Patent GB-655288-A (GB)
Title: Improvements in or relating to photographic shutters having built-in flash lamp synchronising mechanisms
IPC: G03B9/70
Filed: 1948-10-28
Abstract: 655,288. Photographic shutters; shutters combined with flash-lamps. KODAK, Ltd. (Eastman Kodak Co., and Fuerst, C. C.). Oct. 28, 1948, No. 28064. [A Specification was laid open to inspection under Sect. 91 of the Acts on May 23, 1949.] [Class 98 (i)] In a multiple pivoted blade shutter having an oscillatable ring controlling the blade movements which is moved to a cocked position against the action of a driving spring connected between it and the casing, and including a switch for synchronizing a flash lamp with the shutter opening comprising a stationary contact and a movable contact normally spaced therefrom, there is provided a one-way driving connection between the blade ring and the movable contact such that the former drives the latter into engagement with the stationary contact during the initial release movement of the blade ring but allows it to be cocked without moving the movable contact. Fig. 1 shows an everset shutter provided with cover blades as described in Specification 655,279. The synchronizer switch connected to the jack T comprises an insulated stationary contact 69, adjustable to account for different lamp lags by means of a hand knob carried by a cam disc C (Fig. 9, not shown), engaging a lug 74 on the contact 69 and a movable contact pin 68 mounted on a lever 57 geared to an inertia member 61 and pivoted on the shutter casing at 58 and urged clockwise by a spring 57a. A lever 62 pivoted on the lever 57 at 58a is engaged by a pin 64 on the blade ring 27 as the shutter is cocked by the arm 38 of the operating lever 32 engaging a pin 42 on the blade ring and moves aside against the action of a light spring 66 so that the pin 64 slips past it. When the arm 38 slips by the pin 42 and the blade ring is released, the pin 64 returns to drive the lever 62 anticlockwise and this by means of a lug 67 drives the lever 57 also anticlockwise to close the contacts 68, 69. For lamps of zero lag a parallel pair of contacts are provided comprising an insulated spring contact 78 and a pin 84 on the blade ring. The spring 78 is held clear of the path of the pin 84 during cocking by an insulated lug 83 on a lever 80 pivoted at 46 and spring-urged anticlockwise and is prevented from moving into the path of the pin 84 by an insulated pin 85 on the synchronizer setting cam C except when this is set for zero lag. When so set, the switch 68, 69 cannot be closed, and depression of the shutter lever 32 cocks and releases the ring 27 and also at the end of its depression a nose 36 on it pivots the lever 80 clockwise and allows the spring 78 to move into contact with the moving pin 84 as the blades 24 reach their fully open position. Fig. 12 shows the shutter of Fig. 1 modified by the provision of a separate blade ring setting lever 204 and a release trigger 321 for tripping the latch 200 which engages the pin 84 on the ring and so holds the ring set. The spring 45 is longer than that of Fig. 1 and the pin 47 is correspondingly displaced along the blade ring while the blades 24 overlap further and the cover blades are connected by a pin 210 on the trigger passing through slots in both blades. The synchronizing means is also modified in that the switch for lamps of zero lag comprises a spring 781 normally held clear of the moving contact pin 64 on the blade ring by an insulated boss 217 on the lever 57. Specification 650,874 also is referred to.