US3707326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic film rewind device for movie projectors of the small type
Assignee: Ricoh Co Ltd
•
Filing: 1970-09-21
•
Granted: 1972-12-26
•
Expires: 1990-09-21
Abstract
Abstract An automatic film rewind device for movie projectors of the small type effects automatic rewinding of the film rsponsive to detection of tensioning of the film, wound on the shaft of a supply reel, at the terminating stage of film supply. The device further is operable selectively to effect single-frame projection, as well as projection of the film while moving in the rewind direction. Externally excessible operating means are manually operable to effect rewinding of the film. The device includes a control cam group movable between forward film feed, neutral and reverse film feed positions by an externally accessible control knob, and a control lever group is engaged with the control cam group. This control lever group sets the components of the projector to either feed film forwardly or to rewind film, and is locked in the forward feed film position by a holding member which is released responsive to the mentioned tensioning of the film in the last stage of film supply. A locking lever is operable to lock the control cam group in either the forward film feed position or the neutral position, and is released automatically responsive to such tensioning of the film.
Inventors
- 👤 Tatsusuke Kadowaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:35
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/32; G03B21/43
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
336 words
In a small movie projector of the type having a film supply section, a projection lamp, components, including a driving motor, for driving the film in a forward film feed direction and a reverse film rewind direction, a control cam group, externally accessible operating means operable to move the control cam group between forward film feed, neutral, and reverse film feed positions, a control lever group operatively associated with and movable by the control cam group and including an operating lever operable to move a film pressing plate in and out of an operating position, a clutch operating lever controlling a clutch connecting a film supply shaft to the driving motor, and a forward-reverse direction switching lever controlling the direction of film movement, and locking means operable to lock the levers of the control lever group in positions to which they are moved when the control cam group is moved to its forward film feed position: an automatic film rewind device comprising, in combination, resilient means biasing said control cam group to its reverse film feed position; a cam group locking lever operatively associated with said control cam group and operable to releasably lock said control cam group in either its forward film feed position or its neutral position; a pivoted member having an arm engaged with a slack portion of film, secured at its trailing end to said film supply shaft, when the film is screened, and caused to pivot by the film when the film is tensioned to remove the slack; and a release member operable by said pivot member when the latter is pivoted by the film; said release member having an inclined edge engaged with an end of said cam group locking lever; said inclined edge, responsive to movement of said release member by said pivoted member, moving said cam group locking lever to disengage said control cam group, in its forward film feed position, for movement of said control cam group to its reverse film feed position by said resilient means.
Claim 2
Dependent Claim
336 words
In a small movie projector of the type having a film supply section, a projection lamp, components, including a driving motor, for driving the film in a forward film feed direction and a reverse film rewind direction, a control cam group, externally accessible operating means operable to move the control cam group between forward film feed, neutral, and reverse film feed positions, a control lever group operatively associated with and movable by the control cam group and including an operating lever operable to move a film pressing plate in and out of an operating position, a clutch operating lever controlling a clutch connecting a film supply shaft to the driving motor, and a forward-reverse direction switching lever controlling the direction of film movement, and locking means operable to lock the levers of the control lever group in positions to which they are moved when the control cam group is moved to its forward film feed position: an automatic film rewind device comprising, in combination, resilient means biasing said control cam group to its reverse film feed position; a cam group locking lever operatively associated with said control cam group and operable to releasably lock said control cam group in either its forward film feed position or its neutral position; a pivoted member having an arm engaged with a slack portion of film, secured at its trailing end to said film supply shaft, when the film is screened, and caused to pivot by the film when the film is tensioned to remove the slack; and a release member operable by said pivot member when the latter is pivoted by the film; said release member having an inclined edge engaged with an end of said cam group locking lever; said inclined edge, responsive to movement of said release member by said pivoted member, moving said cam group locking lever to disengage said control cam group, in its forward film feed position, for movement of said control cam group to its reverse film feed position by said resilient means.
Claim 3
Dependent Claim
148 words
An automatic film rewind device, as claimed in claim 1, including rotatable means engaged with the film and operable to offer resistance to film movement; a holding member operable to hold and lock said control lever group in the forward film feed position; said externally accessible operating means being effective to move said control cam group to the neutral and reverse feed positions while said holding member holds and locks said control lever group in the forward film feed position; said rotatable means being rendered ineffective responsive to said clutch being disengaged when said control cam group is moved to its neutral position, to effect single-frame projection; said rotatable means being rendered temporarily ineffective and said clutch being engaged responsive to movement of said control cam group to the reverse film feed position to effect projection of the film while the latter is moving in the reverse direction.
Claim 4
Dependent Claim
54 words
An automatic film rewind device, as claimed in claim 2, in which said rotatable means comprises a rubber roller engaged with the film; and means operable to lock said rubber roller against rotation responsive to movement of said holding member to hold and lock said control lever group in the forward film feed position.
Claim 5
Dependent Claim
78 words
An automatic film rewind device, as claimed in claim 2, including externally accessible manually actuated means operable to move said holding member to release its locking of said control lever group to effect rewinding of the film while said components are set to move the film in the forward film feed direction and to effect rewinding of the film on a supply reel shaft when the end of the film is not secured to the supply reel shaft.
Claim 6
Dependent Claim
42 words
An automatic film rewind device, as claimed in claim 1, in which said externally accessible operating means comprises a control knob; and a shaft secured to sAid control knob; the cams of said control cam group being fixedly mounted on said shaft.
Claim 7
Dependent Claim
65 words
An automatic film rewind device, as claimed in claim 5, including a pair of spaced fixed contacts controlling an energizing circuit for said driving motor; and a circuit closure means secured to rotate with said shaft and operable, upon movement of said control knob in either direction from its neutral position, to interconnect said fixed contacts to complete the energizing circuit for said driving motor.
Claim 8
Dependent Claim
67 words
An automatic film rewind device, as claimed in claim 5, in which said control lever group includes a pivoted power source lever; a pair of fixed spaced contacts controlling an energizing circuit for said projection lamp; and a circuit closer on said power source lever operable, upon movement of said control knob to the forward film feed position, to interconnect said contacts to energize said projection lamp.
Claim 9
Dependent Claim
76 words
An automatic film rewind device, as claimed in claim 5, including a horizontally movable support member for said film pressing plate; said pressing plate operating lever being engaged with said support member and operable, responsive to movement of said control knob to the forward film feed position, to move said support member to position said pressing plate in the path of film movement; said holding member holding and locking said support member in its operated position.
Claim 10
Dependent Claim
88 words
An automatic film rewind device, as claimed in claim 5, including a rotation limiting member secured to said shaft; said resilient means comprising a tension spring having an end secured to said rotation limiting member; a first fixed stop engageable by said rotation limiting member upon movement of said control knob to the forward film feed position; and a second fixed stop engageable with said rotation limiting member upon operation of said release means; said second fixed stop carrying resilient sleeve means engageable with said rotation limiting member.
Claim 11
Dependent Claim
60 words
An automatic film rewind device, as claimed in claim 5, in which said control cam group includes a disc cam formed with a cam slot; said normal-reverse direction switching lever having a pin engaged in said cam slot; said switching lever controlling said driving motor to operate in either the forward film feed direction or the reverse film feed direction.
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) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |