Patent ID: 6478542
Filing Date: 2002-11-12
Classification: B64C

Abstract:
A variable pitch propeller apparatus comprising:(a) an input shaft for coupling to a rotary power source on a drive axis; (b) a plurality of propulsion blades rotatably supported relative to the drive shaft on respective blade axes, the blade axes diverging from the drive axis; (c) an actuator having a yoke member supported relative to the drive shaft for movement therewith and coupled to the propulsion blades for rotation thereof about respective ones of the blade axes, the yoke member having a normal range of yoke positions from a high pitch position to a low pitch position, and an additional yoke position outside of the normal range, the propulsion blades having a corresponding normal pitch angle range including a high pitch angle and a low pitch angle, and an additional pitch angle outside of the normal pitch angle range corresponding to the additional yoke position; and (d) a centrifugal lock mechanism for blocking the movement of the yoke member from the normal range of yoke positions toward the additional yoke position in response to rotational speed of the input shaft being greater than a predetermined threshold speed.