GB667372A - Reversible cinematograph apparatus - Google Patents

Abstract

667,372. Kinematograph apparatus. DEBRIE, A. V. L. C. Nov. 12, 1948, No. 29491/48. Class 97 (i). A film feeding mechanism comprises upper and lower film sprockets with between them, a curved film guide in which the gate aperture is formed, and, between the guide and the lower sprocket, a pivoted beater member which is moved downwards periodically in synchronism with the sprockets to feed the film intermittently. A detachable film feed spool and a non-detachable take-up spool are used. The projector shown has a lamp 23, condenser 22 and projection lens shown dotted at 21. The film is wound by sprockets 3, 11 and passes through the film guide 6 and round rollers 5, 8. The latter is pivoted on an arm 9, pivoted at 27 and carrying a laterally projecting cam portion 20 which is struck periodically by one of a number of pins 25 carried by a gear-wheel 17 on the shaft of the sprocket 11. The roller 8 is thus moved downwards to enlarge the film loop 24 at the expense of the loop 26<SP>1</SP> and feed a frame of film through the channel 6 past the aperture 7. The pivot 27 may be adjustable, for example by slide-and-screw mechanism, to maintain accurate framing. The gear-wheel 17, and the similar gear 16 driving the sprocket 3, are driven from a common pinion 18. After projection the film is rewound on to the upper spool merely by reversing the drive to the mechanism. During this movement no loop is formed at 26<SP>1</SP> so that the roller 8 remains in its lowest position and the pins 25 do not strike the cam 20. The detachable feed spool has a circular hole in the centre of one flange, to engage its spindle, and a smaller square hole in the other flange to provide a driving engagement with a squared portion at the outer end of the spindle. Lightening holes are formed in one flange only so that the flanges are distinguishable by touch.