Abstract: The invention relates to a rotor for a rotorcraft having foldable hinged blades, the rotor comprising a hub (10), each blade being connected to the hub via a sleeve, each sleeve being hinged about a pitch axis (15) relative to the hub, the rotor including a respective lag damper (14) associated with each blade, each damper being hinged both to the hub and to the corresponding sleeve, the rotor including a system for controlling the pitch of the blades via respective pitch levers (16) secured to each of the sleeves; the rotor includes two abutments designed to co-operate with tooling for blocking the pitch of the blades, a first abutment presenting a bearing surface (35, 36) matching a shape of revolution about an axis (18) of revolution, and a second abutment (33, 39, 70) designed to act axially along said axis of revolution.

Abstract: In one embodiment, a folding rotor blade for an autogyro device comprises a plurality of connected rotor members. When the folding rotor blade is in a compressed state the folding rotor blade has a compressed length, and some of the connected rotor members are disposed in a non-parallel arrangement. When the folding rotor blade is in an extended state the folding rotor blade has an extended length, which is greater than the compressed length, and the connected rotor members are disposed in a parallel arrangement.

Abstract: A device for locking a holding structure for securing a foldable blade of a rotorcraft rotor to the hub of the rotor. The holding structure is hinged in pitch and in drag relative to the hub and the rotor includes, for the purpose of folding the blade, elements for locking the blade-holding structure in pitch and in drag, which device is remarkable in that the associated drive elements includes brake elements preventing it from turning in flight, in particular under the effect of vibration from the rotor.

Abstract: A fan comprising: a housing unit; a retractable fan blade; and a means for driving the retractable fan blade from a retracted position within the housing unit to an extended position exterior to the housing unit.

Abstract: An electronics cooling fan comprises at least one collapsible fan blade driven by centrifugal force to extend radially as the fan spins and driven by elastic force to retract as spinning slows or stops.

Abstract: A rotor for a wind power installation having at least one rotor blade. The smaller the surface area on which the wind acts, that is to say in particular the rotor blade area, the correspondingly lower is the load level for which installation has to be designed and the correspondingly more easily can the rotor blade be transported. On the other hand the size of the wind power installation entails minimum dimensions which are unavoidable for operation and below which the installation dimensions may not fall. In order to provide a rotor blade which on the one hand has the aerodynamically required surface area but which on the other hand is so designed that the surface area of the rotor blade and therewith the depth thereof can be reduced in predetermined situations a part of the surface of the rotor blade is deformmable or movable.

Abstract: A ceiling fan with retractable fan blades includes an electric motor operable to spin a rotor with a plurality of fan blades attached thereto. Each of the fan blades is operable to move between a closed position and an open position. A rotatable center ring is included on the rotor and connecting rods join each fan blade to the center ring. Rotation of the center ring relative to the rotor moves the plurality of connecting rods and fan blades in unison. The fan blades are spring biased toward the closed position. When the rotor rotates, centrifugal forces acting on the fan blades overcome the spring biasing forces and cause the fan blades to move toward the open position. A governor is positioned between the rotor and at least one of the fan blades to limit the speed of movement of the fan blades between the closed position and the open position. The governor may take the form of a fluid cylinder.

Abstract: A blade pin alignment and positioning system for the installation of helicopter blade pins, including an elongated alignment pin and at least one drive member. The drive member is configured to mate with the top end of the alignment pin for use in driving the alignment pin to its initial position in blade installation. Then the drive member is removed from the top of the alignment pin. The exposed top end of the alignment pin is configured to mate with the insertion end of a blade pin. The other end of the alignment pin is tapered for easy operation in alignment of the blade root holes with the holes in the lead lag link portion of the main rotor hub.

Abstract: A turbine system (10) for capturing energy from a fluid stream includes a torque arm (12). At least a pair of, preferably symmetrical clam shell, turbine blades (14) with the upper (16) and lower (18) halves are oppositely connected to the torque arm (12). A coordinating system (46) is connected to the symmetrical clam shell turbine blades (14). The coordinating system (46) further comprises a first system (48) and second system (52). The first system (48) is connected to control and regulate opening and closing of the upper (16) and lower (18) halves of each individual clam shell turbine blade (14). The second system (52) is connected between each pair of the symmetrical clam shell turbine blades (14) so that as one clam shell turbine blade (14) closes the opposite clam shell turbine blade (14) is forced open.

Abstract: A method comprises providing six helicopters. Each helicopter has a fuselage, a main rotor assembly extending out from the fuselage and rotatable about a main rotor axis, and four main rotor blades coupled to the main rotor assembly. The main rotor blades of each helicopter are moveable relative to the main rotor assembly between a deployed position and a stowed position. The deployed position is a position in which the four main rotor blades extend radially from the main rotor. The main rotor blades have a blade rotor diameter of at least forty seven feet when in the deployed position. The four main rotor blades are coupled to the main rotor assembly when in the stowed position. The method further comprises positioning the six helicopters relative to each other such that all six of the helicopters are simultaneously contained within a parallelepiped region having a height of less than fifteen feet, a width of less than twenty feet, and a length of less than one hundred forty five feet.

Abstract: A redundant fan system for a computer includes two fans installed in series with at least one of the fans having collapsible blades. A fan system of this type reduces the fan inefficiency caused when one fan in a series mounted pair is not operating, either because it is free-wheeling or in a locked rotor condition. When non-operational, the fan blades of the collapsible fan fold inward due to airflow generated by the operational fan over the collapsible blades. The ability of the blades to fold reduces the inefficiency of the operational fan, having less of an effect on fan life. Also, because the flow of air is less restricted, proper airflow can be maintained, thus preventing overheating of the computer.

Abstract: Blade fold hinge units are attachable between each helicopter blade and its hub attachment point, while maintaining continuity of mechanical connection of each blade to its hub portion. A two portion hinge unit has a first portion for blade attachment and a second portion for hub attachment. The first and second portions are hinged via a transverse pin to enable blade drooping downward, before or after a blade is pivoted to an aft position for helicopter storage or shipment. Upon aft pivoting of a blade, undesired further pivoting or knuckling of the hinge unit relative to the hub is prevented by addition of a lock link. After blade folding, the blades may be suitably fixed in position adjacent the aft portion of the helicopter body.

Abstract: A tail boom saddle for use with a helicopter. The helicopter has a fuselage, a main rotor assembly extending out from a forward section of the fuselage, and a plurality of main rotor blades operatively coupled to the main rotor assembly. A tail boom section of the fuselage includes a first frame member, a second frame member longitudinally spaced from the first frame member, a plurality of longerons extending between and intersecting with the first and second frame members, and a tail boom outer skin surrounding the frame members and longerons. The main rotor blades, are movable to a stowed position in which the main rotor blades extend generally rearwardly of the main rotor assembly. The tail boom saddle comprises upper and lower saddle portions adapted to exert clamping forces against the tail boom outer skin. The tail boom saddle is adapted and configured to at least assist in maintaining the main rotor blades in the stowed position. The upper saddle portion includes first and second support beams.

Abstract: On the rotor, between each blade and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held above that one of the two blade pins which is the pivot pin about which the blade can be folded by pivoting, once the other blade pin has been removed. This holding is provided by a cradle formed in a cable support connected to the pivot pin, and by a collar articulated to one edge of the cradle and which can be folded down into the closed position onto the opposite edge of the cradle, to which this collar can be connected detachably by at least one detachable retaining element. The section of cable is manually released from the collar and from the cradle before the removal of the removable pin, which precedes folding, so that this section of cable deforms naturally, following the pivoting of the blade.

Abstract: A turbine system (10) for capturing energy from a fluid stream includes a torque arm (12). At least a pair of, preferably symmetrical clam shell, turbine blades (14) with the upper (16) and lower (18) halves are oppositely connected to the torque arm (12). A coordinating system (46) is connected to the symmetrical clam shell turbine blades (14). The coordinating system (46) further comprises a first system (48) and second system (52). The first system (48) is connected to control and regulate opening and closing of the upper (16) and lower (18) halves of each individual clam shell turbine blade (14). The second system (52) is connected between each pair of the symmetrical clam shell turbine blades (14) so that as one clam shell turbine blade (14) closes the opposite clam shell turbine blade (14) is forced open.

Abstract: The invention relates to a device (3) for simultaneously interlocking a plurality of actuators (1) by means of a first locking element (5) which is assigned to each final control element (2) of an actuator (1) and which interacts with a second locking element (6). The second locking element is fixed inside the housing (4) in an actuating direction of the final control element (2) and is displaced into an interlocking position by spring force and into an unlocking position by an assisting force. The invention provides that a plurality of second locking elements (6) are interconnected and are actuated by a common device (11). As a result, the variety of parts, the safety risk, the weight, and the constructional complexity are reduced which is very important especially when the inventive device is used in helicopter.

Abstract: The present invention is directed to fans having a handle that is disposed in a non-radial manner with respect to the center of the fan portion. In preferred embodiments the handle is substantially parallel to an imaginary circumferential tangent of the fan. In an especially preferred embodiment the fan is expanded at two radial spokes. Each of the spokes has a distal end, and the two distal ends are used to support the handle. An angle formed between the two spokes when the fan is in the expanded configuration is at least 15 degrees.

Abstract: Blower designs for vented enclosures include an impeller having a plurality of blades. The impeller includes a plurality of blades pivotably coupled to an impeller body. The blades pivot to enable operation in one of a closed and an open state. Air flow between blades is substantially restricted when the blades are in the closed state. Air flow between the blades is permitted when the blades are in an open state. In one embodiment, the pivotable couplings are spring loaded to maintain the blades in the closed state when the impeller rotational speed is below a threshold range. The blades pivot to the open state when the rotational speed exceeds the threshold range.

Abstract: On the rotor, between each blade integral with its folding mount and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held, in any position of the blade about the folding axis, above the mount and the radially outer end of the link member on which the mount pivots, in an off-centered position with respect to the folding axis and on the side towards which the blade is designed to be folded. This holding is provided by a cable support tied to the folding pivot and on which an arm, receiving the held part of this section of cable, is mounted in cantilever manner on the folding side.

Abstract: On the rotor, between each blade and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held above that one of the two blade pins which is the detachable pin whose withdrawal allows the folding of the blade by pivoting about the other blade pin forming a pivot pin, by a holding arrangement tied to this detachable pin, in the flight position of the blade. This section of cable is released from its holding arrangement before the withdrawal of the latter and of the detachable blade pin, which precedes the folding, in such a way that this section of cable deforms naturally on following the pivoting of the blade. After deployment of the blade, a part of the section of cable is again held in the holding arrangement, in the flight position of the blade.

Abstract: On the folding-blade rotor, an outer radial length of an electric cable for connection between the hub and a blade has a part forming spare length and wound into an S-shape around two reels each mounted at the end of one of the two blade pins that connect the blade root to the cuff connecting the blade to the hub. The withdrawal of at least one pin with its reel releases a portion of the part forming spare length and allows the blade to be folded without disconnection at the ends of said electrical connecting cable.

Abstract: An improved blade structure for ceiling fan includes a plurality of brackets and a blade element. The brackets are made of wood, bamboo, metal, plastic or the like. The blade element is made of paper, cloth, plastics, thin metal sheet, rubber, synthetic paper or the like. The blade element is bonded to the brackets by adhering, clamping, nailing, snapping, threading, screwing, meshing, stitching, gluing, laminating, riveting or the like to form a foldable blade structure.

Abstract: On the rotor, between each blade and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held above that one of the two blade pins which is the pivot pin about which the blade can be folded by pivoting, once the other blade pin has been removed. This holding is provided by a cradle formed in a cable support connected to the pivot pin, and by a collar articulated to one edge of the cradle and which can be folded down into the closed position onto the opposite edge of the cradle, to which this collar can be connected detachably by at least one detachable retaining element. The section of cable is manually released from the collar and from the cradle before the removal of the removable pin, which precedes folding, so that this section of cable deforms naturally, following the pivoting of the blade.

Abstract: On the rotor, between each blade integral with its folding mount and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held, in any position of the blade about the folding axis, above said mount and the radially outer end of the link member on which the mount pivots, in an off-centered position with respect to the folding axis and on the side towards which the blade is designed to be folded. This holding is provided by a cable support tied to the folding pivot and on which an arm, receiving the held part of this section of cable, is mounted in cantilever manner on the folding side.

Abstract: On the rotor, between each blade and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held above that one of the two blade pins which is the detachable pin whose withdrawal allows the folding of the blade by pivoting about the other blade pin forming a pivot pin, by holding means tied to this detachable pin, in the flight position of the blade. This section of cable is released from its holding means before the withdrawal of the latter and of the detachable blade pin, which precedes the folding, in such a way that this section of cable deforms naturally on following the pivoting of the blade. After deployment of the blade, a part of the section of cable is again held in the holding means, in the flight position of the blade.

Abstract: On the folding-blade rotor, an outer radial length of an electric cable for connection between the hub and a blade has a part forming spare length and wound into an S-shape around two reels each mounted at the end of one of the two blade pins that connect the blade root to the cuff connecting the blade to the hub. The withdrawal of at least one pin with its reel releases a portion of the part forming spare length and allows the blade to be folded without disconnection at the ends of said electrical connecting cable.

Abstract: A torque converter is provided with a stator assembly having a nonrotatable body portion and a plurality of blades pivotally attached to the body portion. The plurality of blades are pivotable between a first position for providing torque multiplication and a second position out of the fluid flow.

Abstract: An improved blade positioning mechanism for folding a helicopter blade attached to a pitch control housing permits a controlled folding of the main rotor blade for increased safety and decreased risk of damage to the helicopter or other equipment. The invention also folds the main rotor blade while the blade remains attached to the pitch control housing, thus eliminating the need to rebalance the blade. In an embodiment of the invention blade positioning mechanism comprises a pitch control housing connection, a rotor blade clamp, and a clamp positioner. The pitch control housing connection is adapted to temporarily attach to the pitch control housing of the helicopter and pivot with two degrees of freedom relative to the pitch control housing. The rotor blade clamp is adapted to temporarily attach to the rotor blade of the helicopter. The clamp positioner is attached to the rotor blade clamp and the pitch control housing connection.

Abstract: The rotor comprises a hub 2 rotated with a mast 1 about an axis of the rotor ZZ, and each blade 3 is connected to the hub 2 by a member 5 on which the blade 3 is mounted so that the blade 3 can pivot about an axis of folding BB between a flight position and a folded-back position. The axis of folding BB is in a substantially radial plane passing through the axis of the rotor ZZ and is inclined with respect to this axis of the rotor ZZ so that it converges towards it, on the opposite side to the rotor mast 1. In automatic folding, the blade 3 is held in a fitting 6 pivoting on the member 5 about the axis of folding BB, whereas in manual folding, the blade 3 is held on the member 5 by two pins 8, one of which is removable to allow the blade to be folded about the other pin 8, the longitudinal axis of which is the axis of folding BB inclined in the radial plane.

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: The device comprises a detachable distance-piece (19') with a pivot (20) retained in a pivoting way in the yoke (7b) of a member (7) connecting a blade (4) to the hub, by one of the two blade pins (15) and a distance-piece yoke (22') in which the blade root (6) is retained pivoting by a fitting pin (18'). The blade (4) is folded by pivoting its root (6) with respect to the distance piece (19') and pivoting the latter with respect to the yoke (7b), with a lateral shift with respect to the conventional folding without a detachable distance-piece (19'), and with a fitting pin (18') which can be inclined with respect to the blade pin (15).

Abstract: The present invention relates to a device for locking the pitch of the blades of a main rotor of a rotary-wing aircraft in which each blade is firstly rotated about an axis of rotation of the rotor by a rotor mast and is secondly constrained to pivot about a longitudinal pitch axis of the blade together with a pitch lever which is controlled by a pitch link connected to a rotary plate rotating with the rotor mast and belonging to a cyclic swash plate mechanism in which the rotary plate is rotatably mounted on a non-rotary plate capable of sliding axially along said rotor mast and of tilting in any direction relative to the rotor mast under the drive of at least three servo-controls each comprising a body fixed on a support secured to the aircraft and a rod having a free end secured to the non-rotary plate. The device includes immobilization means for holding the rod of each of the servo-controls relative to the corresponding body so as to lock the blades in a predetermined pitch position.

Abstract: A flap lock device for restraining the flapping movement of a main rotor blade assembly on a helicopter. The flap lock device includes an first elongate frame member which extends between a first end and a second end and second elongate frame member which also extends between a first end and a second end. A pivot connection pivotally connects the first end of the first frame member with the first end of the second frame member. An outwardly facing contact pad is coupled to each of the frame members and adapted for contact with various positions on the helicopter. An actuating device interconnects the first and second frame members and is used to forcibly move the contact pads outwardly and into contact with the helicopter. The flap lock device is installed between the main rotor blade assembly and the main rotor assembly to forcibly maintain the main rotor blade assembly against the droop stop mechanism.

Abstract: A helicopter's main rotor blades are removably attached to a hub, which is rotatably mounted on a mast. The base of the mast is attached to the helicopter's body by unthreaded, expandable bushing bolts. When inserted, the bolts' centerlines lie in a plane which perpendicularly intersects the axial centerline of the mast. The mast is hollow and encases a drive shaft. Splines at one end of the drive shaft removably engage splines on the engine transmission. The hub has a removal fitting for engaging an end of the drive shaft. When the mast is detached and pulled apart from the helicopter body for storage, the removal fitting forces the drive shaft splines to disengage from the tnansmission splines, and keeps the drive shaft inside the mast while the mast is being removed. The main rotor blades' pitch is controlled by a plurality of pitch control linkages. Each linkage is comprised of a first part connected to the mast and a second part connected to the helicopter body.

Abstract: Rotor blade stowing system for stowing rotor blades that conserves storage space without adding significant weight or cost to the aircraft. The system includes a rotary actuator disposed on a blade grip member. A rotor blade is pivotally connected to the blade grip member. The rotary actuator is operably coupled to a blade pivoting cam and a locking cam. The system includes a cam follower linkage which has a first end which includes a blade pivoting cam follower and a locking cam follower and a second end. The blade pivoting cam follower follows the blade pivoting cam. The locking cam follower follows the locking cam. The second end of the cam follower linkage is coupled to the blade grip member. The system includes a shaft rotatably coupled to the blade grip member, a locking linkage bell crank operably coupled to the shaft, a delay cam coupled to the blade grip member, and a locking linkage idler operably coupled to the locking linkage bell crank.

Abstract: The folding device comprises a fitting pivoting on a cuff about a folding axis which is offset laterally thanks to two lateral bearings of the fitting journal-mounted about bushings retained in lateral devises of the cuff and which are coaxial about the axis by pegs for centering a maneuvering actuator for maneuvering the fitting and the blade about the folding axis.

Abstract: The installation links a supply conductor to an electrical device for de-icing a blade using at least one cable with a first stretch linked to the supply conductor by a connector and to a second stretch with an overhead hook in the form of flattened half loop, itself linked to the device for de-icing the blade by a second connector fitted on the blade, possibly via a straight and flat third stretch and a second overhead hook. The first hook is of nonscreened structure, with an elongate part of substantially flattened rectangular transverse section and with a concavity pointing towards a device for retaining and articulating the blade on a hub.

Abstract: The installation for removing electrostatic charge and passing lightning current between a conductor of each blade of the rotor and a metallic part of the hub comprises at least one conductive member integral with the member for linking the blade to the hub in its angular deflections, and in electrical continuity with the conductor of the blade and held elastically in permanent contact with a conductive terminal integral with the hub and in electrical continuity therewith.

Abstract: A plurality of blade shafts spline-connected to bosses of a plurality of propeller blades are rotatably carried on a propeller boss parallel to the axis of the boss, the propeller blades being rotated so as to increase the propeller-diameter D according to an increase in the centrifugal force, and all the blade shafts are mutually connected through a synchronizer including cranks integrally continuously provided on the blade shafts and a single common synchronizing ring. With this arrangement, it is possible to always equally control opening angles of all the propeller blades despite any partial conditional change.

Abstract: A propeller for a boat having a plurality of recesses and a plurality of land portions arranged circumferentially alternately around an outer periphery of a propeller boss which is fitted over and connected to a propeller shaft. A boss of each of propeller blades and each of blade shafts disposed parallel to an axis of the propeller boss to rotatably support such propeller blade are accommodated in each of the recesses, and each of the land portions is provided with an exhaust passage extending axially through the land portion to permit an exhaust outlet in a body of a propelling device to be opened at a rear end face of the propeller boss. Thus, it is possible to discharge an exhaust gas from an engine through the inside of the propeller boss into water.

Abstract: A propulsion system for a submerged vehicle which operates at a relatively low RPM includes a pair of coaxial drive shafts for producing counterrotating torques. A first propeller unit is attached for rotation with one of the drive shafts and a second propeller units is attached for rotation with the other drive shaft. Each propeller unit includes a plurality of arcuate propeller blades which are deployed upon rotation of their respective drive shaft. Specifically, this deployment is from a first configuration wherein the blades are disposed along the surface of the vehicle and into a second configuration wherein the blades are extended from the surface of the vehicle.

Abstract: A pitch actuation system restraint (PASR) device that provides, inter alia, protection for the pitch actuation system of a helicopter having a main rotor assembly configured for main rotor blade folding operations. The PASR device includes permanent adapter brackets that are permanently mounted in combination with the rotor hub arms of the main rotor assembly. The PASR device further includes a temporary adapter bracket and quick release pins for each main rotor blade to be folded. Prior to implementing blade folding operations, a temporary adapter bracket is temporarily secured in combination with the pitch control horn of each main rotor blade to be folded and the permanent adapter bracket of the adjacent rotor hub arm by means of the quick release pins.

Abstract: A blade retention pin system is operative to secure the blade cuff of a main rotor blade of a helicopter in combination with a spindle assembly of the main rotor hub assembly for main rotor assembly operations and is readily reconfigurable to accommodate blade folding operations. The blade retention pin system includes first and second pin assemblies, each pin assembly including a retainer pin and a handle subassembly, which includes a retainer member and a spring member in superposed abutting combination, pivotably mounted in combination therewith. The first pin assembly includes, in addition, a safety pin subassembly secured in combination therewith. Each retainer pin is inserted into aligned apertures of the blade cuff and spindle assembly and locked in place by pivoting the handle subassembly from an unlocked to a locked position wherein the retainer member engages the retainer pin and the spring member is biased onto the retainer pin to abuttingly engage the retainer member.

Abstract: A method of folding the main rotor blades of a helicopter for storage in which blade supports are removably attached to the nose and tail of the fuselage of the helicopter. A first and second main rotor blades then are aligned with the longitudinal axis running from the forward blade support to the aft blade support. The first and second blades are placed upon, and restrained from rotation in, the blade supports. Then the first and second blades are permitted to fold about the rotor assembly of the helicopter by releasing a locking member of each blade. The first and second blades are folded by rotating the main rotor assembly while restraining from rotation the first and second blades in the forward and aft blades supports, respectively. After the rotor assembly is rotated through approximately 90 degrees, a third and fourth of the rotor blades are aligned with the longitudinal axis running through the forward and aft blade supports and the first and second blades are fully folded.

Abstract: A blade erection damper for a folding propfan blade comprising a blade hammer on the propfan blade engageable with a fluid-filled frangible capsule to dampen erection of the blade.

Abstract: An improved blade folding system for a propfan propulsion system comprises a fan blade journaled for rotation from a folded position substantially tangentially related to the housing of an engine to a radially extending run condition.

Abstract: A mechanism for varying the cycle of a power plant comprising a turbine ene having a housing connected to the rotating spool of the turbine engine with a plurality of propeller blades slideably attached to the housing such that at maximum rotational speed of the turbine engine the blades are extended beyond the cowling of the engine providing external airflow. A nonlinear spring is used for causing the propeller blades to stow within the confines of the cowling of the engine at minimum rotational speed of the engine thus providing no external airflow.

Abstract: This high-efficiency turbine, in particular for the exploitation of wind power for auxiliary power sources in aeronautical applications, comprises a central body which is rotatable about the axis of the turbine and supports at least two vanes which extend radially with respect to the axis of the turbine and are rotatable together with the central body about the turbine axis. The vanes of the turbine are pivoted to the central body to vary the front area of the turbine affected by the rotation of the vanes.

Abstract: A helicopter rotor with foldable blades has, in the hub and blade roots, holes for mounting the blade roots to the rotor hub with connecting bolts passing through these holes in the operating position of the blades. Additionally, at least one blade of two blades and the hub have aligned holes for holding the respective foldable blade in a folded position, whereby one of the regular connecting bolts passes through the aligned holes, which are located as close as possible to the pivoting point connecting a pitch angle control rod to a pitch angle control sleeve.

Abstract: A system for folding a helicopter rotor blade in which the lead-lag damper is mounted to the rotor blade spar, attached to the pitch housing and centered at the vertical pin flap hinge axis. This design of the lead-lag damper corresponding to a specially designed cam has a single actuator used to fold the rotor blade by sequentially engaging the cam with the actuator and lead-lag damper. Connected to the lead-lag damper is a lead-lag damper linkage assembly which is located in the operative position of the rotor blade so that flight loads are transferred directly to the pitch housing thereby uncoupling the actuator and cam from the path of these loads. In addition, this linkage is connected over center during blade folding so that the rotor blade cannot be back driven.