US3598480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
An electromagnetic release device for a motion-picture camera
Assignee: Minolta Co Ltd
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Filing: 1969-09-16
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Granted: 1971-08-10
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Expires: 1989-09-16
Abstract
Abstract A battery-energized electromagnetic release for selecting continuous or single frame advancement of the film comprises two electromagnetic coils and a charged condenser for actuating and holding an armature switch to release a rotary stop mechanism and activate the film drive motor. The condenser is switched from a connection with the battery to discharge through one coil and actuate the armature. An exposure changeover switch connects the two coils to the battery to retain the armature and continuously activate the motor.
Inventors
- 👤 Isamu Kubota
- 👤 Yoshihisa Hayahi
- 👤 Takeshi Ataka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:05
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
160 words
A battery-operated electromagnetic release device for selecting continuous or single frame film exposure, comprising; a motor for driving the film, a switch for activating said motor, first and second electromagnetic coils serially interconnected with one another for holding said switch in a closed position, a condenser electrically connected to one end of said first coil, a two-position switch for connecting said condenser to said battery in one position and for connecting said condenser across said first cOil in a second position, a selector switch interlocked with said two-position switch for selecting either continuous or single frame film exposure and connected to said battery, a release switch serially connecting one end of said second coil with said selector switch, whereby the positioning of said two-position switch in said second position closes said motor switch and said motor switch is retained closed only when said release switch is in its closed position and said selector switch is set for continuous film exposure.
Claim 2
Dependent Claim
160 words
A battery-operated electromagnetic release device for selecting continuous or single frame film exposure, comprising; a motor for driving the film, a switch for activating said motor, first and second electromagnetic coils serially interconnected with one another for holding said switch in a closed position, a condenser electrically connected to one end of said first coil, a two-position switch for connecting said condenser to said battery in one position and for connecting said condenser across said first cOil in a second position, a selector switch interlocked with said two-position switch for selecting either continuous or single frame film exposure and connected to said battery, a release switch serially connecting one end of said second coil with said selector switch, whereby the positioning of said two-position switch in said second position closes said motor switch and said motor switch is retained closed only when said release switch is in its closed position and said selector switch is set for continuous film exposure.
Claim 3
Dependent Claim
50 words
A battery-operated electromagnetic release device as in claim 1, wherein said first and second coils have the same polarity to generate a magnetic force sufficient to retain said motor switch in a closed position when said release switch is closed and said selector switch is set for continuous film exposure.
Claim 4
Dependent Claim
91 words
A battery-operated electromagnetic release device as in claim 1 wherein said motor switch includes a rotatable armature operatively associated with said first and second coils and further comprising a rotary cam driven by said motor, said cam having a notch for engagement with one end of said armature, said armature is normally biased to engage said notch, whereby said armature is withdrawn from engagement with said notch by positioning said two-position switch in said second position, and said motor switch is opened by engagement of said armature end with said notch.
Claim 5
Dependent Claim
75 words
A battery-operated electromagnetic release device as in claim 3 wherein said armature end is retained in a nonengaging position with said notch by the magnetic force generated by said first and second coils connected to said battery by closure of said release switch and said selector switch is set for continuous film exposure, said armature end is positioned to ride on the surface of said cam to retain said motor switch in a closed position.
Claim 6
Dependent Claim
46 words
A battery-operated electromagnetic release device as in claim 3 wherein said motor switch is opened by reengagement of said armature end with said notch upon rotation of said cam when said release switch is open and said selector switch is set for single frame film exposure.
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) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |