Monolithic gimbal for a fast steering mirror

Patent metadata

Field	Value
Publication number	US-11326734-B2
Application number	US-201916592300-A
Country	US
Kind code	B2
Filing date	Oct 3, 2019
Priority date	Oct 3, 2019
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

A monolithic gimbal includes a top body portion having a top surface configured to be mounted to a housing, a middle body portion coupled to the top body portion, and a bottom body portion coupled to the middle body portion. The bottom body portion has a bottom surface configured to be mounted to a device. The monolithic gimbal further includes first flexure blades integrally formed with the top body portion and the middle body portion. The first flexure blades enable rotation of the top body portion and the bottom body portion about a first axis. The monolithic gimbal further includes second flexure blades integrally formed with the middle body portion and the bottom body portion. The second flexure blades enable rotation of the top body portion and the bottom body portion about a second axis that is perpendicular to the first axis.

First claim

What is claimed is:

1. A monolithic gimbal configured to support a device on a housing, the monolithic gimbal comprising:
a top body portion having a top surface configured to be mounted to the housing, and an opposing planar bottom surface;
a middle body portion having a planar top surface facing the bottom surface of the top body portion, and having an opposing planar bottom surface;
a bottom body portion having a planar top surface facing the bottom surface of the middle body portion, and having a bottom surface configured to be mounted to the device;
a first elongate opening formed between the interface of the top body portion and the middle body portion, comprising opposing elongate recesses formed within the bottom surface of the top body portion and the top surface of the middle body portion that extends along a first axis;
a second elongate opening formed between the interface of the middle body portion and the bottom body portion, comprising opposing elongate recesses formed body portion that extends along a second axis, the second axis being formed at a perpendicular angle with the first axis;
a first set of flexure blades integrally formed with and coupling the top body portion and the middle body portion within the first elongate opening, the first set of flexure blades including a first blade that extends at a 45-degree angle between the top body portion and the middle body portion and a second blade that extends at a 45-degree angle between the top body portion the middle body portion and is perpendicular to the first blade, the first set of flexure blades enabling rotation of the top body portion and the bottom body portion about a first axis; and
a second set of flexure blades integrally formed with and coupling the middle body portion and the bottom body portion within the second elongate opening, the second set of flexure blades including a third blade that extends at a 45-degree angle between the middle body portion and the bottom body portion and a fourth blade that extends at a 45-degree angle between the middle body portion and the bottom body portion and is perpendicular to the third blade, the second set of flexure blades enabling rotation of the top body portion and the bottom body portion about the second axis that is perpendicular to the first axis.

2. The monolithic gimbal of claim 1 , wherein the monolithic gimbal is configured to prohibit rotation of the device in third axis that is normal to the first axis and the second axis.

3. The monolithic gimbal of claim 2 , wherein the monolithic gimbal further is configured to prohibit lateral movement of the device in x-axis, y-axis and z-axis directions.

4. The monolithic gimbal of claim 1 , wherein the first set of flexure blades are configured to enable rotation of the top body portion with respect to the middle body portion about the first axis, and the second set of flexure blades are configured to enable rotation of the middle body portion with respect to the bottom body portion about the second axis.

5. The monolithic gimbal of claim 4 , wherein a first gap formed between the top body portion and the middle body portion and a second gap formed between the middle body portion and the bottom body portion define a magnitude of rotation of the top body portion with respect to the middle body portion about the first axis and a magnitude of rotation of the middle body portion with respect to the bottom body portion about the second axis.

6. The monolithic gimbal of claim 5 , wherein the first set of flexure blades includes a fifth blade that extends at 45-degree angles between the top body portion and the middle body portion and a sixth blade that extends at 45-degree angles between the top body portion and the middle body portion and is perpendicular to the fifth blade on an opposite side of the body portions.

7. The monolithic gimbal of claim 6 , wherein the second set of flexure blades includes a seventh blade that extends at 45-degree angles between the middle body portion and the bottom body portion and an eighth blade that extends at 45-degree angles between the middle body portion and the bottom body portion and is perpendicular to the seventh blade on an opposite side of the body portions.

8. The monolithic gimbal of claim 7 , wherein each flexure blade has a width and length sufficient to extend from a corner of a respective elongate opening to an opposite corner of the respective elongate opening.

9. The monolithic gimbal of claim 8 , wherein each flexure has a cross-sectional thickness selected to achieve a desired performance and strength characteristic.

10. The monolithic gimbal of claim 1 , wherein the monolithic gimbal is fabricated from metal, metal alloy or plastic material.

11. A method of fabricating the monolithic gimbal of claim 1 , the method comprising:
providing a blank of material;
machining a perimeter and a central opening in the blank;
machining pockets in the blank to partially create inner flexure blade features;
machining holes in the blank to separate the flexure blade features;
machining triangle pockets on an outside of the blank perimeter to create a body of an outside flexure blade;
from a side of the blank, performing wire EDM cuts in the blank above a center of rotation of the blank, with the flexible blade features being machined to a desired length and thickness;
from a perpendicular side of the blank, performing wire EDM cuts in the blank below the center of rotation of the blank; and
creating a hole pop above the center of rotation and a hole pop below the center of rotation on each axis to allow an EDM wire to be inserted to cut out triangles top and bottom.

12. The method of claim 11 , wherein machining the perimeter and the central opening is performed by a computer numerical control (CNC) machine.

13. The method of claim 11 , further comprising drilling top holes in a top surface of the blank.

14. The method of claim 13 , wherein machining the holes to separate the flexure blade features is performed by a drilling process.

15. The method of claim 11 , wherein a width of the flexible blade features is controlled by a diameter of the center hole and diameters of the holes, a width of the flexure features being reduced by machining a larger center opening and larger holes and being enlarged by machining a smaller center hole and smaller holes.

16. The method of claim 11 , further comprising machining a chamfer on a bottom of the blank to reduce the weight of the blank.

17. The method of claim 11 , further comprising machining a top surface of the blank to make the surface compatible with a device.

18. The method of claim 11 , wherein performing wire EDM cuts are performed by a RAM EDM process, which eliminates machining pockets in the blank.

19. The method of claim 11 , wherein the blank is selected from metal, metal alloy or plastic material.

20. A method of fabricating a monolithic gimbal comprising:
injection molding the monolithic gimbal of claim 1 .

Assignees

• Raytheon Co

Inventors

• Ready Richard
• Gallagher Jeffery M

Classifications

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title

• G02B7/1821 Primary

  for rotating or oscillating mirrors · CPC title

• F16C11/12

  incorporating flexible connections, e.g. leaf springs · CPC title

• G02B7/1827

  Motorised alignment · CPC title

• F16M11/12 Primary

  in more than one direction · CPC title