Patent US3562508A successfully refreshed from Google Patents.
US3562508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash unit
Assignee: Agfa Gevaert AG
•
Filing: 1967-02-06
•
Granted: 1971-02-09
•
Expires: 1987-02-06
Abstract
Abstract Flash unit whose flash circuit comprises a series of parallel branches each having a flashbulb, and means for firing the flashbulb of the first branch. Each but the first branch further comprises a switch which is normally open but is closed on partial or complete melting of a switch opening member which is heated in response to firing of the flashbulb in the preceding branch of the flash circuit. This renders the flashbulb of the second branch ready for firing on renewed actuation of the firing means.
Inventors
- 👤 Franz Hoffacker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:16
CPC Classifications
G; G03; G03B; G03B15/00; G03B15/02; G03B15/03; G03B15/04; G03B15/0452; G03B15/0457
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
A flash unit, comprising a flash circuit having a series of parallel branches including a first branch and at least two additional branches, each of said branches comprising an electrically ignitable flashbulb and each of said additional branches comprising a biased-closed switch and expendable switch opening means consisting of fusible material which normally holds the respective switch open but which melts and thereby effects closing of the respective switch in response to heat developing on firing of the flashbulb in the preceding branch, means for firing the flashbulbs of successive branches, the flashbulb of each succeeding branch being ready for firing upon firing of the flashbulb in the preceding branch and resultant closing of the respective switch, and reflector means for each of said flashbulbs, each of said switch opening means comprising a pin extending through an aperture provided in the reflector means for the flash bulb in the preceding branch and bearing against such flashbulb prior to melting thereof.
Claim 2
Dependent Claim
160 words
A flash unit, comprising a flash circuit having a series of parallel branches including a first branch and at least two additional branches, each of said branches comprising an electrically ignitable flashbulb and each of said additional branches comprising a biased-closed switch and expendable switch opening means consisting of fusible material which normally holds the respective switch open but which melts and thereby effects closing of the respective switch in response to heat developing on firing of the flashbulb in the preceding branch, means for firing the flashbulbs of successive branches, the flashbulb of each succeeding branch being ready for firing upon firing of the flashbulb in the preceding branch and resultant closing of the respective switch, and reflector means for each of said flashbulbs, each of said switch opening means comprising a pin extending through an aperture provided in the reflector means for the flash bulb in the preceding branch and bearing against such flashbulb prior to melting thereof.
Claim 3
Dependent Claim
73 words
A flash unit as defined in claim 1, wherein each of said switches comprises two contacts at least one of which tends to move into current-conducting engagement with the other contact, each of said pins preventing the movement of said one contact in the respective switch into engagement with the other contact of the respective switch prior to melTing of such pin in response to firing of the flashbulb in the preceding branch.
Claim 4
Dependent Claim
57 words
A flash unit as defined in claim 1, wherein said means for firing comprises a source of electrical energy, a resistor and a synchronizing switch, all connected in series with the flashbulb of said first branch, and a capacitor connected in parallel with that part of said series circuit comprising said source of energy and said resistor.
Claim 5
Dependent Claim
19 words
A flash unit as defined in claim 1, further comprising a common enclosure for said flashbulbs and said switches.
Claim 6
Dependent Claim
28 words
A flash unit as defined in claim 4, further comprising a support for said enclosure, said support having a foot connectable with the shoe of a photographic apparatus.
Claim 7
Dependent Claim
16 words
A flash unit as defined in claim 1, wherein said flashbulbs are arranged in a row.
References Cited (Backward Citations)
US2290309A
Cited
US2863021A
Cited
US2985748A
Cited
US3026392A
Cited
DE1192047B
Cited
US3473880A
Cited
US3443875A
Cited
US3459487A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |