# US 2014/0193253 A1 · Propeller Blade With Relatively Movable Counterweight

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- Number: US 2014/0193253 A1
- Document ID: US20140193253A1
- Status: Published application
- Kind: A1
- Application number: 13/735,419
- Filed: 2013-01-07
- Published: 2014-07-10
- Earliest claimed: 2013-01-07
- Assignees: Hamilton Sundstrand Corporation
- Applicants: Hamilton Sundstrand Corporation
- Inventors: Paul A. Carvalho
- Web page: https://patentgrep.com/patent/US20140193253A1

## CPC

- F01D 7/00: Rotors with blades adjustable in operation; Control thereof (for reversing F01D1/30)
- B64C 11/346: {actuated by the centrifugal force or the aerodynamic drag acting on auxiliary masses or surfaces}
- B64C 11/385: {comprising feathering, braking or stopping systems}
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- B64C: AEROPLANES; HELICOPTERS

## Abstract

A propeller rotor has a hub mounting a plurality of blades. A counterweight is movably mounted on the blade. A pitch change mechanism for changing an angle of incidence of an airfoil is associated with each of the blades. The counterweight twists the blades toward an increased pitch direction should the pitch change mechanism fail. A stop member stops rotation of the counterweight as the blade moves to a feather position.

## Claims

### Claim 1

A propeller rotor comprising:
a rotor mounting a plurality of blades, said blades having a root mounted in a hub of said rotor and a counterweight movably mounted on said blades;
a pitch change mechanism for changing an angle of incidence of an airfoil associated with said blades and said counterweight for biasing said blades toward an increased pitch direction should said pitch change mechanism fail; and
a stop member for stopping rotation of said counterweight and said counterweight with said blade as said blade moves to a feathered position.

### Claim 2 (depends on 1)

The propeller rotor as set forth in claim 1, wherein said stop includes a stop pin mounted on said hub.

### Claim 3 (depends on 1)

The propeller rotor as set forth in claim 1, wherein said blade in said feather position includes said airfoils being moved generally parallel to an approaching direction of air.

### Claim 4 (depends on 1)

The propeller rotor as set forth in claim 1, wherein said counterweight is mounted to said blades through an arm, and said arm being connected to a collar which is rotatable about a base of said blade.

### Claim 5 (depends on 4)

The propeller rotor as set forth in claim 4, wherein said collar having a groove with circumferential ends, and said hub including a hub pin, said hub pin contacting one of said ends of said groove such that said counterweight transmits torque to said blade.

### Claim 6 (depends on 5)

The propeller rotor as set forth in claim 5, wherein said counterweight contacts said stop, said hub pin is spaced from said end.

### Claim 7 (depends on 6)

The propeller rotor as set forth in claim 6, wherein said stop contacts said arm.

### Claim 8 (depends on 7)

The propeller rotor as set forth in claim 7, wherein said stop stops further rotation of said arm and said counterweight before said counterweight will cross an envelope of movement of a hub and blade of an adjacent one of said plurality of blades.

### Claim 9

A method comprising:
mounting a plurality of blades in a hub of a rotor and movably mounting a counterweight on each said blade;
changing an angle of incidence of an airfoil associated with each of said blades with a pitch change mechanism, and said counterweight twisting said blades toward an increased pitch direction should said pitch change mechanism fail; and
stopping rotation of said counterweight when said blade moves to a feather position.

### Claim 10 (depends on 9)

The method as set forth in claim 9, wherein said moving said blades to said feather position includes moving said airfoils generally parallel to an approaching direction of air.