GB613537A - Improvements relating to photographic camera shutters - Google Patents

Abstract

613,537. Photographic shutters. KODAK, Ltd. March 6, 1946, No. 6997. Convention date, Jan. 5, 1945. [Class 98 (i)] A photographic camera shutter having blades operated by one or more blade rings incorporates an auxiliary device for opening the shutter for focusing without disturbing the normal release means or exposure setting, said device comprising a pivoted driving member carrying a projection engageable with a recess in a blade ring to move it so as to open the blades. As shown, the shutter itself, of the between-lens setting type, is identical with that of Specification 613,531. On the mechanism base-plate 15 are concentric annular slideways for a pair of blade rings 18, 19, linked by pin-and-slot connections 25, 26 and 27, 28 to an arm 23 pivoted on the base-plate at 24 so that the rings always rotate in opposite directions to open and close double-ended symmetrical shutter blades 3 which are pivoted at 20 on the blade ring 18 and have pin-and-slot connections 21, 22 with the blade ring 19. The shutter is set by moving the operating slide 37 clockwise, when nose 40 engages an arm 30 on the blade ring 19 which in turn engages a pin 31<1> on the master member 31, pivoted at 32 on an arm 33, itself pivotally mounted on the plate 15 at 34 and spring-urged anticlockwise against a stop (not shown), the master member being rotated against a spring 44 to a position where the right-hand end 41 of a lever 57, pivoted on the base-plate at 58, snaps behind a lug 42 on the master member to hold it set. As a result of the setting movement, the tail 50 of a lever 48, pivoted at 49 and spring-urged anticlockwise, moves into engagement with a tooth 53 of the ratchet-wheel 51. The shutter is released by moving the slide 37, which after each actuation is returned to its rest position by springs 137, in an anticlockwise direction when a lug 471 engages arm 47 of the lever 48 to disengage the tail 50 from the ratchet 51 which then rotates clockwise to trip the latch 41 and release the master member to drive the blade rings. The device for opening the shutter for focusing is operable by a knob 10 (Fig. 7, not shown), and consists of a member 62, having a tooth 63 adapted to engage a notch 64 and tooth 65 on the blade ring 18 and also an abutment 63<1>. To operate the device, the shutter must first be set when notch 64 is brought opposite the tooth 63 which together with the abutment rides on the blade ring when the shutter has been released. The usual preexposure adjustments of shutter speed, diaphragm aperture may be made and the knob 10 then rotated anticlockwise against spring action, until the abutment 63<1> engages the ring 18, to open the shutter which may be held open by a " pimple and dimple " latch between the knob and the shutter casing. After focusing this latch is disengaged and the knob 10 returned to its rest position when the shutter is again in the set position ready for anticlockwise movement of the slide 37 to make an exposure.