Patent GB-527449-A (GB)
Title: Improvements in or relating to photographic cameras
IPC: G03B19/04
Filed: 1939-04-12
Abstract: 527,449. Photographic cameras. KODAK, Ltd. April 12, 1939, No. 11099. Convention date, April 12, 1938. Class 98 (i)] The film-winding and shutter-setting means of a roll-film camera are actuated by a single operating member through a differential drive. The camera shown comprises means for winding an imperforate film through a measured distance and for winding a double-blind focal-plane shutter, both operated through a planetary differential gear from the setting-knob 65. The stub shaft 66 secured to this knob carries a flange 76 on which are pivoted planetary gears 79 engaging an inner gear 70 carried by a sleeve 69 which is rotatably mounted on the shaft 66 and formed with lugs engaging in the usual keyway in the end of the film spool 5. The planetary gears also engage internal teeth on a gear ring 80 mounted between the flange 76 and a ring 78 secured to one end of the pivots of the planetary gears. External teeth on the ring 80 mesh with a pinion 83 on a shaft 84, which carries at its lower end a pinion 85 driving a gear 47 through which the roller-blind mechanism is wound. Rotation of the planetary gears by the setting-knob 65 causes them to rotate either the inner gear 70, thus winding the film on to the spool 5, or the ring gear 80, thus winding the shutter, according to which operation offers the greater resistance at the time; completion of one operation locks either the gear 70 or the gear 80 so that continued rotation of the setting-knob completes the other. The imperforate film passes over and rotates a measuring roller 87 having roughened flanges at each end against which the film is pressed by springs 90. The roller rotates through gears 91, 92 a disc 93 having a radial slot 94 in which engages a down-turned projection 97, Fig. 10, on a slide 96, which also carries a projection 99 engaging ratchet teeth on a flange 71 carried by the sleeve 69. When the film is to be wound the slide 96 is moved back against a spring 100 by an external operating button (not shown), withdrawing the projections 97, 99 respectively from the slot 94 in the disc 93 and from the teeth of the flange 71. The film tension then rotates the roller 87 to cause the slot 94 to come out of alignment with the projection 97, preventing the return of the slide until owing to the film advance the disc 93 has made a complete revolution, when the slide returns and locks the flange 71, preventing further rotation of the spool 5. The movements of the slide operate a counter through an arm 110 engaging a ratchet wheel 107. The focalplane shutter comprises a front or leading blind 35 secured to a spring roller 36 and having at the other end cords 38 passing round guide pulleys to winding-up pulleys 26, 27, Fig. 3. The rear or following blind 40 is cut at one end to form straps passing round enlarged ends 33, 34 of the winding-up roller, and to the other end are attached cords 43 passing round guide pulleys to spring-operated pulleys 44. When the gear 47 is rotated, a spring finger 49 secured to it engages a pin (not shown) on the face of the winding pulley 27, causing rotation of both pulleys 26, 27 to wind the leading blind. When this has been wound sufficiently to close the gap between the blinds, a pin 52 on the pulley 27 engages a pin 53 on the roller 31, which then rotates with the pulleys so that both blinds are wound together, To release the shutter, the spring 49 is depressed by a projection on a slidable rod 57. To control the exposure time, the release of the following blind is delayed by a finger 115, Fig. 5, which engages a pin 120 projecting from the end 33 of the blind roller through a slot in the edge of the blind. The finger 115 projects from a plate 114 carried by a slidable spring-urged rod 116, and, after a predetermined movement of the leading blind, a projection 124, Fig. 3, on the face of the pulley 26, engages a ball 123 held in an aperture in a plate 142 and forces it against the plate 114, causing it to move and withdraw the finger 115 to release the following blind. The plate 142 is rotated by the speed-adjusting knob 125 to alter the angular situation of the ball 123, and hence the extent of travel of the leading blind before the release of the following blind.