GB1533792A - Camera shutter mechanism - Google Patents

Abstract

1533792 Camera shutter SEIKO KOKI KK 13 May 1976 [14 May 1975 (2)] 19777/76 Heading G2A A shutter having opening blades 3 and closing blades 6 has a member 9 which, upon closing movement of the closing blades 6, moves the opening blades 3 back towards the closed position so that the exposure aperture 1a is at least partially covered thereby. As shown, the shutter has four opening blades 3 and five closing blades 6. By providing a large number of closing blades 6, the space required adjacent the view-finder a to accommodate them can be reduced. However their light excluding property is also reduced and it is for this reason that the return movement of the opening blades 3 is effected. To make an exposure, arms 4 and 5 are rotated clockwise to move the opening blades 3 clear of the aperture 1a, then arms 7 and 8 are moved clockwise to move the closing blades 6 into position over the aperture. As the closing blades 6 complete their movement, a projection 8h on arm 8 shifts a hook 10 to release a drive member 9 which is moved upwards by a spring 9f. Arms 9c and 9d engage pins 4g and 7g on arms 7 and 8 and thereby return all the blades 3 and 6 to their original positions. In Fig. 6 (not shown) arm 7 releases the hook; in Fig. 7 (not shown) the hook is released by the return of a reflex mirror; in Fig. 8 (not shown) the shutter has two opening and two closing blades; in Figs. 9, 12 (not shown) a pin (12) limits the movement of member 9 to reduce the size of the shutter, the return movement of the blades being only partial in this case; and in Figs. 10, 11 (not shown) only the opening blades 3 are returned by member 9.