Patent GB-770821-A (GB)
Title: Photographic camera
IPC: G03B19/12
Filed: 1955-06-10
Abstract: 770,821. Photographic cameras. DECKEL, H., and DECKEL, F. W. June 10, 1955 [June 11, 1954; July 16, 1954; July 16, 1954; Sept. 17, 1954], No. 16765/55. Class 98(1) A photographic camera with a detachable between-lens shutter and shielding means for the sensitized film is characterized in that the action of detaching or attaching the shutter can be performed only in a particular adjustment position thereof. As shown in Fig. 4, a betweenlens shutter in which an objective lens is mounted has a locking ring 28 with bayonet lugs 32 engaging a complementary ring 42 on the camera. The shutter-setting spindle 20 extends rearwardly through the shutter casing and terminates in a bush 24 formed with a tooth 26, which engages a slot 50 formed in the end of an actuating member 46 in the camera. Member 46 is connected to a film-winding mechanism which also causes the film in the exposure gate to be covered when the film has been wound; when this operation has been completed the slot 50 extends perpendicular to a line joining it to the optical axis. The tooth 26 is turned in the same direction, so that the shutter is set. A similar tooth-and-slot connection connecting the shutter release member to an operating member in the camera is similarly orientated. In this position of the parts the shutter can be rotated to release the bayonet joint. On release of the shutter, the setting members turn until the tooth 26 and slot 50 are radially disposed, so that rotation of the shutter is impossible until the film has been wound, covering the film again. The arrangement described may be applied to a single-lens reflex camera. With other kinds of camera, the removal of the shutter may be effected in its rest position. In a modification, Fig. 11, a ring 202 rotatably mounted in the camera casing has external teeth 210 engaging shutteroperating mechanism in the camera. A detachable shutter unit, in which the shutter elements are similar to those described in Specification 778,933, has a setting spindle 20 carrying a pinion 200 meshing with internal teeth 212 on ring 202. A lug 214 is formed on ring 202 in such a position that when the shutter is not set (as shown in Fig. 11) the lug is close to pinion 200 and by blocking the movement thereof prevents rotation of the shutter unit to disengage the bayonet joint. In setting the shutter, however, ring 202 rotates anticlockwise. The shutter unit can then be turned to release it from the camera, pinion 200 running on teeth 212 to run the shutter spring down. On replacement of the shutter unit, pinion 200 is rotated in the opposite direction to tension the shutter spring again. A lever 300 is fast with a pinion 302 geared to 'a pinion 306, which is connected by a one-way drive to a film spool, so that the lever can be actuated to wind the film and may return under spring action. Pinion 306 is connected by bevel gearing to a drive disc 324, which lies behind a disc 332 fast with a pinion 330 loosely mounted on a shaft 328. Pinion 330 meshes with the external teeth 210 on ring 202, and is thus connected to the setting pinion 200 of the shutter. On operation of lever 300 to wind the film, a lug 326 on drive disc 324 engages a rearwardlyprojecting lug 334 on disc 332, so that pinion 330 is rotated, thus setting the shutter. At the end of the shutter setting movement. a lug 336 on disc 332 engages behind a lug 340 on a pivoted lever 342, holding the shutter in set position. A button 346, when depressed, rocks lever 342 to release the shutter. Another lug 338 on disc 332 engages lug 340 before the shutter action ends; release of button 346 allows completion of the action. The ring 202 may alternatively have only one set of teeth, which engage both the pinions. 202 and 330. In another example. Fig. 19, the shutter has a spring 456 which bears on a flat formed on the bush 24 of the setting spindle 20 to hold it against rotation when the shutter is removed. When the shutter is replaced, a fixed pin 54 engages spring 456 and lifts it clear of the bush 24. The spring 456 may be replaced by a spring loaded pawl.