Patent US3685423A successfully refreshed from Google Patents.
US3685423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Curtain for camera shutters
Assignee: FRITZ VICTOR HASSELBLAD TECHN
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Filing: 1970-06-08
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Granted: 1972-08-22
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Expires: 1990-06-08
Abstract
Abstract A curtain for camera shutters consisting of a thin plastic foil having arranged on at least one side thereof grooves which extend at right angles to the direction of movement of the curtain so as to provide for a high degree of bending resistance perpendicular to the direction of movement of the curtain and a relatively low bending resistance in the plane of movement thereof.
Inventors
- 👤 Lennart G O Dahlgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:13
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
A curtain for camera shutters arranged to pass in a direction of movement over direction changing rollers, characterized in that said curtain consists of a strip of light-proof plastic foil, said plastic foil is provided on at least one side thereof with spaced parallel grooves extending substantially perpendicularly to the direction of movement of said curtain so that each of said grooves affords locations of reduced material thickness whereby said curtain has a high degree of bending resistance at right angles to the direction of movement of the curtain and a small degree of bending resistance in the direction of movement of said curtain.
Claim 2
Dependent Claim
104 words
A curtain for camera shutters arranged to pass in a direction of movement over direction changing rollers, characterized in that said curtain consists of a strip of light-proof plastic foil, said plastic foil is provided on at least one side thereof with spaced parallel grooves extending substantially perpendicularly to the direction of movement of said curtain so that each of said grooves affords locations of reduced material thickness whereby said curtain has a high degree of bending resistance at right angles to the direction of movement of the curtain and a small degree of bending resistance in the direction of movement of said curtain.
Claim 3
Dependent Claim
34 words
A curtain according to claim 1 having grooves arranged on both sides thereof, characterized in that each groove on one side of the curtain is positioned opposite a groove on the other side thereof.
Claim 4
Dependent Claim
50 words
A curtain according to claim 1, characterized in that the grooves are arranged on both sides of said curtain and the grooves on one side of said curtain are offset in the direction of movement of said curtain in relation to the grooves on the other side of said curtain.
Claim 5
Dependent Claim
14 words
A curtain according to claim 1, characterized in that the grooves are unevenly spaced.
Claim 6
Dependent Claim
60 words
A curtain according to claim 1, characterized in that the bases of said grooves are of uniform thickness with the unreduced defining surfaces of said curtain extending parallel to the bottom plane defining the base of said grooves, and the base of said grooves is connected to adjacent unreduced portions by a chamfer for preventing stress concentration at the discontinuities.
Claim 7
Dependent Claim
34 words
A curtain according to claim 1, characterized in that the grooves have a symmetrical curvilinear profile which provides for varying thickness of the reduced portion of the curtain in the direction of movement thereof.
Claim 8
Dependent Claim
37 words
A curtain according to claim 1, characterized in that the plastic material from which the curtain is made is a suitably black, dyed polyester or another polymer or copolymer or other material having substantially equivalent physical properties.
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) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |