US3129085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming spiral lamp tubes
Assignee: Duro Test Corp
•
Filing: 1961-01-30
•
Granted: 1964-04-14
•
Expires: 1981-01-30
Abstract
No abstract record available.
Inventors
- 👤 Andrew H Olsen
- 👤 Donald G Trutner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:59
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/04; C03B23/051; H; H01; H01J; H01J9/00; H01J9/24; H01J9/245; H01J9/247
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
A METHOD OF FORMING AT LEAST ONE HELICAL GROOVE IN THE WALL OF A GLASS TUBE BY DISPLACING THE WALL ALONG A HELICAL PATH BY HEATING THE WALL AT A POINT TO A TEMPERATURE HIGH ENOUGH TO SOFTEN THE WALL THEREAT SUFFICIENTLY SO THAT ON SUBSEQUENT ROTATION THE HEATED WALL WILL SAG INWARDLY, ROTATING THE GASS TUBE ON ITS AXIS AND PROGRESSING THE POINT OF HEATING ALONG A LINE PARALLEL TO THE AXIS OF THE GLASS TUBE AT A RATE PROPORTIONED TO THE SPEED OF ROTATION OF THE GLASS TUBE TO FORM A HELICAL GROOVE OF PREDETERMINED PITCH.
Claim 2
Independent Claim
98 words
A METHOD OF FORMING AT LEAST ONE HELICAL GROOVE IN THE WALL OF A GLASS TUBE BY DISPLACING THE WALL ALONG A HELICAL PATH BY HEATING THE WALL AT A POINT TO A TEMPERATURE HIGH ENOUGH TO SOFTEN THE WALL THEREAT SUFFICIENTLY SO THAT ON SUBSEQUENT ROTATION THE HEATED WALL WILL SAG INWARDLY, ROTATING THE GASS TUBE ON ITS AXIS AND PROGRESSING THE POINT OF HEATING ALONG A LINE PARALLEL TO THE AXIS OF THE GLASS TUBE AT A RATE PROPORTIONED TO THE SPEED OF ROTATION OF THE GLASS TUBE TO FORM A HELICAL GROOVE OF PREDETERMINED PITCH.
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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) | 1967-04-14 | 1967-10-14 | 1968-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-14 | 1971-10-14 | 1972-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-14 | 1975-10-14 | 1976-04-14 | $7700.00 | Window Closed / Lapsed |