US3584252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrically-shielded symbol-display tube
Assignee: Cooper Industries LLC
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Filing: 1969-05-23
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Granted: 1971-06-08
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Expires: 1989-05-23
Abstract
Abstract An electrically conductive layer coextensive with at least a portion of the envelope of a symbol-display tube is operative to shield the tube from external electric fields.
Inventors
- 👤 Richard Du Bois Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:39
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/10; H01J31/12; H01J31/15
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
88 words
In a symbol display tube including a sealed envelope having a substantially cylindrical portion, a plurality of display elements and means for bombarding said display elements with electrons when said tube is connected to a source of external power and switching circuitry, the improvement comprising: an electrically conductive layer disposed on about at least half of the circumference of said cylindrical portion of the envelope to form an electrical shield for the display elements within the envelope, and connecting means for connecting said layer to the external circuitry
Claim 2
Dependent Claim
88 words
In a symbol display tube including a sealed envelope having a substantially cylindrical portion, a plurality of display elements and means for bombarding said display elements with electrons when said tube is connected to a source of external power and switching circuitry, the improvement comprising: an electrically conductive layer disposed on about at least half of the circumference of said cylindrical portion of the envelope to form an electrical shield for the display elements within the envelope, and connecting means for connecting said layer to the external circuitry
Claim 3
Dependent Claim
45 words
The improvement according to claim 1 wherein said connecting means comprises: a. a conductive spring disposed substantially diametrically within the envelope to contact the electrically conductive layer at two points; and b. a lead wire connected to said conductive spring and extending through the envelope.
References Cited (Backward Citations)
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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) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |