Patent US4739147A successfully refreshed from Google Patents.
US4739147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pre-aligned demountable plasma torch
Assignee: Dow Chemical Co
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Filing: 1987-01-30
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Granted: 1988-04-19
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Expires: 2007-01-30
Abstract
Abstract An improved pre-aligned demountable plasma torch wherein the three tubes that are generally used in demountable plasma torches are now joined together with standard taper joints. The axis of the standard taper joints are essentially centrally aligned with the central long axis of the tubes so that the tubes are pre-aligned and essentially concentric in the assembled torch. If any of the tubes becomes damaged in use they can be replaced with a similarly constructed tube with a minimum of interruption and expense, without the need to adjust the tubes to be essentially concentric and in an assembly consisting of only 3 parts.
Inventors
- 👤 Gerhard A. Meyer
- 👤 Harold W. Eberhart
- 👤 Laurence F. Novak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:28
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/30; H05H1/32; H05H1/34; H05H1/38
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
In an improved pre-aligned demountable plasma comprising an inner tube, an intermediate tube and an outer tube, wherein the improvement comprises: (a) the outer tube having a conically shaped section whose axis is essentially centrally aligned with the axis of the outer tube: (b) the intermediate tube having a conically shaped section whose axis is essentially centrally aligned with the axis of the intermediate tube, the conically shaped section of the outer tube inversely friction fit mated to the conically shaped section of the intermediate tube so that the intermediate tube is essentially concentric and prealigned in the outer tube and so that the intermediate tube can be readily disassembled from the outer tube and reassembled thereto in pre-aligned fashion.
Claim 2
Dependent Claim
120 words
In an improved pre-aligned demountable plasma comprising an inner tube, an intermediate tube and an outer tube, wherein the improvement comprises: (a) the outer tube having a conically shaped section whose axis is essentially centrally aligned with the axis of the outer tube: (b) the intermediate tube having a conically shaped section whose axis is essentially centrally aligned with the axis of the intermediate tube, the conically shaped section of the outer tube inversely friction fit mated to the conically shaped section of the intermediate tube so that the intermediate tube is essentially concentric and prealigned in the outer tube and so that the intermediate tube can be readily disassembled from the outer tube and reassembled thereto in pre-aligned fashion.
Claim 3
Dependent Claim
27 words
The improved torch of claim 1 wherein the outer tube and the intermediate tube comprise a material selected from the group consisting of quartz and fused silica.
Claim 4
Dependent Claim
91 words
The improved torch of claim 1 wherein the outer tube has an additional conically shaped section whose axis is essentially centrally aligned with the axis of the outer tube and further comprising the inner tube having a conically shaped section whose axis is essentially centrally aligned with the axis of the inner tube, the conically shaped section of the inner tube inversely friction fit mated to the additional conically shaped section of the outer tube so that the inner tube can be readily disassembled from the outer tube and reassembled thereto.
Claim 5
Dependent Claim
26 words
The improved torch of claim 3 wherein the inner tube comprises a material selected from the group consisting of quartz, fused silica, boron nitride and graphite.
Claim 6
Dependent Claim
91 words
The improved torch of claim 1 wherein the intermediate tube has an additional conically shaped section whose axis is essentially centrally aligned with the axis of the intermediate tube and further comprising the inner tube having a conically shaped section whose axis is essentially centrally aligned with the axis of the inner tube, the conically shaped section of the inner tube inversely friction fit mated to the additional conically shaped section of the intermediate tube so that the inner tube can be readily disassembled from the outer tube and reassembled thereto.
Claim 7
Dependent Claim
26 words
The improved torch of claim 5 wherein the inner tube comprises a material selected from the group consisting of quartz, fused silica, boron nitride and graphite.
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) | 1991-04-19 | 1991-10-19 | 1992-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-19 | 1995-10-19 | 1996-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-19 | 1999-10-19 | 2000-04-19 | $7700.00 | Window Closed / Lapsed |