Patent GB-190710236-A (GB)
Title: Improved Photographic Camera.
Inventor: HOLST LODEWYK JAN RUTGER
Filed: 1907-05-02
Granted: 1908-01-30
Abstract: 10,236. Holst, L. J. R., and Borsum, L. May 2. Cameras ; shutters.-In reflex cameras fitted with shutter mechanism operating in connexion with the mirror whereby the lens aperture is closed before the mirror is raised and after exposure remains covered until after the mirror is re-set, the movement of the mirror, the operation of the shutter for exposure, and the re-setting of the same for focusing are performed in proper sequence by the actuation of a single lever. The casing of the camera is made in two sections a, b, Fig. 1, sliding one within the other. The film rolls m, Fig. 7, are situated in the side recesses immediately behind the front partition e of the inner case. Light-excluding side pieces are provided at the upper side edges of the inner case, the film travelling between these and the walls of the inner case. This prevents any light from getting in from above and past the viewing-hood 2, which folds down upon the flap 6, its end 4 covering a pirt of the camera back. The mirror in its focusing position closes one face of a casing protecting the focal plane, and consisting of side pieces v and a bottom piece u. The mirror carries a bottom piece y with an exposure opening z sufficiently large to expose the whole plate when the mirror is raised. A spring g normally tends to hold the mirror in normal focusing position. A cord 10 attached to the mirror is connected to the arm of a bell-crank lever 11, Fig. 7, the shorter arm 13 projecting through the partition e, to operate in conjunction with the shutter. The shutter comprises two rotating sectors 14, 15, Figs. 3 and 4, the rear sector 15 having two apertures 21, 22 and the front sector one exposure aperture 20. In the normal position, Fig. 1, the apertures 20, 21 coincide, and the sectors are locked by the catch 18. On depression of the operating-lever 39, the links 36, 37 act to draw up the angular lever 34, the effect of which is to impart an end thrust to the link 32, causing both plates 14, 15 to rock downwardly into the position in which the aperture 22 covered by the plate 14 is in front of the exposure opening. The projection 55 then engages the arm 13 of the mirror-lifting device and raises the mirror. The curved arm 46 has by these movements been thrown upwardly, the links 36, 37 have been drawn into alinement with the axis 40 of the lever 39, and the wall of the recess 56 in the sliding plate 52 has moved the lower end of the lever 57 into contact with the pin 59 on the latch 18. The lateral projection 45 at the inner edge of the lever 39 has seated in the recess in the side of the link 37. On further actuation of the lever 32, the link 37 rocks independently of the link 36, and by means of the pin-and-slot connexion 53, 54 the further endways movement of the plate 52 causes the lever 57 to trip the latch 18 and release the. sector 14, which rotates across the aperture, to give the exposure. The lever 39 is then released, when the spring 51 returns the parts to their normal position. In this return movement the projection 55 first moves away from the end 13 of the mirror-lifting lever, permitting reaction of the spring 9, Fig. 1, to restore the mirror to its focusing position, and this occurs before the projection 50 on the curved arm 46 has carried the outer sector 14 down and before the link 32 has drawn the sector 15 up to coincide again with the apertures 20, 21 for focusing, as shown in Fig. 3. A time lever 60 may be turned so as to arrest the exposure blade 14 when coincident with the lens opening. The shutter may be combined with a rotating diaphragm plate 23, rotatable about an axis 24 carried by the under plate 15, the openings coinciding with the lens apertures when the shutter parts are in position for exposure.