Patent GB-927286-A (GB)
Title: Improvements in or relating to photographic cameras
IPC: G03B17/08
Filed: 1959-09-18
Abstract: 927,286. Photographic cameras. ALFRED GAUTHIER G.m.b.H. Sept. 18, 1959 [Dec. 31, 1958], No. 31823/59. Class 98 (1). A photographic camera having a lens diaphragm settable according to an exposure-determining means has two movable setting members each of which may be selectively drivably connected to the spring- loaded diaphragm setting mechanism, one of which members is movable by a drive within the camera into a position determined by the exposure-determining means, the other member being movable by hand into an " automatic " position in which the diaphragm is set by the first member and into a range of " non-automatic " positions, the hand-movable member in the " automatic " position and the first member in the " non-automatic " positions being respectively at the beginning of the exposure, in a position corresponding to maximum or minimum diaphragm aperture and in which the influence of the respective member on the diaphragm is removed. As shown (Fig. 11) a projection 8a on an actuating ring 8 for controlling diaphragm blades 6 is constantly urged by a spring 33 into contact with an arm of a lever 31 which is pivoted at 32 and has a pin 34 controlled either by a cam 15d in an " automatic " setting ring 15 settable in accordance with the photo-electric exposure determining means or by one of the cams 22f, 22g or 22h on a ring 22 controlled by the manual setting ring 41 through a cylindrical connecting portion 22i (Fig. 12). For " automatic " setting of both the diaphragm and shutter, ring 41 is adjusted until the mark " AUTO " on the connecting portion 22i regis. ters with the index 50 on a portion 1d of the camera body 1-a spring detent device 62 (Fig. 18) being provided for releasably holding the ring in this set position. In this position when the shutter is cocked, the setting ring 15 is rotated against spring tension and is locked in an end position corresponding to minimum aperture. On shutter release, the ring 15 is released and runs down under spring tension until a scanning member connected thereto by way of a shaft 17 (Fig. 12) is stopped in known manner by the photoelectric exposure determining means 14 (Fig. 18), the diaphragm aperture then having been set through members 31 and 8 and the shutter speed having been set by means of a setting ring 44 (Figs. 12 and 13) connected for rotation with the ring 15 by an arm 15e thereon and having a cam 44b for controlling the shutter speed control pin 45. The shutter includes a delay mechanism to allow for these setting movements. For " non-automatic " setting of the exposure factors the ring 41 is adjusted to move the mark "AUTO" out of register with the index 50. As a result of this adjustment the galvanometer 19 of the exposure determining means is short circuited by a switch 25 (Fig. 18) controlled by the ring 22 and the ring 15 is driven into the position shown in Fig. 11 in which it does not influence further diaphragm setting. At the same time-prior to each exposure-ring 44 is moved by ring 15 to an end position corresponding to a speed of <SP>1</SP>/ 30 th sec. For Flash exposures, ring 41 is adjusted until the mark " FLASH " registers with index 50 and the required diaphragm value is then set through cam 22f using scale 47 on cylindrical portion 22i and the index 50 (cf. Fig. 17, not shown). For daylight exposures, ring 41 is adjusted until the mark " MAN " registers with index 50 whereupon cam 46a (Fig. 13) on ring 46, rotatable with ring 41, adjusts pin 45 to a position corresponding to a speed of <SP>1</SP>/ 125 th sec., and the diaphragm is then set through cam 22h using an exposure value scale 49 and index 50 (Fig. 16, not shown). For Bulb exposures, ring 41 is adjusted until mark " B " registers with index 50, whereupon a cam portion 41a (Fig. 13) of the ring 41 allows a lever 40 to move into a position in which a projection 40a thereof is able-on shutter release-to engage a projection 38a of shutter driving member 38 and hold when the shutter blades are in their open positions. In the case of " B " exposures the diaphragm is set through cam 22g using scale 48 and index 50 (cf. Fig. 15, not shown). A warning device (Fig. 18) may be arranged so that when the diaphragm setting ring is not in the "AUTO" position and when the shutter release 55 is partly depressed, against spring 57, contacts 53 and 54 are made and a lamp 51 is thereby illuminated in the viewfinder to indicate that automatic setting is not in operation. Alternatively, a flag may be moved by mechanical means into a position visible in the viewfinder when the setting ring is not in the "AUTO" position. In a modification (Fig. 6, not shown) only one cam on ring 22 (For " FLASH " exposures) is provided, and in a further modification (Fig. 1, not shown) the shutter speed setting ring is not operated by ring 15, but is set manually. In this latter modification, in the "AUTO " setting position, the said exposure determining means is adjusted in known mechanical, electrical, or optical manner to compensate for the setting of the shutter speed setting ring, and the diaphragm is adjusted as before.