Patent GB-652532-A (GB)
Title: Improvements in or relating to photographic shutters
IPC: G03B9/70
Filed: 1947-03-14
Abstract: 652,532. Photographic shutters combined with flashlamps. KODAK, Ltd. March 14, 1947, No. 7199. Convention date, March 14, 1946. [Class 98 (i)] A photographic shutter comprising a master member operating the shutter blades, a latch for holding the master member in a " set " position, a spring-operated latch-tripping member which may be held " set " by a catch so that its operating spring is tensioned, and means for releasing the catch whereby the tripping member moves to release the master member, includes a pair of switch contacts adapted for connection in a flashlamp circuit, one contact being coupled to the tripping member when the latter is in its " set " position so that movement of the tripping member moves said contact into engagement with the second contact prior to releasing the master member to synchronize the flash with the shutter opening. As shown, the invention is applied to the setting type shutter described in the first Provisional Specification of Specification 650,874. The shutter is set by moving an arcuate slide 7 clockwise and thus rotating the master member 10 clockwise against its spring 12 to a position where it is latched by a pivoted lever 32, which is itself held stationary by a surface 39 thereon engaging a surface 40 on a member 41 spring-urged anticlockwise, but held against rotation, by a lug 8 (Fig. 1, not shown), on the slide 7. When the slide is subsequently moved anticlockwise it releases the latch 39, 40 by striking the edge 37 of the lever 32, and the tripping member 41 then rotates and drives the latching lever 32 to release the master member to make the exposure. A flashlamp L and battery B are connected to the separate members 63, 62 of a concentric terminal unit 64, the insulated pin 62 being connected by a resilient metal strip 74, insulated from the shutter casing, to a double ended arm 69, carried by the forward end of an insulated member 71 pivoted at 72, one end 70 of which forms the adjustable stationary contact of the flashlamp circuit switch, the contact being adjustable by a cam surface 80, set in accordance with a lamp " lag " scale 86, engaging an upturned lug 77 on an arm attached to the rear end of the member 71. The movable contact is formed by a pin 61 on an arm 60 pivoted at 42 above the tripping member 41 and urged against the shutter casing, which it engages at 68, by one limb 65 of a spring, mounted at 66 on the member 41, bearing against a lug 67 on the arm 60. When the shutter is set, the member 41 is rotated clockwise and the other limb 98 of the spring mounted at 66 urges the tip 88 of a pawl 87 into engagement with a detent 89 on the arm 60. On moving the slide 7 to make an exposure, the tripping member 41 then carries with it the arm 60 to complete the flash circuit at 61, 70 at an interval prior to the release of the master member determined by the position of the contact 70. Thereafter continued movement of the member 41 trips the shutter while a pin 91 on the shutter mechanism plate 15 causes the pawl 87 to pivot clockwise and so release the arm 60 from the member 41 to return to its rest position shown, opening the flash circuit, the arm 69 returning to its rest position under the action of the resilient member 74 which is flexed by movement of the end 73 of arm 69 to which it is attached. To compensate for lamps having long " lags " the movement of the tripping member after closing the flashlamp circuit may be delayed by a retarding gear mechanism 96. Specification 537,209 also is referred to.