US4010022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making fused silica tubing
Assignee: Heraeus Schott Quarzschmelze GmbH
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Filing: 1975-06-16
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Granted: 1977-03-01
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Expires: 1995-06-16
Abstract
Abstract Tubes of transparent, translucent or opaque fused silica are made by heating a hollow cylindrical blank in a drawing zone, drawing the blank from the zone while maintaining its interior under pressure and rotating same about its longitudinal axis, and calibrating the still-plastic tube immediately upon leaving the drawing zone in a calibration zone defined by two graphite plates. Apparatus for carrying out the method includes means for heating the blank to a drawing temperature in a drawing zone, means for drawing the blank from the zone, means for maintaining the interior of the blank under pressure and means for rotating the blank as it is drawn, and calibrating means for calibrating the still-plastic tube immediately upon leaving the drawing zone including two graphite plate means disposed on metal plates through which a coolant can flow.
Inventors
- 👤 Herbert Schul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:16
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/04; C03B23/047
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
187 words
An apparatus for making fused silica tubes from a hollow cylindrical tube of fused silica which comprises a heating zone, means for supplying heat to said heating zone, means for continuously feeding said hollow cylindrical tube to said heating zone, means for rotating said hollow cylindrical tube as it is fed to said heating zone, means downstream of said heating zone for continuously withdrawing said tube from said heating zone, means for rotating the same about its own longitudinal axis as it is withdrawn from said heating zone, means for applying pressure to the interior of said tube while it is being withdrawn from said heating zone and rotated, and calibrating means downstream of said heating zone for calibrating the still-plastic tube immediately upon leaving the heating zone, said calibrating means being disposed adjacent to said heating zone, said calibrating means comprising at least two tube confronting flat graphite plate means disposed upon a support and at a distance from one another corresponding to the desired outside diameter of said tube, said support means including a conduit therein and means for passing a coolant through said conduit.
Claim 2
Independent Claim
187 words
An apparatus for making fused silica tubes from a hollow cylindrical tube of fused silica which comprises a heating zone, means for supplying heat to said heating zone, means for continuously feeding said hollow cylindrical tube to said heating zone, means for rotating said hollow cylindrical tube as it is fed to said heating zone, means downstream of said heating zone for continuously withdrawing said tube from said heating zone, means for rotating the same about its own longitudinal axis as it is withdrawn from said heating zone, means for applying pressure to the interior of said tube while it is being withdrawn from said heating zone and rotated, and calibrating means downstream of said heating zone for calibrating the still-plastic tube immediately upon leaving the heating zone, said calibrating means being disposed adjacent to said heating zone, said calibrating means comprising at least two tube confronting flat graphite plate means disposed upon a support and at a distance from one another corresponding to the desired outside diameter of said tube, said support means including a conduit therein and means for passing a coolant through said conduit.
Claim 3
Dependent Claim
19 words
Apparatus of claim 1 wherein the graphite plate means are flat on the side facing the fused silica tube.
Claim 4
Dependent Claim
23 words
Apparatus of claim 1 wherein one graphite plate means is longer in the longitudinal direction than the graphite plate means disposed opposite thereof.
Claim 5
Dependent Claim
17 words
Apparatus of claim 1 wherein the graphite plate means are adjustable in their spacing from one another.
Claim 6
Dependent Claim
16 words
An apparatus according to claim 1 wherein the said support means is a metal plate means.
Claim 7
Dependent Claim
19 words
An apparatus according to claim 1 additionally comprising means for varying the distance between said tube confronting graphite plates.
Claim 8
Dependent Claim
16 words
An apparatus according to claim 1 wherein said graphite plate means are opposed to one another.
Claim 9
Dependent Claim
26 words
An apparatus according to claim 7 wherein said graphite plate means lie longitudinally along the path of withdrawal of said heated tube from said heating zone.
Claim 10
Dependent Claim
37 words
An apparatus according to claim 1 wherein there are a plurality of means for rotating said hollow cylindrical tube, one of which is upstream of said heating zone and another which is downstream of said heating zone.
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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) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |