What is claimed:
1. A media blasting apparatus comprising:
a chamber in which media are directed toward a work piece;
a part holder for holding said work piece in a desired position within said chamber during a blasting operation;
a recycle assembly coupled to said chamber for recycling media which have been blasted at a work piece for reuse in further blasting operations, said recycle assembly including a hopper coupled to the blasting chamber for collecting the media blasted at a work piece and a mixing chamber for mixing the recycled media with virgin media to produce a recycled media mixture; and
a blasting device positioned within said chamber for directing a stream of media at a work piece, said blasting device being coupled to said mixing chamber for receiving the recycled media mixture therefrom and directing said recycled media mixture at a work piece.
2. A media blasting apparatus according to claim 1 in which said recycled media mixture comprises a mixture of virgin and previously blasted glass beads.
3. A media blasting apparatus according to claim 1 in which said recycle assembly further comprises a separation system connecting said hopper to said mixing chamber for separating the blasted media into media which are of a predetermined range of sizes for reuse in further blasting operations and blasted media which are of a size insufficient for reuse in further blasting operations.
4. A media blasting apparatus according to claim 3 in which a media path is defined from said hopper to said mixing chamber, said separation system comprises first and second screens, said first screen being generally spaced from said second screen in said media path.
5. A media blasting apparatus according to claim 4 in which said first screen is approximately 20 mesh gauge and said second screen is approximately 200 mesh gauge.
6. A media basting apparatus according to claim 4 in which said first and second screens are vibrated to increase the efficiency of a separation operation.
7. A media blasting apparatus according to claim 3 in which said separation system further comprises a filter assembly for collecting said insufficient size blasted media.
8. A media blasting apparatus according to claim 1 in which said mixing chamber comprises a pressure chamber.
9. A media blasting apparatus for blasting a work piece with media, said media blasting apparatus comprising:
a first chamber in which a stream of media are directed at a work piece;
a part holder for holding said work piece in a desired position within said first chamber during a blasting operation;
a blasting device positioned within said first chamber for directing a media blast stream at a work piece;
a hopper coupled to said first chamber for collecting media which have been blasted at a work piece for reuse in further blasting operations;
a second chamber coupled to said blasting device for producing a media blast stream and delivering said media blast stream at a predetermined flow rate to the blasting device, said second chamber being coupled to a media source for supplying the second chamber with virgin media, said second chamber being coupled to said hopper for receiving said recycled blasted media therefrom, said second chamber being adapted to mix said recycled blasted media with said virgin media from said media source to produce a recycled media mixture, said second chamber being coupled to a gas source for suspending the recycled media mixture in gas at a gasmedia mix point;
an automatic gas valve for controlling the supply of gas to said second chamber; and
an automatic media metering valve coupled to said second chamber for automatically controlling the supply of said recycled media mixture to the gasmedia mix point in relation to said predetermined flow rate.
10. A media blasting apparatus according to claim 9 in which said second chamber is held between approximately 70 psi and approximately 80 psi.
11. A media blasting apparatus according to claim 9 in which said automatic media metering valve comprises an automatic shut-down valve.
12. A media blasting apparatus according to claim 9 further comprising a plurality of media supply valves coupled to said second chamber and said media source for supplying media from said media source to said second chamber and a media monitor for monitoring and controlling the quantity of media supplied to said second chamber from said media source, said media monitor controllably operating said media supply valves so that a recycled media mixture includes a predetermined quantity of virgin media.
13. A method of processing a work piece with a media blast stream comprising the steps of:
directing a recycled media mixture at a work piece, said recycled media mixture comprising a mixture of virgin media and recycled media which have been used in a previous blasting operation;
collecting said blasted media;
separating said blasted media into media of a predetermined range of sizes for reuse in further blasting operations and media of a size insufficient for reuse in further blasting operations; and
mixing said predetermined size range blasted media with virgin media to produce a recycled media mixture.
14. A method of processing a work piece with a media blast stream comprising the steps of:
positioning a work piece in a part holder which provides a variable compensating cushioned clamping of the work piece for maintaining the work piece in a predetermined position during a blasting operation;
directing a recycled media mixture at said work piece, said recycled media mixture comprising a mixture of virgin media and recycled media which have been used in a previous blasting operation; and
collecting said blasted recycled media mixture for reuse in a subsequent blasting operation.
15. A method of processing a workpiece with a media blast stream comprising the steps of:
positioning the work piece in a part holder for maintaining the workpiece in at least one predetermined position during a blasting operation;
supplying positive air pressure to deliver ceramic media to a blast nozzle;
directing the ceramic media at the workpiece through the blast nozzle;
exposing multiple surfaces of the workpiece to the ceramic media; and
collecting the ceramic media for reuse in a subsequent blasting operation.
16. A method according to claim 15 wherein said workpiece is a gear and said ceramic media has a mesh dimension of between about 50 and about 100 mesh when added as virgin media.
17. A method according to claim 15 further comprising the step of collecting the ceramic media for reuse in a subsequent blasting operation and wherein the ceramic media is a recycled media mixture including a mixture of recycled and virgin media.
18. A method according to claim 15 wherein the step of exposing multiple surfaces of the workpiece to the ceramic media includes the step of rotating the workpiece at between 8-12 revolutions per minute.
19. A method according to claim 15 wherein the ceramic media is directed at the workpiece at a pressure of between about seventy to about eighty pounds per square inch.
20. A method according to claim 15 wherein the cycle time for directing media at a workpiece is between about 15 and about 80 seconds.
21. A method according to claim 15 wherein the flowrate of the ceramic media being directed at the workpiece is between about 1 and about 4 pounds per minute.
22. A method of processing a metallic gear with media blast stream comprising the steps of:
positioning the metallic gear in a part holder to maintain the metallic gear in one or more predetermined positions during a blasting operation;
directing a ceramic medium at the metallic gear; and
exposing a plurality of surfaces on the metallic gear to the directed ceramic media.
23. A method according to claim 22 wherein the ceramic medium is a ceramic bead including zirconia crystals enclosed in a silica glassy phase.
24. A method according to claim 22 further comprising the step of collecting the ceramic media for reuse in a subsequent blasting operation.
25. A method according to claim 24 wherein the ceramic media is a recycled media mixture including a mixture of virgin media and recycled media.
26. A method according to claim 22 wherein the step of exposing a plurality of surfaces on the gear to the directed ceramic media includes rotating the metallic gear from between about 8 and about 12 revolutions per minute.
27. A method according to claim 22 wherein said ceramic media is directed at the metallic gear at a pressure of between about 50 and 90 pounds per square inch.
28. A method according to claim 22 wherein the ceramic media is directed at the metallic gear at a pressure of between about 25 and about 90 pounds per square inch and wherein the ceramic media has a diameter of between about 0.210 mm and about 0.150 mm when added as virgin media.
29. A method according to claim 22 wherein the Almen intensity of the media blast procedure is between about 17N and about 26N.
30. A method of preparing a compressively stressed region on a tooth surface and a root radius of a plurality of gear teeth of a metallic gear comprising:
positioning a metallic gear in a part holder;
directing a ceramic media of a size, density and selected Almen intensity at the metallic gear to cause residual compressive stresses at a plurality of gear teeth of at least 80 Kpsi at depths between 0.000 inch and 0.002 inch on at least one of the tooth surface and the tooth root radius.
31. A method according to claim 30 wherein the residual compressive stress is at least 80 Kpsi at depths of 0.000 inch, 0.0005 inch and 0.001 inch.
32. A method according to claim 30 wherein the residual compressive stress is at least 130 Kpsi at a depth of between 0.000 inch and 0.001 inch.
33. The method according to claim 30 wherein the residual compressive stress is at least 120 Kpsi at a depth of 0.000 inch, at least 150 Kpsi at 0.0005 inch, at least 180 Kpsi at 0.001 inch, and at least 200 Kpsi at 0.0020 inch.
34. The method according to claim 30 wherein the diameter of the ceramic media is between about 50 mesh and about 100 mesh when added as virgin media.
35. The method according to claim 30 further comprising the step of collecting the ceramic media for reuse in a subsequent blasting operation and wherein the ceramic media is a recycled media mixture including a mixture of recycled and virgin media.
36. The method according to claim 30 wherein the step of exposing multiple surfaces of the workpiece to the ceramic media includes the step of rotating the workpiece at between 8-12 revolutions per minute.
37. The method according to claim 30 wherein the ceramic media is directed at the workpiece at a pressure of between about seventy to about eighty pounds per square inch.
38. The method according to claim 30 wherein the cycle time for directing media at a workpiece is between about 60 and about 80 seconds.
39. The method according to claim 30 wherein the flowrate of the ceramic media being directed at the workpiece is between about 1.5 and about 3 pounds per minute.
40. The method according to claim 30 wherein the ceramic medium is a ceramic bead including zirconia crystals enclosed in a silica glassy phase.
41. The method according to claim 30 wherein the ceramic media is directed at the metallic gear at a pressure of between about 50 and about 90 pounds per square inch and wherein the ceramic media has a mesh dimension of between about 50 and about 120 mesh when added as virgin media.
42. The method according to claim 30 wherein the Almen intensity of the media blast procedure is between about 18N and about 26N.
43. A method of processing a metallic gear with a fine steel media blast stream comprising the steps of:
positioning the metallic gear in a part holder to maintain the metallic gear in one or more predetermined positions during a blasting operation;
directing a fine steel media having a diameter of between about 150 microns and about 200 microns at the metallic gear part; and
exposing a plurality of surfaces on the metallic gear to the directed ceramic media;
44. The method according to claim 43 wherein the flow rate is between about 1 to about 4 pounds per minute.
45. The method according to claim 43 wherein the cycle time is between about 10 and about 60 seconds.
46. The method according to claim 43 wherein the pressure is between about 70 and about 80 psi.
47. The method according to claim 43 wherein the Almen range is between about 18N and about 26N.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A reflective device including;
a substrate with a planar surface; and
a planar, high-contrast, sub-wavelength grating disposed on the surface, wherein the grating is divided into a number of regions that each reflect incident light of a particular wavelength and with a particular angle of incidence into a single diffraction order and associated diffraction angle.
2. The device of claim 1, wherein the planar grating has a substantially uniform thickness.
3. The device of claim 1, wherein the grating is a one-dimensional grating composed of substantially parallel lines that extend above the surface and are separated by grooves.
4. The device of claim 3, wherein within for each region, the line spacing and line widths are selected to reflect the light with the diffraction angle.
5. The device of claim 3, wherein the lines have a thickness that ensures the light reflected is substantially TM polarized.
6. The device of claim 1, wherein the grating is a two-dimensional grating composed of posts.
7. The device of claim 7, wherein within for each region, the spacing between posts and cross-sectional dimensions of the post is selected to reflect the light with the diffraction angle.
8. The device of claim 7, wherein the two-dimensional grating is polarization insensitive.
9. The device of claim 7, wherein the grating has a higher refractive index than the substrate.
10. A method of diffracting light, the method comprising:
directing light with an angle of incidence onto a planar reflective device, wherein the planar reflective device includes a substrate with a planar surface and a planar, high-contrast, sub-wavelength grating disposed on the surface and divided into a number of regions; and
reflecting the incident light from each region into a single diffraction order and associated diffraction angle.
11. The method of claim 10 wherein reflecting the incident light further includes reflecting the light with TM polarization.
12. The method of claim 10 wherein incident light is composed of a number of different wavelengths.
13. The method of claim 10, wherein the planar grating has a substantially uniform thickness.
14. The method of claim 10, wherein the grating is a one-dimensional grating composed of substantially parallel lines that extend above the surface and are separated by grooves.
15. The method of claim 14, wherein within for each region, the line spacing and line widths are selected to reflect the light with the diffraction angle.
16. The method of claim 14, wherein the lines have a thickness that ensures the light reflected is substantially TM polarized.
17. The method of claim 10, wherein the grating is a two-dimensional grating composed of posts.
18. The method of claim 17, wherein within for each region, the spacing between posts and cross-sectional dimensions of the post is selected to reflect the light with the diffraction angle.
19. The method of claim 17, wherein the two-dimensional grating is polarization insensitive.
20. The device of claim 10, wherein the grating has a higher refractive index than the substrate.