Variable pitch propeller device

An airplane comprising an engine, a rotatable propeller shaft powered by the engine, a propeller shaft flange, and a hydraulically-controllable variable pitch propeller device removably mounted on the propeller shaft flange, the propeller device comprising:

• (a) a mounting flange removably mounted on the engine propeller shaft flange to rotate as the engine propeller shaft rotates;
• (b) a propeller hub supporting propeller blades, the hub being supported by the mounting flange to rotate as the mounting flange rotates;
• (c) a propeller hydraulic mechanism supported by the mounting flange and positioned between the mounting flange and the propeller hub, the propeller hydraulic mechanism comprising a cylinder and a piston slideable therein in response to the action of a hydraulic fluid, the cylinder and piston remaining stationary as the mounting flange and propeller hub rotate;
• (d) means for varying the pitch of the propeller blades in response to movement of the piston within the cylinder, said varying means being supported by the mounting flange to rotate as the mounting flange rotates;
• and
• (e) means for supplying hydraulic fluid to the cylinder independent of any other hydraulic system of the airplane;
• wherein the propeller hub, the propeller hydraulic mechanism, and the varying means are axially aligned with the propeller shaft.

A hydraulically-controlled, variable pitch propeller device for use with solid propeller drive shafts comprising:

• a mounting flange removably securable to a flange of said solid propeller drive shaft;
• a propeller hub connected to said mounting flange and having a base portion, said hub having a plurality of openings capable of receiving a plurality of propeller blades, said hub being provided with means to vary the pitch of said propellers up to about 90.degree., said means being disposed within said hub;
• and
• a hydraulic cylinder having a channel for receiving the base portion of said hub, said channel formed to enable said cylinder to float on said hub during operation of said device, said cylinder coupled to the varying means for actuating the varying means, said cylinder being located between the mounting flange and the propeller hub.

A hydraulically-controllable variable pitch propeller device for removable mounting on a propeller shaft flange comprising:

• (a) a mounting flange removably mountable on an engine propeller shaft flange to rotate as the engine propeller shaft rotates;
• (b) a propeller hub for supporting propeller blades, the hub being supported by the mounting flange to rotate as the mounting flange rotates;
• (c) a propeller hydraulic mechanism supported by the mounting flange and positioned between the mounting flange and the propeller hub, the propeller hydraulic mechanism comprising a cylinder and piston slideable therein in response to the action of a hydraulic fluid, the cylinder and piston remaining stationary as the mounting flange and propeller hub rotate;
• and
• (d) means for varying the pitch of propeller blades in response to movement of the piston within the cylinder, said varying means being supported by the mounting flange to rotate as the mounting flange rotates, said varying means including a thrust face cooperating with a face of the piston, both the thrust face and said piston face having mating races in which ball bearings are mounted.