US3823890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic film feed device
Assignee: Individual
•
Filing: 1971-11-22
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Granted: 1974-07-16
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Expires: 1991-11-22
Abstract
Abstract A plurality of rotatable horizontal turntable disks rotate to feed out or take up motion picture film, as it is transported through a projector. Optional threading arrangements enable any of the turntable disks to function as a supply or take up reel. Moreover, the third turntable effectively provides a spare which gives stand-by reliability. Suitable analog sensors detect film tension or broken film conditions and control the film feed accordingly. The analog sensors eliminate hunting as the mechanical operations proceed.
Inventors
- 👤 E Potts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:45
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/32; G03B35/00; G03B35/18; G03B35/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
229 words
An automatic film feed device comprising a plurality of rotatable turntable disks which rotate to feed out or take up a rool of motion picture film as it is transported through a motion picture projector, means for providing a plurality of optional film threading paths which enable any of the turntable disks to function as either a supply or a take up reel without requiring rewinding, means for causing said film to travel from the feed out roll to the take up roll, at least one analog sensor means individually associated with each of the turntable disks for automatically detecting film tension at the associated turntable disks and for controlling the rate at which the associated turntable disks rotate to feed or take up the film responsive to the path selected when the film is threaded through the projector, means as for sensing film movement through said film feed device, means responsive to said sensor detecting a termination of said film movement for stopping said film travel, said means for sensing film movement comprises means for projecting a light beam through sprokect holes in said film, whereby said film movement chops said light beam, means responsive to said chopped light beam for generating a corresponding train of electrical control pulses, and pulse responsive means for enabling said film feed means as long as said train of control pulses continue.
Claim 2
Dependent Claim
229 words
An automatic film feed device comprising a plurality of rotatable turntable disks which rotate to feed out or take up a rool of motion picture film as it is transported through a motion picture projector, means for providing a plurality of optional film threading paths which enable any of the turntable disks to function as either a supply or a take up reel without requiring rewinding, means for causing said film to travel from the feed out roll to the take up roll, at least one analog sensor means individually associated with each of the turntable disks for automatically detecting film tension at the associated turntable disks and for controlling the rate at which the associated turntable disks rotate to feed or take up the film responsive to the path selected when the film is threaded through the projector, means as for sensing film movement through said film feed device, means responsive to said sensor detecting a termination of said film movement for stopping said film travel, said means for sensing film movement comprises means for projecting a light beam through sprokect holes in said film, whereby said film movement chops said light beam, means responsive to said chopped light beam for generating a corresponding train of electrical control pulses, and pulse responsive means for enabling said film feed means as long as said train of control pulses continue.
Claim 3
Dependent Claim
227 words
An automatic film feed device comprising a plurality of rotatable turntable disks which rotate to feed out or take up a roll of motion picture film as it is transported through a motion picture projector, means for providing a plurality of optional film threading paths which enable any of the turntable disks to function as either a supply or a take up reel without requiring rewinding, means for causing said film to travel from the feed out rool to the take up roll, at least one analog sensor means individually associated with each of the turntable disks for automatically detecting film tension at the associated turntable disks and for controlling the rate at which the associated turntable disk rotates to feed out or take up the film responsive to the path selected when the film is threaded through the projector, each of the turntable disks has an upper side and a lower side, said lower side having a drum-shaped race formed thereon, drive means individually associated with each of said turntable disks, said drive means comprising a motor driven capstan running on sAid race, at least one of said turntable disks having an associated brake means, and means for selectively moving said capstan and said brake against and away from said race for selectively enabling said turntable to be driven, to rotate freely, or to be stopped.
Claim 4
Dependent Claim
227 words
An automatic film feed device comprising a plurality of rotatable turntable disks which rotate to feed out or take up a roll of motion picture film as it is transported through a motion picture projector, means for providing a plurality of optional film threading paths which enable any of the turntable disks to function as either a supply or a take up reel without requiring rewinding, means for causing said film to travel from the feed out rool to the take up roll, at least one analog sensor means individually associated with each of the turntable disks for automatically detecting film tension at the associated turntable disks and for controlling the rate at which the associated turntable disk rotates to feed out or take up the film responsive to the path selected when the film is threaded through the projector, each of the turntable disks has an upper side and a lower side, said lower side having a drum-shaped race formed thereon, drive means individually associated with each of said turntable disks, said drive means comprising a motor driven capstan running on sAid race, at least one of said turntable disks having an associated brake means, and means for selectively moving said capstan and said brake against and away from said race for selectively enabling said turntable to be driven, to rotate freely, or to be stopped.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |