US3748028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film rewind device for compact cinecameras
Assignee: Nikon Corp
•
Filing: 1972-07-20
•
Granted: 1973-07-24
•
Expires: 1992-07-20
Abstract
Abstract A film rewind device for compact cinecameras of the type using a film cartridge having no supply spool shaft operable from the exterior thereof but provided with detent means attached to a take-up core, and in which the length of film to be loosely supplied to the take-up chamber of the cartridge can be varied in proportion to the film roll diameter in the supply chamber of the cartridge by the utmost utilization of the fact that the space in each of the supply and take-up chambers varies in proportion to the length of film photographed, and the length of film to be loosely supplied into the take-up chamber can be selected as desired within a predetermined range and that length of film can be rewound exactly.
Inventors
- 👤 Y Iida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:36
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/32; G03B21/43
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
317 words
In a cinecamera of the type using a film cartridge equipped with anti-reversing means attached to a shaft for taking up the film, and including a driving shaft, shutter means operable by said driving shaft; driving means for normally and reversely rotating the driving shaft; means for transporting the film, associated with said driving shaft; and means for preventing the rotation of the take-up shaft while said film transporting means is operated to loosely feed the film into a take-up chamber in the film cartridge and loosely rewind the loosely fed film into a supply chamber in said cartridge; the improvement comprising means for automatically stopping the normal and the reverse rotation of the driving shaft; means for determining the maximum amount of the film which is loosely fed into the take-up chamber and then rewound into said supply chamber; said determining means being associated with the driving shaft to vary said maximum amount in accordance with the amount of film wound on the take-up shaft; first means for operating the automatic stopping means to stop the normal rotation of the driving shaft when the film is loosely fed by the maximum amount into the take-up chamber; and second means for operating said automatic stopping means to stop the reverse rotation of the driving shaft when the film is loosely rewound into the supply chamber by the same length as that of the film loosely fed into the take-up chamber; said automatic stopping means including a disc securely mounted on said driving shaft, a stop member engageable with said disc and mounted for movement between a first position in which said disc is disengaged therefrom to permit the rotation of the driving shaft and a second position in which said disc is engaged therewith to stop the normal and reverse rotation of said driving shaft, and means for biasing said stop member into said first position thereof.
Claim 2
Dependent Claim
317 words
In a cinecamera of the type using a film cartridge equipped with anti-reversing means attached to a shaft for taking up the film, and including a driving shaft, shutter means operable by said driving shaft; driving means for normally and reversely rotating the driving shaft; means for transporting the film, associated with said driving shaft; and means for preventing the rotation of the take-up shaft while said film transporting means is operated to loosely feed the film into a take-up chamber in the film cartridge and loosely rewind the loosely fed film into a supply chamber in said cartridge; the improvement comprising means for automatically stopping the normal and the reverse rotation of the driving shaft; means for determining the maximum amount of the film which is loosely fed into the take-up chamber and then rewound into said supply chamber; said determining means being associated with the driving shaft to vary said maximum amount in accordance with the amount of film wound on the take-up shaft; first means for operating the automatic stopping means to stop the normal rotation of the driving shaft when the film is loosely fed by the maximum amount into the take-up chamber; and second means for operating said automatic stopping means to stop the reverse rotation of the driving shaft when the film is loosely rewound into the supply chamber by the same length as that of the film loosely fed into the take-up chamber; said automatic stopping means including a disc securely mounted on said driving shaft, a stop member engageable with said disc and mounted for movement between a first position in which said disc is disengaged therefrom to permit the rotation of the driving shaft and a second position in which said disc is engaged therewith to stop the normal and reverse rotation of said driving shaft, and means for biasing said stop member into said first position thereof.
Claim 3
Dependent Claim
319 words
A cinecamera as defined in claim 1, wherein said determining means comprises a cam member movable in association with the driving shaft, and a cam follower biased into contact with the cam member and movable between a first position and a second position, wherein said cam member is mounted for displacing the cam follower from its said first position to its said second position thereof while the film is wound on the take-up shaft from the first extremity to the middle thereof and from its said second position to its said first position while the film is wound from the middle to the last extremity thereof; and wherein said first operating means comprises an electrical magnet mounted to move said stop member; an electrical circuit for energizing said magnet to displace the stop member from its said first position to its said second position and for deenergizing said magnet to displace the stop member from its said second position to its said first position; a first switch connected in the circuit and fixedly secured on said cam follower, said first switch being closed when the driving shaft is normally rotated, and said magnet being energized when the first switch is closed and deenergized when the first switch is opened; a first counter member coupled with the driving shaft when said transporting means is operated to loosely feed the film into the take-up chamber and loosely rewind the loosely fed film into the supply chamber; and a pin provided on the first counter member, said first counter member being positioned for the pin thereon to close the first switch when the cam follower is in its said first position, and to open the first switch which is in the displaced position together with the cam follower to thereby stop the normal rotation of said driving shaft when said maximum amount of the film is loosely fed into the take-up chamber.
Claim 4
Dependent Claim
127 words
A cinecamera as defined in claim 2, wherein said second operAting means comprises said first counter member, said pin provided on the first counter member, and a second switch connected in parallel with the first switch and fixedly mounted on the body of the cinecamera for engagement by said pin when both said first switch and cam follower are in their respective first positions, said second switch being closed when the driving shaft is reversely rotated and opened during the engagement of the pin therewith, whereby the pin opens the second switch to thereby stop the reverse rotation of said driving shaft when the film is loosely rewound into the supply chamber by the same amount as that of the film loosely fed into the take-up chamber.
References Cited (Backward Citations)
US3692395A
Cited
US3689137A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |