Patent GB-651414-A (GB)
Title: Improvements in or relating to roll film photographic cameras
IPC: G03B19/04
Filed: 1948-02-06
Abstract: 651,414. Photographic cameras. KODAK, Ltd. Feb. 6, 1948, No. 3572. Convention date, Feb. 8, 1947. [Class 98 (i)] A roll-film camera comprises a casing having an exposure frame, at opposite ends of which are respectively a chamber for accommodating a film spool and a takeup chamber into which the film from the spool is wound in a loose coil, wherein a section of the casing also constitutes a portion of the spool chamber and supports a spindle for accommodating the film, the section being hinged to the remainder of the casing so that it may be swung to an open position in which the spool may be readily mounted on or detached from the spindle. As shown in Fig. 1, the casing 10 has a take-up chamber 20 at one end and a spool chamber 21 at the other. At the spool chamber end, the casing 10 has an arcuate section 27 hinged to the remainder of the casing at 44. The section 27 has side flanges 28 co-operating with double flanges on the top and bottom walls of the camera and flanges 31, 32 co-operating with a double flange 33 on the rear of the casing 10 and a recess 34 in the front wall 17 of the camera to form a light lock. The section 27 carries a support member 35 carrying a spindle 36, Fig. 5, having a cylindrical guide portion 37, a square driving portion 38, and a reduced portion 39 forming a bearing for the spindle in the member 35 and carrying a pinion 40. One flange of the spool 41 has a square aperture for engagement with the driving portion 38 of the spindle. A cylinder 42 having a film passage 43, Fig. 1, is mounted on member 35.to surround the spool. On rotating the knob 53 in a counter-clockwise direction, the gear 54 rotates the pinion 40 and spool 41 to feed the film. A finger 55 extending through the slot 43 directs the film between extensions on the guide 56 to bend the film transversely for removal from the spool and the film moves past the exposure aperture 26 into the receptacle 22. The leading edge of the film, as it passes the exposure aperture, strikes the arm 60 of a lever 61 to bring the end 63 of the lever 61 opposite a notch 64 in a lever 65 and permit the latter to be moved clockwise by a spring 67 when the pins 68 and 69, so spaced that both pins cannot simultaneously enter two standard film perforations encounter two suitably spaced perforations near the end of the film, to prevent the film being drawn right off the spool 41. The gear 54 meshes with a pinion 70 having integral therewith oppositely directed ratchet-wheels 71, 72. The lever 65 has a pawl arm 73 which can engage the ratchet-wheel 71, and a second pawl 74, on the same pivot 66 as the lever 65, can engage the ratchet-wheel 72 under the action of the spring 75. When the pin 68 is allowed to move against the film by the movement of lever 61, the pawl 74 engages ratchet 72 but rides over the teeth thereof, while pawl 73 does not move sufficiently to engage the ratchet 71. When the pins 68, 69 encounter the two perforations near the end of the film, the pawl 73 engages the ratchet 71 to prevent further rotation of knob 53. Fixed to the shaft 76 carrying the knob 53 is a ratchet 77. The re-wind handle 78, Fig. 5, is fixed to a collar secured to a bushing 80 carrying a plate 81 carrying a pawl 82, Fig. 1, and cam 83, and on rotating the handle 78 clockwise the cam 83 bears against a pin 84 on the pawl 73 to rotate lever 65 to remove pawl 73 from engagement with the ratchet 71, the pins 68, 69 from the two perforations, and pawl 74 from the ratchet 72 by means of a lug 85 turned down from the lever 65. The pawl 82 is held out of engagement with the ratchet 77 by engagement of a pin 86 with an arm 87 of the pawl 82, but as arm 87 moves along the pin 86, the pawl 82 gradually engages ratchet 77 to rotate gear 54 and re-wind the film on to spool 41. The cam 83 then permits pin 68 to return to the film, and the pawl 73 to re-engage ratchet 71, but pawl 74 is held from ratchet 72 until pin 68 enters the next film perforation, when pawl 74 engages ratchet 72 and stops the movement of handle 78. The procedure is repeated until the last exposure has been made, when pin 68 is held out by the unperforated end of the film until the end has moved past the arm 60 to permit arm 63 to drop below the notch 64 and prevent pin 68 from moving inwards, thus permitting the leader strip to be wound on to spool 41. The locking means for section 27 comprises a button 88 on a leaf-spring carrying a bevelled pin passing through a hole in the flange 31 of section 27.