GB447761A - Photographic shutters - Google Patents

Abstract

447,761. Photographic shutters. VOIGTLANDER & SOHN AKT.-GES., 7, Campestrasse, Brunswick, Germany. Nov. 20, 1934, No. 33411. Convention date, Nov. 23, 1933. [Class 98 (i)] Relates to a shutter in which, for effecting time exposures, an intermediate member geared with the shutter blade operating member is moved by a hand operated device into a position where it is retained by a catch, the catch being released by a second operation of the hand operated device, and consists in the particular construction of hand operated device described. The lens opening 37 is normally closed by blades 7 pivoted at 38 to the annular plate 1, and is actuated by the member 6 which has pins 40 engaging in slots 39 in the blades. Teeth 5 on a part of the 'circumference of the member 6 are in engagement with teeth 4 on an intermediate disc 2. A coil spring 34 opposes the movement of the disc 2 to open the shutter. The hand device comprises a cylinder 14 containing a plunger 17 operated by a cable against the opposition of a spring 22 and a rod 20 which moves in a slot 25 in the head 24, and is integral with a disc 21 allowing lateral swinging movement of the rod 20. The intermediate member 2 is formed with a concave arm 23. When a " time " exposure is to be made, the rod 20 is actuated, engages the arm 23, and rotates the disc 2 to open the shutter. The disc 2 is held in the extreme position by the nose 12 of a latch 9 engaging a nose 13 on the disc 2. The movement of the disc has moved the rod 20 laterally, but when this rod is withdrawn it returns to its original position. Then when it is moved forward again, it engages the concave arm 11 of the latch 9, releases the nose 13 and allows the disc 2 to turn and close the shutter. For a " bulb " exposure, the latch 9 is retracted by a hand operated cam ring so that it does not engage the nose 13. If it is desired to make an instantaneous exposure, a master member 26 is brought into operative connection with the shutter ring 6. The disc 2 is mounted on a pair of links 32, Fig. 5, so that it can be swung out of engagement with the blade operating ring 6 and into engagement with the teeth 30 of a pivoted pawl 28 which is holding the master member. Rotation of the disc 2 by the rod 20 then swings the lever 28 to release of the master member and open the shutter for a predetermined time. Specification 365,753 is referred to.