Patent GB-872057-A (GB)
Title: Improvements in or relating to photographic cameras
Inventor: BOEHM SIEGFRIED
IPC: G03B19/06
Filed: 1957-10-12
Abstract: 872,057. Photographic cameras, optical systems. KAMERA-WERKE NIEDERSEDLITZ VEB. Oct. 12, 1957, No. 31935/57. Classes 97(1) and 98(1) In a roll-film camera having two alternatively usable film gates each equipped with a focal plane shutter, an inclined mirror is arranged to reflect the image-forming beam from a single objective to either gate and preferably is also movable to allow the beam to form an image on a back focusing screen. The axes of film spools and of the rollers of two roller blind focal plane shutters are parallel to the optical axis of the objective. As shown, in Fig. 1, two films 2, 2<SP>1</SP> are exposed at gates 9, 9<SP>1</SP> above and below a cylindrical cage 48 carrying movable mirror 49 and rotated about the optical axis of objective 18 by knob 64 into either of two positions defined by stops. Which of the two films are in use is indicated by disc 72 driven by gear 74. Mirror 49 is pivoted at 50 (Fig. 7) and moved by slider 53 into an inclined position by rotation of cam 32<SP>1</SP> and tension spring 56 at the beginning of an exposure. Slider 53 simultaneously moves pin 58 to close the objective diaphragm to a pre-selected aperture. When the mirror is in a position to expose film 2 slider 53 co-operates with cam 32. Both roller blind shutters are wound by means of a knob on shaft 20 (Fig. 5). Non-return ratchet 21 fast with shaft 20 carries pawl 23 which drives member 27 loosely mounted on the shaft and carrying gear 28 which meshes with gear 29 which, in turn, meshes with gear 29<SP>1</SP>. Gears 29 and 29<SP>1</SP> carry pins 35, 35<SP>1</SP> which extend through arcuate recesses 34, 34' in wheels 31, 31<SP>1</SP> and 33, 33<SP>1</SP> geared to rollers 12, 12<SP>1</SP> of leading blinds 11, 11<SP>1</SP> and rollers 15, 15<SP>1</SP> of trailing blinds 14, 14<SP>1</SP> respectively. An arm 39 of three-armed lever 25 is coupled to lever 39<SP>1</SP> by means of a pin 47 and both 39 and 39<SP>1</SP> are moved on depression of release button 26 to free pins 38, 38<SP>1</SP> carried on wheels 33, 33<SP>1</SP> to allow the leading blinds 11, 11' to run across. One leading blind 11 or 11<SP>1</SP> is, however, always retained by means of lever 70 or 70<SP>1</SP> actuated by flange 67 of cage 48 so that only the effective shutter is released. Moreover, if cage 48 is not correctly adjusted with respect to either film 2 or 2<SP>1</SP>, lever 81 prevents button 26 from being moved inwardly. Pin 38 or 38<SP>1</SP> is carried during exposure by wheel 33 or 33<SP>1</SP> into contact with arm 46 or 46<SP>1</SP> of a release lever for the trailing blind 14 or 14<SP>1</SP> and another arm of the lever (Fig. 4, not shown) releases pin 44 or 44<SP>1</SP> to allow the trailing blind 14 or 14<SP>1</SP> to run across. On release a return spring 96 becomes operative to move members 27, 28, 29 and 29<SP>1</SP> until the end of recess 94 strikes pin 95. Pin 35 or 35<SP>1</SP> is thus held fast as an abutment to end the movement of blinds 11 or 11<SP>1</SP> and 14 or 14'. Spool core 4 or 4<SP>1</SP> and film 2 or 2' are driven by means of coupling 89 or 89<SP>1</SP> and sprocket 91 or 91<SP>1</SP> geared through wheels 87, 88, 90 and 87', 88<SP>1</SP>, 90<SP>1</SP> to face-wheel devices (Fig. 4, not shown) which in turn are driven by wheels 31, 31<SP>1</SP>, during the winding of the appropriate shutter. The view-finder image may be formed at 104 on a field lens and viewed by means of a simple microscope and prism erecting system (Fig. 8, not shown) or by means of a compound microscope having a reflecting objective (Fig. 9, not shown).