US3754460A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for operating film pressure plate in photographic camera
Assignee: Minolta Co Ltd
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Filing: 1972-02-10
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Granted: 1973-08-28
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Expires: 1992-02-10
Abstract
Abstract A device includes winding means and counter driving means. The winding means has a drive cam rotatable in one direction in operative relation to a film winding operation and to be stopped after completing a definite angle of rotation when the film has been transported by one frame. Under the control of the winding means, the counter driving means is rapidly moved in a first direction upon initiation of the winding operation and returned in a second direction opposite to the first direction upon completion of the winding operation. A film pressure plate is associated with the counter driving means to free the film from pressure simultaneously with the initiation of the film winding operation and press the film upon completion of the winding operation.
Inventors
- 👤 H Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:38
CPC Classifications
G; G03; G03B; G03B29/00; G03B1/00; G03B1/60; G03B1/66; G03B17/00; G03B17/42
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
164 words
A device for operating a film pressure plate in a photographic camera comprising: winding means having a drive cam rotatable in one direction in operative relation to a film winding operation and to be stopped upon completion of one frame of film transport, counter driving means for driving a film counter by one division at a time, said driving means being initiated by said drive cam into a quick movement in a first direction upon initiation of the film winding operation and movable backward in a second direction opposite to the first direction upon completion of the winding operation, and means for coupling said counter driving means with a film pressure plate so as to move said film pressure plate in a direction to free the film from the pressure by the movement of said counter driving means in the first direction and to cause said film pressure plate to press the film by the return of said driving means in the second direction.
Claim 2
Independent Claim
164 words
A device for operating a film pressure plate in a photographic camera comprising: winding means having a drive cam rotatable in one direction in operative relation to a film winding operation and to be stopped upon completion of one frame of film transport, counter driving means for driving a film counter by one division at a time, said driving means being initiated by said drive cam into a quick movement in a first direction upon initiation of the film winding operation and movable backward in a second direction opposite to the first direction upon completion of the winding operation, and means for coupling said counter driving means with a film pressure plate so as to move said film pressure plate in a direction to free the film from the pressure by the movement of said counter driving means in the first direction and to cause said film pressure plate to press the film by the return of said driving means in the second direction.
Claim 3
Dependent Claim
44 words
The device as set forth in claim 1 which includes a shutter cocking member operable in operative relation to said winding means, said shutter cocking member preventing said counter driving means from returning in the second direction until the film winding operation is completed.
Claim 4
Dependent Claim
34 words
The device of claim 1 including control means responsive to the opening and closing of the camera back for respectively effecting the operational disengagement and engagement between said film counter and said driving means.
Claim 5
Dependent Claim
99 words
The device as set forth in claim 3 wherein said counter driving means includes a counter forwarding member for moving a counter plate by one division by the movement of said driving means in the first direction and a lever for preventing reverse rotation of the counter for impeding return of the counter to zero position, and said control means is in operative relation to said counter forwarding member and said reverse rotation preventing lever so as to cause the pressure plate to release the film and initiate zero-returning action of the counter upon opening of the camera back.
Claim 6
Dependent Claim
36 words
The device as set forth in claim 1 wherein said Coupling means comprises a support plate for supporting said film pressure plate and a pin for operatively associating said support plate with said counter driving means.
Claim 7
Dependent Claim
79 words
The device as set forth in claim 5 wherein means for supporting said film pressure plate is provided with a washerlike intermediate member disposed between said pressure plate and said support plate, and said intermediate member is bent along its diametrical line with its bent top portion in contact with one of said pressure plate and said support plate, said intermediate member being in contact with the other plate at two points above and below the bent top portion.
Claim 8
Dependent Claim
88 words
The device of claim 1 wherein said winding means comprises a take-up shaft rotatable a predetermined first angle with the advance of a unit film frame and said drive cam includes a plurality of peripherally equally spaced cam projections, successive cam projections being spaced a predetermined second angle, the quotient of 360* divided by the value of said first angle not being an integer, and the value of said second angle being equal to the greatest common divisor of 360* and of the value of said first angle.
Claim 9
Dependent Claim
19 words
The device as set forth in claim 1 wherein said drive cam serves also as a transport lock cam.
Claim 10
Independent Claim
158 words
A device for operating a film pressure plate in a photographic camera comprising: winding means having a transport lock cam rotatable in one direction in operative relation to a film winding operation and to be stopped upon completion of one frame of film transport, a shutter cocking member operable in operative relation to said winding means, a driving member in contact with said transport lock cam and quickly movable in a first direction under the action of said transport lock cam upon initiation of the film winding operation to be retained by said shutter cocking member in engagement therewith, said driving member being returnable in a second direction opposite to the first direction when freed from the retention upon completion of the winding operation, and coupling means for releasing said film pressure plate from the film and causing the same to press the film by the movements of said driving member in the first and second directions respectively.
Claim 11
Independent Claim
158 words
A device for operating a film pressure plate in a photographic camera comprising: winding means having a transport lock cam rotatable in one direction in operative relation to a film winding operation and to be stopped upon completion of one frame of film transport, a shutter cocking member operable in operative relation to said winding means, a driving member in contact with said transport lock cam and quickly movable in a first direction under the action of said transport lock cam upon initiation of the film winding operation to be retained by said shutter cocking member in engagement therewith, said driving member being returnable in a second direction opposite to the first direction when freed from the retention upon completion of the winding operation, and coupling means for releasing said film pressure plate from the film and causing the same to press the film by the movements of said driving member in the first and second directions respectively.
Claim 12
Dependent Claim
137 words
The device as set forth in claim 9 wherein said winding means further includes a winding gear rotatable in one direction and a shutter cocking cam to be driven one turn by one frame of film transport in operative relation to said gear, and said shutter cocking member is a cocking lever to be reciprocally movable by one turn of rotation of said cocking cam, said cocking lever being movable in a forward direction to retain said driving member and thereby prevent the same from returning in the second direction when said transport lock cam moves said driving member in the first direction upon initiation of the winding operation, said cocking lever being movable in a backward direction to free said driving member from retention and permit the same to be urged backward in the second direction.
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |