Patent GB-449769-A (GB)
Title: Improvements in or relating to photographic roll film cameras
IPC: G03B19/04
Filed: 1935-01-02
Abstract: 449,769. Photographic roll - film cameras. KODAK, Ltd., Kingsway, London.-(Assignees of Kodak Akt.-Ges. ; 27, Lindenstrasse, Berlin) Jan. 2, 1935, No. 141. Convention date, Jan. 16, 1934. [Class 98 (i)] Film feeding and locking mechanism comprises a lever which locks the take-up mechanism when a length of film corresponding to one exposure area has been fed, and a control device for releasing the locking lever comprising two coaxial notched discs coupled together through a lost-motion device, one being driven by the film and the other being manually rotatable from the outside of the camera, so that when the film is being fed the notches in the discs are brought into register and permit the lever to lock the take-up mechanism until the second disc is rotated from outside so as to move the notches out of register and displace the locking lever. The camera is divided into two compartments by a partition 2, the larger compartment containing the supply and take-up spools 4, 5 and a sprocket 6 which engages in perforations in the film. Knobs 11, 42 respectively are provided for winding the film in a forward or a reverse direction, and a ratchet wheel 12 is secured to the end 9 of the spool 4. Two cam discs 17, 21 are mounted coaxially, the disc 17 being rigidly secured to a gear-wheel 16 which engages a pinion 15 rigidly mounted on the shaft 13 that carries the film sprocket 6. The disc 21 has a slot 20 in which moves a pin carried by the cam disc 17, and is manually rotated by a knob 31. Each cam disc 17, 21 has a notch 22, 23 respectively bevelled on one side, and formed with a sharp nose 28 on the other. The locking lever 25, biassed by a spring 26, has a projection 24 which engages the edges of the cam discs 17, 21, and a nose 32 which engages the ratchet wheel 12. Pivoted at 35 on the opposite end of the lever is a pawl 34, the free end 33 of which co-operates with a ratchet wheel 38 mounted on a shaft 37 and coupled to a counting disc 39. As the film is wound on to the take-up spool, the projection 24 rides on the edge of the discs 17, 21, and the nose 32 is held out of engagement with the ratchet 12 until the sprocket 6 has rotated sufficiently to move the pin 19 to the end of the slot 20, thereby bringing the notches 22, 23 into register, and to turn the discs to bring the notches under the projection 24. This position corresponds with an exposure position, and the projection 24 drops, bringing the nose 32 into engagement with the ratchet wheel 12 to lock the take-up mechanism. During this movement, the nose 33 of the pawl 34 moves around the teeth of the ratchet wheel 38, rotation of the latter in the clockwise direction being prevented by the pawl 41. After exposure, rotation of the knob 31 and the disc 21 causes the projection 24 to ride up the chamfered face 30 of the notch 22 in the disc 21, and the lever is turned about its pivot to release the take-up mechanism and to actuate the ratchet wheel 38 and counting disc 39. The film may then be wound through one exposure length as before. When the last exposure has been made, the notches 22, 23 are not in register, and the film may be rewound onto the supply spool without the projection 24 dropping down to lock the mechanism. Specification 8722/85, [Class 98], is referred to.