Patent GB-852816-A (GB)
Title: Improvements in and relating to photographic shutters
IPC: G03B9/42
Filed: 1957-01-24
Abstract: 852,816. Photographic shutters. VOIGTLANDER A. G. Jan. 24, 1957 [Jan. 25, 1956], No. 2609/57. Class 98(1) The shutter is of the sliding plate type and is constructed as a closed, complete and fully operable unit which as such can be mounted in a desired camera body. As shown, the shutter is housed in a casing 2 secured in a photographic roll-film camera by screws 3 and provided with guideways 5, 6 for a film as it passes from a supply spool 7 to take-up spool 8 across an image gate 4 in the casing 2. This image gate is opened by one group of sliding plates 17, 171, 172 and closed by a second group of sliding plates 16, 161, 162 which project through slots in a sub-casing 38 housing the shutter operating mechanism. The plates 16, 17 are respectively supported on carriers 14, 15 slidable on rods 10, 11, the plates 161, 171 are slidable on a rod 12 and plates 162, 172 are slidable on a rod 13, the four rods being parallel to a shorter side of the image gate 4. The carrier 15 is joined by a cord or chain to a drum 52 which is rotated to load the shutter; the drum spindle projects out of the casing 2 and may be connected to the film wind mechanism so that the shutter is loaded as the film is wound on. Such rotation of the drum raises carrier 15 and the slide 17 against the action of a spring 31 and at the same time a lug 49 on carrier 15 engages a pin 50 on carrier 14 so that the latter and the plate 16 also rise against the action of a spring 30. During this upward movement of carrier 14 a lug 29 thereon engages a lug 25 on plate 161 and subsequently a lug 26 on plate 161 engages a lug 28 on plate 162 so that the three plates 16, 161 and 162 move to one side of the image gate 4. At the same time a lug 23 on carrier 15 engages a lug 18 on plate 171 and a lug on this plate subsequently engages a lug 21 on plate 172 so that the plates 17, 171 and 172 move in overlapping relationship to cover the image gate. Throughout the upward movement, the two plates 16, 17 overlap. At the completion of the movement the carriers 14, 15 are latched by pivoted latches 34, 35. The pivot of latch 35 projects outside the casing 2 and may be connected to a shutter release on the camera. The latch 34 is linked at 46 to a push rod 44 projecting from a delay device 48 and adapted to be actuated any desired time after a rod 42 is moved by a lever 41 which is engaged by a pin 39 on carrier 15 during the downward exposure movement thereof. To start such a movement, latch 35 is released so that carrier 15 and its attached plate 17 are pulled down by spring 31 and during this movement, the lug 23 successively engages lugs on the plates 171, 172 so that the plates 17, 171, 172 move into overlapping relationship to the lower side on the image gate 4. After the required delay introduced by device 43, latch 34 is released and plates 16, 161, and 162 move downwardly to cover the image gate 4. The delay device is adjustable by a spindle 48 which projects out of casing 2 and may be coupled with a shutter speed setting member on the camera. The width of the slit formed between the two groups of plates is adjustable by varying the position at which lever 41 projects into the path of pin 39.