US5343022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyrolytic boron nitride heating unit
Assignee: General Electric Co
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Filing: 1992-09-29
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Granted: 1994-08-30
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Expires: 2012-09-29
Abstract
Abstract A pyrolytic boron nitride heating unit composed of a dielectric base of boron nitride and a pyrolytic graphite heating element having contact ends for connection to an external power supply through a contact assembly comprising graphite posts connected to the contact ends with each post having a pyrolytic boron nitride coating and exposed attachment ends spaced a predetermined minimum distance from the contact ends for connection to the power supply. The contact assembly preferably also includes flexible graphite washers for connection between the contact ends and the graphite posts.
Inventors
- 👤 Michael H. Gilbert, Sr.
- 👤 Timothy J. Hejl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:23
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/145; H05B3/02; H05B3/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
A pyrolytic boron nitride heating unit for use in a reactive atmosphere comprising a dielectric base of boron nitride, a heating element of pyrolytic graphite superimposed upon said base and arranged in a serpentine pattern with said heating element having a pair of contact ends for providing a series electrical path through said pyrolytic graphite between the contact ends thereof and a contact assembly for connecting said contact ends to an external power supply with said contact assembly comprising a graphite post for each contact end of said heating element with one end of said graphite post attached to a corresponding contact end of said heating element and having an opposite end spaced a predetermined distance from said one end for attachment to said external power supply and a pyrolytic boron nitride coating encapsulating said heating element and covering each graphite post so as to form an integral pyrolytic boron nitride covering except at the ends of said graphite posts for attachment to said external power supply.
Claim 2
Dependent Claim
167 words
A pyrolytic boron nitride heating unit for use in a reactive atmosphere comprising a dielectric base of boron nitride, a heating element of pyrolytic graphite superimposed upon said base and arranged in a serpentine pattern with said heating element having a pair of contact ends for providing a series electrical path through said pyrolytic graphite between the contact ends thereof and a contact assembly for connecting said contact ends to an external power supply with said contact assembly comprising a graphite post for each contact end of said heating element with one end of said graphite post attached to a corresponding contact end of said heating element and having an opposite end spaced a predetermined distance from said one end for attachment to said external power supply and a pyrolytic boron nitride coating encapsulating said heating element and covering each graphite post so as to form an integral pyrolytic boron nitride covering except at the ends of said graphite posts for attachment to said external power supply.
Claim 3
Dependent Claim
28 words
A pyrolytic boron nitride heating unit as defined in claim 1 wherein each contact end of said heating element has an opening for attachment to said graphite post.
Claim 4
Dependent Claim
30 words
A pyrolytic boron nitride heating unit as defined in claim 2 further comprising flexible graphite washers for use between each contact end of said heating element and each graphite post.
Claim 5
Dependent Claim
38 words
A pyrolytic boron nitride heating unit as defined in claim 3 wherein said contact assembly further comprises a graphite screw for each graphite post with each graphite post having a corresponding threaded opening to receive the graphite screw.
Claim 6
Dependent Claim
25 words
A pyrolytic boron nitride heating unit as defined in claim 4 wherein each graphite post is of a length of between 1 to 3 inches.
References Cited (Backward Citations)
US1528388A
Cited
US2640861A
Cited
US3637980A
Cited
DE2402111A1
Cited
DE2654606A1
Cited
US4264803A
Cited
US4164646A
Cited
US4755658A
Cited
FR2627658A1
Cited
US4927994A
Cited
US5031229A
Cited
US5059770A
Cited
US5155652A
Cited
US5233165A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-29 | 1998-02-28 | 1998-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-29 | 2002-02-28 | 2002-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-29 | 2006-02-28 | 2006-08-30 | $7700.00 | Window Closed / Lapsed |