Abstract: A propeller blade arrangement comprising a propeller blade attached to and rotatable with a hub, via a retention bearing, the blade being rotatable about a center line of the blade, the retention bearing configured to tilt the blade such that its center line is tilted with respect to the hub.

Abstract: A counterweight for use in a variable-pitch propeller system (includes a weighted element having walls forming a sealed chamber). The sealed chamber contains a weighting material, and an arm. The counterweight is configured to be coupled to a propeller blade the walls of the weighted element and the arm comprise a single piece, and are an additively manufactured single piece. The weighting material may comprise a powder element. The sealed chamber may have been sealed during the additive manufacturing process, or after the additive manufacturing process has been completed.

Abstract: Disclosed approaches for guiding actions in processing a circuit design include a design tool identifying first violations of design checks and determining severity levels of the first violations. The design tool determines for each violation, suggested actions associated with the violation and presents on a display, first data indicative of the suggested actions in order of the severity levels of the first violations. The first data include selectable objects, and each selectable object has an associated executable procedure. The design tool can execute the procedure associated with one of the selectable objects in response to selection and modify the circuit design in response to execution of the procedure.

Abstract: An elastic torsion element for connecting a rotor blade to a rotor hub of a rotor, the elastic torsion element comprising at least two elastically deformable plates, wherein each one of the at least two elastically deformable plates comprises fiber reinforced polymers, wherein respective fibers of the fiber reinforced polymers of each one of the at least two elastically deformable plates are at least arranged along one of a first and a second dominant fiber directions, wherein the first dominant fiber direction crosses the second dominant fiber direction in a predetermined fiber direction crossing region, and wherein the elastic torsion element comprises an integrated elastic lead-lag hinge that is formed at the predetermined fiber direction crossing region.

Abstract: A bistable pitch propeller includes a ball, a spring, and a clutch module where the clutch module has a range of rotational movement between a locked end position and a released end position. The clutch module includes a detent, where the ball sits inside and outside of the detent when the clutch module is in the locked end position and released end position, respectively. In response to an input torque and a spring force from the spring, the clutch module rotates toward the released end position and the locked end position, respectively. The bistable pitch propeller also includes an aircraft blade where the aircraft blade is at the first pitch angle and the second pitch angle when the clutch module is in the locked end position and the released end position, respectively.

Abstract: An adjustable fan damping apparatus for exerciser includes a casing having an annular chamber defined therein and an annular intake structure is disposed to an inner side of the annular chamber. A centrifugal impeller is rotatably received in the annular chamber. Multiple adjust blades is pivotally mounted onto the annular intake structure and surrounds the annular intake structure, wherein each adjust blade has two pivots longitudinally extending from two opposite ends of the adjust blade and a driven element extending from one side of then adjust blade where the two pivots extends. A drive device is connected to the driven element of each of the multiple adjust blades. The drive device includes a driving element is rotatably coupled with the driven element of each of the multiple adjust blades for simultaneously driving the multiple adjust blades in a same angle relative to the annular intake structure.

Abstract: The invention relates to a device (1) for controlling the setting of the blades (2) of a rotor (3) of a propeller, including a radial shaft (6), the rotation of which modifies the setting of the blade (2), a main spring (13), a first end (14) of which is connected to the rotor (3) and a second end (15) of which is connected to a part (8, 10) having an axial movement which drives the rotation of the radial shaft, and has a movement, the travel of which is offset relative to the first end in a direction (7) that is orthogonal to the axial direction (5), the main spring exerting a resilient force which aims to move the parts toward a position in which the cord of the profile of the blade is orthogonal to the plane of rotation of the propeller, in the absence of part control by means of a jack.

Abstract: In response to a torque that is applied to a clutch module not exceeding a torque threshold, the clutch module is locked where a blade is configured to be at a first pitch angle in response to the clutch module being locked. In response to the torque that is applied to the clutch module exceeding the torque threshold, the clutch module is released where the blade has a range of motion which extends from the first pitch angle to a second pitch angle in response to the clutch module being released.

Abstract: Disclosed is a tilt-type rotation blade apparatus for vertical-type power generation. When a blade member is rotated in a backward direction to a wind direction, the blade member is tilted so that the blade plate is horizontal to the wind direction, thereby applying only the forward rotational force to the vertical power shaft, so that the wind power generation efficiency is maximized. A tilt structure is improved to smoothly perform a tilt operation and the structure of the blade member is improved so that the blade member is rotated in a vertical direction to the ground surface, thereby efficiently generating wind power without the limitation of an installation space.

Abstract: An axial-flow turbine assembly that includes one or more features for enhancing the efficiency of the turbine's operation. In one embodiment, the turbine assembly includes a turbine rotor having blades that adjust their pitch angle in direct response to working fluid pressure on the blades themselves or other part(s) of the rotor. In other embodiments, the turbine assembly is deployable in an application, such as an oscillating water column system, in which the flow of working fluid varies over time, for example, as pressure driving the flow changes. In a first of these embodiments, the turbine assembly includes a valve that allows the pressure to build so that the flow is optimized for the turbine's operating parameters. In a second of these embodiments, one or more variable-admission nozzle and shutter assemblies are provided to control the flow through the turbine to optimize the flow relative to the turbine's operating parameters.

Abstract: Systems and methods for real-time design checking of an integrated circuit design, include the operations of receiving at a design tool, design elements of an integrated circuit design entered by an integrated circuit designer; the design tool performing real-time design checks on the design elements as they are entered by the integrated circuit designer to determine whether a design element violates a design rule; when the design tool detects a violation of a design rule based on the design checks alerting the integrated circuit designer; and the design tool presenting a correction to correct the violation of the design rule. The real-time design checks can include, comparing each design element to one or more known non-compliant design elements stored in a database to determine whether a non-compliant design element was entered or is being entered by the integrated circuit designer.

Abstract: A sealless-type centrifugal pump includes a casing that forms a pump chamber having a liquid inflow port and an outflow port, an impeller disposed in the pump chamber and rotatably supported by a pivot bearing, and a magnetic coupling device including a driven permanent magnet built into the impeller and a driving magnet that rotationally drives the driven permanent magnet through a partition. The impeller supported in the direction of the rotation axis with respect to the casing is driven by the magnetic coupling device, and pressure is applied to liquid introduced from the direction of the rotation axis through the inflow port to send the liquid through the outflow port in a radial direction. The magnetic coupling device is disposed on a line inclined from an impeller rotating surface to the inflow port side toward the center of the rotation axis.

Abstract: A sealless-type centrifugal pump includes a casing that forms a pump chamber having a liquid inflow port and an outflow port, an impeller disposed in the pump chamber and rotatably supported by a pivot bearing, and a magnetic coupling device including a driven permanent magnet built into the impeller and a driving magnet that rotationally drives the driven permanent magnet through a partition. The impeller supported in the direction of the rotation axis with respect to the casing is driven by the magnetic coupling device, and pressure is applied to liquid introduced from the direction of the rotation axis through the inflow port to send the liquid through the outflow port in a radial direction. The magnetic coupling device is disposed on a line inclined from an impeller rotating surface to the inflow port side toward the center of the rotation axis.

Abstract: A supersonic compressor rotor. The supersonic compressor rotor includes a substantially cylindrical disk body that includes an upstream surface, a downstream surface, and a radially outer surface that extends generally axially between the upstream surface and the downstream surface. The disk body defines a centerline axis. A plurality of vanes are coupled to the radially outer surface. Adjacent vanes form a pair and are oriented such that a flow channel is defined between each pair of adjacent vanes. The flow channel extends generally axially between an inlet opening and an outlet opening. At least one supersonic compression ramp is positioned within the flow channel. The supersonic compression ramp is selectively positionable at a first position, at a second position, and at any position therebetween.

Abstract: A variable vane damping assembly includes an inner bushing and an outer bushing. The inner bushing comprises an elastomeric material.

Abstract: A blade assembly for a wind turbine has a hub, a plurality of inboard and outboard blades, and a plurality of cables. The inboard blades are spaced apart from one another and are mounted on the hub. Each outboard blade is pivotally connected to one of the inboard blades such that it is capable of rotation to a desired swept angle relative to the inboard blade to which it is connected. The cables extend between the outboard blades and the inboard blades to actuate rotation of the outboard blades to the desired swept angle.

Abstract: A device is described for generating energy. The device includes at least two ultralight airfoils rotating along their own axis, which functionally reproduce the characteristics of a propeller. The ultralight airfoils which characterize such aerodynamic configuration use pulling members (such as cables or tie-rods) to keep their shape when operating. An important weight reduction of the structure is thus obtained, which allows different applications in the aeolian generation field.

Abstract: A vane assembly for a gas turbine engine, the assembly including a plurality of vanes 14 with an asymmetric organic metal/ceramic matrix composite lay up, such that when the vanes 14 are placed in tension or compression the profile of the vane 14 will alter by twisting or untwisting. Other materials may be provided for the vanes 14, and/or other methods may be used for placing the vanes 14 in tension or compression to provide positive changes to the profile thereof.

Abstract: A wind turbine for generating electricity has been developed. The turbine includes a housing for securement to a support. A wheel is mounted within the housing and is rotatable about a horizontal axis. The wheel has an axle assembly and a number of blade assemblies affixed thereto. Each of the blade assemblies has a frame with a spaced-apart pair of uprights and a crosspiece connecting the uprights. Each of the blade assemblies also having a pair of movable blades positioned within the frame with each of the blades being hingedly fastened to a respective one of the uprights. A brake actuator assembly is associated with each of the blades for relieving pressure imparted by strong winds on the blades. A brake operator assembly, disposed principally within said axle assembly, synchronizes the movement of the blades. An electrical current generator is connected to the wheel so as to be powered thereby.

Abstract: The lifetime of plural shock absorbing resilient inserts of an adjustable pitch propeller with feathering blades may be increased. According to an embodiment, stops are implemented between metal surfaces that may be reached only in the event of shocks of great violence and following a certain elastic deformation of the shock absorbing inserts, which remain partially compressed. At the bottom of each circular cavity housing a respective annular insert of elastomer of the flange of a first cylindrical sleeve directly keyed on the drive shaft of the propeller a hole coaxial and of greater diameter than the diameter of a central hole of the annular insert and of the relative engaging pin is formed. Pins projecting from the face of the terminal flange of a second circular sleeve extend through the coaxially formed holes at the bottom of the respective circular cavities of the flange of the first sleeve.

Abstract: An improved coaxial rotor assembly for a helicopter includes an upper rotor system having a multiple of upper rotor blades each having outer tips and mounted on and extending outwards from a central rotor shaft and a lower rotor system having a multiple of lower rotor blades each having outer tips and mounted on and extending outwards from the central rotor shaft with the upper rotor system spaced an axial distance from the lower rotor system on the central rotor shaft. A rotor blade support ring extends circumferentially around each of the upper and lower rotor systems which movably engages and supports the outer tips of the upper and lower rotor blades in spaced apart relation such that the upper and lower rotor systems rotate in opposite directions and the rotor blade support ring means prevents contact between the upper and lower rotor systems during operation thereof.

Abstract: The present teachings relate to a fluid mechanical converter having at least one energy-accumulator mass system that can be powered by a power drive. To provide a fluid mechanical converter, which improves overall efficiency using the simplest components, it is proposed according to the present teachings that the displacement of the driven energy accumulator-mass system is overlaid with a displacement that is caused by at least one inertial force.

Abstract: A rotorcraft blade is provided having at least one spar and an outer covering. At the root of the blade, the spar is subdivided into at least one bottom tape and at least one top tape. The blade further includes a hollow cuff whose outer wall includes the outer covering secured to the bottom and top tapes.

Abstract: Controllable pitch blade non-ducted propeller for a jet engine, comprising a rotor member comprising radial housing for mounting blade support plates, each plate being attached in a ring centered and guided in rotation in a housing of the rotor member and comprising external toothing engaged and locked in internal toothing of the ring, to withstand the centrifugal forces to which the propeller blades are subjected in operation.

Abstract: A wind driven energy source is providing utilizing a turbine wheel comprising a peripheral rim attached to a central hub via a series of spokes. A plurality of airfoil blades are assembled to the wheel, each blade being secured to a pair of spokes and positioned proximate an interior edge of the rim and extend only partially down the length of the spoke. This provides a central opening allowing airflow through the innermost region of the wheel. The blades are pivotally assembled to the spokes and can include an incident angle adjusting mechanism as well as a breakaway feature.

Abstract: A ceiling fan (50) is disclosed having a motor housing (51) which encases an electric motor (53). The motor includes a bottom mounting plate (54) that rotates and thereby drives an annular array of blade irons (56), each having a blade (57) mounted thereto in conventional fashion. Each blade iron is mounted for pivotal and radial movement relative to the bottom mounting plate. An annular segmented balancing ring (68) made of a plurality of links (69) causes pivotal and radial movement of other blade irons (76) in response to the radial movement of an off-balanced blade iron.

Abstract: A rotor, especially for a rotary-wing aircraft, with a rotor mast and one or more adjustable rotor blades includes a rotor blade adjustment device without a swash plate and arranged on a carrier device that automatically rotates synchronously with the rotor blades, the rotor blade adjustment device rotating along with the carrier device in a manner that is free of relative movement with respect to the carrier device as well as with respect to the rotor mast and the rotor blades. The rotor blade adjustment device includes all of the blade actuators and kinematic elements required for a synchronized, cyclic and collective rotor blade adjustment as well as a control signal interface via which the control signals for the blade actuators can be transmitted from a stationary rotor section to the rotor blade adjustment device that is rotating along. Also, a rotary-wing aircraft, especially a helicopter, including at least one such rotor.

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: This invention refers to a hydraulic or pneumatic machine with tilting blades, running either as an engine on a fluid flow or on pressure fluid or as a pump or a compressor. The hydraulic or pneumatic machine on a fluid flow according to the invention consists of a cylindrical casing with inlet and outlet openings, radially arranged, diametrically oposed, along the fluid flowing direction, some disk like rotors with tilting blades, hinged over their front faces and provided with driving mechanisms of their own, and some fixed drums located between the rotors, concentrically to them, making inside the machine some channels, symetrically arranged on one or several stages. Flowing through the channels, the fluid drives the tilting blades causing the movement of the rotors, all the rotors moving to one sense being coupled to the same outlet shaft of the machine.

Abstract: In an electronic system, a method for operating a cooling fan comprises rotating an impeller about a rotational axis and detecting fan failure. The impeller is spatially expanded in response to the detected fan failure whereby airflow through the failed fan is blocked.

Abstract: A wind power generating apparatus having a plurality of rotary wings can reduce the load and resistance on the rotary wings due to wind to obtain a highly effective rotation power as well as to flexibly absorb the impact applied to the rotary wings due to varying wind pressure. Each one of the rotary wings has a radius of rotation different from the others and rotates separately according to the direction of the wind, by which the rotation power resulting from load and resistance in the integrally elongated rotary wings in relation to the wind is prevented from being canceled, and the wind acceleration via the accelerator covers and the wind distribution to the rotary wings result for highly efficient rotation power.

