Patent GB-190312403-A (GB)
Title: Improvements in Photographic Shutters.
Inventor: TAYLOR WILLIAM
Filed: 1903-05-30
Granted: 1904-05-12
Abstract: 12,403. Taylor, W. May 30. Shutters.-Relates to shutters for timed and instantaneous exposures and with separate adjustments for regulating the aperture and the time of exposures and for throwing out of action the automatic mechanism for closing the shutter. The diaphragm consists of a number of leaves a, Figs. 5 and 6, having reentrant angular edges round the aperture and pivoted symmetrically round a stop plate b. The diaphragm is actuated from a push h through one arm of a lever d, the other arm of which is connected through a pair of links e, e<1> to one of the leaves a. A third link e<2> is pivoted at one end to the junction of e, e<1> and at the other end to a sector plate f pivoted at its centre. By rotating an outside graduated dial f<4>, the pin f mounted eccentrically on an inner disc, moves along a slot in the plate f, thereby varying the position of the fixed pivot of the link e<2>, which regulates the aperture through the links e, e'. The operating- mechanism is contained in a slotted tube r, in which work the pistons i, k, which are kept apart at a fixed distance by a compression spring h<3>. By pressing the push h, the spring h<2> is compressed against the piston i, which, through the spring h<3>, urges a pin k<1> projecting from the piston k to override a stop l<1> on a controlling-plate l. This plate l, mounted on hinges l<4>, which are parallel to the tube r, carries a wing l<3>, Fig. 7, which is pressed against the pin i<1> projecting from the piston i ; as soon as i<1> moves far enough, the wing l<3> engages behind it as in Fig. 7<a>, and the pin k<1> is released. The piston k then slides along, pushing a pin d' in the lever d, which opens the shutter. For a time exposure, the automatic device for closing the shutter is put out of action by turning a dial o' on the outside. In this case, a rib h<1> on the push h, which has a slight rotational freedom, is deflected by the wing l<3>, and the push returns to its normal position leaving the pin i locked and the shutter open. When again pressed, the rib h' is deflected by the wing l<3>, and wedges a spring catch-piece h<5>, Figs. 6 and 7<a>, against the wing, thereby releasing the pin i<l> and allowing the spring h<4> to return the cylinders k, i, and the push h, and thus close the shutter. When the automatic device is in operation, a frame m, hinged on the outer ends of the pivot l<4>, is urged by a spring m<1> to bring the end of a finner m<3> on to a piston n' of a constant-leakage pneumatic cylinder. When the pitton is nearly depressed, an. adjustable screw stop m<4> on the frame m encounters an upward projection l<7> of the controlling-gate and raises the wing l<3>, thereby releasing the shutter. The piston is returned by a spring lightly coiled in the cylinder. By rotating a graduated dial n<6> attached to the cylinder, the piston is also rotated, and a pin n<3>, attached to the piston and working in guides, traverses a cam-surface, the piston being thus projected beyond the cylinder to any desired extent. This regulates the interval intervening before the frame m releases the controlling-wing l<3>. A further adjustment is made by adjusting the screw top m<4>. Modifications are described for further regulation of the capacity of the cylinder and for adjustments of the links e, e'.