US3922699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm mechanism for single lens reflex camera adapted to facilitate substitution of interchangeable lenses
Assignee: Individual
•
Filing: 1974-05-03
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Granted: 1975-11-25
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Expires: 1994-05-03
Abstract
Abstract A cam equipped with a plurality of cam surfaces for controlling the aperture setting of a camera is rotatably mounted in a camera. A diaphragm ring is coupled to said cam and provided with matching aperture value graduation scales and a plurality of different mounting members equipped with means for controlling the angle of rotation are provided to adapt the camera to accept interchangeable lenses of different makes.
Inventors
- 👤 Michihiro Yamaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:26
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/20; G03B9/00; G03B9/02; G03B9/07
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
169 words
In a lens attachment for a camera comprising an adjustable aperture-defining diaphragm and a rotatable actuating plate connected to actuate said diaphragm when rotated, said diaphragm and plate being mounted on a common axis, the improvement which comprises: a cam plate rotatably mounted on said common axis and having a plurality of distinct peripheral cam surfaces having different contours, mounting means for connecting said attachment to a camera, diaphragm control means mounted to engage a peripheral cam surface and connected to limit the rotation of said actuating plate in dependence on the point at which said diaphragm control means engages said cam surface, interengaging means carried by said cam plate and said mounting means respectively for rotating said cam plate, and limit means on said mounting means for restricting the movement of said interengaging means and consequently of said cam plate to a selected one of a plurality of predetermined ranges, in each of which said diaphragm control means engages only a selected one of said peripheral cam surfaces.
Claim 2
Dependent Claim
169 words
In a lens attachment for a camera comprising an adjustable aperture-defining diaphragm and a rotatable actuating plate connected to actuate said diaphragm when rotated, said diaphragm and plate being mounted on a common axis, the improvement which comprises: a cam plate rotatably mounted on said common axis and having a plurality of distinct peripheral cam surfaces having different contours, mounting means for connecting said attachment to a camera, diaphragm control means mounted to engage a peripheral cam surface and connected to limit the rotation of said actuating plate in dependence on the point at which said diaphragm control means engages said cam surface, interengaging means carried by said cam plate and said mounting means respectively for rotating said cam plate, and limit means on said mounting means for restricting the movement of said interengaging means and consequently of said cam plate to a selected one of a plurality of predetermined ranges, in each of which said diaphragm control means engages only a selected one of said peripheral cam surfaces.
Claim 3
Dependent Claim
23 words
An attachment as claimed in claim 1 comprising spring-biassed means for rotating said actuating plate to alter the aperture defined by said diaphragm.
Claim 4
Dependent Claim
81 words
An attachment as claimed in claim 1 in which said means for rotating said cam plate also comprises an adjusting ring encircling said common axis and carrying on its periphery indicia indicative of the aperture opening, and said attachment comprises also a window ring encircling the indicia bearing periphery of said adjusting ring and adjustably attached to said attachment so that only a selected portion of said indicia are visible through said window in any one position of said window ring.
Claim 5
Dependent Claim
50 words
An attachment as claimed in claim 1 in which said cam surface engaging means comprises a cranked lever mounted to rotate about fixed point on said attachment, said lever having a first arm pivotally connected to said actuating plate and a second arm carrying a pin which engages said cam.
Claim 6
Dependent Claim
38 words
An attachment as claimed in claim 1 comprising a plurality of interchangeable mounting means each adapted to limit the rotation of said cam plate in dependence on the aperture value graduation scale of a different make of camera.
Claim 7
Dependent Claim
33 words
An attachment as claimed in claim 5 in which the contour of each cam surface is adapted to reflect the aperture value graduation scale of a different one of said makes of cameras.
Claim 8
Dependent Claim
39 words
An attachment as claimed in claim 1 in which said interengaging means comprise an arm attached to said cam plate anD parallel to said axis, and a fork member fixed to an adjusting ring carried by said mounting means.
Claim 9
Dependent Claim
34 words
An attachment as claimed in claim 7 in which said interengaging means comprise a click-stop surface on a stationary portion of said mounting means which engages a ball resiliently supported by said fork member.
References Cited (Backward Citations)
US2929308A
Cited
US3657988A
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 |