Abstract: A flexbeam (1) having flapping portions (3) and lead-lag and feathering portions (5). Each lead-lag and feathering portion has: a central portion with an elongated and narrow width; middle portions each of which continuously connects to the central portion and branches from both ends of the central portion extending along the longitudinal direction thereof, and extends upward and downward; and edge portions each of which continuously connects to the middle portion and bends from each end of the middle portions and extends almost in parallel with the central portion. At corners formed on branch portions (40, 50) and/or bending portions (60, 70), concaves (41-43, 51-53, 61, 62, 71, 72) each of which has a cross-section of an approximate arc shape and which continuously and smoothly connects to two surfaces forming each of the corners and is formed inside extended planes of the two surfaces.

Abstract: An airflow apparatus (e.g., a fan, a blower) is provided for impeding or facilitating airflow through a channel when the apparatus is inoperative. The apparatus comprises a set of blades or airfoils that, when operating, promote or force a flow of air through the channel. The apparatus includes a bias mechanism for biasing the blades of the apparatus toward failure positions blocking or opening the airflow when the apparatus is at rest or turned off. When the apparatus begins spinning, the bias mechanism is overcome and the blades take their normal operating positions. The bias mechanism may comprise a spring or elastic material that resists rotation, extension or other type of blade transition from the failure position to the operating position. Or, the bias mechanism may involve a blade design (e.g., edge weighting) that attempts to place a blade in its failure position.

Abstract: A pitch governing mounting assembly for a windmill blade and a windmill incorporating such an assembly. The assembly has a first member coupled to a second member in a manner which causes simultaneous axial and rotational movement of the second member relative to the first member. Input for axial movement of the second member relative to the first member is provided by centrifugal force arising from rotation of the windmill blades secured to the second member about a windmill input shaft. A biasing member is provided acting between the second member and the first member to urge the second member toward its first position relative to the first member as centrifugal input diminishes.

Abstract: An airflow apparatus (e.g., a fan, a blower) is provided for impeding or facilitating airflow through a channel when the apparatus is inoperative. The apparatus comprises a set of blades or airfoils that, when operating, promote or force a flow of air through the channel. The apparatus includes a bias mechanism for biasing the blades of the apparatus toward failure positions blocking or opening the airflow when the apparatus is at rest or turned off. When the apparatus begins spinning, the bias mechanism is overcome and the blades take their normal operating positions. The bias mechanism may comprise a spring or elastic material that resists rotation, extension or other type of blade transition from the failure position to the operating position. Or, the bias mechanism may involve a blade design (e.g., edge weighting) that attempts to place a blade in its failure position.

Abstract: A pitch governing mounting assembly for a windmill blade and a windmill incorporating such an assembly. The assembly has a first member coupled to a second member in a manner which causes simultaneous axial and rotational movement of the second member relative to the first member. Input for axial movement of the second member relative to the first member is provided by centrifugal force arising from rotation of the windmill blades secured to the second member about a windmill input shaft. A biasing member is provided acting between the second member and the first member to urge the second member toward its first position relative to the first member as centrifugal input diminishes.

Abstract: A rotor is intended to rotate in a fluid flowing in a flow direction and comprises a plurality of rotor blades, at the most four blades, which are arranged to rotate about an axis of rotation. Each blade forms a single-curved surface, the generatrix of which extends in a plane normal to the axis of rotation, and an imaginary plane interconnecting the leading edge and trailing edge of the blade forms an acute angle with the axis of rotation. In addition, each blade is pivotally mounted for pivotal movement about a pivot shaft in order to adjust the acute angle, the pivot shaft extends in a plane that is normal to the axis of rotation and is parallel to and spaced a distance from an imaginary radius radiating from the axis of rotation. The rotor is very silent and provides efficient energy conversion, for example extraction of wind power.

Abstract: A sail-type windmill wheel is provided in which the area of the wheel facing into the wind is adjusted by an automatic variation of the blade angle of the sails. The wind wheel comprises a hub (22) with a plurality of radially extending spars (18), substantially triangular sails (10) secured along one edge to said arms, the clew of said sails secured through a sheeting cable (24) to drawbar extension springs (28), and the drawbar extension springs secured to the tip of the next adjacent arm. During high wind speeds the automatic blade angle adjustment reduces the frontal area of the wind wheel with a corresponding reduction in the force of the wind upon the wheel. During normal working wind speeds the present invention maintains the sails within an optimum blade angle range for extracting energy from the wind.

Abstract: A featherable propeller assembly for fitment to a drive shaft has a blade carrying assembly which is carried by a hub assembly. The blade carrying assembly is rotatable relative to the hub assembly within relative limits of rotation. Blades are pivotally mounted on the blade carrying assembly. The relative rotation of the hub assembly and blade carrying assembly provides for different positions of respective stop abutments, thus allowing the blades to assume each of the following conditions: (a) a forward drive condition under a forward drive rotation of the shaft; (b) a feathering condition when not under drive from the shaft where the blades are substantially free to move into an orientation which is aligned with the flow of water past the propeller; and (c) a reverse driving condition under a reverse drive rotation of the shaft.

Abstract: The present invention relates to an improved helicopter rotor system including a contoured flexure strap having a simplified geometrical configuration. The flexure strap serves to join the rotary hub assembly with the rotor blades and is formed of fiberglass. The primary load carrying fibers of the flexure strap preferably extend in the same direction as the spanwise axis of the flexure strap in order to withstand the centrifugal forces acting on the strap. The inboard end portion of the flexure strap includes two separate ends, with one of the ends extending in a vertically upward direction and the other end in a vertically downward direction. This allows the ends of flexure straps positioned on opposite sides of the rotary hub assembly to overlap one another and be retained in place by a single pin and bolt assembly.

Abstract: A sail system for wind turbines of the vertical shaft type is disclosed. The sail system has a vertical rotating shaft, a plurality of support arms radially extending from an upper portion of the rotating shaft, and a sail pivoted to the tip of each support arm. The sail is provided with a longitudinal horizontal slit and is eccentrically pivoted to the tip of each support arm by means of a hinge. A holding rod is pivoted to an outside portion of the arm and penetrates the longitudinal slit of the sail. A spring is fitted over the holding rod between the spring stopper of the holding rod and the outer surface of the sail. The sail system not only prevents the sail from sagging due to the sail's weight, it also tightly pivots the sail to the arm regardless of the sail's configurations. The maximum turning angle of the sail relative to the arm is limited and adjusted by the spring.

Abstract: A wind turbine apparatus having a frame assembly consisting of a hub and an outer rim interconnected by a series of spokes. Several wind vanes are rotatably secured within the frame assembly so as to extend from the hub radially outwardly around the frame assembly. Each wind vane consists of an impeller and an impeller shaft, the impeller shaft being positioned so that it does not pass through the center of wind moment of the impeller. Thus, when a wind vector reaches the impeller, the impeller and shaft rotate in direct accordance with the wind's velocity, thus ensuring that the impeller faces optimally into the wind. A biasing device is attached to each impeller shaft, the biasing device serving to retard the rotation of the wind vanes when the wind vector exceeds a given velocity, thus ensuring that the impellers maintain a constant rotational speed. A link means interconnects the adjacent impeller shafts so as to ensure that the wind vanes rotate simultaneously.

Abstract: There is provided a self-actuating variable pitch marine propeller which incorporates two or more blades, each independently rotatable, relative to the propeller hub, between a first lower and a second higher pitch. The blades are preferably mechanically linked by coordinating devices and are caused to move preferably by a combination of centrifugal force effect resulting from inertial masses means and the hydrodynamic forces acting upon the blade hydrodynamic surface. The rotation of the blades relative to the propeller hub is restrained until the restraint is overcome by the forces acting to pivot the blades to the higher pitch position. Most preferably there is also provided a mechanical bias, such as a spring to hold the blades in the lower pitch position. Initially, the hydrodynamic force can also tend to hold in the blades in the lower pitch position, or to move the blades towards the higher pitch.

Abstract: An automatic centrifugal force variable pitch propeller assembly includes a plurality of propeller blades mounted within a housing, each of the propeller blades being mounted to permit limited radial travel in its entirety and simultaneous incremental rotation about its longitudinal axis, the limited radial travel of each of the propeller blades in its entirety being caused by a centrifugal force developed by rotation of the propeller assembly and extending between an inward position corresponding to rotation of the propeller assembly at an idle speed and outward position corresponding to rotation at a maximum speed.

Abstract: An undesirably long axial length of a ram air turbine may be reduced in a construction including a hub (110) mounted for rotation about a rotational axis (112), at least one turbine blade (114) rotatably mounted on the hub (110) for rotation between coarse and fine pitch positions about a blade pitch axis (116) which is different from the rotational axis (112) and a counterweight assembly (120) for each turbine blade (114) and mounted on the hub (110) for rotation between coarse and fine pitch positions about the blade pitch axis (116) in spaced relation to the rotational axis (114) and disposed when rotated about the rotational axis (112) to bias the turbine blade (114) towards its coarse pitch position. A limited lost motion connection (143, 144, 145, 146, 147, 148, 150) is located between the turbine blade (114) and the counterweight assembly (120).

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: There is provided a self-actuating variable pitch marine propeller which incorporates two or more blades, each independently rotatable, relative to the propeller hub, between a first lower and a second higher pitch. The blades are preferably mechanically linked by coordinating means and are caused to move preferably by a combination of centrifugal force effect resulting from inertial mass means and the hydrodynamic forces acting upon the blade hydrodynamic surface. The rotation of the blades relative to the propeller hub is limited primarily as to speed of rotation by restricted viscous fluid flow damping means operably connected to the blades. In one preferred embodiment, the viscous flow means further acts as an initial restraint against all motion by closing off the viscous flow orifice until a certain minimum propeller rotational speed is achieved.

Abstract: A multi-blade, variable pitch wind driven propeller in which a shock absorber is connected with each blade to dampen movement in both the radially inward and radially outward movements of the blade. Tension springs are connected with the blades to move them inwardly against centrifugal force, and in a preferred form of the invention, the tension spring has a variable rate so that it exerts greater resistance near its limit of outward travel. A coil compression spring may also be connected with each blade to absorb loads at the inner limit of travel of the blade and to impart an initial impetus to outward movement of the blade. In addition, retrofit lock nut means is provided for attachment to the ball stud connected to the butt end of each blade to extend along substantially the entire length of the stud and achieve a ratio of ball stud diameter, in inches, to rotor radius, in feet, of least as much as 0.100, thereby minimizing the risk of failure of the stud.

Abstract: A windmill is provided which automatically compensates for increased wind velocity, causing the blades to feather and rotate at a substantially constant velocity rather than overspeeding. This is accomplished by pivotally mounting the blades so that they are rotatable between positions of relatively high angle with respect to the direction of the wind and positions of relatively shallow angle, with a resilient means biasing them to the former position. Tabs projecting forwardly at obtuse angles from the outer ends of the leading edges of the blades cause the blades to be pivoted to the feathered position when wind velocity increases.

Abstract: A multi-blade rotor for a windmill-type apparatus, including a hub supported on a shaft or a fixed angle, and rotor blades that are connected to the hub, via bearing arrangement, in such a way that the rotor blades are rotatable about their longitudinal axes. The inventive easy-to-manufacture, and relatively lightweight, hub has rotationally symmetrical hollow bodies, the number of which correspond to the number of rotor blades. The hollow bodies are mounted on rod-like or tubular pressure members, the number of which correspond to the number of hollow bodies. The pressure members are mounted on the shaft or fixed axle via bearing plates in such a way that their longitudinal central axes are respectively disposed at or nearly at the point of concentration of the bending moment surface of the pertaining hollow body.