Patent US2006636A successfully refreshed from Google Patents.
US5158750A
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Boron nitride crucible
Assignee: Praxair ST Technology Inc
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Filing: 1991-08-27
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Granted: 1992-10-27
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Expires: 2011-08-27
Abstract
Abstract A boron nitride crucible having a closed end, an open end, an internal surface and an external surface, and wherein at least a portion of the external surface, preferably proximate the open end of the crucible, has a duplex coating comprising an undercoat of pyrolytic graphite and a top coat of pyrolytic boron nitride. A process for making the boron nitride crucible is also disclosed.
Inventors
- 👤 Robert L. Finicle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:07
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B23/06; C30B23/066; C23; C23C; C23C14/00; C23C14/22; C23C14/24; C23C14/243; C23C16/00; C23C16/01; C23C16/22; C23C16/30; C23C16/34; C23C16/342; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10T; Y10T117/00; Y10T117/10; Y10T117/1024; Y10T117/1032; Y10T117/1092
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
79 words
A boron nitride crucible having a closed end, an open end, a length extending from the open end to the closed end; an internal surface and an external surface; wherein at least a portion of the external surface of the crucible has a duplex coating comprising an undercoat of pyrolytic graphite and a top coat of pyrolytic boron nitride completely superimposing the undercoat and wherein neither the undercoat nor the top coat is the structural member of the crucible.
Claim 2
Dependent Claim
79 words
A boron nitride crucible having a closed end, an open end, a length extending from the open end to the closed end; an internal surface and an external surface; wherein at least a portion of the external surface of the crucible has a duplex coating comprising an undercoat of pyrolytic graphite and a top coat of pyrolytic boron nitride completely superimposing the undercoat and wherein neither the undercoat nor the top coat is the structural member of the crucible.
Claim 3
Dependent Claim
20 words
The boron nitride crucible of claim 1 wherein the undercoat of pyrolytic graphite is from 0.001 to 0.1 inch thick.
Claim 4
Dependent Claim
22 words
The boron nitride crucible of claim 1 wherein the top coat of pyrolytic boron nitride is from 0.002 to 0.04 inch thick.
Claim 5
Dependent Claim
35 words
The boron nitride crucible of claim 1 wherein the undercoat of pyrolytic graphite is from 0.001 to 0.01 inch thick and the top coat of pyrolytic boron nitride is from 0.004 to 0.01 inch thick.
Claim 6
Dependent Claim
28 words
The boron nitride crucible of claim 1 wherein the duplex coating extends for said length of 10 to 80 percent of the length of the boron nitride crucible.
Claim 7
Dependent Claim
17 words
The boron nitride crucible of claim 1 wherein the crucible is a single walled boron nitride crucible.
Claim 8
Dependent Claim
16 words
The boron nitride crucible of claim 1 wherein the crucible is a multi-wall boron nitride crucible.
Claim 9
Dependent Claim
39 words
The boron nitride crucible of claim 1 wherein the duplex coating extends on the external surface from the open end of the crucible for a length of 10 to 80 percent of the length of the boron nitride crucible.
Claim 10
Dependent Claim
35 words
The boron nitride crucible of claim 8 wherein the undercoat of pyrolytic graphite is from 0.001 to 0.1 inch thick and the top coat of pyrolytic boron nitride is from 0.002 to 0.04 inch thick.
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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) | 1995-10-27 | 1996-04-27 | 1996-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-27 | 2000-04-27 | 2000-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-27 | 2004-04-27 | 2004-10-27 | $7700.00 | Window Closed / Lapsed |