Patent US3640611A successfully refreshed from Google Patents.
US3640611A
Expired / Lapsed
US
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Control for motion picture projectors
Assignee: EPRAD Inc
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Filing: 1969-11-21
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Granted: 1972-02-08
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Expires: 1989-11-21
Abstract
Abstract Controls for motion picture projectors are designed to automatically change over the operation from one projector to the other to provide continuous showing of sequential reels of film. The controls embody a pickoff device in each projector having two contact shoes, one of which is effective to initiate changeover and the other of which is effective to operate auxiliary controls or circuits. The controls further prevent changeover from one projector to the other in the event of a film break which would cause circuits to be completed through both shoes. An alarm system is also provided which is effective to signal the operator in the event of a film break or lamp failure and also to signal the beginning of a show and the end of the last reel thereof.
Inventors
- 👤 Angelo Boudouris
- 👤 Stanley J Kulish Jr
- 👤 Harold M Plumadore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:48
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/32; G03B21/34; G03B1/00; G03B1/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
143 words
A changeover system for motion picture projectors, each having a pair of contact shoes mounted therein normally in engagement with a conducting film sprocket when there is no film between said shoes and said sprocket, first circuit means connecting one of said shoes and said sprocket and effective to change over the operation to a second projector when a conducting path is completed between said one shoe and said sprocket, additional circuit means connected to the other shoe and the sprocket for activating an auxiliary circuit when a conducting path is completed between said other shoe and said sprocket, and means associated with said first circuit means for preventing operation of the second projector when there is no film between said shoes and said conducting sprocket and conducting paths are completed between both of said shoes and said sprocket of said first projector.
Claim 2
Dependent Claim
143 words
A changeover system for motion picture projectors, each having a pair of contact shoes mounted therein normally in engagement with a conducting film sprocket when there is no film between said shoes and said sprocket, first circuit means connecting one of said shoes and said sprocket and effective to change over the operation to a second projector when a conducting path is completed between said one shoe and said sprocket, additional circuit means connected to the other shoe and the sprocket for activating an auxiliary circuit when a conducting path is completed between said other shoe and said sprocket, and means associated with said first circuit means for preventing operation of the second projector when there is no film between said shoes and said conducting sprocket and conducting paths are completed between both of said shoes and said sprocket of said first projector.
Claim 3
Dependent Claim
76 words
A changeover system according to claim 1 characterized further by a remotely located signal, means for continuously operating said signal in the event of a film break in the operating projector or in the event of a light failure in the operating projector, and means for operating said signal for a short period of time when one of the projectors is first started and when the last reel of film of a show is substantially finished.
Claim 4
Dependent Claim
118 words
A changeover system for motion picture projectors, each having a pair of contact shoes mounted thereon, each of said projectors also having an arc lamp, first circuit means connecting one of said shoes and effective to change over the operation to a second projector when a conducting path is completed between said one shoe and an adjacent film sprocket, additional circuit means connecting the other shoe for activating an auxiliary circuit when a conducting path is completed between said other shoe and said sprocket, and timing means associated with said first circuit means for supplying a predetermined number of sequential pulses at predetermined intervals to the arc lamp of the projector to which change over is being made.
Claim 5
Dependent Claim
118 words
A changeover system for motion picture projectors, each having a pair of contact shoes mounted thereon, each of said projectors also having an arc lamp, first circuit means connecting one of said shoes and effective to change over the operation to a second projector when a conducting path is completed between said one shoe and an adjacent film sprocket, additional circuit means connecting the other shoe for activating an auxiliary circuit when a conducting path is completed between said other shoe and said sprocket, and timing means associated with said first circuit means for supplying a predetermined number of sequential pulses at predetermined intervals to the arc lamp of the projector to which change over is being made.
Claim 6
Dependent Claim
71 words
A changeover system according to claim 3 characterized further by a relay electrically associated with lamps of both projectors, said relay being deenergized in the event of a failure of the lamp of the projector in operation, and means to energize said relay for a predetermined period during a change over from one projector to the other to prevent deenergization of said relay if both lamps are out during the period.
Claim 7
Dependent Claim
73 words
A changeover system according to claim 3 characterized further by each of said projectors having a runout switch effective to open and shut down the projector in the case of a film break, said first circuit means being effective to maintain the first projector in operation after change over to the other projector, until the runout switch of the first projector opens, thereby enabling the film on the first reel to run out.
Claim 8
Dependent Claim
124 words
A control system for controlling sequential operation of motion picture projectors comprising control means associated with the first projector for changing operation to a second projector at a predetermined time relative to the operation of the first projector signal means producing a signal, means for continuously operating said signal means in the event of a film break in the operating projector, means for continuously operating said signal means in the event of a lamp failure in the operating projector, means for operating said signal means for a short, predetermined period of time when a projector is started, and means for operating said signal means for a predetermined period of time when the last reel of film of a motion picture show is substantially finished.
Claim 9
Dependent Claim
124 words
A control system for controlling sequential operation of motion picture projectors comprising control means associated with the first projector for changing operation to a second projector at a predetermined time relative to the operation of the first projector signal means producing a signal, means for continuously operating said signal means in the event of a film break in the operating projector, means for continuously operating said signal means in the event of a lamp failure in the operating projector, means for operating said signal means for a short, predetermined period of time when a projector is started, and means for operating said signal means for a predetermined period of time when the last reel of film of a motion picture show is substantially finished.
Claim 10
Dependent Claim
71 words
A control system according to claim 6 characterized further by each of said projectors having a runout switch effective to open and shut down the projector in the case of a film break, and circuit means effective to maintain the first projector in operation after change over to the other projector, until the runout switch of the first projector opens, thereby enabling the film on the first reel to run out.
Claim 11
Dependent Claim
33 words
A control system according to claim 6 characterized further by means for temporarily rendering said signal means inoperative during a portion of a change over of operation from one projector to the other.
References Cited (Backward Citations)
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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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |