Patent US3677628A successfully refreshed from Google Patents.
US3677628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reversible endless loop cartridge projector for teaching machines
Assignee: PALISADES EDUCATIONAL FOUNDATION Inc
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Filing: 1970-11-02
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Granted: 1972-07-18
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Expires: 1990-11-02
Abstract
Abstract A motion picture projector for educational purposes is provided using an endless loop cartridge. The projector has a step advance for projecting single frames or motion pictures and has also a continuous drive operable alternatively to scan the film forwardly or rewind the film at high speed and to stop in either direction at any selected frame. The endless loop cartridge has special means to keep the film roll in a loose condition to permit continuous drive of the film in either direction without jamming.
Inventors
- 👤 Richard K Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:51
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/32; G03B21/321; G03B21/323; G03B21/325; G03B19/00; G03B19/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
152 words
A cartridge for an endless film comprising a case, a reel and an endless supply roll of film on said reel having a loop between the inner and outer convolutions of the reel, said case having an opening exposing a portion of said loop to permit engagement of a drive means with said loop to drive the film in either direction, and means frictionally engaging the film where the loop leads tangentially from said outer convolution for vibrating the supply roll to keep the convolutions thereof in a loose condition as the film is propelled by said drive means wherein said vibrating means comprises a rocker pivoted at the center thereof to said case, a pair of non-circular friction rollers with peripheral flats journaled to the ends of said rocker, and means mounting said case in an upright position with said supply roll supported partially in cradle fashion by said non-circular rollers.
Claim 2
Dependent Claim
152 words
A cartridge for an endless film comprising a case, a reel and an endless supply roll of film on said reel having a loop between the inner and outer convolutions of the reel, said case having an opening exposing a portion of said loop to permit engagement of a drive means with said loop to drive the film in either direction, and means frictionally engaging the film where the loop leads tangentially from said outer convolution for vibrating the supply roll to keep the convolutions thereof in a loose condition as the film is propelled by said drive means wherein said vibrating means comprises a rocker pivoted at the center thereof to said case, a pair of non-circular friction rollers with peripheral flats journaled to the ends of said rocker, and means mounting said case in an upright position with said supply roll supported partially in cradle fashion by said non-circular rollers.
Claim 3
Dependent Claim
27 words
The film cartridge set forth in claim 1 including means engaging said roll approximately diametrically opposite to said rocker for biasing the roll against said non-circular rollers.
Claim 4
Dependent Claim
38 words
The film cartridge set forth in claim 1 wherein said reel has a flange at one side and said reel has a peripheral edge of reducing diameter proceeding from said flange to the other side of the reel.
Claim 5
Dependent Claim
41 words
The film cartridge set forth in claim 1 wherein said rocker is made of a spring material responsive to the impact of said non-circular rollers against the supply roll to accentuate the vibrating effect of said rollers on the supply roll.
Claim 6
Dependent Claim
116 words
A film projector having an endless loop cartridge including a supply roll of film having a loop between the inner and outer convolutions thereof, an intermittent drive mechanism for advancing said loop of the film one frame at a time, a scan and rewind drive mechanism for continuously driving said loop of the film in either direction, means in said cartridge for keeping said convolutions in an open condition during the continuous driving of the film, means for biasing each of said drive mechanisms out of engagement with the film when the drive mechanism is in a stopped condition, and means selectively operable to engage one or the other of said drive mechanisms with the film.
Claim 7
Dependent Claim
116 words
A film projector having an endless loop cartridge including a supply roll of film having a loop between the inner and outer convolutions thereof, an intermittent drive mechanism for advancing said loop of the film one frame at a time, a scan and rewind drive mechanism for continuously driving said loop of the film in either direction, means in said cartridge for keeping said convolutions in an open condition during the continuous driving of the film, means for biasing each of said drive mechanisms out of engagement with the film when the drive mechanism is in a stopped condition, and means selectively operable to engage one or the other of said drive mechanisms with the film.
Claim 8
Dependent Claim
29 words
The film projector set forth in claim 5 wherein said intermittent and continuous drive mechanisms are independent of each other, and switch means for selectively activating said drive mechanisms.
Claim 9
Dependent Claim
121 words
A film projector having an endless loop cartridge, a reversible scan mechanism for driving the film in either direction including a reversible drive motor, a sprocket wheel engageable with the film, a belt-type speed reduction coupling between said motor and said sprocket wheel, a ratchet wheel secured to the shaft of said sprocket wheel, and a pawl engageable with said ratchet wheel to bring said sprocket wheel to a sudden stop with momentary slippage in said coupling, wherein said pawl is of a double-arm type shiftable to engage said ratchet wheel at diametrically opposite sides to latch said ratchet wheel in either direction, including separate electrically energizable means for rocking said pawl to engage said separate arms with said ratchet wheel.
Claim 10
Dependent Claim
121 words
A film projector having an endless loop cartridge, a reversible scan mechanism for driving the film in either direction including a reversible drive motor, a sprocket wheel engageable with the film, a belt-type speed reduction coupling between said motor and said sprocket wheel, a ratchet wheel secured to the shaft of said sprocket wheel, and a pawl engageable with said ratchet wheel to bring said sprocket wheel to a sudden stop with momentary slippage in said coupling, wherein said pawl is of a double-arm type shiftable to engage said ratchet wheel at diametrically opposite sides to latch said ratchet wheel in either direction, including separate electrically energizable means for rocking said pawl to engage said separate arms with said ratchet wheel.
Claim 11
Dependent Claim
122 words
A film projector having an endless loop cartridge, a reversible scan mechanism for driving the film in either direction including a reversible drive motor, a sprocket wheel engageable with the film, a belt-type speed reduction coupling between said motor and said sprocket wheel, a ratchet wheel secured to the shaft of said sprocket wheel, a pawl engageable with said ratchet wheel to bring said sprocket wheel to a sudden stop with momentary slippage in said coupling, a frame, a rocker plate pivoted to said frame, means journaling said sprocket wheel on said rocker plate whereby the sprocket wheel is shifted into and out of engagement with the film as said rocker plate is shifted, and a solenoid for shifting said rocker plate.
Claim 12
Dependent Claim
122 words
A film projector having an endless loop cartridge, a reversible scan mechanism for driving the film in either direction including a reversible drive motor, a sprocket wheel engageable with the film, a belt-type speed reduction coupling between said motor and said sprocket wheel, a ratchet wheel secured to the shaft of said sprocket wheel, a pawl engageable with said ratchet wheel to bring said sprocket wheel to a sudden stop with momentary slippage in said coupling, a frame, a rocker plate pivoted to said frame, means journaling said sprocket wheel on said rocker plate whereby the sprocket wheel is shifted into and out of engagement with the film as said rocker plate is shifted, and a solenoid for shifting said rocker plate.
Claim 13
Dependent Claim
57 words
The film projector set forth in claim 8 where said pawl is pivoted to said rocker plate including means for shifting said pawl into engagement with said ratchet wheel to stop the drive of said sprocket wheel and for thereupon controlling said solenoid to cause the sprocket wheel to be shifted out of engagement with the film.
Claim 14
Dependent Claim
39 words
The film projector set forth in claim 9 including interacting means between said pawl and said frame to cause the pawl to be maintained in engagement with the sprocket wheel while the sprocket wheel is disengaged from the film.
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) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |