Patent GB-523131-A (GB)
Title: Improvements in or relating to photographic bellows
IPC: G03B17/04
Filed: 1939-02-24
Abstract: 523,131. Bellows for photographic cameras. KODAK, Ltd. Feb. 24, 1939, No. 6158. Convention date, Feb. 24, 1938. [Class 98 (i)] The folds in a camera bellows are made by clamping the ends of the ,blank to form substantially fluid tight joints, applying fold-forming means to the sides of the blank, admitting fluid under pressure into the blank to force the walls outwardly between the fold-forming means, and applying end pressure to compress the blank and form the folds, during which last operation the fold-forming means move towards one another. In the machine shown, the smaller end of a tapered four-sided blank is attached to a lower clamp 30 by means of pivoted clamping-members 31, Fig. 10, which are moved apart by means of a screw and have hooked upper ends which engage the metal end frame of the bellows and clamp the end of the bellows against a rubber pad 36 to form a sufficiently air-tight joint. The large end of the bellows is similarly clamped against a pad 41, Fig. 7, in an upper clamp comprising sliding hooked clamping-members which are moved apart by a wedge operated by a screw. The fold-forming members comprise four sets of plates 7 pivoted at 6 between uprights 5 on carriages 3 slidable in guides 2 towards and from the corresponding wall of the blank, each carriage 3 being urged inwardly by a spring 4 and carrying a roller 17 engaging one section of a four-part cam 19. The plates 7 are initially held by springs (not shown) against stops 11, 12, 14 in the position shown in Fig. 2, in which position they are simultaneously moved until their inner -foldforming edges engage the walls of the blank by rotating the cam 19 by means of an arm 47 with an operating handle 49. The cam is formed so that two opposite sets of plates B continue to move inwardly from this position, in order that the folds on the corresponding sides of the bellows may lie between those on the other two sides, and the fold-forming edges of these plates are staggered with respect to those of the two sets A to produce staggering of the folds on adjacent sides of the bellows. During movement of the cam 19, air under pressure is admitted to the bellows by way of a pipe 39 under control of a spring-closed valve 40, Figs 1 and 2. This valve is opened by a cam carried by a latched slide on the arm 47 and engaging the head 62, the latch being released when the arm has completed its stroke so that the slide moves under the action of a spring to withdraw the cam from contact with the valve head 62, thus cutting off the air supply. During the return movement of the arm 47 to its position of rest the slide is returned to its latched position by means of a cam, so that the valve is again opened in the next operation of the machine. During the inward movement of the fold plates and the admission of air the two ends of the bellows are moved towards one another. For this purpose the lower clamp 30 is carried by a plate 70 which is itself carried on the vertically-slidable airpipe 39 and from which depend two posts 74 engaging inclined upper surfaces on a cam 71 which rotates together with the cam 19. The resulting upward movement of the clamp 30 produces an opposite movement of the upper clamp through a linkage comprising a pivoted arm 78 carrying the upper clamp and connected by a link 81 to a lever 83 having a curved face 91, Fig. 7, which engages the plate 70. During compression, the plates 7 close towards one another, as shown in Fig. 7. When the arm 47 is returned to its initial position compression of the bellows is maintained by means of a pivoted latch bar 95, Fig. 14, which engages a collar 93 on the pipe 39 when the latter is raised. The creasing of the bellows is then completed by pressure on a pedal 99, which still further raises the pipe 39 through a connecting-rod 102 having a lost-motion connection to the collar 93. Modified means for moving the upper clamp, in which a separate cam is employed for this purpose, are described.