Patent US4317667A successfully refreshed from Google Patents.
US4317667A
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Method and apparatus for fabricating lightguide preforms
Assignee: AT&T Inc
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Filing: 1981-01-05
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Granted: 1982-03-02
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Expires: 2001-01-05
Abstract
Abstract A lightguide starting tube or rod (12) passes through opposed lateral openings (51--51) in a chamber (31) which contains an oxy-hydrogen torch (14) used to deposit particulate glass on the rod. Frusto-conical, laminar flow, gas shields (71 and 72) are formed about the rod (12) on both sides of said openings (51--51) to permit the rod to pass therethrough in spaced relation to the openings while sealing said openings to prevent gas or undeposited particulate from passing therethrough and preventing contaminants from entering the chamber (31).
Inventors
- 👤 Carroll D. Spainhour
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:17
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/01486; C03B37/018; C03B37/01846
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
64 words
A method for preventing contaminants from escaping through an opening in a chamber as an elongated article passes through and in spaced relation to the periphery of the opening, the method comprising the step of: directing a first, laminar flow, gas shield from a first slit circumferential of the opening, into the chamber, towards a point along the axis of the article passing therethrough.
Claim 2
Independent Claim
64 words
A method for preventing contaminants from escaping through an opening in a chamber as an elongated article passes through and in spaced relation to the periphery of the opening, the method comprising the step of: directing a first, laminar flow, gas shield from a first slit circumferential of the opening, into the chamber, towards a point along the axis of the article passing therethrough.
Claim 3
Dependent Claim
48 words
The method as set forth in claim 1, characterized by: directing a second, laminar flow, gas shield from a second slit circumferential of the opening, away from the chamber, towards a point along the axis of the article passing therethrough to prevent airborne contaminants from entering said chamber.
Claim 4
Dependent Claim
16 words
The method as set forth in claim 1, wherein: the article is a cylindrical lightguide preform.
Claim 5
Dependent Claim
18 words
The method as set forth in claim 1, wherein: the article rotates and translates relative to the opening.
Claim 6
Dependent Claim
26 words
The method as set forth in claim 1, wherein: the article reciprocates relative to the opening; and the diameter of the article increases upon each reciprocation.
Claim 7
Dependent Claim
27 words
The method as set forth in claim 2, wherein: the outer cross-sectional geometry of the article and the geometry of the first and second slits are similar.
Claim 8
Dependent Claim
22 words
The method as set forth in claim 1 which is characterized by: cooling the gas which is used to form the shield.
Claim 9
Independent Claim
59 words
A method of preventing gaseous contaminants, containing particulate matter therein, from passing through an opening in a chamber, the method comprising the step of: directing a first laminar flow, gas shield through a first slit circumferential of the opening in such a manner that the slit forms the base of the gas shield having an apex within the chamber.
Claim 10
Independent Claim
59 words
A method of preventing gaseous contaminants, containing particulate matter therein, from passing through an opening in a chamber, the method comprising the step of: directing a first laminar flow, gas shield through a first slit circumferential of the opening in such a manner that the slit forms the base of the gas shield having an apex within the chamber.
Claim 11
Dependent Claim
57 words
The method as set forth in claim 8, characterized by: directing a second, laminar flow, gas shield through a second slit circumferential of the opening, away from the chamber, in such a manner that the slit forms the base of the gas shield having an apex outside the chamber to prevent airborne contaminants from entering the chamber.
Claim 12
Dependent Claim
26 words
The method as set forth in claim 9, wherein: the first and second slits are circular; and the laminar flow gas shield has a conical shape.
Claim 13
Independent Claim
63 words
An apparatus for preventing contaminants from escaping through an opening in a chamber as an elongated article passes through and in spaced relation to the periphery of the opening, the apparatus comprising: means for directing a first, laminar flow gas shield from a first slit circumferential of the opening, into the chamber, towards a point along the axis of the article passing therethrough.
Claim 14
Independent Claim
63 words
An apparatus for preventing contaminants from escaping through an opening in a chamber as an elongated article passes through and in spaced relation to the periphery of the opening, the apparatus comprising: means for directing a first, laminar flow gas shield from a first slit circumferential of the opening, into the chamber, towards a point along the axis of the article passing therethrough.
Claim 15
Dependent Claim
49 words
The apparatus as set forth in claim 11, comprising: means for directing a second, laminar flow, gas shield from a second slit circumferential of the opening, away from the chamber toward a point along the axis of the article passing therethrough to prevent airborne contaminants from entering said chamber.
Claim 16
Independent Claim
62 words
An apparatus for preventing gaseous contaminants, containing particulate matter therein, from passing through an opening in a chamber, the apparatus comprising: means for directing a first conical, laminar flow, gas shield through a circular slit circumferential of the opening in such a manner that the slit forms the base of the conical gas shield and the apex thereof is within the chamber.
Claim 17
Independent Claim
62 words
An apparatus for preventing gaseous contaminants, containing particulate matter therein, from passing through an opening in a chamber, the apparatus comprising: means for directing a first conical, laminar flow, gas shield through a circular slit circumferential of the opening in such a manner that the slit forms the base of the conical gas shield and the apex thereof is within the chamber.
Claim 18
Dependent Claim
62 words
The apparatus as set forth in claim 13, comprising: means for directing a second conical, laminar flow, gas shield through a circular slit circumferential of the opening, away from the chamber, in such a manner that the slit forms the base of the conical gas shield and the apex thereof is outside the chamber, to prevent airborne contaminants from entering the chamber.
References Cited (Backward Citations)
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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) | 1985-03-01 | 1985-08-31 | 1986-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-01 | 1989-08-31 | 1990-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-01 | 1993-08-31 | 1994-03-02 | $7700.00 | Window Closed / Lapsed |