Patent GB-354228-A (GB)
IPC: G03B19/18
Filed: 1930-05-01
Abstract: 354,228. Kinematograph projectors. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin.-(Assignees of Projector Ges. ; 28, Wilhelmstrasse, Berlin.) May 1, 1930, No. 13477. Convention date, May 2, 1929. [Class 97 (i).] In projectors in which rewinding is effected by reversing the direction of feed, and the film is rewound over its normal path, at high speed, by a driving force applied only to the top spool, a pin coupling controls the direction of feed, is arranged on a shaft carrying parts of the rewinding gear train, and is controlled by a single lever, the arrangement being such that the driving motor may be totally disconnected so that the film remains stationary although the motor is running. As shown, a reversible motor 8 drives a vertical shaft 9 carrying a worm 14 meshing with a worm wheel 12 loose on a shaft 15 carrying the bottom sprocket 7. A coupling sleeve 16, having a longitudinal slot engaging a pin 19 on the shaft 15, is slidable to bring a pin 17 carried by it into engagement with a hole 18 in the wheel 12, thus coupling the motor to the sprocket 7 for forward feeding of the film. A belt pulley 20 secured to the sleeve 16 or to the shaft 15 drives a pulley on the spindle of the bottom spool, and a chain wheel 22 keyed on shaft 15 drives a chain wheel 24 secured to the shaft 25 of the top sprocket 5. A heater mechanism is driven by a shaft 11 through worm gearing 10 from the shaft 9. The rewinding gear train to the top spool comprises a sleeve 26, loose on the shaft 15, carrying a belt pulley 27 driving a pulley 36 secured to a sleeve 38 which is loose on the shaft 25 and carries a second belt pulley 37 driving a pulley connected to the top spool. The sleeve 26 is bored to house a helical spring 31 secured to it at one end 32, the other end being free. The spring surrounds a sleeve 30 projecting from the wheel 12, and slips over or grips the sleeve 30 in accordance with the direction of rotation of the sleeve. During forward running of the film, the spring slips, and the sleeve 26 is still, but, when the rotation of the motor and of the sleeve is reversed, the spring grips, and the sleeve 26, pulley 27, &c., are driven to rewind the film. A similar spring device 33 holds the sleeve 26 during forward. running of the film and permits it to rotate for rewinding. An arrangement is described of two springs, similarly provided in connection with the spindle of the bottom spool to effect a positive connection between the spool and its spindle during forward running, and a braking action during rewinding. The coupling sleeve 16 is controlled by a lever 46 on a sleeve 48 surrounding a rotatable rod 50 and carrying a hand-lever 49. The rod 50 operates the motor switch, and carries a hand-lever 51 and also a lever 52 projecting through a recess 53 in the sleeve 48 to engage a pivoted member 55. The member 55 contacts with a pin fixed on an axially-slidable, lens carrier ; the carrier is secured to the movable part of the gate. Projection may be stopped, without stopping the motor, by movement of the lever 49 to disengage the pin 17 from the wheel 12. Rewinding is effected by movement of the lever 51 to reverse the motor, driving connection between the wheel 12 and the sleeve 26 being then established to drive only the top spool; the gate is opened before the rewinding owing to the movement of the member 55. If the lever 49 has not been previously moved, movement of the lever 51 for rewinding also moves the lever 46, by engagement between the lever 52 and one edge of the recess 53, thus ensuring disengagement of the pin 17 and wheel 12. Racing of the motor when it is running without load is prevented by means of a governor 61 carrying a brake disc 62 engaged by a brake arm 63 at excessive speeds. A switch for the projection lamp may be operatively connected to the motor switch to avoid illumination of the film during rewinding.