A hinged propeller comprising a hub and one or more blades is disclosed. In various embodiments, a blade is connected to the hub via a hinge, wherein at least a substantial part of the blade has a longitudinal axis that is substantially parallel to a line extending radially from a center of the hub, and wherein the hinge has an axis of hinge rotation that is oriented at a non-zero acute angle to a line that is perpendicular, in a plane of rotation of the hub, to said longitudinal axis.

A propeller blade includes a first material and a second material. The first material includes fibers. The second material is different from the first material. The fibers are interspersed through the second material and the fibers are oriented in a same direction within the second material. The propeller blade is anisotropic and includes sections of the fibers.

A propeller blade includes a first material and a second material. The first material includes fibers. The second material is different from the first material. The fibers are interspersed through the second material and the fibers are oriented in a same direction within the second material. The propeller blade is anisotropic and includes sections of the fibers.

To provide an unmanned aerial vehicle that eliminates or minimizes the laboriousness involved in optimal pitch adjustment of propellers while eliminating or minimizing complexity and instability in airframe structure and/or flight programs. This object is solved by an unmanned aerial vehicle that is provided with a plurality of rotors and that includes: a center frame that is a central portion of an airframe of the unmanned aerial vehicle; and a plurality of arms extending radially from the center frame in plan view. A plurality of motors that are driving sources of the respective rotors are provided in the center frame. The plurality of rotors are supported by the respective arms. Each arm of the arms has a hollow cylindrical structure. A motive power transmission member configured to transmit a driving force of each motor of the motors to the each rotor is provided in the each arm.

To provide an unmanned aerial vehicle that eliminates or minimizes the laboriousness involved in optimal pitch adjustment of propellers while eliminating or minimizing complexity and instability in airframe structure and/or flight programs. This object is solved by an unmanned aerial vehicle that is provided with a plurality of rotors and that includes: a center frame that is a central portion of an airframe of the unmanned aerial vehicle; and a plurality of arms extending radially from the center frame in plan view. A plurality of motors that are driving sources of the respective rotors are provided in the center frame. The plurality of rotors are supported by the respective arms. Each arm of the arms has a hollow cylindrical structure. A motive power transmission member configured to transmit a driving force of each motor of the motors to the each rotor is provided in the each arm.

A propeller includes a blade free to rotate. A first stop is positioned to mechanically engage one or both of a first portion of the blade and a first structure coupled to the blade when the blade is in a first position at a first end of the rotational range of motion. A second stop is positioned to mechanically engage one or both of a second portion of the blade and a second structure coupled to the blade when the blade is in a second position at a second end of the defined rotational range. The blade rotates to the first position against the first stop when the propeller is rotated in a first direction and to the second position against the second stop when the propeller is rotated in a second direction.

The present invention includes an apparatus and method for automatically adjusting the tracking of one or more blades comprising: a blade tracking adjustment mechanism connected to one or more blades of an aircraft; a blade tracking measurement system that measures the tracking of the one or more blades; and a computer that receives an output from the blade tracking measurement system with tracking information for each of the one or more blades; wherein the computer outputs instructions for the blade tracking adjustment mechanism to change a pitch of one or more of the blades to correct blade tracking.

A self adjusting variable pitch aircraft propeller assembly includes a mount, hub assembly and propeller. The mount has a threaded shaft and a slot. The hub assembly has a front hub and a rear hub, both the front hub and the rear hub have a hole for passage of the shaft. The propeller seats within the hub assembly and selectively rotates automatically in the hub assembly and the RPM of the engine increases and decreases. The propeller has a pin that is coupled to a sled in a slot of the mount. A spring and a nut are configured to be coupled around the threaded shaft with the spring between the hub assembly and the nut. The hub assembly is configured to translate along the mount in accordance with a speed of rotation of the hub assembly.

A self adjusting variable pitch aircraft propeller assembly includes a mount, hub assembly and propeller. The mount has a threaded shaft and a slot. The hub assembly has a front hub and a rear hub, both the front hub and the rear hub have a hole for passage of the shaft. The propeller seats within the hub assembly and selectively rotates automatically in the hub assembly and the RPM of the engine increases and decreases. The propeller has a pin that is coupled to a sled in a slot of the mount. A spring and a nut are configured to be coupled around the threaded shaft with the spring between the hub assembly and the nut. The hub assembly is configured to translate along the mount in accordance with a speed of rotation of the hub assembly.

Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example blade apparatus includes: a collet including a slot to receive an end of a blade; and a plurality of retainers including a first retainer positioned on a first end of the collet and a second retainer positioned on a second end of the collet to provide axial retention for the blade in the slot.