Patent US3763757A successfully refreshed from Google Patents.
US3763757A
Expired / Lapsed
US
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Electrically controlled shutter for photographic cameras
Assignee: Nidec Precision Corp
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Filing: 1972-01-25
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Granted: 1973-10-09
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Expires: 1992-01-25
Abstract
Abstract An electrically controlled shutter for photographic cameras comprising a magnet lever for operating a closing blade locking lever, a sectoral lever for delaying the rotary movement of said magnet lever, a bulb exposure lever engageable with said sectoral lever, and a changeover cam for switching the operative positions of said sectoral lever within the latter''s scope of movement; and being operative so that, when the power source battery has become consumed and no longer usable or when a bulb exposure performance is required, the shutter function can then be controlled mechanically to obtain a proper exposure time.
Inventors
- 👤 T Hayami
- 👤 A Nakatani
- 👤 M Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:25
CPC Classifications
G; G03; G03B; G03B15/00; G03B15/02; G03B15/03; G03B15/04; G03B15/0452; G03B9/00; G03B9/58
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
122 words
An electric shutter for photographic camera comprising: an electromagnet controlled of its energization time, a magnet lever positioned adjacent to said electromagnet and adapted to be attracted to said electromagnet and held thereto continuously so long as said electromagnet is being energized, a holding lever positioned to be engageable with said magnet lever and adapted to be rotated by said magnet lever upon deenergization of said electromagnet to start shutter closing movement, a sectoral lever positioned to be engageable with said magnet lever and capable of delaying the rotary movement of said magnet lever, and a changeover cam positioned to be engageable with said sectoral lever and capable of moving said sectoral lever into and out of engagement with said magnet lever.
Claim 2
Dependent Claim
122 words
An electric shutter for photographic camera comprising: an electromagnet controlled of its energization time, a magnet lever positioned adjacent to said electromagnet and adapted to be attracted to said electromagnet and held thereto continuously so long as said electromagnet is being energized, a holding lever positioned to be engageable with said magnet lever and adapted to be rotated by said magnet lever upon deenergization of said electromagnet to start shutter closing movement, a sectoral lever positioned to be engageable with said magnet lever and capable of delaying the rotary movement of said magnet lever, and a changeover cam positioned to be engageable with said sectoral lever and capable of moving said sectoral lever into and out of engagement with said magnet lever.
Claim 3
Dependent Claim
43 words
An electric shutter according to claim 1, in which said changeover cam has a cam face for altering interlockingly the position of engagement of said magnet lever with said sectoral lever as said sectoral lever is moved into engagement with said magnet lever.
Claim 4
Dependent Claim
66 words
An electric shutter according to claim 1, in which said electric shutter further comprises a bulb exposure lever positioned to be engageable with said changeover cam for moving said sectoral lever into engagement with said magnet lever when said changeover cam has been set to the bulb exposure position and for enabling said bulb exposure lever to lock said sectoral lever during the shutter release operation.
References Cited (Backward Citations)
US3638544A
Cited
US3650193A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |