US3922697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm shutter for photographic cameras
Assignee: Rollei Werke Franke und Heidecke GmbH and Co KG
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Filing: 1974-05-03
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Granted: 1975-11-25
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Expires: 1994-05-03
Abstract
Abstract A diaphragm shutter combining the functions of the diaphragm and a shutter. A pair of slides move relative to each other to open the exposure aperture to start the exposure. A pair of pivoted blades then swing relative to each other to close the exposure aperture to terminate the exposure. A rotating cam controls the speed at which the slides move in an opening direction, in such manner that the opening movement starts relatively slowly and then progresses faster. This enables the total exposure time to be somewhat increased for a given exposure value or quantity of light falling on the film, as compared with the shorter total exposure time needed for the same quantity of light on the film, if the opening slides move at a uniformly high speed. The longer exposure time, for a given exposure value, results in more accurate operation of the shutter.
Inventors
- 👤 Heinz Waaske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:08
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/10; G03B9/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
115 words
A shutter for photographic cameras, comprising opening elements movable relative to each other to provide a lightadmitting opening to initiate an exposure, closing elements movable relative to each other to block light to terminate the exposure, and control means for controlling movement of said opening elements at a relatively slow speed at the beginning of an exposure and gradually increasing the speed of opening movement of said opening elements during a subsequent interval of the exposure, said control means comprising an actuating device for directly actuating said opening elements, and a cam for driving said actuating device, said cam having a shape effective to produce said relatively slow speed followed by said gradually increasing speed.
Claim 2
Dependent Claim
115 words
A shutter for photographic cameras, comprising opening elements movable relative to each other to provide a lightadmitting opening to initiate an exposure, closing elements movable relative to each other to block light to terminate the exposure, and control means for controlling movement of said opening elements at a relatively slow speed at the beginning of an exposure and gradually increasing the speed of opening movement of said opening elements during a subsequent interval of the exposure, said control means comprising an actuating device for directly actuating said opening elements, and a cam for driving said actuating device, said cam having a shape effective to produce said relatively slow speed followed by said gradually increasing speed.
Claim 3
Dependent Claim
18 words
The invention defined in claim 1, wherein said actuating device has a substantial mass acting as a flywheel.
Claim 4
Dependent Claim
19 words
The invention defined in claim 1, wherein said cam is coupled to an additional mass acting as a flywheel.
Claim 5
Dependent Claim
33 words
The invention defined in claim 1, wherein said actuating device is rotatable about an axis and has a pin parallel to and offset from said axis, and wherein said cam engages said pin.
Claim 6
Dependent Claim
57 words
The invention defined in claim 1, further comprising a toothed rack movable longitudinally, a spring biasing said rack for movement in one longitudinal direction, a pinion meshing with said rack to be turned by longitudinal movement of the rack, and a coupling between said pinion and said cam to turn the cam upon rotation of the pinion.
Claim 7
Dependent Claim
53 words
The invention defined in claim 1, further comprising additional opening elements (18) spaced from and mOvable simultaneously with said first mentioned opening elements (1), and a photocell (19) placed behind said additional opening elements (18) in position to receive light only when said additional elements provide a passage for light to said photocell.
Claim 8
Dependent Claim
79 words
The invention defined in claim 1, further comprising a lever for operating said closing elements, a spring tending to move said lever to a position closing said closing elements, an electromagnet for holding said lever in a position in which said closing elements are open so long as current is flowing in said electromagnet, and a timing device for stopping flow of current in said electromagnet so that said spring may move said lever to close said closing elements.
Claim 9
Dependent Claim
153 words
A diaphragm shutter for photographic cameras, comprising opening elements movable relative to each other to provide a light-admitting opening to initiate an exposure, closing elements movable relative to each other to block light to terminate the exposure, the extent to which the opening elements open before the closing elements become effective serving to determine the effective aperture at which the exposure is made, an actuating member (9) operatively connected to said opening elements to move them, a driving element (21) for driving said actuating member, and a cam (11) operatively interposed between said driving element and said actuating member to control the rate of movement of said actuating member in response to a given degree of force exerted by said driving element; said cam being shaped to drive said opening elements at different rates of speed during different portions of their opening movements, for a given uniform rate of movement of said cam.
Claim 10
Dependent Claim
153 words
A diaphragm shutter for photographic cameras, comprising opening elements movable relative to each other to provide a light-admitting opening to initiate an exposure, closing elements movable relative to each other to block light to terminate the exposure, the extent to which the opening elements open before the closing elements become effective serving to determine the effective aperture at which the exposure is made, an actuating member (9) operatively connected to said opening elements to move them, a driving element (21) for driving said actuating member, and a cam (11) operatively interposed between said driving element and said actuating member to control the rate of movement of said actuating member in response to a given degree of force exerted by said driving element; said cam being shaped to drive said opening elements at different rates of speed during different portions of their opening movements, for a given uniform rate of movement of said cam.
Claim 11
Dependent Claim
132 words
A photographic shutter comprising a single pair of opening blades movable relative to each other from closed position to open position to initiate an exposure, a single pair of closing blades movable relative to each other from open position to closed position to terminate an exposure, said opening blades being movable through an initial range of movement from a rest position to a position in which they just start to open for passage of light and through a subsequent range of movement during which they open to a progressively increasing extent, and means for moving said opening blades at a relatively fast rate during said initial range, then at a slower rate at the beginning of said subsequent range, and at a gradually increasing rate during a portion of said subsequent range.
Claim 12
Dependent Claim
132 words
A photographic shutter comprising a single pair of opening blades movable relative to each other from closed position to open position to initiate an exposure, a single pair of closing blades movable relative to each other from open position to closed position to terminate an exposure, said opening blades being movable through an initial range of movement from a rest position to a position in which they just start to open for passage of light and through a subsequent range of movement during which they open to a progressively increasing extent, and means for moving said opening blades at a relatively fast rate during said initial range, then at a slower rate at the beginning of said subsequent range, and at a gradually increasing rate during a portion of said subsequent range.
References Cited (Backward Citations)
US3375769A
Cited
US3668988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |