Patent GB-809068-A (GB)
Title: Improvements in or relating to photographic camera shutters
IPC: G03B9/58
Filed: 1955-04-27
Abstract: 809,068. Photographic camera shutters. GAUTHIER G.m.b.H., A. April 27, 1955 [May 13, 1954], No. 12173/55. Class 98(1) In a photographic camera shutter having a self-timer delay mechanism which is normally released by the running down movement of the shutter operating mechanism, which latter is then locked while the delay mechanism runs down for a predetermined period as in Specification 770,041, means are provided whereby the delay may be held in its tensioned position while the shutter mechanism runs down and whereby the said locking means for the shutter operating mechanism is rendered inoperative. In the embodiment shown in Fig. 1, the delay mechanism comprises the usual toothed segment 5 which is wound against the action of the driving spring 4 by the lever 7, which is operated by the shutter setting lever. The delay is held in its tensioned position by a double armed lever 9, mounted on a pivot 10, the end 9a engaging a pin 12 on the wheel 11 of the delay mechanism. The delay is released in known manner by the arm 13 on the blade ring striking the end 9b of the lever 9 and rocking it anticlockwise. The arm 13, after releasing the delay, is held by the nose 15a of the lever 15, pivoted at 14, until the delay has run down sufficiently, when the arm 7b of the lever 7 engages a projection, 15b on the lever 15 and rocks the latter to release the arm 13. This locking mechanism is similar to that described in Specification 770,041. To prevent the delay running down when arm 13 rocks lever 9, a second lever 26 is provided, pivoted also at 10 and biased by the spring 31 so that its end 26b tends to engage the pin 12. The lever 26 is normally held out of engagement with pin 12 however since one end 26a rests against a pin 28 on the switch ring 27. To render the lever 26 operative so that the delay is prevented from running down, the switch ring 27 is turned in an anticlockwise direction so that the pin 28 rides off the arm 26a. As the switch ring 27 is rotated further, the pin 28 engages an arm 15c of the lever 15 and turns the latter in an anticlockwise direction, thus removing the nose 15a from the path of the arm 13 and rendering the shutter ring locking mechanism inoperative. In the embodiment shown in Fig. 2, the lever 33 which, like lever 9 in Fig. 1, normally holds the delay in the tensioned position and which is released by the blade ring arm 13, is mounted on a plate 35, the latter being pivoted at 34. In order to prevent the delay from being released by arm 13, the pin 28 is moved in the direction, of the arrow and pivots plate 35 in a clockwise direction. This moves the lever 33 into the position shown in dotted lines so that its end 33a is not struck by the arm 13; the end 33b however, remains in engagement with the pin 37. A locking lever such as 15 in Fig. 1, is provided and this is rendered inoperative as in that Figure. In the embodiment shown, the shutter is fitted with a selector ring giving "M", "X" and "V" positions and the pin 28 is arranged on this ring so as to rock the arm 35 when in the "X" position and at the same time, to render locking lever 15 inoperative as in Fig. 1. Figs. 3 and 4 show parts of a further embodiment for use in a shutter having "M", "X" and "V" settings, the delay comprising two parts which can be coupled for self-timer delay ("V" setting), and uncoupled for flash synchronization ("M" setting). The delay is wound with the shutter setting by a lever 39 and held in its tensioned position by a pawl 40 as in Fig. 1 from Which it is released by arm 13. The mechanism for locking the arm 13 while the delay runs for a certain period comprises an arm 42 biased by a spring 43 so that its nose 42a engages the arm 13 (dotted position). It is released when the lever 39 has moved sufficiently to rock the lever 42 clockwise about its pivot 41 (compare Specification 770,041). The selector ring may be moved so that its pointer 47b is on the "M", "X" or "V" positions, but it uncouples the escapement of the delay mechanism only in the "M" position. Attached to the selector ring is an arm 47e which in the "M" and "X" positions engages the underside of the pellet 45 and locks it against the pellet wheel 46, thus preventing the delay escapement running down. This does not effect "M" synchronization since the escapement is uncoupled in that setting. The selector ring carries also a further cam arm 47b, shaped as shown, and a projection 42b on the locking lever 42 engages the underside of the cam surface 47b. In the "X" position (shown in Fig. 3), the cam 47b holds the lever 42 out of the path of the arm 13. Thus, in the "V" setting, the delay parts are coupled, the pellet 45 is free to move and the locking arm 42 is operative, self-timer exposures being possible with flash contact when the shutter blades are fully open ("X" synchronization). In the "X" position the delay remains coupled and the pellet 45 is looked, thus preventing the delay from operating; locking lever 42 is rendered inoperative by cam 47b and the shutter is used normally without the delay and with "X" synchronization while the delay remains permanently tensioned. In the "M" setting, the pellet 45 is still locked, but since the parts of the delay are uncoupled, the tensioned part can be used for "M" synchronization with the locking means 42 operative. German Specification 853,709 also is referred to.