Patent US2952225A successfully refreshed from Google Patents.
US4289952A
Expired / Lapsed
US
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Process for controlling powder size with optical energy
Assignee: Massachusetts Institute of Technology
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Filing: 1979-12-12
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Granted: 1981-09-15
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Expires: 1999-12-12
Abstract
Abstract Metal or ceramic powders having a narrow size distribution are produced by passing a gas entrained powder through an intense light beam which couples preferentially with the larger particles to heat and selectively vaporize a portion of the larger particles until their diameter approximates the desired size.
Inventors
- 👤 John S. Haggerty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:29
CPC Classifications
B; B23; B23K; B23K26/00; B23K26/12; B23K26/123; B22; B22F; B22F1/00; B22F1/14; B22F1/142; B23K26/36; B23K26/40; C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/591; B23K2103/00; B23K2103/50; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3206; C04B2235/3217; C04B2235/3231; C04B2235/3232; C04B2235/34; C04B2235/3418; C04B2235/38; C04B2235/3817; C04B2235/3826; C04B2235/3852; C04B2235/3873; C04B2235/40; C04B2235/405; C04B2235/407; C04B2235/42; C04B2235/428; C04B2235/65; C04B2235/66; C04B2235/665
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
82 words
The process for producing a metal or ceramic powder having a narrow size distribution which comprises forming a dilute mixture of a metal or ceramic powder in a gas and passing said mixture through a collimated beam of intense light which coupled with the larger particles in said mixture to vaporize a portion of said larger particles until said larger particles have a diameter that approximates a minimum wavelength of said beam, and recovering the particles which have passed through said beam.
Claim 2
Dependent Claim
82 words
The process for producing a metal or ceramic powder having a narrow size distribution which comprises forming a dilute mixture of a metal or ceramic powder in a gas and passing said mixture through a collimated beam of intense light which coupled with the larger particles in said mixture to vaporize a portion of said larger particles until said larger particles have a diameter that approximates a minimum wavelength of said beam, and recovering the particles which have passed through said beam.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein said powder is a ceramic.
Claim 4
Dependent Claim
11 words
The process of claim 2 wherein said powder is silicon nitride.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein said powder is a metal.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein said light beam is a laser.
Claim 7
Dependent Claim
34 words
The process of claim 1 wherein said beam is a truncated light beam formed by passing a broad band light source through a filter thereby to reduce the wavelength of said broad band source.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |