the plurality of reference numbers (22) as the link (10) rotates.

Abstract: A propeller blade having (i) a planar configuration (ii) an inner end portion, (iii) an outer end portion, (iv) a relatively sharp, outwardly swept back leading edge portion, and (v) a cylindrical stub axially aligned with the plane of the blade and affixed to the inner end portion of the blade. Also described is a mechanism that enables the pitch of the blades to be adjusted by the operator through a continuum of positions ranging from fast forward to fast reverse so that the boat can be operated at a full range and variety of speeds, can be stopped rapidly, and can be maneuvered with precision. The mechanism can be used for operating flat-bottom boats ("mud boats") in swamps, shallow water, bayous, lakes, rivers and the like, and pass through wet mud and swampy marshes choked with mud or vegetation without excessively fouling the propellers. The mechanism can be serviced and repaired easily and quickly, and can be employed to operate small craft such as mud boats with a minimum loss of interior boat space.

Abstract: A blade angle control device for an axial flow fan, the blades (7) of which are adjustable between two extreme positions during operation, comprises a control ring (9) coaxial with the hub (1) of the fan impeller and connected, through links (15), with control arms of each blade. In an initial position, where the blades are in one extreme position, the control ring (9) abuts on one face of the hub (1) which is located in a radial plane of the impeller. A pneumatically operated piston device (11,12,14) connected to the control ring (9) and located radially within the ring may shift the ring axially from the initial position towards a position in which the blades are in their other extreme position. A plurality of precompressed springs are located in tubes (18) extending through bores in the hub radially outside the piston device. Each spring surrounds a pin (19) connected to the control ring and biases the ring towards its initial position.

Abstract: In an impeller for use in an axial flow fan and having blades (5) which are adjustable during operation of the fan, each blade (5) is, through a blade shaft (7) connected to a hub (1) designed as a compact unit.The blade shaft (7) and an axial thrust bearing device (9) on which the blade (5) is journalled in such a manner that it can, through a control mechanism, be pivoted about its axis for controlling the blade angle, are retained axially in a bearing housing (8) screwed into a threaded bore (18) in the periphery of the hub (1).For adjusting the radial distance between the periphery of the hub (1) and the blade tip the thrust bearing device (9) is held against a closed end of the bearing housing (8) by a spring (43) and a nut (14) screwed onto a threaded portion (15) of the blade shaft (7) and lockable in an arbitrary position by a lock screw (16).

Abstract: A non-rotating actuating system for pitch control of a fan in a bypass turbine engine in which the actuating sleeve, that rotates with a fan and is moved axially to change to the pitch ofthe fan blade, is supported by a part of the fixed structure thereby to minimize loading of the disc supporting structure.

Abstract: A pitch control mechanism for propellers uses an elongated flat strip twisted into a helicoidal. The helicoidal is longitudinally slidable within a hollow propeller shaft. A cup-shaped cylindrical control ring coaxially mounted with respect to the front transverse surface of the propeller shaft is supported by an inner bearing ring permitting both longitudinal and rotational movement of the control ring relative to the propeller shaft. The control ring has a rectangular slot in its disc-shaped front face which fits conformally over the transverse cross section of the helicoidal. Longitudinal motion of the helicoidal therefore causes rotation of the control ring. Propeller blades are fastened to support rods terminating in downward extending, bifurcated fork-like support structures. The front tine of each fork is rotatably supported in a radial hole in the control ring, while the rear tine is rotatably supported by an axial hole in the propeller shaft.

Abstract: A centrifugal fan includes a fan wheel having airfoil blades mounted for pivotal movement about their center of gravity. A yoke mechanism exterior of the fan wheel, when moved axially of the fan wheel drive shaft axis, causes actuator rods to move through the sidewall of the fan wheel. The axial movement of the actuator rods is translated first into rotary movement of a quill hub relative to the fan wheel and finally to radial movement of blade pivoting levers interior of the fan wheel. The movement of the blade pivoting levers causes the pitch of the individual fan blades to be changed in accordance with the degree of movement of the yoke mechanism. The yoke mechanism, actuator rods, quill hub and blade pivoting levers operate independently of the fan wheel so that blade pitch can be varied over an operating range irrespective of whether the fan wheel is stopped or is rotating.

Abstract: Each blade is fixed to the hub by the root part of the spar, arranged in the form of a loop surrounding a connection element bolted on the hub, with the interposition of rigid rings by a pin simultaneously fixing the hub on a drive sleeve transmitting thereto the driving torque of the central shaft. The hub comprises two coaxial cylindrical walls in each of which is pierced, for each blade, a circular opening in which the member for controlling the angle of attack which is fast with the blade root is mounted to rotate via self-lubricating rings. The invention is particularly applicable to helicopters.

Abstract: Each blade is fixed to the hub by the root part of the spar, arranged in the form of a loop surrounding a connection element bolted on the hub, with the interposition of rigid rings by a pin simultaneously fixing the hub on a drive sleeve transmitting thereto the driving torque of the central shaft. The hub comprises two coaxial cylindrical walls in each of which is pierced, for each blade, a circular opening in which the member for controlling the angle of attach which is fast with the blade root is mounted to rotate via self-lubricating rings. The invention is particularly applicable to helicopters.

Abstract: Blade collective pitch control is provided for a rotor system by rotary actuators located between adjacent blades. Each actuator is connected to the leading edge of one adjacent blade and the trailing edge of the other adjacent blade.

Abstract: A rotatable bladed device for vehicles, such as especially a helicopter rotor, which has its blade pitch controlled by a setup which includes a swash plate setup controlled by a set of hydraulic actuators and the particular swash plate setup position and attitude in turn controls the blade pitch by a plurality of rods pivoted together at one end at one particular point movable longitudinally of the rotor axis, one of which rods has its other end pivoted at a point on the pitch arm by which it controls pitch and another of which rods is also pivoted at a point fixed by the rotational position at any particular time of the rotor hub.

Abstract: An apparatus for adjusting the track of rotor blades through remote control, especially of a helicopter during flight. Each rotor blade has a two-part, lengthwise adjustable control rod with a servomotor which is associated with the supply unit for rotor blade control. A receiving/transmitting part is provided, and a control device (potentiometer) as well as a measuring device are installed in the control rod and are operatively connected with an operating station having an indicator or monitor. The receiving/transmitting part, and the energy source of the servomotor associated with the supply unit for rotor blade control, are integrated in the control rod and are combined with the servomotor to a structural unit and are accommodated in a common housing.

Abstract: A variable pitch propeller hub with fluid motor actuating means wherein blading is controllably pitched and feathered by a hub having cylinder and piston means responsive to engine oil pressure and rotating the blades on their radial axes to a full pitch position by link and lever means biased toward a feathered position by an adjustor means having adjustable stops and means for maintaining moderate pitch until the engine is stopped.

Abstract: A rotor shaft for helicopters in which a main rotatable shaft is tubular and supports in its interior a shaft (25) which is angularly fixed relative to the helicopter body and disposed coaxially to said main shaft; a swivel plate assembly being coupled to said fixed inner shaft and being disposed, together with at least part of a plurality of kinematic linkages connecting said swivel plate to the rotor blades and a plurality of actuator means controlling the position of said swivel plate, inside the space lying between said main shaft and said inner shaft.

Abstract: A variable pitch propeller is disclosed having a crank arm attached to the shaft of each propeller blade and a telescoping drive arm having one end pivotally attached to the propeller hub and the other end pivotally attached to a control rod. The telescoping arm rotates the crank arm to adjust the pitch of the propeller blades through an angle substantially greater than 90.degree. as the control rod is moved longitudinally along the longitudinal axis of the hub of the propeller.

Abstract: The apparatus includes a first connecting link having a pair of axially opposing ends with one of the ends being coupled through a uniball to a drive portion of an actuator. A second connecting link includes a pair of axially opposing ends. One of the ends of the second connecting link is coupled to a driven portion, e.g., a butterfly valve. Coupling means, including a mating plug and socket, is provided for adjustably coupling the remaining opposing ends of the first and second links. The mating plug includes four sides and one hole disposed eccentrically therethrough and parallel to the sides. The remaining end of the second link includes a socket for mating with the plug. The plug can be mated in eight different rotational positions with respect to the socket. At each of the eight different rotational positions, the eccentric hole is disposed in a position which determines one of a predetermined number of available couplings between the first and second links.

Abstract: In a helicopter rotor, a blade control linkage is externally supported on the rotor hub and connected to the root end of a torque tube to provide torsion inputs to the blade by twisting the flexible spar member, which is enveloped by the torque tube and joined to the torque tube at a predetermined blade radial location. The linkage forms a parallelogram with the torque tube, and short vertical ball joint mounted links incline in two directions to accommodate blade lead/lag and flapping motions without introducing pitch coupling.

Abstract: A variable-pitch, multi-blade propeller specially usable as a rear rotor of a rotary-wing aircraft and a process for manufacturing the same are described. The propeller comprises a number of pairs of blades emanating from a central hub, each pair comprising a single elongate strip secured at its center to the hub. The strip is composed of two flat bundles of fibres and defining an aperture for a sliding shaft at their center. The shaft is used to control the pitch angles of the blades and aerodynamic blade shells are secured to the fibre bundles by adhesive synthetic cellular or foam material.