# US 12,760,658 B2 · Variable vane lever arm

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- Number: US 12,760,658 B2
- Document ID: US12760658B2
- Status: Granted
- Kind: B2
- Application number: 19/041,823
- Filed: 2025-01-30
- Published: 2026-07-30
- Granted: 2026-10-13
- Earliest claimed: 2025-01-30
- Assignees: Rtx Corporation
- Applicants: RTX Corporation
- Inventors: Samuel B. Hoyt; Fadi Samir Maalouf
- Web page: https://patentgrep.com/patent/US12760658B2

## CPC

- F01D 17/165: {for radial flow, i.e. the vanes turning around axes which are essentially parallel to the rotor centre line (F01D17/167 takes precedence)}
- F01D 9/041: {using blades (F01D5/148 takes precedence)}
- F05D 2260/50: Kinematic linkage, i.e. transmission of position
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A vane arm has first and second holes in its shank proximate first and second ends. First and second tabs each project laterally opposite each other from the shank proximate the second end and have: a bend; and a distal portion distally of the bend. The second tab distal portion partially overlaps the first tab distal portion. A third hole is in the second tab distal portion overlapping a distal end edge of the first tab and having a proximal edge and a distal edge. At least along a region across an axis of the second hole, the third hole distal edge and proximal edge diverge from each other in a direction toward the first end and/or the first tab distal end edge and the third hole proximal edge diverge from each other in a direction toward the first end.

## Claims

### Claim 1

A vane arm comprising:
a first end and a second end;
a shank extending between the first end and the second end and having a first face and a second face;
a first hole in the shank proximate the first end;
a second hole in the shank proximate the second end;
a first tab projecting laterally from the shank proximate the second end and having:
a bend; and
a distal portion distally of the bend; and
a second tab projecting laterally from the shank proximate the second end laterally opposite the first tab and having:
a bend;
a distal portion distally of the bend and partially overlapping the first tab distal portion; and
a third hole in the second tab distal portion overlapping a distal end edge of the first tab and having a proximal edge and a distal edge,
wherein at least along a region across an axis of the second hole:
the third hole distal edge and proximal edge diverge from each other in a direction toward the first end; and/or
the first tab distal end edge and the third hole proximal edge diverge from each other in a direction toward the first end.

### Claim 2 (depends on 1)

The vane arm of claim 1 wherein:
the first tab distal end edge and the third hole proximal edge diverge from each other in the direction toward the first end by an angle of 10° to 25°.

### Claim 3 (depends on 2)

The vane arm of claim 2 wherein:
the third hole distal edge and proximal edge diverge from each other in the direction toward the first end along a majority of a length of the third hole.

### Claim 4 (depends on 3)

The vane arm of claim 3 wherein:
the third hole distal edge and proximal edge diverge from each other in the direction toward the first end by an angle of 10° to 25°.

### Claim 5 (depends on 4)

The vane arm of claim 4 wherein:
the first, second, and third holes are in a single metallic piece.

### Claim 6 (depends on 5)

The vane arm of claim 5 wherein:
the first, second, and third holes are the only holes in the vane arm.

### Claim 7 (depends on 1)

A vane assembly including the vane arm of claim 1 and further comprising a vane having an airfoil and a shaft protruding from an end of the airfoil, wherein:
the vane shaft extends through the second hole;
the vane shaft abuts the third hole proximal edge and the first tab distal end edge;
the vane shaft has a shoulder; and
a nut holds the vane arm to the shaft compressed between the nut and the shoulder.

### Claim 8 (depends on 7)

The vane assembly of claim 7 wherein:
a tab washer is between the nut and the vane arm and has a tab received in an open channel in the second end.

### Claim 9 (depends on 7)

The vane assembly of claim 7 wherein:
the vane shaft has a first face abutting the third hole proximal edge; and
the vane shaft has a second face abutting the first tab distal end edge.

### Claim 10 (depends on 9)

The vane assembly of claim 9 further comprising:
a pin mounted in and protruding from the first hole.

### Claim 11 (depends on 7)

A vane stage comprising a plurality of vane assemblies of claim 7 and further comprising:
a synchronizing ring coupled to the vane arms and having an axis; and
for each vane assembly one or more bearings mounting the vane for rotation about an axis of the vane wherein, rotation of the synchronizing ring about its axis rotates the vanes about their respective axes.

### Claim 12 (depends on 1)

A method for using the vane arm of claim 1, the method comprising:
installing the arm to a vane so that:
a shaft of the vane extending from an end of an airfoil of the vane passes through the third hole and second hole; and
the vane shaft abuts the third hole proximal edge and the first tab distal end edge; and
installing a nut to a threaded portion of the shaft to hold the vane arm to the shaft compressed between the nut and a shoulder of the shaft.

### Claim 13 (depends on 12)

The method of claim 12 further comprising:
installing a pin to the first hole.

### Claim 14 (depends on 13)

The method of claim 13 wherein:
the method is performed with a plurality of vane arms and the respective pins are mounted to a shared synchronizing ring.

### Claim 15 (depends on 1)

The vane arm of claim 1 wherein:
the third hole distal edge and proximal edge diverge from each other in the direction toward the first end along a majority of a length of the third hole.

### Claim 16 (depends on 15)

The vane arm of claim 15 wherein:
the third hole distal edge and proximal edge diverge from each other in the direction toward the first end by an angle of 10° to 25°.

### Claim 17 (depends on 15)

The vane arm of claim 15 wherein:
the first, second, and third holes are in a single metallic piece.

### Claim 18 (depends on 1)

The vane arm of claim 1 wherein:
the third hole distal edge and proximal edge diverge from each other in the direction toward the first end by an angle of 10° to 25°.

### Claim 19 (depends on 1)

The vane arm of claim 1 wherein:
the first, second, and third holes are in a single metallic piece.

### Claim 20 (depends on 1)

The vane arm of claim 1 wherein:
the first, second, and third holes are the only holes in the vane arm.