Patent US5158750A successfully refreshed from Google Patents.
US5158750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Boron nitride crucible
Assignee: Praxair ST Technology Inc
•
Filing: 1991-08-27
•
Granted: 1992-10-27
•
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 18:37
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.
References Cited (Backward Citations)
US1475650A
Cited
US1721994A
Cited
US1709729A
Cited
US3345059A
Cited
US3986822A
Cited
US4058579A
Cited
US4090851A
Cited
US4264803A
Cited
SU866381A1
Cited
US4446357A
Cited
US4596700A
Cited
US4613306A
Cited
US4773852A
Cited
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 |