Patent GB-916462-A (GB)
Title: Photographic camera
IPC: G03B7/00
Filed: 1959-07-02
Abstract: 916,462. Photographic cameras. AGFA AÀG. July 2, 1959 [July 12, 1958], No. 22776/59. Classes 97 (1) and 98 (1). A photographic camera having for exposure value setting a diaphragm setting means and a shutter speed setting means, the diaphragm setting means being selectively couplable, one at a time, both with said shutter speed setting means and with a focus setting means, comprises for effecting such coupling and for operation of all three specified setting means a common master setting means having a plurality of defined axial coupling positions and including a setting ring which is coaxial with the objective and is rotatable and axially displaceable with respect thereto and on the said ring a radially movable slide adapted to couple the said ring for common rotational movement either with a control ring for the focus setting means or with a slide axially movable into a plurality of coupling positions for control of the exposure value setting. As shown (Figs. 1 and 2), a camera includes a shutter speed setting ring 3, a fixed index 80 for co-operation with both a speed scale 4 and an aperture scale 61 and may also include a bayonet locking ring 6 for attaching interchangeable objectives.. Such an objective tube includes-as shown-bayonet lugs 8 and a tube sheath 7 on to a fine thread 10 of which is screwed a bush 11. On a coarse thread 13 of this bush 11 is mounted an axially displaceable lens carrier 14, which is prevented from rotating by a pin and groove arrangement of known construction. The bush 11 encloses a diaphragm mechanism (not shown) which is coupled to a diaphragm setting ring 54 through a projection 84 and arms 83, 85 of a ring 36. For flashlight photographs the camera is used in the set position shown in Figs. 2 and 3 in which position the diaphragm and focus setting means (described hereafter) are coupled in such a way as to maintain a constant flash guide number. Rotation of a common master setting means comprising ring 23 and slide 26 is transmitted to the lens carrier 14 for focusing adjustment of the camera through engaging toothed portions 27, 28, a control-ring 20, coupling means 19, a focus scale support 18 through which a fixed index on a ring 33 is visible (see Fig. 1) and members 17, 16 and 11. At the same time (see Fig. 3), movement of the ring 20 is transmitted to the diaphragm setting ring 54 through a conversion gearing comprising a segment wheel 39 having a pin 38 engaging in a cam slot 37 cut in the ring 20, pinion gears 42, 43 and a gear-wheel 44, and also through a toothed member 45 fixed to a disc 46, and toothed coupling portions 51 and 56. To set a different flash guide number, slide 26 is depressed against loading of a spring 25, and the master setting means 23, 26 is displaced a short distance in the direction of the arrow " x," whereupon the conversion gearing and members 20, 41, 46 and 66 are similarly displaced, toothed coupling portions 51, 56 are disengaged, and a ball catch 74 engages in a groove 65. On rotation of the setting means 23, 26 in this position, with the slide 26 still depressed, the diaphragm ring 54 is rotated through now-engaged coupling means 71, 68 and 70, 58. The new flash guide number is indicated through a window 76 by a scale sheath 60 which is connected for rotation with the ring 54 by an arm 62. For daylight photographs, the setting means 23, 26 is displaced, as described above, and is rotated with the slide 26 depressed, until the required diaphragm value on the scale 61 on the cover ring 59 attached to the ring 54 registers with the index 80. Alternatively, the index 81 on the ring 59 is set to the required light value on a scale 5. -The setting means 23, 26, may be used in this displaced position for focusing the camera, by releasing slide 26, whereupon a guide projection 29 thereon engages with the middle groove 31 of three position-defining annular grooves 30, 31, 32 provided in the ring 33, coupling 68, 71 is broken, and toothed portions 27, 28 of the focusing mechanism are re-engaged. For changing the shutter speed-diaphragm aperture combination at constant light value, the slide 26 is depressed and the setting means 23, 26 is displaced further in the direction " x " into its rear end position, in which position projection 29 corresponds to groove 30, and ball catch 74 engages in one of the holes 64. Rotation of the setting means 23, 26 (with slide 26 depressed) is then transmitted through couplings 71, 68 and 69, 73 to the shutter speed setting ring 3, and through couplings 71, 68 and 74, 64, to the diaphragm setting ring 54. Should the diaphragm setting ring 54 arrive in one of its two end positions during this rotation, the ball 74 is displaced into one of the other holes 64, and the light value is changed. The camera may be focused in this rear end position by rotating setting means 23, 26 with slide 26 released. As an indication that the common master setting means is in its correct axial position for the purpose required, symbols 78, and 79 (Fig. 1) are arranged so that only one is visible at a time, the particular one depending on the position of the said setting means. Depth of focus indication.-The focusing scale support 18 is transparent and overlies part of a fixed ring 33, the front end of which is cut in steps 35 (Fig. 1). Underneath this ring, is an axially movable indicator ring 82 (Figs. 1 and 2) which co-operates with the steps 35 and the focusing scale for indicating the depth of focus and which has one tongue 87 guided by a groove 86 in the ring 36 and another tongue 88 guided in an axial groove 89 in the ring 33.