GB563523A - Improvements in and relating to photographic cameras - Google Patents

Abstract

563,523. Photographic roll - film cameras. COVILL, H. Jan. 14, 1944, No. 723. [Class 98 (i)] Relates to cameras of the kind described in Specification 497,579 in which mechanism for releasing the shutter and advancing the film is characterised by a toothed rack-bar which is caused by a trigger to slide and rotate a toothed wheel having a cam surface which operates the shutter mechanism, the continuing movement of the rack-bar operating a second rack-bar and wheel for winding the take-up spool. According to the invention, a slidable operating rod is pivoted to a toothed sector engaging a rack-bar whose movement on depression of the rod first releases the shutter, then through a linkage displaces a second rack-bar operating a filmfeed sprocket which is geared to a take-up spool, and finally actuates an exposure counter ; whereafter on release of the rod the parts are returned to their original positions by springs. As shown, the operating rod 18, Fig. 3, is pivoted within the camera near to the edge of a toothed sector 21, turning on a spindle 23 and engaging a rack-bar 22 carrying a shutterreleasing member 28. A pin on bar 22 is adapted to engage a lever 33 pivoted to the camera at 34 and having a tail adapted to engage a second rack-bar 26 meshing with a film feed sprocket gear 29 coupled to a wheel 30 driving a take-up spool through a slipping clutch. The rack-bar, 22 carries also a pawl 25 adapted to actuate an exposure counter 24 rotatable on the spindle 23. In operation, depression of the rod 18, through sector 21, displaces the rack-bar 22 so that in succession (1) the member 28 releases the shutter, (2) the lever 33 displaces the rack-bar 26 to feed the exposed film, and (3) the pawl 25 turns the counter 24; and on release of the rod 18, springs 32 return the parts to their original positions. On exhaustion of the film roll, a lever on the camera case is turned to insert a spring-biassed shield between the film and its feed sprocket, thereby lifting the film from the sprocket teeth so that it may be wound back into the supply cassette by turning a knob provided thereon.