US3620704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for forming and drawing fused metal-oxide tubes
Assignee: Texas Instruments Inc
•
Filing: 1969-12-18
•
Granted: 1971-11-16
•
Expires: 1989-12-18
Abstract
Abstract A technique and apparatus for forming a fused metal-oxide structure, for example a fused silica tubing, by depositing a metal oxide on a deposition mandrel by vapor phase hydrolysis, heating the thus-deposited metal to a temperature sufficiently high to form a viscous glass melt, and drawing the structure from this glass melt.
Inventors
- 👤 Foster Lee Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:19
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/14; C03B19/1484; C03B19/1492; C03B17/00; C03B17/04; C03B19/1415; C03B19/1423; C03B19/1453; C03B2207/00; C03B2207/04; C03B2207/06; C03B2207/12; C03B2207/20; C03B2207/42; C03B2207/50; C03B2207/54
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
12 words
The apparatus of claim 1 wherein said mandrel is composed of platinum.
Claim 2
Dependent Claim
38 words
The apparatus of claim 1 wherein said mandrel has a frustoconicAl die portion near the lower end thereof, the major circumference of the die portion being the lower end of the mandrel over which the structure is drawn.
Claim 3
Dependent Claim
25 words
The apparatus of claim 1 including means for circulating a nonoxidizing gas between the interior surface of said structure and the surface of the mandrel.
Claim 4
Dependent Claim
21 words
The apparatus of claim 3 wherein said mandrel, including the die portion thereof, is composed of graphite coated with silicon carbide.
Claim 5
Dependent Claim
48 words
The apparatus of claim 1 wherein the means for depositing comprises a plurality of vapor phase hydrolysis torches attached to the support member and positioned to deposit a metal oxide on the mandrel, said torches including means for feeding vaporous metal halide and combustible gas to each thereof.
Claim 6
Dependent Claim
51 words
The apparatus of claim 6 wherein the said torches each include a centrally located aperture for directing a gaseous stream of metal halide, circumvented by an aperture for directing a gaseous stream of oxygen and further circumvented by a plurality of apertures for selectively directing gaseous streams of a combustible gas.
Claim 7
Dependent Claim
13 words
The apparatus of claim 1 further including auxiliary heating means circumventing said mandrel.
Claim 8
Independent Claim
153 words
An apparatus for continuously drawing a hollow tubelike structure from a fused plastic mass of metal oxide, comprising: a. a support member; b. a vertically suspended substantially cylindrical mandrel rotatably associated with the support member near the upper end of said mandrel, said mandrel having a frustoconical die portion near the lower end thereof with a major circumference at the lower end thereof; c. means for rotating said mandrel; d. a plurality of vapor phase hydrolysis torches attached to said support member and positioned to deposit a vitreous metal oxide on the mandrel, each of said torches directing a flaming gaseous stream radially inward toward said mandrel, said gaseous stream comprising oxygen, a combustible gas and a vaporous metal halide; e. heating means for maintaining said deposited oxide in a plastic state; and f. means for continuously drawing a hollow tubelike fused metal-oxide structure downward from the major circumference of said die portion.
Claim 9
Independent Claim
88 words
A method for continuously forming a hollow tubelike structure from a fused metal oxide, comprising: a. depositing a plastic, vitreous mass of a metal oxide by vapor phase hydrolysis on a deposition zone of a selectively shaped vertically suspended mandrel; b. rotating said mandrel about its vertical axis; c. continuously drawing a hollow tubelike structure downward from the plastic oxide mass surrounding the lower end of said mandrel as the metal oxide is deposited; and d. cooling the drawn structure to a temperature below which it becomes rigid.
Claim 10
Dependent Claim
26 words
The method of claim 10 wherein said metal oxide is deposited from a flaming gaseous stream comprising oxygen, a combustible gas and a gaseous metallic compound.
Claim 11
Dependent Claim
12 words
The method of claim 11 wherein said metallic compound is silicon tetrachloride.
Claim 12
Dependent Claim
23 words
The method of claim 10 wherein said mandrel has a frustoconical-shaped lower end portion with a major circumference at the lower end thereof.
Claim 13
Dependent Claim
20 words
The method of claim 10 further comprising heating said deposition zone with an auxiliary heat source circumventing said deposition zone.
Claim 14
Dependent Claim
24 words
The method of claim 10, wherein the deposition zone is heated to a temperature within the range of from 1,800* to 2, 200* C.
Claim 15
Dependent Claim
22 words
The method of claim 14 wherein said auxiliary heat source is a radiofrequency induction source and said mandrel serves as a susceptor.
Claim 16
Dependent Claim
31 words
The method of claim 10 wherein the drawn end of the tubelike structure is sealed and the method further includes introducing a nonoxidizing gas into the interior of the drawn structure.
Claim 17
Dependent Claim
27 words
The method of claim 10 further including the step of drawing the structure through a selectively shaped die while the structure is still in a plastic state.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |