Abstract: A model helicopter rotor pitch control mechanism is provided.

Abstract: In an individual rotor blade control device for a helicopter main rotor with a rotor shaft that can be driven by a main drive, with an even number of rotor blades that are arranged on the periphery of a rotor hub, with primary control mechanisms for collective and sinusoidal, cyclic rotor blade adjustment, which include a transfer element for the control movements from a non-rotating system to a rotating system and with actuators that are individually allocated to the rotor blades, wherein the actuator control movement is superimposed onto the control movement of the primary control mechanisms and each actuator is equipped with a safety device in order to bring the actuator into its final position and keep it there, if necessary, it is suggested that the setting angle change of one half of the rotor blades have an opposed direction due to the securing of the actuators in their final positions, like the setting angle change of the other half of rotor blades, and that the rotor blades of each half be distribute

Abstract: The subject tiltrotor aircraft has three modes of operation: airplane mode, helicopter mode, and transition mode. A tilting mast, which transitions the aircraft between airplane mode and helicopter mode, is controlled by systems that allow selective movement of the rotor blades between the flight modes. A hub couples the rotor blades to the tilting mast such that torque and thrust are transferred, while allowing rotor thrust vector tilting. A main swash plate controls rotor thrust vector direction. Pitch horns are coupled to the rotor blades and the main swash plate via pitch links such that swash plate inputs are communicated to the rotor blades. The pitch links are coupled at “delta-3” values that are not optimum. A feedback swash plate and feedback links receive disk tilting inputs from the rotor blades, and supply inputs to the main swash plate, which compensates for the less than optimum delta-3 coupling.

Abstract: A helicopter with rotor blades rotatably connected to a rotor head. The rotor head is non-rotatably connected with a rotor mast (1) pivoted in a transmission housing and driven by a transmission via at least one driving mechanism. A pitch of the rotor blades, relative to a plane of rotation of the rotor blades, is controlled via a swash plate, control rods (12) and via individual actuators (9) allocated to each individual rotor blade. The control rods (12) and the actuators (9) are mounted in the rotor mast (1) and the rotor head and those components act, via a mixing lever (11) and a control rod (8), upon a pivoted arm (7) which adjusts the pitch of the rotor blade. The control devices of the rotor blades do not interfere with the air flow, are affected only to a limited extent by centrifugal forces and additional stresses, and are also protected against influences of the weather.

Abstract: The invention is based on a helicopter having the following features: one rotor head (1) is non-rotatably connected with a rotor mast (3) which is rotatably mounted in a housing (5) of a transmission (6); one or more driving mechanisms actuate the rotor mast (3) via the transmission (6) with a summarizing gear (11) fastened on said rotor mast (3), one swash plate (17) is supported by its stationary part (18) via a first fork in a non-rotatable but axially displaceable manner and tiltably in all directions relative to this axis of said rotor mast (3); a rotatable part (19) of said swash plate (17) is rotatably supported against said stationary part (18) of said swash plate (17) via axial and radial bearings (23) and non-rotatably hinged on said rotor head (1) by means of a second fork.

Abstract: A starting device of a toy engine comprises a spring, a starting piece, and a unidirectional bevel gear. The motion of the spring between the two fulcrums serves to ensure that the control rod is kept securely in place at a disengaging position and an engaging position. The unidirectional bevel gear is mounted behind the engine propeller and is controlled by the starting piece to prevent the propeller from turning in reverse at the time when the engine is started. The clutch is formed of two clutch pieces which are mounted between the propeller and the engine head. One of the two clutch pieces is mounted on the front end of the propeller shaft for imparting the engine power. Other one of the two clutch pieces is mounted in front of the propeller. The two clutch pieces are symmetrical in construction to each other and are therefore capable of joining together to enable the propeller shaft to actuate the propeller to turn.

Abstract: A cyclic and collective pitch control device for a helicopter rotor, fitted about a fixed casing having an axis, and having a substantially sleeve-shaped movable element fitted in axially-sliding manner to the casing; a rocking-plate assembly fitted coaxially to the movable element so as to rock in any direction with respect to the movable element, and in turn having an angularly-fixed first annular element, and a second annular element rotating on the first annular element together with a drive shaft of the rotor fitted through the casing; supporting and actuating means cooperating with the first annular element to move the assembly and the movable element jointly along the axis with respect to the casing, and to rock the assembly with respect to the movable element; and prismatic connecting means between the movable element and the casing to prevent angular displacement of the movable element with respect to the casing.

Abstract: The rotating plate of the system is fixed in rotation with the rotor by a driver with two rigid driving tracks extending axially and diametrically opposite in being fixed in rotation with the rotor. Each track engages with one of two driving fingers fixed in rotation with the rotating plate and diametrically opposite on this latter. Each track has two webs between which one finger is engaged with the result of following on this track a rectilinear trajectory, parallel to the rotor axis and a circular arc trajectory centerd on this axis, respectively in the case of change of collective and cyclic pitch.

Abstract: The swash-plates are oscillating mounted by the non-rotating plate on a central ball joint sliding axially around a guide fixed to the structure and on which the ball joint is locked from rotation by internal splines engaging with external splines of the guide. Two parts slide on diametrically opposite raised sectors on the ball joint, and the non-rotating plate pivots on trunnions of the parts around one of two perpendicular axes the other of which is the one around which the parts pivot and which is perpendicular to the rotor axis.

Abstract: The swash-plates are oscillating mounted by the non-rotating plate on a central ball joint sliding axially around a guide fixed to the structure and on which the ball joint is locked from rotation by internal splines engaging external splines of the guide. Two cotters slide in diametrically opposite grooves in the external face of the ball joint, and the non-rotating plate pivots on trunnions of the cotters around one of two perpendicular axes the other of which an axis around which the cotters pivot and which is perpendicular to the rotor axis.

Abstract: In a helicopter with the rotor blades controlled by a swash plate with a stationary part (11) and a rotary part (9) and hydraulic adjusters (4) in a stationary part of the helicopter or in a rotating system, it is proposed to fit a pump, especially a multi-cylinder reciprocating piston pump, between the stationary part (11) and the rotary part (9) of the swash plate. Besides reducing space needs, weight and costs, this provides a short, reliable oil distribution system to the consumers.

Abstract: The rotating and non-rotating swash-plates are guided in axial translation and in tilting on the rotor axis by two non-rotating pillars and slides provided with runners with a cylindrical external face permanently tangentially engaged and sliding against the internal faces of the pillars, the slides bearing two diametrically opposite trunnions allowing the pivoting of the non-rotating plate around a diametrical axis, whereas the sliding and pivoting of the runners on the pillars guide the pivoting of the non-rotating plate around a second diametrical axis, which is the axis of the cylindrical face of the runners.

Abstract: In a helicopter having three or more rotor blades, and with mechanical actuation of the rotor blades by a swash plate and a superimposed electrohydraulic active control system, in addition to three regulating units (18) is an actuator (4) between a rotatable part (9) of the swash plate and a rotorblade mount (2) of each rotor blade. This arrangement allows for the safe actuation of individual blades in helicopter noise reduction, and increased efficiency at a modest constructional effort.

Abstract: The rotating and non-rotating swash-plates are guided in axial translation and in tilting on the rotor axis by a non-rotating axial guide arrangement, such as two pillars, and slides on each of which slides one of two pads carrying diametrically opposite trunnions, enabling the pivoting of the non-rotating plate around a first diametrical axis, whereas the sliding movements of the pads on the slides guide the pivoting movements of the non-rotating plate around a second diametrical axis perpendicular to the rotor axis and first diametrical axis, and which is the axis of the cylindrical face of the slides.

Abstract: The non-rotating plate of the device is stopped from rotating around the rotor axis by a stop arm with at least one rigid stop track extending substantially axially and secured to the structure of the rotor aircraft. The track works together with a stop pin, integral with the non-rotating plate to stop the latter from rotating. The track has two flanges between which the pin is engaged so as to follow on this track a straight trajectory, parallel to the rotor axis and a circular arc trajectory centered on this axis, in the case of variation in the collective and cyclic pitch respectively. The stop pin includes a pad sliding between the two flanges of a slide constituting the said track and hinged around its fastening axis on the non-rotating plate.

Abstract: A cycloidal propeller to achieve strictly a rudder operation includes accessory apparatuses containing accessory drives. Clutches are used to couple the accessory drives to the propeller shafts, and additional clutches are provided to disengage the fixed connection of the normal propeller mechanism to the wing shafts in cruising operation.

Abstract: A helicopter blade assembly for permitting rapid forward flight in a helicopter having separate means for providing a forward impetus. The assembly has a set of rotatable blades attached to a substantially vertical mast. These blades slope downward near to their distal ends, thereby creating an inverted disk virtual air foil when the blades are rapidly rotated by the mast. In a preferred embodiment the camber of the blades and, therefore, the shape of the virtual air foil is controllable.

Abstract: A swashplate is provided for use in helicopters having a vertical main rotor axis. The swashplate includes a bearing, a first race member including a channel, a second race member including a channel, and a third race member including a channel. The channels of the first, second, and third race members cooperate to form a bearing-receiving slot. The bearing is positioned to lie in the bearing-receiving slot. The first and second race members are adjustably coupled to change the respective positions of their channels.

Abstract: A system for controlling functions of a propeller having a plurality of blades is disclosed. The system comprises an electronic control for controlling the functions of the propeller. A plurality of backup devices are provided for backing up the electronic control upon the occurrence of conditions. These conditions include at least one of testing, manual override, and a malfunction in the electronic control causing at least one of the functions to endanger safety. The system further includes a bypass device for bypassing the electronic control and for invoking at least one of the plurality of backup devices to acquire control over at least one of the functions. The bypass devices include a mechanism for determining the occurrence of at least one of the conditions and for actuating electronic control override.

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 composite rotating swashplate for a helicopter rotor system which includes rotor blades with associated control rods. The control rods control the pitch of the rotor blades. The composite rotating swashplate according to the present invention includes an outer tubular ring with an inner tubular ring located within the outer ring. The outer ring is made from braids of tri-axial graphite fibers interwoven with unidirectional plies. The inner tubular ring is made from braided .+-.45 degree graphite fibers. A support ring is located within the outer ring and external to an inboard periphery of the inner tubular ring. A plurality of apertures are formed through the outer and inner rings. The apertures are adapted to receive the terminal ends of the control rods. Mounting bolts extend through at least one wall of the outer and inner rings and attach the terminal ends of the control rods to the swashplate.

Abstract: An apparatus for compensating for spatial phase angle phase errors in the flapping angle oscillations of a rotor blade is disclosed. The apparatus receives a measured aircraft roll and a measured aircraft pitch. Gyroscopic moments resulting from these measured rolls and pitches are determined, and compensating gyroscopic moments are then generated and summed with commanded pitch and roll accelerations. Flapping angle phase lags of the rotor blade swashplate are added to the summed signals to cancel any flapping angle phase leads, caused by changes in aircraft or rotor blade speed caused by installation configurations of the rotor blade swashplate.

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: A failure of any one of three swashplate actuators of a helicopter rotor blade is detected. Once such a detection is made, the position of this nonfunctional swashplate is locked and measured. The inputted commanded swashplate collective position, commanded swashplate x-axis rotational position, and commanded swashplate y-axis rotational position are then passed to a failure-mode control matrix. The failure-mode control matrix computes swashplate actuator commanded positions for the two operable swashplate actuators so that aircraft attitude control is maintained. These two swashplate actuator commanded positions instruct positional movement of the rotor blade swashplate to thereby meet the commanded swashplate x-axis rotational position and the commanded swashplate y-axis rotational position which will control attitude. A quasi-swashplate-collective-position corrector computes the quasi-swashplate collective position that will occur because of the successful control of the aircraft's attitude.

Abstract: A control system has an HHC actuator having a basal portion and a movable portion. A load acting on the control system is detected by a semiconductor gauge. The load detected by the semiconductor gauge is compared with a threshold value in a computer. If the detected load is larger than the threshold load, the movable portion is fixed to the basal portion by a fixing mechanism. By detecting the sign of stall of blades, the HHC actuator is fixed in a neutral position, allowing safe flight. A fixing switch is provided for allowing the fixing mechanism to operate regardless of the result of the comparison with the computer.

Abstract: A main rotor is provided for use in a rotary winged model aircraft. The main rotor includes a rotor hub assembly rotatable about a vertical axis and at least two main rotor blades. Each of the main rotor blades extends in a radial direction from the rotor hub assembly. The main rotor blades each include a tip end positioned to lie in spaced-apart relation to the rotor hub assembly and a root end coupled to the rotor hub assembly for pivotable folding movement from an initial horizontal position perpendicular to the vertical axis about a horizontal axis through a desired folding angle of about 90.degree.. Forces transmitted to the rotor hub by the rotor blade during a crash-landing of a rotary winged model aircraft including the main rotor are minimized due to movement of the rotor blades through the desired folding angle.

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: For each blade, the cuff which is rigid in torsion, surrounding the corresponding rotor attachment twistable arm, bears two opposed pitch levers each articulated to one respectively of two intermediate connecting rods which are moreover articulated to one and the same transmission lever on either side of a pivoting link by means of which this lever pivots on a pivot secured to the rotor mast. The transmission lever is additionally articulated to the pitch-control rod at a point which is offset with respect to its pivoting link. A crossmember is articulated to the connecting rods and interacts with an assembly having a drag damper, this assembly itself being articulated to a fixed point secured in terms of rotation to the rotor mast.

Abstract: This invention is directed to stopped rotor Flipped Airfoil X-wing (FAX-WING.sup..TM.) aircraft which comprises:(a) A rotary wing flight mode which operates similar to a helicopter, wherein all main rotor airfoils rotate with leading edges into the oncoming airstream (neglecting forward motion) to provide lift, and utilize an anti-torque rotor to cancel main rotor torque. The fixed wing flight mode, including supersonic flight, utilizes all stationary main rotor airfoils for primary lift, such that all airfoil leading edges are positioned forward, meeting the oncoming airstream generated by forward aircraft motion. Two airfoils are forward swept 45 degrees, and the other two airfoils are aft swept 45 degrees. The transition mode for converting from rotary wing to fixed wing flight, and vise-versa, causes two adjacent airfoils to flip 180 degrees (in approximately 1/16 second) about their pitch axis, such that all airfoils have leading edges in the correct orientation for a particular flight mode.

Abstract: The invention relates to a low-vulnerability device for the operation of a lifting and propulsing helicopter rotor by means of a cyclic plate mechanism, in which the non-rotating plate (5) is coupled at four points (1, 2, 3, 4) to four hydraulic actioning servocontrols each comprising a power jack (9), an anchoring system (10) and a servocontrol-distributor (41, 42), three servocontrols being used when normally working, the fourth being used in back-up in the event of a failure of one of the other three. Each power jack (9) is supplied by an independent hydraulic circuit which comprises the servocontrol-distributor (41, 42) operated by a mechanical input, connected to the cockpit by linkage (13), and a disengageable anchoring system.

Abstract: The control device is of the type including two annular disks (3,6), a rotating and non-rotating disk, assembled by at least one ball bearing (20) and mounted concentrically about the rotor shaft (1). The non-rotating disk (3) is mounted so as to oscillate with respect to the shaft (1) via a mechanism consisting of swivel/laminated articulations (2, 10). The mechanism for tilting, for axial displacement and for retention in rotation of the non-rotating disk includes two swivel joints (2) which are diametrically opposite on either side of the axis of rotation of the shaft (1) and are centered on the longitudinal tilting axis (A--A) of the non-rotating disk (3). Each swivel joint is retained between a disk support (5), which is mounted so as to slide parallel to the axis of the shaft (1) along a disk guide (4) which is itself coaxial with the shaft (1) and fixed about the latter, and an element (9) for fixing to the non-rotating disk (3).

Abstract: A helicopter blade pitch control system allows blade pitch to be controlled with regard to the degree of rotational position of the blade with respect to the direction of travel and also the degree of pitch. The invention provides an improved arrangement wherein speed paddles attach to rotor blades can change in pitch around the circle of rotation of the blade and also the amount of pitch change can be adjustably changed by the pilot. The apparatus includes a cylindrical member surrounding the rotor of the helicopter and being static with respect thereto so that variable pitch speed paddles connected to and forming a part of the blade assembly and which carry rotating foot members track the upper surface of the cylindrical member changing the pitch of the blade as it moves through a 360 degree rotation.

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: An anti-drive device for restraining against rotation the stationary ring of a rotor control system of a rotary wing aircraft includes a drive tube driveably connected to an engine through a transmission, a rotating ring driveably connected to the drive tube and supported on the stationary ring, pitch links connecting the rotating ring to pitch arms of a rotor that supports rotor blades for rotation and for pivoting motion, and a four bar linkage connecting the stationary ring to the transmission casing. The linkage defines a nearly linear path along which its attachment to the stationary ring travels as the rotor and control system are axially displaced along the rotor shaft and angularly tilted in accordance with the selective actuation of control servos attached to the stationary ring.

Abstract: A swashplate configuration for helicopter which eliminates the need for scissors linkages through the use of a centering member capable of tilt and axial translation while driving torque to the rotating swashplate member through the use of elastomeric bearing assemblies each consisting of a first stack of flat laminates and a second stack of spherical laminates.

Abstract: A swashplate configuration for a helicopter which eliminates the need for a uniball centering bearing and either a stationary or rotating scissors linkage through the use of elastomeric bearing assemblies consisting of a first stack of flat laminates oriented both vertically and radially with respect to the axis of the main rotor shaft and a second stack of spherical laminates having a center axis oriented radially with respect to the main rotor shaft axis and which reacts centering and torque loads through compression of the laminate stacks.

Abstract: A flexible composite scissor assembly is disclosed which utilizes one or more composite straps disposed either in a radial or non-radial relationship between a hub attached to a rotor and an inner or outer ring of a helicopter swashplate. The composite material has sufficient edge-wise stiffness to allow effective torque transmission between the rotor shaft and the swashplate yet has sufficient flexibility to allow for a vertical and angular displacement of the swashplate relative to the rotor shaft. Utilizing a flexible composite scissor assembly eliminates the need for mechanical linkages having pins and bearings which are a frequent source for wear, increasing the reliability of the rotor assembly, while reducing weight.

Abstract: The rotor damping and control power value can be made arbitrary by controlling a cyclic pitch control mechanism with a signal proportional to the angular acceleration of the attitude angle .theta., a signal proportional to the angular velocity of the attitude angle .theta., and a correction signal based upon the difference between the attitude angle .theta. and assumed attitude angle .theta..sub.0, plus the cyclic pitch control input .PSI. applied to a cyclic pitch lever of a pilot. Thus, the rotor damping and control power are brought to their optimum values in response to the actual flight conditions of a helicopter for ideal operability, resulting in both high stability and operability, and, for example, fully automatically controlled hovering can be accomplished without producing any vibration in the attitude angle control response.

Abstract: An omnidirectional variable thrust propeller for a vehicle includes a hub, plurality of blades, and a plurality of shafts. Each shaft is coaxially rotatably connected to a respective blade and extends through the hub at an acute angle to a hub longitudinal axis. Each shaft has a lever arm and an inner end portion which terminates inside the hub. A reciprocably moveable device engages the inner end portions of the blade shafts to uniformly rotate the blades in one direction when the device moves longitudinally in one direction and uniformly rotate the blades in an opposite direction when the device moves in an opposite direction to enable a change of thrust. Another device pivotally supports the reciprocably movable device at a variable acute angle to the longitudinal axis. Another device selectively move the reciprocably movable device about the pivot point to nonuniformly change the rotation or pitch of the blade that alters the propeller's thrust direction.

Abstract: The invention relates to a control device for monocyclic pitch in a fixed reference system and multicyclic pitch in a rotating reference system, for the blades (7) of a rotor craft.In addition to conventional swashplates (27, 38), one (38) of which rotates (39) on the other (27) held in rotation by a nonrotating compass (28), but which slides axially (4) and oscillates (25) about the rotor mast (1), through the action of pilot control (30), it comprises multicyclic jacks (45) in a number equal to the blades (7), and each of which is implanted in the rotating plate (38) and directly drives a pitch control rod (44) of a corresponding blade (7). Each multicyclic jack (45) is a dual-action, hydraulic linear jack controlled by a servovalve (49) also implanted on the rotating plate (38).

Abstract: A control system for providing individual blade control inputs to a four-bladed helicopter rotor. Limited authority series actuators located in a non-rotating portion of the helicopter are driven by a computer which receives inputs from individual blade sensors and aircraft stabilization sensors, summed with cockpit control inputs, and the resultant motions transmitted to the rotor blades through a conventional swashplate which drives four blades of the rotor and a translatable differential sleeve and summing linkage which drives only two blades. The differential sleeve is adapted for axially raising or lowering the swashplate. The combined motion of swashplate and differential sleeve is shown mathematically to result in individual blade control in pitch. Computer individual blade commands are converted from the rotating reference frame to cyclic, collective and differential blade pitch commands in the fixed reference frame through a coordinate transformation matrix.

Abstract: A five or six degree of freedom device which includes a two or three degree of freedom wrist action hand controller and in which additional degrees of freedom are provided by motion of an operator's forearm connected to a mounting member that carries or supports the wrist action hand controller.

Abstract: A three or four degree of freedom device which includes a two or three degree of freedom wrist action hand controller and in which the additional degree of freedom control is provided by motion of an operator's forearm connected to a mounting member that carries or supports the wrist action hand controller.

Abstract: A novel electro-hydraulic control system for use with a helicopter includes a plurality of electro-hydraulic modules which provide control signals to corresponding blade actuators. A controller receives helicopter parameter input signals as well as pilot command signals and generates the control signals in accordance with preestablished algorithms. The system is characterized by a hydraulic slip ring that transmits the hydraulic control signals from the fuselage to the rotating assembly. Consequently, the present system provides "fly by wire" operation with individually addressable helicopter blades.

Abstract: A helicopter composite swashplate ring that has a triaxial braided tubular ring that withstands both forces in-plane and normal to the plane of the swashplate. The triaxial braided tubular ring comprises substantially circumferential fibers interwoven with angled fibers oriented at a predetermined angle to the circumferential fibers. The tubular ring contains a composite circumferential spacer ring that comprises an upper ring plate connected to a lower ring plate by a plurality of first tubular support members. The upper ring plate and lower ring plate are adjacent the inside upper and insider lower surfaces of the tubular ring, respectively. The upper and lower plates have openings in alignment with the first tubular support members. The ring plates have a plurality of sections extending radially outward. The sections have lug openings that are in alignment with a plurality of second vertical support members to form channels therethrough for accepting servo or control rod lugs.

Abstract: A dual redundant servomechanism for moving aircraft control surfaces is disclosed. The servomechanism is of the type whose input commands, from the pilot of the aircraft, are transmitted electrically. Force fight, which is associated with such dual servomechanisms when they are connected to a common aircraft control surface, is minimized. This is accomplished by providing the control system for each servomechanism with input signals which are electrically summed. Each control system includes electrical transducers which provide a signal indicative of actuator position and the pressure associated with the hydraulic motor used in each servomechanism.

Abstract: A controllable lifting rotary wing for an aircraft wherein each rotor blade is mounted in such a manner that it has freedom to oscillate in pitch about its feathering axis. The aerodynamic center on each rotor blade is displaced forward of this feathering axis over at least a portion of the span. Cyclic aerodynamic forces on this spanwise portion cause the blade to change pitch sinusoidally once-per-revolution of the rotor whenever the rotary wing aircraft experiences a change in flight attitude or velocity. The result is that the rotor blades automatically and continuously change pitch to cancel out cyclic lateral flapping moments which are normally produced on a helicopter rotor blade by such a flight disturbance. This rotary wing has greatly improved stability by virtue of this self-feathering action. Cyclic pitch control moments are applied to the rotor blades by indirect means which do not interfere with automatic blade feathering. Means for control of collective pitch of the blades are also provided.