Patent GB-816914-A (GB)
Title: Improvements in or relating to a roll film photographic camera
IPC: G03B19/04
Filed: 1956-12-11
Abstract: 816,914. Photographic roll-film cameras. KODAK Ltd. Dec. 11. 1956 [Dec. 12. 1955]. No. 37774/56. Class 98(1) A roll film photographic camera includes a rotatable film winding member which during operation enters into driving connection with shutter setting mechanism through a spring clutch which, after seting the shutter, is automatically disconnected from the film winding member to free it for continued film winding without affecting the shutter setting mechanism. As shown in Figs. 1 and 2, a film winding knob 11 has a shaft 12 journalled in the camera wall 10, with a coil-clutch spring 14 preconnected to the film spool in known manner. A disc 17 is loosely mounted on a bushing 16, which is fast with shaft 12 and carries a coil-clutch spring 19. A lever 25, pivoted at 26 to the camera wall 10, has arms 27, 28 extending on opposite sides of the bushing 16, and an arm 29 connected by a link 31 to bell crank lever 34, Fig. 5, which is in turn connected by a link 40 to a bell crank lever 44 pivoted on a pin 43 on a shutter support plate 37. When knob 11 is turned to wind the film, spring 19 grips bushing 16 and its end 20 engages the pin 18 and rotates disc 17. Pin 18 engages a slope 58 on arm 27 of lever 25, which is thereby rocked into its dottedline position, Fig. 1, setting the shutter as described below. When pin 18 has cleared slope 58 it advances to its dotted line position, wherein the other end 21 of spring 19 engages a lug 60 on arm 28 of lever 25 to release the spring from the bushing 16. This allows shaft 12 to turn until the film winding operation is complete. When, on release of the shutter, lever 25 returns to its full-line position, the lug 60 clears the end 21 of spring 19, and the shutter-setting mechanism is once more ready for operation. The shutter consists of a cover plate 61, Fig. 5, pivoted on pin 43 and a shutter plate blade 63 pivoted on the other side of the support plate 37 at a point slightly below pin 43. The cover plate is initially held in the position shown in Fig. 5 by a latch lever 64. A pin 77 on the shutter blade extends through an arcuate slot 76 in support plate 37, and a hairpin spring 80 is connected between the pin 77 and a pin 79 on cover plate 61. When lever 25 is rocked to its dotted-line position, Fig. 1, bell-crank lever 34 is rocked by links 31 and bell-crank lever 44 is rocked by link 40 against action of a spring 73 which acts on cover plate 61, and a spring-urged detent 91 on a lever 83, Fig. 5, engages the end of link 40 to hold the parts in position. When the end 53 of the shutter release lever 50 is depressed, as shown in Fig. 6, bell-crank lever 44 is rocked about pivot pin 43 by a link 47 so that its nose 55 engages latch lever 64 and rocks it against action of spring 68, releasing cover plate 61 which turns clockwise under action of the spring 73. This causes pin 79 to move, tensioning spring 80 so that when pin 79 passes a dead-centre position, spring 80 acting on pin 77 turns the shutter blade 63 anticlockwise. The exposure aperture 60a in the support plate 37 is first uncovered by cover plate 61 and then covered by blade 63, so that an exposure is effected. Cover plate 61, near the end of its clockwise movement, engages the lever 83 to disengage its detent 91 and release link 40, whereupon the parts return to their initial positions, lever 50 being returned by a spring 94. A lug 57 on lever 50 engages a nose 56 on bell-crank lever 34 to prevent double exposures.