US3756534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film cartridge
Assignee: Ernst Leitz Wetzlar GmbH
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Filing: 1970-08-31
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Granted: 1973-09-04
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Expires: 1990-08-31
Abstract
Abstract The take-up spindle of a super-8 format film cartridge is maintained in position by friction means. Rewinding of the spindle is accomplished by overcoming the resistance of the friction means. The take-up spindle has cams on its surface and the friction means includes a friction ring mounted in the cartridge and surrounding the take-up spindle having two resilient tongues.
Inventors
- 👤 H Keiner
- 👤 H Richter
- 👤 W Schafer
- 👤 W Goldberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:12
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/26; G03B17/265
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
185 words
A film cartridge for super-8 format film including a take-up spindle mounted for forward and reverse rotation rotatably mounted in said cartridge and friction means operative on said spindle to resist but not block reverse rotation thereof, wherein the take-up spindle has a plurality of cams on the surface thereof and wherein said friction means includes a friction ring mounted in said cartridge and surrounding the take-up spindle, said ring having a bore defined by two substantially semicircular arcs, the centers of said arcs being displaced with respect to each other in the direction toward the ends of the semicircles, the two arcs having branches which are clear cut and undercut and which form two resilient tongues, the end of each tongue being beveled at an angle of about 45* whereby the curved path facing the cams on said spindle during forward rotation of said spindle forms an obtuse angle with the rotational path of the cams and whereby the curved path facing the cams on said spindle during reverse rotation of said spindle forms an acute angle with the rotational path of the cams.
Claim 2
Dependent Claim
185 words
A film cartridge for super-8 format film including a take-up spindle mounted for forward and reverse rotation rotatably mounted in said cartridge and friction means operative on said spindle to resist but not block reverse rotation thereof, wherein the take-up spindle has a plurality of cams on the surface thereof and wherein said friction means includes a friction ring mounted in said cartridge and surrounding the take-up spindle, said ring having a bore defined by two substantially semicircular arcs, the centers of said arcs being displaced with respect to each other in the direction toward the ends of the semicircles, the two arcs having branches which are clear cut and undercut and which form two resilient tongues, the end of each tongue being beveled at an angle of about 45* whereby the curved path facing the cams on said spindle during forward rotation of said spindle forms an obtuse angle with the rotational path of the cams and whereby the curved path facing the cams on said spindle during reverse rotation of said spindle forms an acute angle with the rotational path of the cams.
Claim 3
Dependent Claim
21 words
A film cartridge according to claim 1, wherein said friction ring is positioned for lateral reciprocation with respect to said spindle.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |