Patent GB-969334-A (GB)
Title: Photographic camera with an exposure value setting device
IPC: G03B7/12
Filed: 1960-12-28
Abstract: 969,334. Photographic cameras. AGFA A. G. Dec. 28, 1960 [Dec. 30, 1959], No.44526/60. Heading G2A. A photographic camera comprises an exposure value setting device providing a plurality of optional control programmes in each of which a different predetermined series of shutter speed and diaphragm aperture pairings is available corresponding to the same range of exposure values, a changeover device being provided for the preselection of the desired control programme. To set programme I the programme selector 50, Fig. 1, is rotated until the symbol I registers with a fixed index. The cam surface 48 positions a rod 40 opposite a slot 43 in the fixed plate 42. On depression of a measuring key 8, a spring 4 rotates the ring 1 until the slide 12 is arrested by its follow up arm 33a contacting the pointer 25 of an exposure meter 26 clamped by jaws 23, 24. A pin 36 on ring 1 rotates a ring 37 which moves pin 40 along slot 43. Pin 40 abuts a surface 55a to rotate ring 53 to set the diaphragm, whilst moving freely in a slot 52b to leave the shutter setting ring 54 unmoved. When the diaphragm is fully adjusted, . pin 40 reaches an abutment 58 and begins setting the shutter speed. Selector 50 is rotated until pin 40 is opposite slot 44 for programme II in which position pin 40 abuts the surface 57 and slides in a slot 51b, or opposite slot 45, for programme III in which position both rings are rotated through half the angle of ring 37. For manual setting, selector 47 is rotated until the symbol H registers with the fixed index. In this position shields 100, 101 uncover milled edges 72, 74 of rings 70, 71 and a cam 83b permits a locking pin 82 to enter the notches 85-88 in rings 53, 54, 70, 71 respectively. Rings 70, 71 are set manually and retained in their set positions by ratchets 68, 69. A further setting range 91 is provided to set very slow shutter speeds. Pin 82 also enters notch 5b to prevent actuation of key 8. Ring selector 57 may be replaced by a slide or lever (Figs. 3 and 4 (not shown) ). In a second embodiment, Figs. 6 and 7, programme II is set by moving a selector 224 axially until a spring ring 226 engages an annular notch 225a. In this position a pinion 214 meshes with toothed portions 216, 232 on a diaphragm setting ring 215 and the selector 224 which also acts as shutter setting ring. On actuation of the measuring button 207, an arm 203 rotates taking with it pinion 214 until a cylinder 210 is arrested by the pointer 211 of an exposure meter 212. Since ring 215 is braked by a spring brake 235, selector 224 rotates through twice the angle of arm 203. When the shutter is fully adjusted, the selector is immobilised and the force of spring 325 is overcome to set the diaphragm. When spring ring 226 engages the notch 225b, spring 235 engages the surface 224e of selector 224 and is lifted clear of ring 215, for operation according to programme I. Programme III is selected by engaging ring 226 with notch 225c in which position a pin 233 enters an aperture 234 to lock the selector 224 to ring 215. For manual operation, ring 226 engages notch 225 and selector 224 and ring 215 are rotated by means of finger pieces 230, 222 respectively. In a third embodiment, the programmes are selected by rotating a cam 266, Fig. 8, coupled to a selector 267. In the position shown cam follower 254a is in contact with a raised portion 266a of cam 266 and, on rotation of the ring 260 coupled through a bar 259 and ring 250 to a slide 258, the lug 264b engages pin 264b. Cam follower 265a on low portion 266b of cam 266 does not engage pin 271 for diaphragm adjustment until shutter adjustment is complete. When selector 267 is in the position for hand setting a pin 297 engages a slide 300 which brings pins 314, 315 into contact with ratchets 295, 296 to permit hand setting of rings 276 and 282 by finger pieces 293 and 294.