Patent GB-190811687-A (GB)
Title: Improvements in or relating to Photographic Shutters.
Filed: 1908-05-29
Granted: 1909-05-27
Abstract: 11,687. Kodak, Ltd., [Marks, P. J.]. May 29. Iris diaphragms have exposure blades shaped to form a star-shaped opening and controlled by mechanism mounted on one assembling plate; this plate carries a rotatable ring operating the iris - diaphragm blades. The front lens system is carried by a collar 5, Fig. 3, on the front 3, which is secured to the back 1 by screws or rivets 4; the rear lens system is carried by a collar 6 mounted in the usual carriage on the camera front. A flange 7 on the collar 6 is secured by screws &c. to the casing 1; between them is a ball-race for balls 9 carrying a ring 10 defining the exposure aperture. The balls are retained by a ring 12, . which is screwed on the ring 10 and provides an adjustment for wear. The forward edge of the ring 10 is expanded tightly within a ring 14, which carries five shutter blades 16. The blades during their closing and opening movements form a five-pointed star-shaped aperture. Bosses 17, Figs. 11 and 14, form pivots for the blades which have shoulders 23 forming bearings, and similar shoulders 24 working round bosses 22 formed in the casing 1. Each blade is provided with a projection 25, Fig. 11, to maintain it in its relative position. Hollow pins or collars 35 on the diaphragm blades 32 are upset in apertures in an adjusting-ring 36 rotating within an assembling-ring 30, which carries the remainder of the shutter mechanism. The ring 36 is secured by the heads of screws 39 to the ring 30, which has slots 34 guiding pins 33 on the diaphragm blades. To adjust the diaphragm, the ring 36 has a shoulder 40, Fig. 2, with fingers 41 receiving a pin 42. Fig. 1, carried by a ring 44 and working in a slot 43 in the front 1 of the shutter. The ring 44 has an arm 45 bent round a scale 46, which serves to keep the ring 44 in position. The assembling-plate 30, Figs. 11 and 14, has apertures 29 receiving the bosses 22, and rests on the shoulders 24 of the shutter blades 16, retaining them in position; the pivots 17 slide in apertures 50 in the plate 30. A projection 52, Fig. 2, on the blade-operating ring 14 extends through an aperture 51 in the plate 30, and is actuated by a finger 54 at one end of a master member 63 pivoted at 53. The projection 52 is held by a spring 57 against a shoulder 28 in. the slot 51. The finger 54 is bevelled so as to ride over the projection 52 when rotated forwards. A shoulder 55 on the member 63 moves the projection 52 and-opens the shutter blades, and the end 56 of the finger 54 is shaped to hold the projection 52 in retracted position until the end 56 has moved out of its path. The spring 57 is loosely coiled around a screw 58, and has one end looped around the end of a spring 60 coiled on the pivot 53; this spring 60 has an end 61 bearing against a projection 62 on the master member to return the latter to its normal position. The operating-finger 65 is pivoted at 64 and has a projection 66 engaging a projection 67 on the member 63, which is released when the paths of the projections separate. The finger 65 is returned by a spring 68 and the underside of the projection 67 is bevelled for it to ride over the finger 65. The shutter as shown in Fig. 2 is set for a time exposure; on movement of the member 91 for bulb exposures, a projection 97 on the limb 96 engages a cam-surface on the time lever 77 and moves it outwards, out of action. The index ring 95, Fig. 1, retains in position the diaphragm-actuating ring 44 and also the bulb lever 104, which has a projection engaging a boss 107, Fig. 2, on the operating-finger 65. The depression of this finger releases the bulb lever 70 before the master member 63, so that the projection 73 is caught on the stop 72 and is not released until the finger 65 is released which moves the lever 70 inwards. On the next movement of the member 91, the projection 97 engages a cam 99 on the bulb lever 70 and moves it inwards out of action. This gives an instantaneous exposure. Upper and lower journal bearings are provided on the parts pivoted on the studs 53, 64, 71, as by an ear 108, Fig. 3, on the member 63 pivoted at 53; these bearings also provide bearings for the operative springs carried by the pivots.