Patent GB-704246-A (GB)
Title: Improvements in and relating to photographic cameras using perforated roll films
IPC: G03B1/66
Filed: 1950-10-24
Abstract: 704,246. Photographic roll film cameras. HEIDECKE. R, [trading as FRANKE & HEIDECKE]. Oct. 24, 1950 [Oct. 31, 1949], No. 25890/50. Class 98(1) In a photographic camera for perforated rollfilm of the kind in which the take-up spool is automatically locked after each feeding movement of the film through the length of a frame and controlled by a measuring roller engaged by the film, and the measuring roller is provided with a disc which, through the medium of a link or the like, effects locking of the take-up spool on completion of the film wind, the link and the measuring roller' disc are each provided with one element of a locking device by means of which the roller is locked and released in accordance with the locking and unlocking of the take-up spool. As show in Figs. 1 and 2, the film from a spool 1 is fed over a toothed measuring roller 2 to a take-up spool in a cassette 3. The film-winding and shutter-setting mechanisms are operated by rotation of a knurled knob 6. As shown in exploded view in Fig. 5, the knob 6 has a squared aperture 8 fitting on a pin 9, by which it is secured to a bush 10 rotatable in the camera wall and encircled by a spring so that it can rotate only in the direction of the arrow A. A disc 12 is eccentrically mounted on bush 10 so that, on rotation of pin 9, it engages (1) a pin 14 on a T- shaped slide 15 mounted by a slot 15a on a pin 17a fixedly mounted in the camera, (2) a pin 16 on an L-shaped slide 17 mounted by slots 17b, 17c on pin 17a and a second fixed pin 17d, and (3) a lever 35 operating the film pressure plate. A pin 18 on slide 15 engages in an aperture 19 in slide 17. A lever 20, pivoted at 20a to the camera wall, has a pin 25 engaging a slot 26 in slide 15 and projects into a slot 21 in a ring 22. Ring 22 is rotatable about the axis of the camera shutter, and has a projection 29 which engages either the shutter setting lever 24 or the shutter release lever 23. A link 5, guided for vertical movement on pins 5a, 5b. has a lug 38 engaging the pin 14, a lug 41 engaging a pivoted pawl 42 engagable with a ratchet 55 (Fig. 1) on the film-winding shaft, and a projection 39 engagable with the end face 56 of a disc 4 rotatable with the measuring roller 2 and with a radial recess 40 in an extension of fhe disc. A supplementary locking device, which prevents release of the shutter until movement of knob 6 is complete, comprises a lever 30, see also Fig. 5a, pivoted on pin 17d and carrying a pin 31 extending below the lever 20. A toothed wheel 43 and a ratchet wheel 44 are freely mounted on bush 10 and are connected together as shown, in Fig. 7 by pins 46 and slots 45, being' urged into the position shown by one or more springs 47. A pawl 48, pivoted on a drum 32 mounted on the pin 9, has a nose 49 engageable with ratchet wheel 44. Drum 32 is partly enclosed in a semi-circular channel 72a in a guide plate 72, and as long as a rib 50 on the pawl 48 is engaged by the channel, the ratchet wheel 44, and hence also wheel 43, are driven by the drum 32. Wheel 43 meshes with an idler wheel 51 (Fig. 1) which is in turn in mesh with a toothed wheel 52, which is connected through a friction coupling to the ratchet 55 on the film-winding shaft. A measuring disc 57, freely mounted on pin 9, has a series of annular teeth 58 engagable by a pawl 59 on drum 32. Immediately after an exposure, link 5 is in its lowermost position, the projection 39 thereon being engaged with recess 40 to prevent movement of the measuring drum 2, and the pawl 42 being engaged with ratchet 55. The slides 15, 17 are in their lowermost positions. The upper end 27 of slide 15 is in the path of a lever 28 connected to the shutter release knob 7. When knob 6 is turned drum 32 turns with it, but as the rib 50 of pawl 48 is at first clear of channel 72a, the drive to the take-up spool is not connected. The action of disc 12 on pin 14 raises slide 15, the movement being transmitted shortly afterwards to slide 17 through pin 18 and aperture 19. Slide 15 also rocks clockwise slightly as it is raised, so that its end 27 moves clear of lever 28. The movement of pin 25 rocks lever 20, thus turning ring 22 in the direction of the arrow B so that the projection 29 moves lever 24 to set the shutter. As slide 15 approaches its upper position, pin 14 engages lug 38 to raise link 5 and to disengage projection 39 from recess 40. The lug 41 raises pawl 42 from ratchet 55. Pawl 42 then blocks movement of the lever 28. During this movement, disc 12 also engages the end 37 of the lever 35, which is rocked to raise the film presser plate. As rotation of knob 6 continues, pawl 48 enters the channel 72a and is thus engaged with ratchet wheel 44 so that the film is wound on to the take-up spool, the measuring roller 2 and the disc 4 being turned by the movement of the film. Also, the disc 12 passes beyond pin 14 so that slide 15 moves downwards, at the same time rocking anti-clockwise about pin 17a, so that its end 27 is again in the path of lever 28. Pin 14 also disengages from lug 38, so that projection 39 rides on end face 56 of disc 4. After one revolution, the disc is stopped by a step 40a thereon engaging projection 39, which then falls into the recess 40, locking the measuring roller 2 and allowing pawl 42 to engage ratchet wheel 55, so that the film feed is stopped. At the moment when pawl 42 moves away from lever 28, a rim 33 extending from drum 32 and passing outside the guide plate 72 engages a projection 34 (Fig. 5a) of lever 30, so that pin 31 moves up against lever 20 to prevent it from moving in the clockwise or shutter-release direction. Disc 12 also disengages from lever 35, but a shoulder 37a on the lever remains engaged with the end of slide 17, so that the pressure plate is still retracted. As slide 15 moves downward it is accompanied by slide 17 and during the last part of the film wind pin 16 on slide 17 is engaged by disc 12 to move the slides to their lowermost positions. When the film feed is stopped, slide 17 disengages from shoulder 37a, releasing lever 35 and the film pressure plate. Rim 33 being now disengaged from projection 34, lever 20 can rock clockwise as the slides move down, the movement stopping when projection 29 on ring 22 is just short of shutter-release lever 23. Depression of shutter release 7 will then cause lever 28 to engage the upper end of slide 15, which is thus further depressed to rock lever 20 and rotate ring 22 the further distance required to actuate shutterrelease lever 23. Because of the pin-and-slot connection 45, 46 between gear wheel 43 and ratchet wheel 44, the ratchet wheel can be turned an additional distance after the film feed has been stopped. When knob 6 is released, the ratchet wheel 44 is moved back by spring 47, carrying with it drum 32 and knob 6, so that the pawl 59 on drum 32 rides over one of the teeth 58 on disc 57. Graduations on the disc are thus advanced at each operation of knob 6 to count the exposures. In order to disconnect disc 4 from the measuring roller to free the film e.g. for rewinding into a cassette, the disc may be axially movable and may carry one element of a dog clutch, the other being carried on the measuring roller. The disc may be moved out of engagement by means of a lever connected to means for opening and closing the cassette. Specification 704,245 is referred to.