Secondary mirror positioning mechanism

Patent metadata

Field	Value
Publication number	US-9632282-B2
Application number	US-201414549163-A
Country	US
Kind code	B2
Filing date	Nov 20, 2014
Priority date	Nov 20, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Systems that provide an active adjustment of mirrors and specifically of secondary mirrors, and that provide active adjustment of secondary mirrors in six degrees of freedom, and that can carry the additional load during launch.

First claim

The invention claimed is:

1. An apparatus for adjusting motion of a strut, the strut being a component in a positioning mechanism, the apparatus comprising:
a linear motion actuator located substantially parallel to the strut; the strut not being constrained to one dimensional motion; an axis of the linear motion actuator being a distance away and different from an axis of the strut; the linear motion actuator moving along the axis of the linear motion actuator;
a lever arm component operatively attached at one end to a moving portion of the linear motion actuator and operatively attached to a strut mounting component at a location between the one end and another end; and
a flexure operatively attached to the lever arm component at an edge of the lever arm component closest to the strut; the flexure being parallel to the strut and extending from the edge of the lever arm component closest to the strut to a base component; the base component located away from another edge of the lever arm component; the base component being operatively attached to a nonmoving portion of the linear motion actuator and extending from the nonmoving portion of the linear motion actuator to at least a location at which the flexure is attached; a pivot point of the lever arm component being located at a position along the flexure; the flexure being located in a main load path of the strut; a center line of the flexure being a distance away and different from the axis of the strut and from the axis of the linear motion actuator.

2. The apparatus of claim 1 wherein the pivot point is located at a midpoint of the flexure.

3. The apparatus of claim 1 wherein the strut mounting component comprises a strut mount operatively connected to a U joint flexure; the U joint flexure comprising a 2-Axis flexure.

4. The apparatus of claim 1 wherein the flexure, the lever arm component and the base component are fabricated from a same material; thereby minimizing thermal expansion mismatch.

5. The apparatus of claim 4 wherein the same material comprises titanium.

6. The apparatus of claim 1 further comprising a position sensor configured to sense displacement of the strut.

7. The apparatus of claim 6 wherein the position sensor comprises a Linear Variable Differential Transformer (LVDT).

8. An apparatus for remotely positioning a component, the apparatus comprising:
a plurality of struts configured to hold a mount for the component; each strut from the plurality of struts being operatively attached to a strut mount at a strut end opposite another strut end operatively connected to the mount for the component; each strut mount operatively attached to a motion adjustment apparatus; the motion adjustment apparatus comprising:
a linear motion actuator located substantially parallel to the strut; the strut not being constrained to one dimensional motion; an axis of the linear motion actuator being a distance away and different from an axis of the strut the linear motion actuator moving along the axis of the linear motion actuator;
a lever arm component operationally attached at one end to a moving portion of the linear motion actuator and operationally attached to said each strut mount at a location between the one end and another and; and
a flexure operatively attached to the lever arm component at an edge of the lever arm component closest to the strut; the flexure being parallel to the strut and extending from the edge of the lever arm component closest to the strut to a base component; the base component located away from another edge of the lever arm component; the base component being operatively attached to a nonmoving portion of the linear motion actuator and extending from the nonmoving portion of the linear motion actuator to at least a location at which the flexure is attached; a pivot point of the lever arm component being located at a position along the flexure; the flexure being located in a main load path of the strut; a center line of the flexure being a distance away and different from the axis of the strut and from the axis of the linear motion actuator;

and a rigid component, the base component of each motion adjustment apparatus being operatively attached to the rigid component.

9. The apparatus of claim 8 wherein the plurality of struts comprises six struts; and wherein six degrees of freedom can be adjusted in positioning the component.

10. The apparatus of claim 8 wherein the pivot point is located at a midpoint of the flexure.

11. The apparatus of claim 8 wherein the strut mount comprises a strut mounting subcomponent operatively connected to a U joint flexure; the U joint flexure comprising a 2-Axis flexure.

12. The apparatus of claim 8 wherein the flexure, the lever arm component and the base component are fabricated from a same material; thereby minimizing thermal expansion mismatch.

13. The apparatus of claim 12 wherein the same material comprises titanium.

14. The apparatus of claim 8 further comprising a position sensor configured to sense displacement of the strut.

15. The apparatus of claim 14 wherein the position sensor comprises a Linear Variable Differential Transformer (LVDT).

16. The apparatus of claim 8 wherein the component is a secondary mirror.

17. The apparatus of claim 11 wherein the strut mount is fabricated from a material selected to substantially match thermal expansion of a strut material.

18. The apparatus of claim 17 wherein the strut mount is fabricated from Invar.

19. The apparatus of claim 3 wherein the strut mounting component is fabricated from a material selected to substantially match thermal expansion of a strut material.

20. The apparatus of claim 19 wherein the strut mounting component is fabricated from Invar.

21. The apparatus of claim 3 wherein the strut mounting component further comprises two threaded components disposed along an axis of the strut mounting component, the strut being mounted substantially along said axis; one threaded component being disposed on one end of the strut mounting component and another threaded component being disposed at an opposite end of the strut mounting component; the two threaded components being configured for positioning during ground-based setup and testing.

22. The apparatus of claim 11 wherein the strut mount further comprises two threaded components disposed along an axis of the strut mounting subcomponent, the strut being mounted substantially along said axis; one threaded component being disposed on one end of the strut mounting subcomponent and another threaded component being disposed at an opposite end of the strut mounting subcomponent; the two threaded components being configured for positioning the component during ground-based setup and testing.

Assignees

• Raytheon Corp
• Raytheon Co

Inventors

• Van Lue David
• Bullard Andrew L
• Naepflin Hans P

Classifications

• G02B7/183

  specially adapted for very large mirrors, e.g. for astronomy, {or solar concentrators} · CPC title

• G01D5/14

  influencing the magnitude of a current or voltage · CPC title

• G02B7/182 Primary

  for mirrors · CPC title

• F16H25/20

  Screw mechanisms (with automatic reversal F16H25/12) · CPC title

• G02B7/1827 Primary

  Motorised alignment · CPC title