Patent GB-770040-A (GB)
Title: Improvements in photographic shutters
IPC: G03B9/70
Filed: 1954-06-25
Abstract: 770,040. Photographic camera shutters. GAUTHIER GES., A. June 25, 1954 [Nov. 18. 1953], No. 18742/54. Class 98(1) In a photographic shutter having a selftimer delay, part of which is disengageable so that the remaining part constitutes a contact delay for the flash contacts and in which tensioning of the shutter and the delay mechanism are effected simultaneously, means are provided, controlled by the shutter setting ring, to automatically disengage the said part of the delay mechanism when the shutter is set to "bulb" or "time." As shown in Figs. 1 and 2, the delay mechanism comprises a fixed gear train consisting of a geared segment 17 and gears 18, 19, 23 and 24, and a disengageable part consisting of gears 20, 25 and 26, pallet wheel 21 and pallet 22, mounted on a bridge 27 which can be rocked about the axis of wheel 21. A spring 28 urges the bridge 27 into its engaged position. The delay mechanism is wound simultaneously with the shutter setting by means of the lever (not shown) which turns the segment 17 clockwise against the action of spring 29. It is held in this position by the end 33<SP>1</SP> of the arm 33 which engages the gear 24. The delay mechanism is released as soon as the shutter blade ring begins to turn since the latter carries an arm 34 which strikes the end 33<SP>11</SP> of the lever 33, rocking it about 32 and releasing the other end 33<SP>1</SP> from engagement with the gear 24. The arm 34 is then locked until the delay has run a certain distance as described in Specification 770,041. The self-timer mechanism is operative only when the selecting ring 16 is set to "V". At the "M" and "X" settings the arm 16<SP>111</SP> secured to the ring 16 engages the bridge 27 and rocks it anticlockwise, causing disengagement. Even on the "V" setting, however, the bridge 27 is disengaged if the shutter speed setting ring is set to "B" or "T". In Fig. 1 this is effected by a lever 45 pivoted at 30, having one end 45<SP>1</SP> resting on a lip 27<SP>1</SP> of the bridge 27, and the other end 45" working in a cam slot 47 in the shutter speed setting ring. When the latter is set to "B" or "T", the part 47" of the slot comes opposite the end 45<SP>11</SP> and rocks the arm clockwise which in turn rocks the bridge 27 anticlockwise. In Fig. 2, an arm 51 pivoted to the bridge 27 at 50, slides on a fixed pin 52. The bridge is disengaged when the pin 54 on the shutter speed setting ring moves the arm 51 to the left, i.e. in the "B" or "T" positions. The flash contacts are similar to those in Specification 684,502 and constitute a central pin 11 which may be contacted by levers 12 or 13. Lever 12 is pushed into contact by arm 14 only when the blades are fully open, whilst lever 13 may pivot to make contact as soon as the blades start to move, i.e. when pin 15 the shutter blade ring is moved from its path. However, in the "X" and "V" positions, lever 13 is rendered inoperative since its end is blocked to movement by lug 16<SP>1</SP> on the selector ring 16. German Specification 853,709 and U.S.A. Specification 2,435,161 also are referred to.