US3737086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film retention means for film cartridges
Assignee: Bell and Howell Co
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Filing: 1971-09-23
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Granted: 1973-06-05
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Expires: 1991-09-23
Abstract
Abstract A film cartridge for a projector having an end of film sensing means for blocking the film driving means from feeding film into the cartridge while maintaining engagement of the film end with the driving means whereby the driving means can conveniently feed the film out of the cartridge.
Inventors
- 👤 J Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:36
CPC Classifications
G; G03; G03B; G03B23/00; G03B23/08; G03B23/12; G03B21/00; G03B21/14; G03B21/32; G03B21/321; G03B21/323; G03B21/43
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
214 words
An apparatus for retaining the free end of a film in a cartridge driven by a motor within a projector comprising: storage means for the film; means coupled to the projector motor for driving the film to and from said storage means; and means sensing the end of the film for blocking said driving means to maintain engagement of the film with said driving means; said sensing means having a first position determined by the presence of film permitting film movement by said driving means and having a second position determined by the absence of film for stopping film movement by blocking said driving means, said sensing means being normally urged toward said second position; said sensing means including a plate having a first position determined by the presence of film for permitting film movement by said driving means and a second position determined by the absence of film for stopping film movement by blocking said driving means; and supporting means including a pivot means for supporting said plate for movement between said first and second positions and means for biasing said plate toward said second position about said pivot means; said driving means including a tooth member and said plate including a pawl for engaging said tooth member for blocking said driving means.
Claim 2
Independent Claim
214 words
An apparatus for retaining the free end of a film in a cartridge driven by a motor within a projector comprising: storage means for the film; means coupled to the projector motor for driving the film to and from said storage means; and means sensing the end of the film for blocking said driving means to maintain engagement of the film with said driving means; said sensing means having a first position determined by the presence of film permitting film movement by said driving means and having a second position determined by the absence of film for stopping film movement by blocking said driving means, said sensing means being normally urged toward said second position; said sensing means including a plate having a first position determined by the presence of film for permitting film movement by said driving means and a second position determined by the absence of film for stopping film movement by blocking said driving means; and supporting means including a pivot means for supporting said plate for movement between said first and second positions and means for biasing said plate toward said second position about said pivot means; said driving means including a tooth member and said plate including a pawl for engaging said tooth member for blocking said driving means.
Claim 3
Dependent Claim
137 words
A film cartridge comprising: a magazine; a sprocket wheel rotatably mounted adjacent said magazine, said sprocket wheel having a plurality of teeth engageable with apertures in a filmstrip; means for rotating said sprocket wheel in opposite directions with said teeth engaging said filmstrip apertures to feed said filmstrip into and out of said magazine; a plate operable to engage said sprocket wheel for preventing rotation of said sprocket wheel in one direction; and a spring biasing said plate against said filmstrip and toward engagement with said sprocket wheel whereby said spring moves said plate into engagement with said sprocket wheel when the trailing end of the film passes said plate and the trailing end of said filmstrip remains in engagement with said sprocket wheel to permit said rotating means to feed said filmstrip out of said magazine.
Claim 4
Dependent Claim
137 words
A film cartridge comprising: a magazine; a sprocket wheel rotatably mounted adjacent said magazine, said sprocket wheel having a plurality of teeth engageable with apertures in a filmstrip; means for rotating said sprocket wheel in opposite directions with said teeth engaging said filmstrip apertures to feed said filmstrip into and out of said magazine; a plate operable to engage said sprocket wheel for preventing rotation of said sprocket wheel in one direction; and a spring biasing said plate against said filmstrip and toward engagement with said sprocket wheel whereby said spring moves said plate into engagement with said sprocket wheel when the trailing end of the film passes said plate and the trailing end of said filmstrip remains in engagement with said sprocket wheel to permit said rotating means to feed said filmstrip out of said magazine.
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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |