US3739704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focal plane shutter control mechanism for a photographic shutter
Assignee: Minolta Co Ltd
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Filing: 1971-11-08
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Granted: 1973-06-19
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Expires: 1991-11-08
Abstract
Abstract A focal plane shutter control mechanism wherein means are provided for equlizing the inertias of the front and rear screens and their associated drive mechanisms so as to eliminate uneven exposures. A transmission means for driving first and second wind-up gears associated respectively with the front and rear screens is disengaged and a cam member is actuated by over-driven bias means to compensate for the overlap of the front and rear screens in their cocked positions.
Inventors
- 👤 K Akiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:32
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/28; G03B9/32; G03B9/34
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
264 words
A focal plane shutter control mechanism for a camera having front and rear screens respectively biased to be driven from cocked positions to rest positions, a first retaining member for retaining said front screen in said cocked position, a second retaining member for retaining said rear screen in said cocked position, a first wind-up shaft for winding said front screen, and a second wind-up shaft for winding said rear screen, comprising: driving means rotatable in response to shutter wind-up operation; first and second wind-up gears; transmission means for driving said first and second wind-up gears in shutter wind-up directions in response to the movement of said driving means; first means for interconnecting said first wind-up shaft with said first wind-up gear when said first wind-up gear is driven in the shutter wind-up direction; second means for interconnecting said second wind-up shaft with said second wind-up gear when said second wind-up gear is driven in the shutter wind-up direction; said driving means including means for disengaging said transmission means therefrom when said front and rear screens are in said cocked positions, and said transmission means being biased to return to a rest position with said wind-up gears when said driving means Disengages said transmission means therefrom; said first means disconnecting said first wind-up gear from said first wind-up shaft when said first wind-up gear is driven in a direction opposite to said shutter wind-up direction; and said second means disconnecting said second wind-up gear from said second wind-up shaft when said second wind-up gear is driven in a direction opposite to said shutter wind-up direction.
Claim 2
Dependent Claim
264 words
A focal plane shutter control mechanism for a camera having front and rear screens respectively biased to be driven from cocked positions to rest positions, a first retaining member for retaining said front screen in said cocked position, a second retaining member for retaining said rear screen in said cocked position, a first wind-up shaft for winding said front screen, and a second wind-up shaft for winding said rear screen, comprising: driving means rotatable in response to shutter wind-up operation; first and second wind-up gears; transmission means for driving said first and second wind-up gears in shutter wind-up directions in response to the movement of said driving means; first means for interconnecting said first wind-up shaft with said first wind-up gear when said first wind-up gear is driven in the shutter wind-up direction; second means for interconnecting said second wind-up shaft with said second wind-up gear when said second wind-up gear is driven in the shutter wind-up direction; said driving means including means for disengaging said transmission means therefrom when said front and rear screens are in said cocked positions, and said transmission means being biased to return to a rest position with said wind-up gears when said driving means Disengages said transmission means therefrom; said first means disconnecting said first wind-up gear from said first wind-up shaft when said first wind-up gear is driven in a direction opposite to said shutter wind-up direction; and said second means disconnecting said second wind-up gear from said second wind-up shaft when said second wind-up gear is driven in a direction opposite to said shutter wind-up direction.
Claim 3
Dependent Claim
26 words
A focal plane shutter control mechanism as claim 1, wherein said driving means is a gear and said means for disengaging is a non-toothed segment thereof.
Claim 4
Dependent Claim
45 words
A focal plane shutter control mechanism as in claim 2, wherein said front and rear screens in said cocked positions partially overlap with each other, and further comprising means for compensating said partial overlap when said first and second screens are released for an exposure.
Claim 5
Dependent Claim
129 words
A focal plane shutter control mechanism as in claim 3, further comprising a first cam member mounted on said first wind-up shaft to rotate therewith and engageable with said first retaining member, and a second cam member mounted on said second wind-up shaft to rotate therewith and engageable with said second retaining member, said first cam member is rotatable beyond the position to be engaged by said first retaining member with said second cam member rotating to the position to be engaged by said second retaining member whereby said first cam member is returned through the bias for the first screen until said first cam member engages with said first retaining member thereby compensating for said overlap when said first wind-up gear is disconnected from said first wind-up shaft.
Claim 6
Dependent Claim
105 words
A focal plane shutter control mechanism as in claim 3, wherein said first and second means each comprises a first pin respectively rotatable with said first and second wind-up gear, a second pin respectively rotatable with said first and second wind-up shaft, and a coil spring energized in the direction opposite to said shutter wind-up direction of said first or second wind-up gears, and said coil spring having an extension for engaging said first and second pins whereby said first pin drives said second pin by means of said coil spring when said first or second wind-up gear is driven in the shutter wind-up direction.
Claim 7
Dependent Claim
72 words
A focal plane shutter control mechanism as in claim 5, wherein the gear ratio of said transmission means and said first wind-up gear and the gear ratio of said transmission means and said second wind-up gear are so selected that both said first and second wind-up gears rotate more than one revolution until said transmission means rotates to said rest position, whereby said coil springs also drive said front and rear screens.
Claim 8
Dependent Claim
123 words
A focal plane shutter control mechanism as in claim 4, wherein each of said first and second means comprises a first pin respectively rotatable with said first and second wind-up gear, a second pin respectively rotatable with said first and second wind-up shaft, an intermediate member having a slot to receive said first pin, and means for moving said intermediate member in accordance with the relative movement of said first or second wind-up shaft and with said first or second wind-up gear whereby said intermediate member is engageable with said second pin with said first or second wind-up gear driven in the shutter wind-up direction and disengaged from said second pin with said first or second wind-up gear driven in the reverse direction.
Claim 9
Dependent Claim
42 words
A focal plane shutter control mechanism as in claim 7, wherein said means for moving comprises a threaded portion formed on said first and second wind-up shafts, and an internally threaded bore formed in said intermediate member and engaging said threaded portion.
Claim 10
Dependent Claim
105 words
A focal plane shutter control mechanism as in claim 1, wherein said first and second means each comprises a first pin respectively rotatable with said first and second wind-up gear, a second pin respectively rotatable with said first and second wind-up shaft, and a coil spring enErgized in the direction opposite to said shutter wind-up direction of said first or second wind-up gears, and said coil spring having an extension for engaging said first and second pins whereby said first pin drives said second pin by means of said coil spring when said first or second wind-up gear is driven in the shutter wind-up direction.
Claim 11
Dependent Claim
72 words
A focal plane shutter control mechanism as in claim 9, wherein the gear ratio of said transmission means and said first wind-up gear and the gear ratio of said transmission means and said second wind-up gear are so selected that both said first and second wind-up gears rotate more than one revolution until said transmission means rotates to said rest position, whereby said coil springs also drive said front and rear screens.
Claim 12
Dependent Claim
123 words
A focal plane shutter control mechanism as in claim 1, wherein each of said first and second means comprises a first pin respectively rotatable with said first and second wind-up gear, a second pin respectively rotatable with said first and second wind-up shaft, an intermediate member having a slot to receive said first pin, and means for moving said intermediate member in accordance with the relative movement of said first or second wind-up shaft and with said first or second wind-up gear whereby said intermediate member is engageable with said second pin with said first or second wind-up gear driven in the shutter wind-up direction and disengaged from said second pin with said first or second wind-up gear driven in the reverse direction.
Claim 13
Dependent Claim
42 words
A focal plane shutter control mechanism as in claim 11, wherein said means for moving comprises a threaded portion formed on said first and second wind-up shafts, and an internally threaded bore formed in said intermediate member and engaging said threaded portion.
Claim 14
Dependent Claim
40 words
A focal plane shutter control mechanism as in claim 1, wherein the inertia of said front screen and members driven with the front screen is approximately equal to that of said rear screen and members driven with said rear screen.
Claim 15
Dependent Claim
134 words
A focal plane shutter control mechanism as in claim 13, further comprising winding members around which a respective one end of said front screen and said rear screen is wound, the other end of said front and rear screen is respectively wound around respective ones of said first and second wind-up shafts and rotatable with respect to each of said first and second wind-up shafts; and rotatable biasing means between said first and second wind-up shafts and said winding members to drive respectively said front and rear screens to said rest positions from said cocked positions relative to said first and second wind-up shafts; and at least one of said first or second wind-up shafts is rotatable and the rotating position thereof is fixed adjustably to said winding member in the rest position thereof.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |