Patent GB-318092-A (GB)
Title: Improvements in photographic cameras
IPC: G03B17/53
Filed: 1928-05-25
Abstract: 318,092. Josepho, A. M. May 25, 1928. Magazine cameras for roll films and with connected action between shutter and changing mechanism.-A camera of the kind provided with means for intermittently feeding the sensitized film, and for actuating the shutter to effect exposure of each section of the film while the film is stationary, is characterized by (1) a take-up spool in a light-tight holder, the spool being driven continuously by a winding element which is directly geared to an intermittent feed device acting on the film near the point of entry to the take-up spool holder so as to push the film into the holder during the feed-stroke; (2) chambers for receiving the light-tight film holders, with strip-guiding means therebetween, and means actuated by a cover-plate on the camera for spreading the guiding means to facilitate insertion of the film; (3) an exposure-counting mechanism; and (4) an operating-handle external to the casing for driving a main shaft which effects all the operations of the camera, and means controlled by the sensitive strip for locking the driving-mechanism when the supply spool is empty. A reflecting prism between the objective and the focal plane for optically reversing the image is also described. In the form shown, the sensitive strip B is delivered from a spool 12 in a light-proof holder A loaded into a chamber F, and passes between a fixed guide-plate 16, and a guide plate 18 having a hinged apertured portion 18<x>, to a take-up spool 14 in a similarly-housed holder Ax. Adjacent the chamber F<1> for take-up holder A<x>, the strip passes between feed-rolls 20, 21, driven through gearing from a shaft 10 operated by an external handle. Corresponding portions of the peripheries of the rolls are cut away so that, as the rolls are continuously driven, the strip will be fed intermittently into the take-up holder. Alternatively, the rolls may have unbroken peripheries, and may be driven intermittently by interposing a cam-actuated ratchet and pawl gear in the gear-train between the rolls and the shaft 10. The hinged portion 18<x> of the guide plate 18 is normally pressed against the guide plate 16 by the action on the end of a slidable rod 24 of a side cover-plate 7 giving access to the stripholding chambers F, F<1>. Removal of this plate, which is held in closed position by a pair of locking lugs 25 actuated by an external slidable member 26, frees the rod 24, and permits the hinged plate 18<x> to open away from the plate 16 to facilitate insertion therebetween of the part of the strip B extending between the holders A, A<x>. The end of the take-up spool 14 has an axial driving-aperture shaped to fit on a stud shaft, for example of hexagonal section, extending through an aperture in the holder A<x>, and journaled on the camera casing. A gear wheel 36 on this shaft is driven continuously through gearing from the shaft 10 at such a speed that the strip is wound on the spool 14 at a slower rate than it is fed by the rolls 20, 21 during their active feed period. A slack length of strip therefore accumulates in the holder A<x> during each feed-period of the rolls 20, 21, and is wound on the spool 14 during the following period of rest of the rolls, i.e. when the strip remains stationary between the plates 16, 18 for exposure. A spring pawl device is provided adjacent to one of the wheels of the feed gear train in order to lock this train and prevent reverse rotation of the feed rolls 20, 21 if the external handle operating the shaft 10 should inadvertently be reversely rotated. On completion of the feeding of the strip, and in order to facilitate its withdrawal, the feed rolls 20, 21 are locked in a position in which they no longer grip the strip by the engagement with a segmental ratchet 76<x> on the roll 21 of a spring-urged pawl 73 carrying a finger 71 which is normally pressed down by the strip to maintain the pawl 73 inoperative, but which rises to render the, pawl operative when the end of the strip has emerged from the holder A and passed the upper end of the finger. Means controlled by the side coverplate 7 is provided in the alternative construction employing intermittently rotated feed rolls, whereby the lower roll is depressed away from the upper roll to permit insertion or withdrawal of the strip; and in this construction also means is provided for locking the feed-gear train when all the exposures are completed. Behind the objective 8 is a reflecting prism 50 adapted to project an optically-reversed image from the objective in a direction at right angles to the axis of the objective, so that it falls on the strip B through the focal aperture in the hinged plate 18<x>. A shutter of any kind is actuated by a rod 9 con. nected to a lever 46 operated by a cam 48 on the shaft of a gear 39 in the film-feed driving train. A counter drum 60, bearing on its periphery two columns of figures for indicating through apertures in the casing respectively the exposed and unexposed sections of the strip, is driven through a ratchet gear 61 controlled by the lever 46.