GB207637A - Improvements in or relating to shutters for photographic cameras - Google Patents

Abstract

207,637. Houghton-Butcher Manufacturing Co., Ltd., Denniss, A. J., and Edwards, V. W. Sept. 8, 1922. Shutters.-A tortuous or zig-zag guideway and a co-operating pin are introduced into the shutter mechanism between the shutter and a pivoted or hinged member, so that the latter is caused to oscillate during the exposure. The invention is applicable for fixed speed shutters and is adaptable as the controlling means for variable speed shutters. In a fixed speed sliding plate shutter the pin A<1>, Fig. 1, on the shutter blade A engages the zig-zag slot D<1> in a plate D pivoted at one end C to the camera front B. In a variable speed sliding plate shutter, Fig. 5, one arm of the lever M has a pin engaging the slot N<1> in the pivoted plate N and the shutter speed is controlled by setting the other arm in the path of the shutter pin L<1> according to a speed scale and so varying the length of travel of the pin in the slot N<1>. In a fixed speed pivoted blade ever-set shutter, Fig. 4, a pin J<1> on the operating bell crank lever J, travels in the zig-zag slot H<1> on an oscillating plate H which is pivoted at one end H<2> to the shutter blade G. In a variable speed shutter of the diaphragm type, Fig. 6 the end Q<1>, of a lever Q is raised against a spring R by a hand operated lever (not shown) until the latter clears and releases the end Q<1> which permits the spring R to operate the shutter leaves S, S<1>. A fixed pin Q<2> on the lever Q works in a slotted link T, to one end T<1> of which is pivoted a plate U having the zig-zag slot U<1> which moves over a fixed pin V. The other end T<2> of the link T is pivoted to a bell-crank lever W rocking on a fixed pivot W<1>, the longer arm W<2> of which acts as a setting lever to vary the retarding effect of the link T and plate U.