US3897233A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc tube forming process
Assignee: General Electric Co
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Filing: 1974-01-14
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Granted: 1975-07-29
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Expires: 1994-01-14
Abstract
Abstract A quartz arc tube forming process providing a one-piece construction having better uniformity, strength and precision than the prior three-piece construction. The vitreous tubing is heated to plasticity and necked down by cone-sections to a short neck at two places close together. The upstanding double-cone portion between the two necks is then heated and stretched in order to reduce it to the same diameter as the two necks without excessive wall thickening. This procedure is repeated on the tubing at intervals corresponding to the arc tube length and the tubing is severed at the stretched portions to release the formed units.
Inventors
- 👤 Imre Szilagyi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:07
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/04; C03B23/047; C03B23/0473
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
A PROCESS FOR FORMING SMALL NECK ENVELOPES FROM VITEROUS TUBING COMPRISING THE STEPS OF: HEAT-SOFTENING AND NECKING DOWN THE VITEROUS TUBING AT TWO PLACES TO PROVIDE TWIN SMALL NECKS WHICH ARE SHORT REALTIVE TO THEIR SHOULDERS WITH AN UPSTANDING PORTION OF VITEROUS TUBING BETWEEN THEM, ALLOWING THE QUARTZ TO COOL SUFFICIENTLY TO BE RIGID AT LEAST IN THE SHOULDERS REMOTE FROM SAID UPSTANDING PORTION, THEN HEAT-SOFTENING AND STRETCHING THE UPSTANDING PORTION WHILE SHRINKING IT DOWN TO APPROXIMATELY THE SAME DIAMETER AS THE TWIN NECKS IN ORDER TO PROVIDE A LONG NECK WITHOUT EXCESSIVE WALL THICKNESS, SAID STRETCHING RESULTING FROM MECHANICAL APPLICATION OF TENSION TO THE TUBING AND SAID SHRINKING RESULTING FROM APPLICATION OF HEAT WITHOUT USE OF A DIE, REPEATING THE FOREGOING STEPS TO FORM IN A SIMILAR WAY ANOTHER LONG NECK PORTION WITHOUT EXCESS WALL THICKNESS AT ANOTHER PLACE IN THE TUBING, AND THEN SEVERING THE TUBING AT THE TWO LONG NECK PORTIONS IN ORDER TO RELEASE A FORMED UNIT HAVING NARROW NECKS AT BOTH ENDS.
Claim 2
Dependent Claim
167 words
A PROCESS FOR FORMING SMALL NECK ENVELOPES FROM VITEROUS TUBING COMPRISING THE STEPS OF: HEAT-SOFTENING AND NECKING DOWN THE VITEROUS TUBING AT TWO PLACES TO PROVIDE TWIN SMALL NECKS WHICH ARE SHORT REALTIVE TO THEIR SHOULDERS WITH AN UPSTANDING PORTION OF VITEROUS TUBING BETWEEN THEM, ALLOWING THE QUARTZ TO COOL SUFFICIENTLY TO BE RIGID AT LEAST IN THE SHOULDERS REMOTE FROM SAID UPSTANDING PORTION, THEN HEAT-SOFTENING AND STRETCHING THE UPSTANDING PORTION WHILE SHRINKING IT DOWN TO APPROXIMATELY THE SAME DIAMETER AS THE TWIN NECKS IN ORDER TO PROVIDE A LONG NECK WITHOUT EXCESSIVE WALL THICKNESS, SAID STRETCHING RESULTING FROM MECHANICAL APPLICATION OF TENSION TO THE TUBING AND SAID SHRINKING RESULTING FROM APPLICATION OF HEAT WITHOUT USE OF A DIE, REPEATING THE FOREGOING STEPS TO FORM IN A SIMILAR WAY ANOTHER LONG NECK PORTION WITHOUT EXCESS WALL THICKNESS AT ANOTHER PLACE IN THE TUBING, AND THEN SEVERING THE TUBING AT THE TWO LONG NECK PORTIONS IN ORDER TO RELEASE A FORMED UNIT HAVING NARROW NECKS AT BOTH ENDS.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein the vitreous tubing is necked down into twin small necks by heating to plasticity at the selected places and rolling down.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein the vitreous tubing is necked down into twin small necks by heating to plasticity and molding at the selected places.
Claim 5
Dependent Claim
52 words
The process of claim 1 wherein the vitreous tubing is necked down by cone sections to produce twin small cylindrical necks at the two selected places with an upstanding double cone portion between them which is then heated to plasticity, and stretched as it is shrunk down into a long neck portion.
Claim 6
Dependent Claim
58 words
The process of claim 1 wherein the vitreous tubing is necked down by cone sections to produce twin small cylindrical necks at the two selected places with an upstanding double cone portion between them, and the double cone portion is then heated to plasticity and stretched as it shrinks through a prolate spheroid into a long neck portion.
Claim 7
Dependent Claim
30 words
The process of claim 5 wherein the length and extent of stretch of the double cone portion are chosen to result in substantially constant wall thickness in the neck portions.
References Cited (Backward Citations)
CH232333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |