Apparatus for optical materials fabrication by ultrasonic machining

• US 5,230,182 A
• Filed: 07/31/1992
• Issued: 07/27/1993
• Est. Priority Date: 07/31/1992
• Status: Expired due to Term

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Chuang, Steven, Mathur, D. P., Daniell, Keith, Magida, Matthew B., Magner, Joann
• Primary Examiner(s): Rose, Robert A.
• Application Number:
  US07/922,910
• Time in Patent Office: 361 Days
• Field of Search: 51/59 SS, 51/317, 51/284 R
• US Class Current: 451/165
• CPC Class Codes: B24B 1/04 subjecting the grinding or polishing tools, the abrading or polishing medium or work to vibration, e.g. grinding with ultrasonic frequency polishing or abrading surfaces on work by means of tumbling apparatus B24B31/00, involving oscillating or vibrating containers B24B31/06; superfinishing surfaces on work, e.g. by means of abrading blocks reciprocating with high frequency, B24B35/00
• CPC Class Codes: B24B 13/00 Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor edging optical work, e.g. lenses, prisms B24B9/14

Abstract

A slurry of abrasive particles 17 is placed on the surface of an optic material 28. A tool tip 16 driven by an ultrasonic transducer 12 is immersed in the slurry 17 where it is used to ultrasonically vibrate the particles in the slurry 17. The vibration of the abrasive particles causes matter removal from the surface of the optic material 28 by abrasion. The tool tip 16 is moved relatively over the surface of the material 28 by moving a precision translation stage 18 having the material 28 mounted thereon so as to machine the surface thereof.

Claims

1. An apparatus for performing ultrasonic machining of a surface of an optical material to remove matter from the surface thereof smoothly and precisely, said apparatus comprising:

an ultrasonic transducer;

a slurry of abrasive particles on the surface of said optical material;

a tool for directing ultrasonic vibrations from said ultrasonic transducer to the slurry on the surface of said optical material;

a coupler coupling said ultrasonic transducer and said tool so as to direct ultrasonic vibrations from said ultrasonic transducer to said tool;

a multi-dimensional translation stage positioned proximal to said tool so as to provide a movable platform for holding said optical material in the vicinity of said tool; and

means for counterbalancing a force exerted by said tool on the surface of said optical material, said counterbalancing means including means for supporting said multi-dimensional translation stage on a counterbalance stage.

2. The apparatus of claim 1, wherein the slurry comprises cubic boron nitride particles dispersed in water.

3. The apparatus of claim 2, wherein the content of cubic boron nitride particles is in the range of 30 to 50 percent by volume.

4. The apparatus of claim 2, wherein the size of the cubic boron nitride particles ranges from zero to five microns.

5. The apparatus of claim 1, wherein the slurry comprises cubic boron nitride particles dispersed in oil.

6. The apparatus of claim 5, wherein the content of the cubic boron nitride particles is in the range of 30 to 50 percent by volume.

7. The apparatus of claim 5, wherein the size of the cubic boron nitride particles ranges from zero to five microns.

8. The apparatus of claim 1, wherein the slurry comprises aluminum oxide particles dispersed in water.

9. The apparatus of claim 8, wherein the content of the particles is in the range of 30 to 50 percent by volume.

10. The apparatus of claim 8, wherein the size of the particles is in the range of zero to five microns.

11. The apparatus of claim 1, wherein the slurry comprises aluminum oxide particles dispersed in oil.

12. The apparatus of claim 11, wherein the content of the particles is in the range of 30 to 50 percent by volume.

13. The of apparatus claim 11, wherein the size of the particles is in the range of zero to five microns.

14. The apparatus of claim 1, wherein the tool is fabricated from 304 stainless steel.

15. The apparatus of claim 1, wherein the tool is cylindrical.

16. The apparatus of claim 15, wherein the diameter of said cylindrical tool is in the range of 1 to 3 mm.

17. An apparatus for performing ultrasonic machining of a surface of an optical material so as to remove matter from the surface smoothly and precisely, said apparatus comprising:

an ultrasonic transducer;

a slurry of abrasive particles on the surface of said optical material;

a tool for directing ultrasonic vibrations from said ultrasonic transducer to the slurry on the surface of said optical material;

a coupler inserted between said ultrasonic transducer and said tool so as to direct ultrasonic vibrations from said ultrasonic transducer to said tool;

a counter balancing platform so as to provide a means for counterbalancing a force exerted by said tool on the surface of said optical material; and

a multi-dimensional translation stage supported by said counter balancing platform and positioned proximal to said tool so as to provide a movable platform for holding said optical material in the vicinity of said tool.