Patent GB-563304-A (GB)
Title: Improvements in or relating to roll film cameras
IPC: G03B19/04
Filed: 1943-02-03
Abstract: 563,304. Roll-film cameras. KODAK, Ltd., and NAGEL, H. Feb. 3, 1943, No. 1794. [Class 98 (i)] A roll-film camera is provided with a plurality of film feed latching devices which are rendered independently operative after different feeding movements of the film and are connected to a common manually operable member by which they may be simultaneously held in inoperative positions to permit unrestricted feeding of the film, for example when winding the leading or tail portions. In the camera described, which is intended particularly for photographing X- ray screen images, three latching devices are provided respectively for latching the filmfeeding means after each fresh area of film has been fed to the exposure position, after a predetermined number of exposures have been made, and when the supply roll of film is substantially exhausted. To feed a fresh exposure area of film, the end of a lever 9 projecting through a slot in the back of the camera is depressed, thereby rotating a drum by means of a chain 19 secured to the other end of the lever and passing round the drum, which is loosely mounted on the sprocket shaft 10. A disc 23 rotating with the drum carries a pawl 27 which engages one of three teeth 22 on a number 21 secured to the sprocket shaft, which is thereby turned through one-third of a revolution to feed the film. At the end of the movement a projection 35 on the disc 23 engages in a notch 34 in a spring-urged latch lever 32, so preventing return movement of the chaindrum and the operating lever 9, and another projection 30 engages the arm 31 of a microswitch 29 in the tube-energizing circuit, thereby allowing an exposure to be made: After the exposure, a solenoid 38 is energized for a short period, raising the plunger 37 and then allowing it to fall so that a pin 36 carried by it strikes the lever 32 and turns it to release the projection 35, upon which a spring 45 rotates the chain drum and disc 23 to restore the operating lever 9 to the position shown, and cause the pawl 27 to engage the next tooth 22 in readiness for the next feeding movement. A pawl 221 engaging pins 211 on the member 21 prevents reverse rotation of the member. A second latch device, operated 'as described in the abridgment of Specification 563,305, after a predetermined number of exposures have been made, consists of a lever 73 which is turned so that the upper end of a recess in it is engaged by a projection 77 on the lever 9 if an attempt is made to feed the film. A third latch, operated as described in the abridgment of Specification 563,306 when the film is exhausted, consists of a lever 86 having a hook which engages a pin 87 on the lever 9. All three latches 32, 73 and 86 may be moved to an inoperative position by operation of a lever 101 to rock a plate 103 anti-clockwise to which plate are pivoted links 104, 105 having lost-motion pin-and-slot connections to the levers 32, 86 respectively, and which carries a pin 106 which engages the end of the lever 73. Specifications 549,194, 563,305, 563,306, 563,307 and 563,308 are referred to.