Patent US3825769A successfully refreshed from Google Patents.
US3825769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alternate light lighting fixture
Assignee: Individual
•
Filing: 1972-06-23
•
Granted: 1974-07-23
•
Expires: 1992-06-23
Abstract
Abstract A primary lamp and a spare standby lamp are interconnected in parallel with a source of electrical energy through an automatic lamp changing device in order to provide illumination from the standby lamp should there be burn out of the primary lamp. Lamp change-over operation is effected by momentarily switching off the lamp energizing circuit following burn out of the primary lamp and involves a single relay device connected in series with the standby lamp to maintain the same energized in a circuit parallel to that of the primary lamp when operating.
Inventors
- 👤 R Alford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:08
CPC Classifications
H; H05; H05B; H05B39/00; H05B39/10; H05B39/105
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
194 words
In combination with a source of electrical energy and a pair of lamps alternatively energized by said source for providing illumination, automatic lamp changing means comprising a relay device having a relay coil, a relay switch actuated in response to energization of the relay coil, a normally closed contact engaged by the relay switch and a normally open contact engageable by the relay switch when actuated, a relay energizing circuit connecting said relay coil to the source in series with one of the lamps through the normally closed contact and the relay switch in engagement thErewith, a lamp energizing circuit connecting said one of the lamps to the source in by-pass relation to the relay coil through the normally open contact and the actuated relay switch in engagement therewith, and standby circuit means connecting the other of the lamps to the source in parallel with the relay and lamp energizing circuits through the relay switch for alternatively maintaining the relay coil and the other of the lamps energized whereby the other of the lamps is maintained energized in response to de-energization of the relay coil following burn out of said one of the lamps.
Claim 2
Dependent Claim
194 words
In combination with a source of electrical energy and a pair of lamps alternatively energized by said source for providing illumination, automatic lamp changing means comprising a relay device having a relay coil, a relay switch actuated in response to energization of the relay coil, a normally closed contact engaged by the relay switch and a normally open contact engageable by the relay switch when actuated, a relay energizing circuit connecting said relay coil to the source in series with one of the lamps through the normally closed contact and the relay switch in engagement thErewith, a lamp energizing circuit connecting said one of the lamps to the source in by-pass relation to the relay coil through the normally open contact and the actuated relay switch in engagement therewith, and standby circuit means connecting the other of the lamps to the source in parallel with the relay and lamp energizing circuits through the relay switch for alternatively maintaining the relay coil and the other of the lamps energized whereby the other of the lamps is maintained energized in response to de-energization of the relay coil following burn out of said one of the lamps.
Claim 3
Dependent Claim
53 words
The combination of claim 1 wherein said other of the lamps is connected in series with the relay coil to the source by the standby circuit means to maintain the relay coil energized, the relay coil being initially energized through the relay energizing circuit opened in response to actuation of the relay switch.
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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |