GB537208A - Improvements in or relating to photographic shutters having built-in flash lamp synchronising devices - Google Patents

Abstract

537,208. Synchronizing flash-lamps and photographic shutters. KODAK, Ltd. Aug. 26, 1940, No. 13469. Convention date, Jan. 23. [Class 98 (i)] In a setting-type shutter with built-in flash lamp synchronizing means, a setting-lever, after setting the master-member, is movable relatively to it, but without releasing it, to a set position in which it is held by a trigger release; after release of the setting-lever by the trigger a contact movable with it engages a fixed contact to complete the flash-lamp circuit before the setting-lever releases the mastermember to open the shutter blades, in order to allow for the lag in the operation of the lamp. In the form shown, a master-member 6 pivoted at 7 and urged in a counter-clockwise direction by a spring 9 operates the blade ring in known manner through a latch 33 pivoted to it. The setting lever L is carried by an arcuate member 16 slidable in a similar slot 17 in the shutter body. On moving it from the unset to the set position shown, a pin 14 carried by it operates in a slot in the master-member to rotate this member to its set position, after which the pin moves out of the slot and rides over a shoulder 13 latching the master-member. The lever L is latched against the action of a return spring 18 by one arm of a bell-crank lever 23 which engages a lug 24 on the arcuate member 16. On depression of the release trigger 5, a nose 28 on it engages an upturned ear 29 on the other arm of the lever 23 which is rocked to release the arcuate member 16, and with it the setting- lever L, which then move to the left, under the action of the spring 18. During the first part of this movement, while the pin 14 is riding back over the shoulder 13 of the mastermember, which is still latched by it, a contact member 42 on the arcuate member 16 wipes past the end 43 of a spring contact member 40, and completes the flash lamp circuit. Subsequently the pin 14 enters the slot in the mastermember, which then operates the shutter blades. To prevent closure of the lamp circuit on setting the shutter, the end 43 of the contact member 40 is normally retracted from the path of the member 42, but when the trigger 5 is depressed to make the exposure an insulated lug 47 on it engages the member 40 and forces the end 43 into the path of the contact 42. The interval between the closing of the lamp circuit and the operation of the shutter blades may be varied by adjustment of the speed of movement of the setting-lever by varying the tension of the spring 18, for which purpose the pin 19 to which the spring is attached is adjustable along the periphery of the shutter casing. The electric leads are connected by means of a plug 52, one connection being by way of the metal body of the plug and the metal parts of the shutter to the contact 42, and the other by way of a central insulated prong in the plug which contacts with the insulated spring contact member 40. Specification 540,476 is referred to.