Bistable pitch propeller system with bidirectional propeller rotation

Patent metadata

Field	Value
Publication number	US-10843790-B2
Application number	US-201615225018-A
Country	US
Kind code	B2
Filing date	Aug 1, 2016
Priority date	Aug 1, 2016
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

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.

First claim

What is claimed is:

1. A propeller, comprising:
a blade free to rotate about a longitudinal axis of the blade within at least a defined range of motion;
a first mechanical stop positioned to engage mechanically one or both of a first portion of the blade and a first structure coupled mechanically to the blade when the blade is in a first position at a first end of said defined rotational range of motion, wherein:
the first portion of the blade includes a first side of the blade,
the first mechanical stop includes a first blade stopper configured to mechanically stop the first side of the blade when the blade is in the first position, and
a position of the first blade stopper is adjustable; and

a second mechanical stop positioned to engage mechanically one or both of a second portion of the blade and a second structure coupled mechanically to the blade when the blade is in a second position at a second end of said defined rotational range of motion, wherein:
the second portion of the blade includes a second side of the blade, and
the second mechanical stop is configured to mechanically stop the second side of the blade when the blade is in the second position;

wherein in a first direction of propeller rotation, the blade rotates to the first position against the first mechanical stop corresponding to a first blade pitch and in a second direction of propeller rotation, the blade rotates to the second position against the second mechanical stop corresponding to a second blade pitch different from the first blade pitch.

2. The propeller of claim 1 , wherein the first structure is the same as the second structure.

3. The propeller of claim 1 , wherein the first position is associated with hovering and the second position is associated with forward flight.

4. The propeller of claim 1 , wherein:
the first structure and the second structure are a same rotatable bearing;
a peg is connected to the rotatable bearing;
the first mechanical stop includes a first peg stopper configured to mechanically stop the peg when the blade is in the first position; and
the second mechanical stop includes a second peg stopper configured to mechanically stop the peg when the blade is in the second position.

5. The propeller of claim 1 , wherein:
the first structure and the second structure are a same rotatable bearing;
a peg is connected to the rotatable bearing;
the first mechanical stop includes a first peg stopper configured to mechanically stop the peg when the blade is in the first position;
the second mechanical stop includes a second peg stopper configured to mechanically stop the peg when the blade is in the second position; and
a position of the first peg stopper is adjustable.

6. The propeller of claim 1 , wherein:
the first blade stopper is configured to directly contact and mechanically stop the first side of the blade when the blade is in the first position; and
a second blade stopper configured to directly contact and mechanically stop the second side of the blade when the blade is in the second position.

Assignees

• Kitty Hawk Corp

Inventors

• Vander Lind Damon
• Reichert Todd

Classifications

• B64C27/08

  with two or more rotors · CPC title

• B64U30/20

  Rotors; Rotor supports · CPC title

• B64C11/343

  actuated by the centrifugal force or the aerodynamic drag acting on the blades · CPC title

• B64C11/46

  Arrangements of, or constructional features peculiar to, multiple propellers {(B64C11/306 takes precedence)} · CPC title

• B64C11/325 Primary

  comprising feathering, braking or stopping systems · CPC title