GB708684A - Photographic pivoted apertured disc shutters provided with flashlight synchronising devices - Google Patents

Abstract

708,684. Photographic shutters including flashlamp synchronizers. AGFA CAMERA-WERK AKT.-GES. March 10, 1952 [March 31, 1951], No. 6206/52. Class 98(1) In a pivoted apertured disc shutter provided with a flashlight synchronizing device of the type in which a contact pin on the shutter disc is moved to engage a spring contact in a mounting insulated from the disc, the distance between the contact pin and the circuit making portion of the spring contact is adjustable without altering the distance between the said portion of the spring and the axis of the disc. As shown, the exposure disc 1 of a disc and cover blade shutter bears a pin 4 which engages a contact spring arm 5a mounted in an insulated boss 7 to close the flashlamp circuit prior to the opening of the shutter to compensate for the lamp lag. The circumferential position of the spring is adjusted during manufacture by sliding its supporting limb through the boss 7 which is provided with a clamping screw and which also serves as a stop limiting the exposure movement of the disc 1, the supporting limb of the spring 5 being a circular arc centred on the blade pivot. To avoid drain on the flashlamp battery if the lamp filament does not completely fuse when fired and a prolonged exposure is being made, the spring arm 5a has a depression 5b so that while the aperture 3 in the disc 1 is held over the exposure aperture 2, the contacts 4, 5a are out of engagement.