Patent US3687044A successfully refreshed from Google Patents.
US3687044A
Expired / Lapsed
US
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Focal plane shutter device
Assignee: Pentax Corp
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Filing: 1971-01-20
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Granted: 1972-08-29
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Expires: 1991-01-20
Abstract
Abstract A focal plane shutter drive for simultaneously cocking and sequentially releasing the leading and trailing curtains of a focal plane shutter. One of a pair of coaxial curtain gears is formed with an arcuate slot while the other carries a pin received in this slot for engaging an end thereof to provide for simultaneous turning of both gears during cocking of the shutter. A cocking gear is coaxial with the curtain gears and all of the gears are supported for free rotation independently of each other about their common axis. A releasable motion transmission extends between the cocking gear and one of the curtain gears for transmitting motion therebetween during cocking of the shutter, this transmission being interrupted preparatory to sequential release of the curtain gears. This motion transmission is situated in its entirety between the common axis of the gears on the peripheries thereof so that an exceedingly compact, lightweight assembly is provided.
Inventors
- 👤 Koichiro Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:48
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/58; G03B17/00; G03B17/42; G03B9/08; G03B9/28; G03B9/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
183 words
In a focal plane shutter drive, a pair of coaxial curtain gears for simultaneously cocking and separately releasing leading and trailing shutter curtains, one of said gears being formed with an arcuate slot extending along a circle whose center is in the common axis of said gears and the other of said gears fixedly carrying a drive pin extending into said slot for engaging an end thereof to provide for simultaneous rotation of both gears during cocking of the shutter while said pin and slot enable said gears to rotate sequentially upon release of the shutter, a cocking gear coaxial with said curtain gears, support means supporting all of said gears for rotation independently of each other about their common axis, and releasable motion-transmitting means extending between said cocking gear and one of said curtain gears for transmitting motion therebetween during cocking of the shutter and for releasing said cocking gear from the latter curtain gear in preparation for releasing the shutter, said motion-transmitting means being situated in its entirety between the common axis of said gears and the peripheries of said gears.
Claim 2
Dependent Claim
183 words
In a focal plane shutter drive, a pair of coaxial curtain gears for simultaneously cocking and separately releasing leading and trailing shutter curtains, one of said gears being formed with an arcuate slot extending along a circle whose center is in the common axis of said gears and the other of said gears fixedly carrying a drive pin extending into said slot for engaging an end thereof to provide for simultaneous rotation of both gears during cocking of the shutter while said pin and slot enable said gears to rotate sequentially upon release of the shutter, a cocking gear coaxial with said curtain gears, support means supporting all of said gears for rotation independently of each other about their common axis, and releasable motion-transmitting means extending between said cocking gear and one of said curtain gears for transmitting motion therebetween during cocking of the shutter and for releasing said cocking gear from the latter curtain gear in preparation for releasing the shutter, said motion-transmitting means being situated in its entirety between the common axis of said gears and the peripheries of said gears.
Claim 3
Dependent Claim
100 words
The combination of claim 1 and wherein said releasable motion-transmitting means includes a pair of projecting portions respectively carried by said cocking gear and that one of said curtain gears to which motion is transmitted by said motion-transmitting means, said projecting portions being situated at the same radial distance from said common axis during transmission of motion by said motion-transmitting means, and means connected with one of said projecting portions for displacing the latter to a location at a different radial distance from said common axis than the other projecting portion for preventing transmission of motion by said motion-transmitting means.
Claim 4
Dependent Claim
46 words
The combination of claim 2 and wherein said one projecting portion is carried by said cocking gear and said means for displacing said one projecting portion with respect to said common axis including a lever turnable on said cocking gear and carrying said one projecting portion.
Claim 5
Dependent Claim
22 words
The combination of claim 3 and wherein said other projecting portion is formed by a free end portion of said drive pin.
Claim 6
Dependent Claim
83 words
The combination of claim 4 and wherein said curtain gear which is formed with said slot is situated between said curtain gear which carries said drive pin and said cocking gear, said drive pin extending through and beyond said slot and having its free end portion situated in overlapping relationship with respect to said projecting portion carried by said lever with both of said projecting portions situated at the same radial distance from said axis when motion is transmitted by said motion-transmitting means.
Claim 7
Dependent Claim
119 words
The combination of claim 5 and wherein said curtain gear which carries said drive pin is a leading curtain gear and is adapted to be connected with the leading curtain of the shutter for cocking said leading curtain and releasing the latter in advance of the trailing curtain while the other curtain gear is adapted to be connected with the trailing curtain of the shutter for cocking the trailing curtain simultaneously with the cocking of the leading curtain and for releasing the trailing curtain subsequent to the release of the leading curtain, so that said pin moves along said slot when the leading curtain is released while said slot moves around said pin when the trailing curtain is released.
Claim 8
Dependent Claim
44 words
The combination of claim 6 and wherein a pair of releasable holding means are respectively connected operatively with said curtain gears for releasably holding them in their cocked positions and for sequentially releasing first said leading curtain gear and then said trailing curtain gear.
Claim 9
Dependent Claim
33 words
The combination of claim 7 and wherein a pair of rotary pinions respectively mesh with said leading and trailing curtain gears, and a pair of curtain winding shafts respectively fixed to said pinions.
Claim 10
Dependent Claim
40 words
The combination of claim 6 and wherein said curtain gears are turnable one with respect to the other through an angular range within the angular length of said slot while said cocking gear is turnable through a greater angular range.
Claim 11
Dependent Claim
16 words
The combination of claim 9 and wherein said cocking gear is turnable through a full revolution.
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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |