Patent GB-923487-A (GB)
Title: Photographic camera with exposure regulating device
IPC: G03B7/14
Filed: 1959-09-02
Abstract: 923,487. Photographic cameras. AGFA A.G. Sept. 2, 1959 [Sept. 2, 1958], No. 30005/59. Class 98(1). In a photographic camera having a device for the control of diaphragm and shutter speed settings according to any one of a plurality of predetermined schedules of shutter speed/diaphragm aperture combination said device includes a plurality of selectively operable transmission members, each arranged to transmit setting movement to shutter speed and diaphragm setting members in accordance with a different one of said control schedules, and means for limiting the path of movement of said transmission members in accordance with the exposure value indicated by an exposure meter. As shown (Fig. 1), an arm 8 of a diaphragm setting ring 3 is spring urged against a cam 12 on a transmission member 15. Similarly, an arm 10 of a shutter speed setting ring 4 is also spring urged against a cam 14 on the member 15. The member 15 is displaceably supported in a guide 16 and is coupled through a lever 19 to a known type of exploratory member for an exposure meter. On depression of a release 20, member 15 is depressed to an extent depending on the prevailing light value and the diaphragm and shutter and thereby set according to a predetermined control schedule to a suitable combination of aperture and exposure time. Further depression of the release 20 against a spring 21 then actuates shutter release. A second set of control cams 11, 13 mounted on further transmission member 22 provides an alternative control schedule and is controlled by a second release 38 through an axially displaceable member 31 and a pivoted lever 27 in a manner similar to that described above for release 20. The two alternative control schedules may be such that one provides the maximum permissible shutter speed adjustment and is therefore suitable for action photographs, and the other provides the maximum depth of focus adjustment and is therefore suitable for photographs of still subjects. More than two control schedules may be provided. In an alternative embodiment (Fig. 2) the release 20 is connected by way of an axially displaceable transmission member 15 and a pin-and-slot connection 46, 44 to a rotatable setting ring 40 which is coaxial with the objective 2 and has a cam portion 47 formed therein for controlling a shutter speed setting pin 69. The ring 40 also has a projection 49 for engaging with a projection 51 on a rotatable diaphragm setting ring 52, the blades 54 of the diaphragm being pivoted at 53 and having a pin 55 engaging in a control cam 56 of a fixed ring 57. On depression of release 20, the member 15 is depressed as before to an extent depending on the light value and the shutter and diaphragm are adjusted through the ring 40, according to a first predetermined schedule, to a suitable time/aperture combination for exposure. A second release (not shown) is provided, as in the first embodiment, and this controls the shutter and diaphragm setting according to a second predetermined schedule by way of further transmission member 31 and a further setting ring 41. In a modification, rings 40, 41 may adjust the diaphragm and ring 52 the shutter speed. Specification 888,973 is referred to.