Patent GB-489865-A (GB)
Title: Improvements in photographic apparatus
IPC: G03B19/02
Filed: 1937-02-06
Abstract: 489,865. Multiple-photograph cameras; shutters. BRAUN, J. Feb. 6, 1937, Nos. 3602 and 3603. Convention dates, Feb. 6, 1936 and Feb. 4, 1937. [Class 98 (i)] A photographic camera for obtaining a large number of small pictures on a surface of given area by means of successive displacements of the lens combined with perpendicular displacements of the sensitive surface, all these movements being preferably produced by means of a single cranked handle which also operates the shutter, is characterized in that the lens support, which takes up a fixed position for each picture is combined with a mechanism permitting an automatic adjustment of the position of the lens on said support for each picture-taking position thereof, in such a manner as to compensate for the offsetting of the corresponding picture on the sensitive surface produced by the displacement of the lens with respect to the object to be photographed, taking into account the distance of the object from the camera. One form is shown in Fig. 1 and in Fig. 2 (section at II-II of Fig. 1). A carriage 2a is moved forward in uniform steps. To this is attached a masking device to define the area of plate exposed. The mount of the lens is attached to a subsidiary carriage slidable relative to the main carriage 2a. The lever 68a is pivoted to the carriage 2a at 67a and to the subsidiary carriage at 49a. The end 51, of this lever moves in a longitudinal slot in a member 52. Due to the inclination of this member the lens is offset relative to the exposure area by an amount which increases as the lens is translated. The member 52 is pivoted at 69a and connected at 89 to a vertically slidable member 90. A link 91 couples this to an eccentrically mounted pin carried by a gear wheel 92 meshing with a pinion 94 integral with the focusing knob 93 which rotates through worm-gearing 100 the focusing mount of the lens 1. A link 103 couples this to a similar mount of a view finder lens 101. The inclination of the member 52, and hence the offsetting of the lens, thus varies with the distance of the object. The step-bystep movement is transmitted to the carriage 2a by the toothed sector 10b engaging racks 9a, 9b, Fig. 2, and gearing 89, 85, 87 from the shaft 84. This carries the toothed wheel 83 moved forward one tooth for each revolution of the main operating handle 19 by a pin 82 on a disc 81. The plate 2a is held stationary in each of its stopping positions by a sector 104 which engages the notches 107. After each row of exposures the plate is moved downwards and a parallel row produced. The sector 10b and racks 9a, 9b cause the movement of the lens to be reversed after each half revolution of the shaft 84. This corresponds to six exposures since the wheel 83, Fig. 2, has twelve teeth and one exposure is made for each revolution of the handle 19. After each six exposures an escapement device allows the plate holder to be moved downward by a spring. When the whole plate has been exposed the shaft 80 is locked to prevent further rotation of the operating handle. The extension 107, Fig. 14, of the mount of the lens 1 engages a sliding member 108 carried by a guide 109 rigid with the plate 110 in front of the plate 7. This plate carries two guides 111 for two superimposed plates 112, 113 forming the elements of a shutter. Apertures 114, 115 in these two plates and the aperture 140 in the plate 110 correspond in length to the total travel of the lens. The action of the shutter is shown in Fig. 12. In Fig. 12 the plate 113 covers the aperture 114 in the plate 112. A cam 135 on the shaft 80 sets the shutter by rotating the lever 116 anticlockwise. This engages the pin 120 to lift the plate 112 which also carries a lug 121 which lifts the plate 113. The plate 112 is held by the end 131 of a spring- pressed lever 132, engaging a pin 130, and the plate 113 by a notch 127 on the pivoted lever 128 engaging the pin 126, On further rotation of the shaft 80 a cam surface 137 engages a similar surface 139 on the lever 132. The pin 130 is released, and the plate 112 moves downwards under the action of a spring 124. The pin 141 acting on the cam edge 142 of the lever 128 then releases the plate 113 after a certain movement of the plate 112 and this moves downward under the action of the spring 123. During the movement the apertures 114, 115 overlap and exposure takes place. In an alternative arrangement the shutter is formed of a rotating disc, with a sector removed of sufficient radial length to accommodate the traverse of the lens. The shaft 80 also carries a ratchet 172 to prevent reverse rotation of the operating handle 19, and a counter 174, Fig. 1.