Patent GB-909242-A (GB)
Title: Reflex camera
IPC: G03B19/12
Filed: 1959-07-20
Abstract: 909,242. Single-lens reflex cameras. AGFA A.G. July 20, 1959 [Aug. 2, 1958], No. 24903/59. Class 98 (1). In a single lens reflex camera having a manual release arranged on actuation to cause limited displacement of a shutter release through a coupling means, and a spring driven mechanism, triggered by the manual release, for carrying out the exposure functions (which are the functions which must be carried out in a single lens reflex camera in order to make an exposure, starting from the position in which the camera is set for use as a viewfinder), the said mechanism is arranged to effect opening of the shutter by moving the shutter release beyond its limit of displacement by the manual release, is then arranged to allow it to return to the said limit to engage the manual release through the coupling means and is arranged so that when set to bulb exposures, closing of the shutter does not take place until the manual release is liberated, thereby allowing the shutter release to complete its return movement. The camera is shown ready for exposure in Fig. 1. The sequence of events leading to an exposure is as follows. On depression of a manual release 53, a release strip 53b fixed thereto is moved downwards until stopped by a fixed plate 52, a release slide 43 is moved downwards, due to the engagement of a projection 51 by the end of a strip 53b, and a shutter release 48 is displaced through an amount insufficient to release the shutter by an extension 46 of slide 43. At the same time, a detent portion 56 carried by the slide 43 is moved out of the path of an abutment 37 and a crown-wheel 16 forming part of the spring-driven mechanism is thereby freed to rotate in the direction of the arrow under spring loading. As the wheel 16 rotates, drive transmitted through a gear-wheel 59 is used to close the shutter blades and to adjust the diaphragm aperture (in known manner) to a predetermined value. At the same time, control discs (not shown) carried by the crownwheel spindle 17 are used to pivot upwards the mirror and cover flap (not shown). Near the end of the rotation of the wheel 16, a projection 36 comes against a lever 38, which is connected to the slide 43 by way of a pin-and-slot connection 41, 42, and the shutter release 48 is thereby further displaced by an amount sufficient to effect shutter release. At the end of the exposure time, the shutter blades close automatically unless the shutter is set for a " B " exposure, in which case they remain open until release 53 is liberated, release 48 and slide 43 then returning to their original positions (shown in Fig. 1) under spring loading. When the film is wound on by turning a quick-setting lever 8 in an anticlockwise direction, a gear-wheel 12 is rotated in the direction of arrow 34 by means of gear-wheels 11, and, at the same time, claw 19 of a lever 18 is engaged and moved to the right by a pin 13, a slide 21 is moved to the right by the lever 18 pivoted thereon, shutter setting ring 30 is rotated in an anticlockwise direction by the slide 21 having a pin-and-slot connection 27, 28 therewith, and the shutter setting spindle 32 is rotated by the toothed portion 31 of the ring 30 for cocking of the shutter. While this is happening, a gear-wheel 15 is rotated due to the engagement of a pin 14 by a pin 13, and wheel 16 is thereby rotated against its spring loading until a projection 37 becomes engaged by the detent 56, as a result of which the mirror and cover flap are pivoted downwards through the aforementioned control discs on spindle 17 and the shutter blades and diaphragm aperture are opened wide by rotation of gear-wheel 59. The lever 8 has an idle return stroke.