Patent GB-483053-A (GB)
Title: Improvements in or relating to photographic shutters of the pivoted-blade-between-lens type
IPC: G03B9/22
Filed: 1936-10-08
Abstract: 483,053. Photographic shutters. SOKAL, S. (Ihagee Kamerawerk Steenbergen & Co.) Oct. 8, 1936, No. 27367. [Class 98 (i)] Two relatively adjustable rings bearing cam-like projections are retarded in their running down movement by means of a single escapement mechanism, and the projections successively operate a system of catches and levers to give a delay action and a shutter action of adjustable period. The actuating ring 3, Fig. 11, for the pivoted blades is oscillated by a pivoted rocking arm 9, 10 which has a pin 13 engaging a fork-like carrier 15 on the ring 3. A spring 12 urges the shutter ring 3 to the " open " position but is normally restrained by levers governing the exposure: Two adjusting rings 22, 23 are rotatably mounted on the objective ring 21 of the camera, the ring 23 having a carrier pin which engages in holes 26 in the ring 22. Cam-shaped projections 30, 31 are mounted on the rings 22, 23 respectively so as to be adjustable in angular relation. A helical spring 28 extends between a pin 27 on the ring 22 and a stationary pin 29. The shutter mechanism is wound up by turning the rings 22, 23 and tensioning the spring 28. The ring 22 is coupled with one 33 of a series of pinions comprising the retarding device, the series being mounted on a swinging support 34 so that they are out of engagement with the ring 22 when the shutter is wound up. A locking hammer 42 acts as the anchor of the retarding device. A series of two armed levers are pivotally mounted inside the shutter casing. The lever 48, 49 engages at the end 48 with the rocking arm 9, 10, and at the end 49 with the locking hammer 42. The release 19 swings the lever 48, 49 against the action of a spring 63. The lever 50, 51 is also pressed by a spring 65 against the rocking arm 10, and its other end 51 rests against a pin 66, on a pivoted lever 58, 59. A spring 67 stronger than the spring 65 turns this lever in a clockwise direction against a stationary pin 68. The arm 58 is wedge shaped and the lever is axially displaceable against a compression spring. The lever 54, 55 is loosely mounted and co-operates with a pin 70 on the projection 30. The lever 56, 57 has a stop 72 in the path of the cam 30, and at the other end a hook 57 engaging a hook 62 on the lever 48, 49. When the shutter is tensioned and the release 19 pressed, the end 48 moves away from the rocking arm 10 and the end 49 releases the hammer 42 which oscillates and allows the braking device to run down for the period of delay action. As the rings 22, 23 turn, the wedge shaped cam 31 passes under the lever arm 58 which is raised and released from the locking pin 68. The lever 58, 59 thereby swings in a clockwise direction, engaging the lever 50, 51 and moving it away from the rocking arm 10. The spring 12 then moves the arm 10 to open the shutter. The lever 55, pin 72 and carrier pin 40 are not in the path of the projection 31, but the cam 30 has a pin 70 which engages the lever arm 55 to swing the rocking arm 10 back into the shutter closing position. Finally the cam 30 strikes the pin 72 and releases the hook 57, allowing the lever 48, 49 to return to normal position. When the shutter is rewound the cam 31 moves the lever 58 over the pin 68. For exposures without delay action or for time and bulb exposures, the adjusting lever 20 is pressed and moves a locking tooth 52 into a recess 64 in the lever arm 50 which is at the same time lifted away from the locking arm 10. The lever part 53 then comes into the path of the cam 31. For " Bulb " exposures a cam is caused to swing away the locking lever 56, 57 so that when the release is actuated, the shutter blades are operated, and when released, the blades are closed. For instantaneous exposures, the rings 22, 23 are turned until the cam 31 strikes the lever 53. When released, the shutter remains open until the cam 30 causes the closing of the shutter in the manner previously described.