GB1071940A - Improvements in or relating to cameras - Google Patents

Abstract

1,071,940. Film feed mechanisms. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. Oct. 12, 1965 [Oct. 15, 1964], No.43211/65. Heading G2A. In a photographic camera particularly for taking X-ray photographs on an intermittently movable film, an electric motor is switched on and a delivery spool 4 driven. Film 3 from the spool is fed through a tunnel 17 to a driven roller 18 around which it is guided by a curved guide 19, then through the exposure gate 14 to pass between a transport roller 21 and a tension roller 22, and then guided by guide 24 around a roller 23 to open contacts 25, 26 of a switch 27. This causes a lamp (48) Fig. 2 (not shown) to light up, indicating the film is correctly positioned for exposure, and causes a relay (37) to be deenergized, thereby de-energizing relays 42-45 and switching off an electromagnetic spindle coupling 28, so that springs 49, 50 swing the guides 19, 24 to the dotted line positions, cams 46 are free to rotate and roller 23 stops rotating. An operating switch (51) is closed to switch on the motor (39) by which the cams 46 are rotated so that a pressure plate 29 clamps the film in the exposure gate 14, continued rotation of the spool 4 causing a loop 30 of the film to be formed. Further rotation of the cams releases the pressure and allows the loop 30 to be fed by the roller 21, thus forming a loop 31 which, when large enough, closes contacts 32, 52 to energize a relay (53). This energizes the spindle coupling 28 and the roller 23 feeds the film through a tunnel 33 to a take-up spool 5, and also opens a switch (55) to prevent re-energizing of relays 42-45. While the loop 31 is being fed to the take-up spool, the cams 46 rotate to raise the pressure plate 29 and clamp the film in the gate 14 for a further exposure. The pressure plate is lowered and the newly exposed film advanced to enlarge the loop 31 which has almost completely disappeared. The roller 23 rotates continuously since a contact (56) is closed by the relay (53) to bridge the contacts, 32, 52. When the trailing end of the film has passed between the contacts 25, 26 the switch 27 is reclosed and the light 48 goes out, indicating that more film is required. The spools 4, 5 are provided in magazines 6, 7 which are rendered light-tight on removal from the camera by means of slides 12, 13.