Patent GB-130380-A (GB)
Title: Improvements in or relating to Photographic Cameras.
Inventor: RAM GEORGES DE
IPC: G03B19/02
Filed: 1918-02-05
Abstract: 130,380. Ram, G. de. Oct. 30, 1917, [Convention date]. Magazine hand cameras with connected action between shutter and changing-mechanism, and with rotary change; aeronautical photography and apparatus.-In cameras for use more especially on aircraft, in which a constant-speed motor operates through mechanism to cause exposures at regular time intervals, means are provided for varying the time intervals. The invention may be applied to any camera the working of which may be controlled by the rotary movement of any device, each revolution of such device corresponding to one exposure, and is described in connexion with a camera having a rotating magazine as set forth in Specification 130,374. The magazine a is rotatable about an axis b and is turned by an air-driven screw or other motor through a shaft 32 carrying a pinion 2 engaging a wheel 3 which may be clutched to a wheel 4 in engagement with a ring 5 of the magazine. A spring tends to keep the clutch between the wheels 3, 4 in gear, but when the magazine is required to be stationary, a sliding rod 13 is pressed downwards by a catch 21 and disengages the clutch. The catch 21 is pivoted on a lever 22 which is itself pivoted at 45 and carries a roller 23 which engages a cam 24 on the magazine under the pressure of a spring 47. The shaft 32 also drives a wheel 12 through a pinion 1 and wheels 10, 11, the wheels 10, 11 being carried by a lever 17 which may be turned about a shaft 18 against the action of a spring 53 to disengage the wheels 1, 10. As shown in Fig. 1, the wheel 12 carries studs 19, 38 which strike respectively against one arm of a forked lever 20 and an arm 37 moving with the lever 17, the wheel 12 being urged in a counterclockwise direction by a spiral spring. The other arms of the forked lever 20 are connected respectively to a bell-crank lever 33 oscillating about the shaft 45, and by a link 35 to a bell-crank lever 36 which operates a release 41 for a focalplane shutter, the link 35 bearing a stop 49 which operates a lever 31 having one end engaging a recess in a cam 30 carried by the magazine to hold it stationary. When in the position shown, the stud 19 pushes the lever 20 and rotates it so as to operate the shutter release 41, free the locking-lever 31 from the recess in the cam 30, and bring the lever 33 into engagement with the catch 21 and turn it to permit the rod 13 to slide upwards. This movement allows the wheels 3, 4 to become clutched and the rotation of the magazine to be started. As the magazine rotates the cam 24 lifts the roller 23 and turns the lever 22 about the shaft 45 to bring its upper end against the lever 17 and turn the wheel 10 out of engagement with the pinion 1. The spiral spring then rotates the wheel 12 in a counterclockwise direction until the stud 38 engages with the arm 37, the wheel 12 then remaining stationary until the completion of the revolution of the magazine permits the lever 22 to resume the position shown, with the result that the wheel 10 again comes into engagement with the pinion 1 and is rotated until the stud 19 again engages the lever 20 and rotation of the magazine recommences, the lever 20 having meanwhile resumed the position shown under the action of a spring 51. The period during which the wheel 10 is rotated by the pinion 1 and the magazine is stationary may be made variable by making the arm 37 adjustable with respect to the lever 17, or by providing means by which the relative positions of the studs 19 38 may be changed. In a modification, Fig. 4, the means for varying the period during which the magazine is stationary may comprise a continuously-driven plate 55 having pins 56 arranged in circles and dividing the circumferences thereof into different numbers of parts. A slide 58 is adjusted on a rock-shaft 57 so as to contact with the pins on one of the circles, and when contact takes place, the shaft 57 is rocked and operates the lever 20. The shutter is carried by a frame 25 which is lowered to permit rotation of the magazine. The lowering is effected by a wheel 6 engaging the ring 5 and rotating a disk having a cam-groove 14 which operates a lever 27 connected by a rod 54 to the frame 25. The wheel 6 also engages a wheel 7 which winds an endless chain 15 round chain-wheels 8, 9. The chain 15 carries tappets 16, one of which, when the frame 23 is lowered, engages a slide 28 connected to the winding-roller 40 of the shutter and draws it back to the release 41. and so sets the shutter. The chain is adjustable on the wheels 8, 9, so that the tappets may be arranged to engage the slide 28 in any position it may be caused, by variation of the shutter opening, to assume. The apparatus may be stopped when the last plate in the magazine has been exposed, by means of a counter which then acts upon the lever 17 to keep the wheel 10 out of gear with the pinion 1.