Patent GB-450766-A (GB)
Title: Improvements in or relating to film footage indicators for motion picture apparatus
IPC: G03B21/43
Filed: 1935-01-23
Abstract: 450,766. Kinematograph apparatus. KODAK, Ltd., Kingsway, London.-(Assignees of Mihalvi. J. : 333. State Street. Rochester. New York. U.S.A.) Jan. 23, 1935. No. 2223. Convention date, Aug. 31, 1934. [Class 97 (i)] Relates to a film footage indicator for motion picture apparatus wherein the film strip after being wound from one spool on to a second spool is rewound from the second spool on to the first and comprises an indicating device having two sets or groups of graduations and actuated first in accordance with the amount of film carried by one spool when it will indicate only on one group of graduations, the length of film remaining on that spool while the film is being wound on the second spool and then (after reversal and inversion of the magazine) actuated in accordance with the amount of film carried by the second spool when it will indicate only on the second group of graduations, the length of film remaining on this second spool while the film is being rewound on the first spool. As applied to a motion picture camera employing a reversible magazine similar to that described in Specification 426,240 and a film feed mechanism similar to that described in Specification 426,239, the reversible I magazine, Fig. 2, is provided with a spindle 47 carrying footage indicator dials 53, 56, Fig. 4. When the magazine, containing full and empty film spools 39, 34 is placed in the camera casing as shown in Fig. 1, an actuating connection is effected between a shaft 43<1> driven by the spring motor 14, and a magazine sprocket 42 over which the film is fed past the shutter casing 13 and thence to the take-up spool 34 driven by a resilient belt 35. A spring- pressed feeler arm 48 secured to the spindle of the footage dials rests on the outer convolution of the film roll 46 and, as the diameter of the roll diminishes the feeler arm rotates the footage dials and indicates progressively, through an orifice 60, the feet remaining in the roll. When the roll is substantially exhausted, the feeler arm slips past the roll and abuts against the outer convolution 46<1> of the film newly-rolled upon the second spool 34, the footage dial then indicating " Reverse." The second half of the width of the film may then be similarly exposed by removing the magazine, reversing, inverting and reinserting it so that the film may be passed back to the spool 39, the length coiled on the spool 34 being progressively indicated on the footage dial 56 until, at the exhaustion point the feeler arm slips past the coil and abuts against a stop, the dial then indicating " End of Film." In order to arrest the film-driving mechanism when a spool is substantially exhausted a stop device 38, Fig. 1, rotated by the driving train is provided, and the footage dials are provided with apertures which permit the entry at the appropriate times, of one extremity of a lever 65, the other extremity moving into the path of the stop device 38 and locking the feed mechanism. In order to prevent the second run of the film being made without entirely completing the first run and to ensure that after completion of both runs a second exposure cannot inadvertently be made, the apertures in the footage dials are arranged so that under any of the above circumstances their presence prevents (during reinsertion of the magazine) the lever 65 from being displaced to liberate the stop device 38.