GB296728A - Improvements in cinematographic apparatus - Google Patents

Abstract

296,728. Oehmichen, E. Sept. 6, 1927, [Convention date]. Kinematograph apparatus. - In apparatus which is not provided with toothed continuousfeed sprockets between the spools and the gate, means are provided to prevent displacement of the film in the gate and excessive tension in the film due to variations in the running of the spools. As shown in Fig. 1, the film 2 from the pay-out spool 6 passes round rollers 8, 9, 10 which are geared together and are driven by the projector to have a peripheral speed slightly greater than the mean speed of the film through the gate. The rollers 8, 9 have fixed spindles, but the spindle of the roller 10 is carried by an arm 13 pivoted about the spindle of the roller 9 and supported by a spring 14. Shortening of the film loops around the rollers causes the film to engage the rollers tightly and to be drawn from the spool at an increased speed. The film passing to the take-up spool 7 may pass round stationary friction members 21, 22, 23, or around members which, although not fixed, serve to reduce the velocity of the film. Fig. 2 shows a modification wherein the film passes round roller? 29, 30, 31, the spindle of the roller 30 being. carried by a pivoted arm 32 acted upon by a spring 34. The arm 32 is connected by a cord 59 to a brake band 58 engaging a drum 56 carrying the planet pinions 57 of a differential gear in a driving connection for the pay-out spool 28. Shortening of the film loops round the rollers causes the brake band to be operative and the drive for the spool to be effective. A subsidiary loop in the film between the roller 31 and the gate may be formed by air supplied from a nozzle 62 or by a weak spring. Similar means may be provided between the gate and the take-up spool 35, the cord 71 being arranged to cause the brake band 70 to be effective when the film loops enlarge. Specifications 305,550, 305,776 and 307,270 are referred to.