Variable pitch propeller blade hub and drive and adjusting mechanism therefor

A cylindrical hollow hub having a cylindrical exterior wall, said wall having on opposite sides thereof and extending therethrough, an aperture for receiving a cylindrical stub disposed on the inner end portion of an axially rotatable propeller blade having a leading edge portion which has (i) an inner leading edges segment and (ii) an inner end portion, said hub additionally having disposed on opposite sides of the exterior perimeter of said wall and in proximity to the respective apertures, an arcuate recess shaped;

• sized and positioned for (a) individually receiving therein said inner end portion of said leading edge portion of one of the respective propeller blades when the cylindrical stub on the inner end portion of that blade is received by the proximate aperture, and (b) accommodating arcuate movement of said inner end portion of said leading edge portion upon axial rotation of said stub and blade, to enable said inner leading edge segment to project substantially tangentially from said hub when the blade is transverse or substantially transverse to the axis of said hub;
• each said recess becoming deeper when proceeding in the direction from (A) the place where said blade is transverse to the axis of the hub to (B) either one of the respective ends of the recess, and having a maximum depth less than the thickness of said wall such that the recess does not cut through said wall.

A variable pitch propeller drive and adjusting mechanism which comprises:

• a) a hollow drive shaft;
• b) an open-ended hollow housing mounted on the end of the shaft and rotatable therewith;
• c) a hub end cap detachably secured to the housing to cover the open end thereof and thereby form a hollow hub;
• d) a pitch adjusting shaft rotatable with and longitudinally moveable in the drive shaft;
• e) means within the hub translating longitudinal movement of the pitch adjusting shaft into opposed rotational movement of the hereinafter-referred-to cylindrical stubs about an axis perpendicular to an extending through the axis of the drive shaft;
• said hollow hub being characterized by having a cylindrical exterior wall, said wall having on opposite sides thereof and extending therethrough, an aperture for receiving a cylindrical stub disposed on the inner end portion of an axially rotatable propeller blade having a leading edge portion which has (i) an inner leading edge segment and (ii) and inner end portion, said hub additionally having disposed on opposite sides of the exterior perimeter of said wall and in proximity to the respective apertures, an arcuate recess shaped, sized and positioned for (1) individually receiving therein said inner end portion of said leading edge portion of one of the respective propeller blades when the cylindrical stub on the inner end portion of that blade is received by the proximate aperture, and (2) accommodating arcuate movement of said inner end portion of said leading edge portion upon axial rotation of said stub and blade, to enable said inner leading edge segment to project substantially tangentially from said hub when the blade is transverse or substantially transverse to the axis of said hub;
• each said recess becoming deeper when proceeding in the direction from (A) the place where said blade is transverse to the axis of the hub to (B) either one of the respective ends of the recess, and having a maximum depth less than the thickness of said wall such that the recess does not cut through said wall.