Patent GB-675264-A (GB)
Title: Improvements in or relating to devices comprising electrical contact mechanisms for use in flash-light lamp photography
IPC: G03B15/04
Filed: 1947-01-24
Abstract: 675,264. Synchronizers for flash-lamp photography. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. Jan. 24, 1947 [Oct. 6, 1943], No. 2271/47. Class 98 (i). A timing device for use in flash-lamp photography comprises a camera shutter release mechanism and an electrical contact mechanism for operating a flash-lamp, and includes an operating member 1, Fig. 1, arranged, when operated, to compress a spring 4, to compress a spring 3 connected through a piston 2 to a shutter release member, and to release a flywheel 18 so that it is able to rotate under the action of a tensioned spiral spring 21; the flywheel carrying an electrical contact 65 which makes contact, during the travel of the flywheel, with a fixed contact pre-adjustable along the path of the contact 65, and a stop 22 which, towards the end of the fly-wheel travel, causes piston 2 to be released and the shutter-release member to be operated by spring 3; and the operating member 1 carrying also a stop 10 which, when the operating member is released and restored to its operable position by spring 4, engages the arm of a bell-crank lever 60 and moves a toothed segment 9 engaged with a pinion 20 fixed to the fly-wheel 18 to tension the spiral spring 21, whereby the device is re-set for subsequent operation. The operating member may carry a second stop which, when the operating member is operated, engages an arm 11 of a bell-crank lever 12 and disengages a pawl 15 from a recess 17 in the periphery of the flywheel 18, which is thereby released, and the stop 22 on the fly-wheel engages an arm 57 of a bell-crank lever 23, so removing a detent 7 from the path of piston 2 to release it. As shown, the operating member 1 is cylindrical and slides axially in a casing 50 which encloses the mechanism. The bell-crank lever 12 is pivoted at 13 and its arm 11 lies in the path of a projection on the member 1; its arm 16 carries the pawl 15 pressed by a spring 54 into the recess 17 of disc 18. The bell-crank levers 60, 23 are freely pivoted on a common shaft 24, and the detent 7, formed on the arm of lever 23, protrudes through a slot in the wall of member 1 into the path of a collar 6 formed on piston 2, which slides inside member 1. Spring 3 is enclosed between the ends of the members 1 and 2, while spring 4 surrounds the member 1 and presses on a collar 63 thereof at one end and on the casing 50 at the other. To actuate the device, the operating member 2 is depressed. The piston 2 is restrained by the detent 7 engaging its collar 6, so that both springs 3 and 4 are compressed. Near the end of its travel, the projection on the operating member 2 engages the arm 11, rocking it and lifting the pawl 17 to free the disc 18. As the disc rotates its contact 65 makes contact with a contact member 55, Fig. 3, on a rotatable disc fitted in the casing 50, thus closing a flash-lamp igniting circuit. The time at which contact is made depends on the angular position of the disc, as adjusted by a handle 69, in relation to a scale 64 on the casing, and is chosen to precede the opening of the shutter by the time taken for the lamp in use to attain maximum intensity after the closing of the contacts. When the disc 18 has rotated nearly 360 degrees, its pin 22 engages arm 57 which stops the disc, and is also rocked to withdraw the detent 7 from the collar 6, allowing the piston 2 to move under the influence of spring 3 to operate a camera shutter through a flexible release 27. Rotation of the disc also rocks lever 8 through the pinion 21 and gear segment 9 until it re-engages the stop 10 in its lower position. On release of the operating member 1, the stop 10 rocks the lever 8 reversing its motion and that of the segment 9, pinion 21, and disc 18. The lever 11 is released, so that the pawl 16 presses the edge of the disc 18 and eventually snaps into the recess 17, all the parts having returned to their original positions.