US4815276A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Borescope plug
Assignee: United States Department of the Air Force
•
Filing: 1987-09-10
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Granted: 1989-03-28
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Expires: 2007-09-10
Abstract
Abstract The invention comprises a borescope plug for sealing a borescope inspection port on a turbine engine having a fluid flowpath and multiple casings. The borescope plug comprises a plug body having an interlocking drive interface, a plunger portion positioned for sliding coaxial movement relative to the plug body and spring means engaging both the plug body and the plunger. The spring means presses the plunger towards a fully extended position relative to the plug body. The plunger comprises a fixedly attached tip portion shaped to conform with the fluid flowpath. Key means is provided for aligning the tip to conform with the fluid flowpath and the tip is cooled with a cooling airflow.
Inventors
- 👤 Harold R. Hansel
- 👤 Vincent M. Drerup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:18
CPC Classifications
F; F01; F01D; F01D25/00; F01D21/00; F01D21/003
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
101 words
A borescope plug for sealing a borescope inspection port on a turbine engine having a fluid flowpath and casings, the borescope plug comprising: a plug body including a drive tool interface, a plunger portion positioned for sliding coaxial movement relative to said plug body; a spring means engaging said plug body and said plunger which forces said plunger portion towards a fully extended position; a tip portion fixedly attached to said plunger portion, said tip portion shaped to conform with a fluid flowpath surface of the turbine engine; and key means for aligning said tip portions with the fluid flowpath surface.
Claim 2
Dependent Claim
101 words
A borescope plug for sealing a borescope inspection port on a turbine engine having a fluid flowpath and casings, the borescope plug comprising: a plug body including a drive tool interface, a plunger portion positioned for sliding coaxial movement relative to said plug body; a spring means engaging said plug body and said plunger which forces said plunger portion towards a fully extended position; a tip portion fixedly attached to said plunger portion, said tip portion shaped to conform with a fluid flowpath surface of the turbine engine; and key means for aligning said tip portions with the fluid flowpath surface.
Claim 3
Dependent Claim
23 words
The borescope plug of claim 1 wherein said plunger portion further comprises cooling holes for directing a cooling airflow to said tip portion.
Claim 4
Dependent Claim
28 words
The borescope plug of claim 1 wherein said probe body further comprises a threaded portion for engagement with a threaded borescope plug hole in an engine inner casing.
Claim 5
Dependent Claim
19 words
The borescope plug of claim 1 wherein said tip portion is angled to conform with the fluid flowpath surface.
Claim 6
Dependent Claim
37 words
The borescope plug of claim 1 wherein said probe body further comprises an axial cavity for accepting sliding engagement of said plunger portion and for positioning said spring means between said plug body and said plunger portion.
Claim 7
Dependent Claim
25 words
The borescope plug of claim 5 further comprising retention means for preventing exit of said plunger portion from said axial cavity of said plug body.
Claim 8
Dependent Claim
21 words
The borescope plug of claim 6 wherein said plunger portion further comprises a retention shoulder for engagement with said retention means.
Claim 9
Dependent Claim
16 words
The borescope plug of claim 1 wherein said drive tool interface further comprises tool interlocking means.
Claim 10
Dependent Claim
26 words
The borescope plug of claim 2 wherein said plunger portion further comprises a sealing flange for preventing leakage of the cooling airflow around said tip portion.
Claim 11
Dependent Claim
96 words
A borescope port assembly for a turbine engine comprising: a borescope port penetrating an inner and outer turbine casing; and a plug body including a drive interface, a plunger portion slideably positioned for coaxial movement relative to said plug body; a spring means engaging said plug body and said plunger which forces said plunger portion towards a fully extended position; a tip portion fixedly attached to said plunger portion, said tip portion shaped to conform with a fluid flowpath surface; and a key means for aligning said borescope plug tip portion with the fluid flowpath surface.
Claim 12
Dependent Claim
96 words
A borescope port assembly for a turbine engine comprising: a borescope port penetrating an inner and outer turbine casing; and a plug body including a drive interface, a plunger portion slideably positioned for coaxial movement relative to said plug body; a spring means engaging said plug body and said plunger which forces said plunger portion towards a fully extended position; a tip portion fixedly attached to said plunger portion, said tip portion shaped to conform with a fluid flowpath surface; and a key means for aligning said borescope plug tip portion with the fluid flowpath surface.
Claim 13
Dependent Claim
24 words
The borescope port assembly of claim 10 wherein said plunger portion further comprises cooling holes for directing a cooling airflow to said tip portion.
Claim 14
Dependent Claim
18 words
The borescope port assembly of claim 10 further comprising seal means for restricting airflow about said borescope plug.
Claim 15
Dependent Claim
25 words
The borescope port assembly of claim 12 wherein said seal means further comprises a tube seal substantially surrounding said plunger portion of the borescope plug.
Claim 16
Dependent Claim
26 words
The borescope port assembly of claim 12 wherein said seal means further comprises a ring seal which sealingly engages said plug body of the borescope plug.
Claim 17
Dependent Claim
45 words
The borescope port assembly of claim 12 wherein said seal means further comprises a sealing flange positioned on said plunger portion of said borescope plug for engagement with a flowpath mating shoulder adjacent to a fluid flowpath surface in order to prevent cooling air leakage.
Claim 18
Dependent Claim
18 words
The borescope port assembly of claim 10 wherein said inner casing further comprises an internally threaded mating collar.
Claim 19
Dependent Claim
30 words
The borescope port assembly of claim 16 wherein said plug body further comprises an externally threaded section and a seating shoulder for seating engagement with said internally threaded mating collar.
Claim 20
Dependent Claim
45 words
The borescope port assembly of claim 10 wherein said key means comprises a key fixedly positioned in said borescope port and a key way on said plunger portion for engagement with said key in order to align said borescope plug relative to the fluid flowpath.
Claim 21
Dependent Claim
106 words
A borescope plug for sealing a borescope inspection port on a turbine engine having a fluid flowpath and casings, the borescope plug comprising: a plug body including a drive tool surface, a plunger portion positioned for sliding coaxial movement relative to said plug body; a spring means engaging said plug body and said plunger which forces said plunger portion towards a fully extended position; and a tip portion fixedly attached to said plunger portion, said tip portion shaped to conform with a fluid flowpath surface of the turbine engine and wherein said plunger portion comprises cooling holes for directing a cooling airflow to said tip portion.
Claim 22
Dependent Claim
106 words
A borescope plug for sealing a borescope inspection port on a turbine engine having a fluid flowpath and casings, the borescope plug comprising: a plug body including a drive tool surface, a plunger portion positioned for sliding coaxial movement relative to said plug body; a spring means engaging said plug body and said plunger which forces said plunger portion towards a fully extended position; and a tip portion fixedly attached to said plunger portion, said tip portion shaped to conform with a fluid flowpath surface of the turbine engine and wherein said plunger portion comprises cooling holes for directing a cooling airflow to said tip portion.
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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) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |