US3644028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slide changer mechanism for slide projectors
Assignee: Robert Bosch Photokino GmbH
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Filing: 1969-02-17
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Granted: 1972-02-22
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Expires: 1989-02-17
Abstract
Abstract Slides in a slide projector are movable from their tray to projection position and vice versa by a reciprocable carriage which is driven by an electric motor through the intermediary of a friction clutch when it transports slides back into the tray and through the intermediary of the friction clutch and a second clutch, which latter can transmit a weaker force than the friction clutch, when the slides are moved from the tray to projection position so that a slide which jams during movement toward projection position can be returned to the tray because the carriage is driven with a greater force when it moves slides back into the tray.
Inventors
- 👤 Helmut Rube
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:59
CPC Classifications
G; G03; G03B; G03B23/00; G03B23/02; G03B23/04; G03B23/046; Y; Y10; Y10T; Y10T74/00; Y10T74/18; Y10T74/18056; Y10T74/18248; Y10T74/18256
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
358 words
In a slide projector, a combination comprising a support; a supply of slides carried by said support, each of said slides being movable to a predetermined transfer position; and slide changer means carried by said support and including a slide engaging device movable from a first position in which it is ready to engage a slide in said transfer position to a second position to thereby normally move a slide from said transfer position to a projection position, said slide engaging device being further movable from said second to said first position to thereby normally return a slide from said projection position to said transfer position, a prime mover, and a motion transmitting connection between said slide engaging device and said prime mover, said motion transmitting connection comprising means for transporting said slide engaging device from said second to said first position with a first force which is one of a first range of forces and for transporting said slide engaging device from said first to said second position with a second force which is one of a second range of forces, the upper limit of said second range of forces being below the upper limit of said second range of forces so that said slide engaging device comes to a halt when a slide offers to the movement of said slide engaging device to said second position a resistance which exceeds the upper limit of said second range of forces, said transporting means comprising a friction couplIng which normally transmits motion during transport of said slide engaging device in either direction and a second coupling which normally transmits motion only when said slide engaging device is transported from said first to said second position, said second coupling comprising first and second coupling elements respectively connected with said friction coupling and with said slide engaging device so that said first coupling element normally engages with the second coupling element during movement of said slide engaging device from said first to said second position, one of said coupling elements being yieldable in response to a predetermined resistance offered by said slide engaging device to movement toward said second position.
Claim 2
Dependent Claim
358 words
In a slide projector, a combination comprising a support; a supply of slides carried by said support, each of said slides being movable to a predetermined transfer position; and slide changer means carried by said support and including a slide engaging device movable from a first position in which it is ready to engage a slide in said transfer position to a second position to thereby normally move a slide from said transfer position to a projection position, said slide engaging device being further movable from said second to said first position to thereby normally return a slide from said projection position to said transfer position, a prime mover, and a motion transmitting connection between said slide engaging device and said prime mover, said motion transmitting connection comprising means for transporting said slide engaging device from said second to said first position with a first force which is one of a first range of forces and for transporting said slide engaging device from said first to said second position with a second force which is one of a second range of forces, the upper limit of said second range of forces being below the upper limit of said second range of forces so that said slide engaging device comes to a halt when a slide offers to the movement of said slide engaging device to said second position a resistance which exceeds the upper limit of said second range of forces, said transporting means comprising a friction couplIng which normally transmits motion during transport of said slide engaging device in either direction and a second coupling which normally transmits motion only when said slide engaging device is transported from said first to said second position, said second coupling comprising first and second coupling elements respectively connected with said friction coupling and with said slide engaging device so that said first coupling element normally engages with the second coupling element during movement of said slide engaging device from said first to said second position, one of said coupling elements being yieldable in response to a predetermined resistance offered by said slide engaging device to movement toward said second position.
Claim 3
Dependent Claim
22 words
A combination as defined in claim 1, wherein said second coupling is interposed between said slide engaging device and said friction coupling.
Claim 4
Dependent Claim
73 words
A combination as defined in claim 1, wherein said slide engaging device is reciprocable between said first and second positions thereof and comprises first and second arms respectively arranged to push slides from said transfer position to said projection position and vice versa in response to reciprocation of said slide engaging device between said first and second position, one of said arms being movably secured to the remainder of said slide engaging device.
Claim 5
Dependent Claim
62 words
A combination as defined in claim 1, wherein said slide engaging device comprises a carriage which is reciprocable between said first and second positions, said motion transmitting connection further comprising a crank arm which is rotated by said friction coupling and carries said first coupling element, said second coupling element constituting said yieldable coupling element and being pivotably mounted on said carriage.
Claim 6
Dependent Claim
31 words
A combination as defined in claim 4, wherein said second coupling further comprises resilient means for biasing said second coupling element into the path of movement of said first coupling element.
Claim 7
Dependent Claim
44 words
A combination as defined in claim 4, wherein said carriage comprises an elongated face which is engaged by said first coupling element during a portion of each revolution of said crank arm to thereby move said carriage from said second to said first position.
Claim 8
Dependent Claim
24 words
A combination as defined in claim 4, wherein said second coupling element constitutes one leaf of a hinge which is mounted on said carriage.
Claim 9
Dependent Claim
25 words
A combination as defined in claim 1, wherein said prime mover is an electric motor and said motion transmitting connection further comprises a reducing gear.
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) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |