Patent GB-500626-A (GB)
Title: Improvements in or relating to photographic cameras
IPC: G03B19/04
Filed: 1937-08-11
Abstract: 500,626. Photographic cameras. STEENBERGEN, J., DIEBEL, 0., FRAUENSTEIN, H., ENGLISCH, E., SCHUBERT, H., and KOCH, C., (trading as IHAGEE KAMERAWERK STEENBERGEN & CO.). Aug. 11, 1937, No. 22134. Convention date, Feb. 3. [Class 98 (i)] A roll-film camera includes a cassette, a film winding spool, and means for driving said spool through a one-way clutch whereby the spool is positively coupled to said means during movement thereof in one direction and is automatically uncoupled therefrom during movement thereof in the other direction and also free rotation of the spool in the reverse direction is allowed independently of the driving device for the purpose of enabling the film to be rewound into the cassette. In the application to a reflex camera as shown, the film is wound from a cassette on to a spool W, Fig. 8, and the end gripped by a spring W<1>. Each feed movement is produced by rotating, through nearly 360‹, a handle 69 rigid with a sleeve 74 loose on a shaft 40. The sleeve carries at its lower end a cam 77, Fig. 10, which during the rotation strikes a pin 81 on a pawl 80, Fig. 9, pivoted to the gear-wheel 79 loose-on the shaft 40. The pawl is thus swung into engagement with the ratchet 78, keyed on to the shaft 40, and the shaft thus rotated. Sprockets (not shown) engaging the margins of the film are driven from the shaft shaft 40 through gearing 82, 83, 84. After the winding stroke, the handle 69 is released and is returned to its initial position by a spring 75. A gear 94 keyed to the shaft 40 drives, through a shaft 95 carrying pinions 93, 96, a gear 97 loose on the sleeve 74. The hub 98 of this gear is in frictional engagement with a film counting device 70<1>. The pinion 93 is normally engaged by a pawl which allows it to rotate in one direction only, and can be rendered inoperative to allow the film to be rewound into the cassette by means of an external key. When the bulk of the film has been rewound into the cassette, but the outer end is still attached to the spool W, it is severed close to the cassette by a knife operated from outside the casing. The shutter consists of two blinds 41 and 42, Fig. 6, which may be wound on to rollers 47, 48 from rollers 43, 44 containing tension springs. The pinions 49, 50, by which the winding is effected, engage respectively with gears 102 and 100, Figs. 11 and 12. the former freely mounted upon the shaft 101, the latter keyed to it. The pinion 50 engages a pinion 99 engaging the gear 79 forming part of the film feed mechanism. Thus during the feed movement, the blind 41 is wound directly and the blind 42 by means of pins 103, 1()4 projecting from the gears 100, 102 by which the gear 100 rotates the gear 102. The pinion 99 is then held by the pawl 110. The gear 102 is engaged by a pawl 127 with an arm 128 projecting above the gear 100. The pawl 126 projects between the gears 100 and 102 and is arranged to engage the pin 104 but not the pin 103. An arm 125 Attached to this pawl projects above the gear 100, The lenght of exposure is determined by the position of a pin 109 attached to a head 106 and projecting through one of a series of holes in the gear 100, and may be varied by lifting the head 106 against the pressure of the spring 107 and placing the pin 109 in a different hole. The shutter release button acts on a member 118 with a pin 124 co-operating with pawls 126. 127 and also formed with an arm 122 cooperating with the pawl 110. In an instantaneous exposure, the release lifts the pawl 99, and allows the gear 100 to rotate and the blind 41 to open. Simultaneously, the pawl 127 is lifted but the gear 102 is retained by the pawl 126 engaging the pin 104. It is released by the pin 109 striking the arm 125 and releasing the pawl 126. The pinion 49 thus rotates and the shutter blind 42 terminates the exposure. For a " bulb " exposure, the position of the pin 109 is such that after the release of the first blind it will not strike the arm 125 but will bear against the arm 128 and prevent the return of the pawl 127. Thus, when the shutter button is released, to allow the pin 124 to lift the pawl 126 from the pin 104, the closing blind is allowed to operate. For a " time " exposure, the operation is similar except that the pin 109 does not reach the arm 108. Release of the operating button therefore re-engages the pawl 127 with the gear 102 and releases the pawl 126. A further pressure on the button lifts the pawl 127 and allows the closing blind to operate. The Specification as open to inspection under Sect. 91 contains also the subject-mutter of Specifications 500,791 and 500,866 It also describes a reflex finder system, Fig. 14 (Cancelled), incorporating a glass block 56 with a mat under surface 58 to receive the image and a spherical upper surface for magnifying purposes. This subject-matter does not appear in the Specification as accepted.