Patent GB-190825849-A (GB)
Title: Improvements in or relating to Photographic Cameras of the Type known as Reflecting or Reflex Cameras.
Inventor: ADAMS ARTHUR LEWIS
Filed: 1908-11-30
Granted: 1909-12-30
Abstract: 25,849. Adams, A. L., and Roberts, W. G. Nov. 30. Cameras.-The mirror of a reflex camera is fitted with a sliding flap which is projected forwards beyond the edge of the mirror to shut off the top ground glass screen completely when the mirror is raised for exposure, and is withdrawn when the mirror is re-set for focusing. The mirror is re-set when the shutter is wound by the same winding- mechanism. A single release lever is used for ordinary, time, and bulb exposures, the mirror being released and raised before the shutter is released. The shutter described in Specification No. 2485, A.D. 1907, is fitted to the camera. The mirror 2, Figs. 1, 2, and 4, pivoted by two side plates 22 and supported by levers 24, 25, 26, is raised into horizontal focusing position by the spring 31 when released from the retaining- catch 3a. The sliding flap 30, Fig. 4, is mounted between two plates 32 sliding on the side edges of the mirror, and is projected forwards by the lever 26 to which the plates 32 are pivoted. The mirror is re-set when the shutter is wound, by a pin 40 on the wheel 38 geared to the shutter winding-wheel 33. The pin 40 depresses a loosely-mounted lever arm 41 which carries-the pin 23<a> and arm 42 with it, the arm 42. being rigidly mounted on the mirror shaft 23. To effect an exposure, the release pin 7 is depressed by the outer release 10 or by pneumatic means; thereby depressing the lever 3 and releasing the mirror. The lever 3 is pivoted at its front end 4, and kept against the pin 7 by a spring 6.' As the mirror rises, the arm 42 operates the link connexions 43, 44. 45 and raises the pawl 47 holding the shutter. In running-down, the pin 40 on the wheel 38 passes the loosely pivoted arm 41, which is retained against the pin 23<a> by a spring. For bulb exposures, a'lever D<1> engages. a stud E on the inner face of the toothed wheel behind the wheel 36 and controlling the "follower" blind. For time exposures, an additional bell-crank lever A, A' engages a stud B on the wheel driving the " follower " blind roller 37<b>. For instantaneous exposures, the lever A A' is thrown out of action by the indicator C, and the winding-disk 33a is set so that the projecting cam H thereon retracts the lever D<1>from the path of the stud E. as it is passing, by engaging the pin 21 on the lever D<1>. In making a bulb exposure, the release.pin 7, which in addition to releasing the mirror passes through a slotted arm 12, turns the' spindle 13; thereby actuating the lever connexions 14, 15, 17, 19. The arm 19 releases the pin 21, which allows the arm D' to be drawn by the spring D<x> into the path of the stud E, thereby retaining the " follower" blind until the release is liberated, whereupon the arm 19 is drawn back by the movement of the pin 7, retracting the pin-21 and lever D<1>; and releasing the "follower" blind to complete the exposure. In making time exposures, the indicator C is turned to free the lever A, A', which is pressed into operative position by the spring A<x>. On the first release; the lever D<1> engages the stud E as in the action for bulb exposures, and on freeing the release the stud escapes from the lever D', but the arm A<1> engages the stud B retaining the " follower" blind roller 37<b>. On the second release, the upper end of the arm 19 engages the pin 21<a> on the arm A, and releases the "follower" blind to complete the exposure.