GB591106A - Improvements in or relating to photographic shutters - Google Patents

Abstract

591,106. Photographic shutters. KODAK, Ltd. Aug. 17, 1944, No. 15762. Convention date, Sept. 4, 1943. [Class 98 (i)] A photographic shutter has an adjustable diaphragm and a setting lever which are interconnected so that the diaphragm leaves cap the exposure aperture prior to the tensioning . operation, a spring-urged member acting on the diaphragm lever being rendered inoperative during the setting movement and allowing a weaker spring to move the 'diaphragm leaves to the position of the desired aperture for the exposure. The diaphragm leaves 4 are pivoted at 5 and have a pin-and-slot connection 7, 8 with the diaphragm ring 9. The latter carries an arm 10 engaged by a pin 12 on an arm 13, the upper part of which is a spring finger running in a series of notches on the cover to determine the aperture setting. A pin and slot 18, 19 connects the ring 9 and a lever 20. The pivot point 21 of the lever 20 is encircled by a spring 22 which urges the lever anti-clockwise, bringing the arm 11 up against the pin 12. The spring 22 is, however, weaker than a spring 24 which moves a member 25 against the lever 20 in a clockwise direction and normally holds the leaves closed. When the setting lever 29 and slide 28 are moved to tension the shutter, a cam projection 38 on the slide engages a pin 39 on the member 25 to swing it aside, in which position it is held by a pivoted latch lever 32, and the spring 22 then swings the diaphragm leaves to the aperture position previously determined by the setting of the arm 13. When the exposure is made and the shutter runs down, a cam 40 engages a pin 41 on the latch 35 and releases the member 25 which closes the diaphragm leaves. The shutter is of the symmetrical opening type with doubleended blades actuated by two oppositely moving concentric rings and a connected master member. Specification 491,885 is referred to.