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

Variable-pitch multi-blade propeller incorporating individually dismountable blades made of composite materials, process for manufacturing such blades and blades thus produced

Wind generator apparatus employs an induction generator with a wind-driven rotor. Connection of the induction generator to AC power lines is controlled by apparatus that compares generator rpm and line frequency. The rotor blades have a pretwisted, varying-chord inboard portion and an untwisted, constant-chord outboard portion. The blades are self-starting, operate efficiently over a range of wind speeds with constant pitch maintained by a torsional biasing mechanism, and pitch up automatically when the normal rpm operating range is exceeded. An improved blade-supporting spar of low torsional stiffness has an I-beam configuration with filament-wound flanges. A pitch damper prevents torsional oscillations while permitting the blades to pitch up readily. The rotor, which includes a teetering hub, is free to weather-vane about the axis of a supporting tower, but a yaw damper limits angular velocity. A guy wire and gin pole arrangement stabilizes the tower and permits easy raising and lowering of the tower.

Wind-driven generator apparatus and method of making blade supports _therefor

An improved rotor for a helicopter comprises a yoke at the inner end of each arm engaging the rotor hub by way of a spherical abutment

Rotor for rotating wing type aircraft

Un tissu impregne de resine (12) prolonge la longueur d'un joint (10) avec une paire de panneaux espaces les uns des autres (24a, 24b) qui croisent et sont entrelaces avec un panneau intermediaire s'etendant lateralement (20). A resin-impregnated cloth (12) extends the length of a seal (10) with a pair of panels spaced apart from each other (24a, 24b) which cross and are interwoven with one intermediate panel extending laterally (20). Un noyau de renforcement (14) s'etend entre les panneaux espaces les uns des autres (24a, 24b) sur un cote du panneau s'etendant lateralement (20). A reinforcing core (14) extends between the panels spaced apart from each other (24a, 24b) on a side panel extending laterally (20). Trois noyaux (16, 18a, 18b) sont disposes sur l'autre cote du panneau s'etendant lateralement (20). Three cores (16, 18a, 18b) are arranged on the other side of the panel extending laterally (20). Le noyau intermediaire (16) de ces trois panneaux est dispose entre les panneaux espaces entre eux (24a, 24b) et est renforce (30a, 30b) de maniere a presenter une resistance a une charge de torsion. The intermediate core (16) of the three panels is disposed between the spaced panels together (24a, 24b) and is reinforced (30a, 30b) so as to present a resistance to a torsional load. Les deux autres noyaux sont renforces (34, 30) pour permettre d'obtenir transversalement des proprietes variables de support de charge. The other two rings are reinforced (34, 30) to allow to obtain transversely of the load bearing variable properties.

Composite structural skin spar joint and method of making.

An improved elongated blade or blade spar comprises successive low-pitch circumferentially wrapped convolutions of a synthetic resin impregnated tape having elongated cut glass and substantially parallel and equal length filaments wherein successive convolutions are overlapped approximately 50% and wherein the axis of the elongated strands lie at an angle of less than 30° from the elongated spar axis Preferably, resin impregnated filamentary strands are circumferentially wrapped around the mandrel substantially parallel with the direction of the tape wrap between selected tape layers The improved blade spar mandrel wrapping apparatus includes a split ring support for the mandrel and through which the mandrel extends The support ring halves may be separated, moved and rejoined during the mandrel wrapping process

Blade or spar

A plastics rotor blade, particularly for a helicopter, is formed with elongate filaments or rovings forming a loop for securing to a hub pin. The loop contains a metal socket secured to an extension extending between the loop walls.

August Hanns Leonhard Euler

Papers

Plastics rotor blade

Rotorblatt aus kunststoffmaterial