Patent GB-411347-A (GB)
Title: Improvements in or relating to photgraphic cameras
IPC: G03B19/04
Filed: 1933-09-28
Abstract: 411,347. Photographic roll-film cameras. KILFITT, H., 51, Scheibenstrasse, Dusseldorf, Germany. Sept. 28, 1933, No. 26760. [Class 98 (i).] In a camera employing perforated film strips, means are provided (a) for measuring-off the picture strip and pressing the measured strip flat on the focal window by a plate actuated by the film sprocket rollers ; (b) for simultaneously tensioning the objective shutter, the duration of exposure being regulated by a tension spring and a brake device ; and (c) for moving a lever arm carrying a filter disc or additional lens, which lever arm, when rocked in front of the objective, automatically lengthens the period of exposure. The gearing 59, 60, 61 between the conveyer roller 2 and the winding spool 62 is selected so that at the commencement less film is wound up than is fed forward by the conveyer roller, while subsequently the reverse action takes place owing to the increase in circumference of the winding spool, compensation being thus effected without any resilient connection. With twenty-four teeth on the wheel 59 and twenty-five on the wheel 61, a reference mark 63 on the rotatable knob 1 on the film carrier is stepped forward over a scale 64 at each picture change and serves as a device for counting the exposures. When by means of the film feed knob 1 the film is moved forward, the sprocket rollers 2 are carried round by the perforations, and a pin 3 on one roller 2 displaces a projection 4 carried by a rotatable toothed segment 6 as far as a stop 7 on a bearing plate 5 in which the segment 6 is displaceably mounted. Simultaneously with this measuring-off movement, the apertured shutter disc 10 is moved into the exposure position by the gearing 6, 8, and the return spring 11 is tensioned. Exposure, however, does not take place until a knob 14 is depressed to lift a covering lever 16 from the objective opening 15 and move the segment 6 so as to release its projection 4 and allow backward movement of the shutter. The shutter spring 11 consists of a series of narrow turns and a series of wide turns of the same wire, the end of the wide turns being so fixed to a spindle 12 that the wide turns can be in part rolled up and placed out of action to vary the tension and thus the period of exposure. Additional regulation of the exposure period is provided by a cam 19, Fig. 10, on the spindle 12 varying the effective action of a tiltable brake device 22 comprising a toothed wheel 24 with a fork-shaped stop bar 23. A small toothed wheel 25 engages the wheel 24 and is controlled by an anchor device 26. According to the inclination of the casing 22 produced by the cam 19, the bar 23 engages more or less over a nose 21 of the disc 18 on the shutter spindle 9, thus braking the rotation thereof. Inside the camera there is provided a rocking lever 27 carrying a yellow screen 27<a> or an additional lens for covering the objective opening, the lever 27 being rotatable on a sleeve 28 about the spindle 12. The knob 13, Fig. 6, turns the spindle 12 for varying the exposure period by varying the tension of the spring 11, while when the knob 29 turns the sleeve 28 for interposing the filter, the spindle 12 is rotated frictionally therewith, and the period of exposure is automatically lengthened. To ensure the film 34 lying flat on the support 33, Fig. 8, the film feed roller 2 has flats which receive stops 38 on a spring-pressed plate 37, which thereupon presses a pivoted plate 39 against the film strip. Specifications 410,071 and 410,449 are referred to.