GB129810A - Improvements in or relating to Feeding and Measuring Devices for Rolls of Photo-sensitive Material Employed in Photographic Cameras. - Google Patents

Abstract

129,810. Herbert, Sir A., and Miles, L. July 18, 1918. Cameras, roll-film; enlarging, copying, and reducing.-Means are provided in a camera, particularly of the kind used in copying drawings or the like, for feeding and exposing graduated amounts of the sensitized strip. The screen F is unwound from the roller E, against the action of a spring, by bands F<1> passing over pulleys E<3> actuated by pinions E<5>, G and a handle G<2>, and passes over guide-rollers E<1>, E<2> near the focal plane. The sensitized strip C is unwound in the focal plane from a pulley B, over a guide-roller, and is held against the winding-off roller B<1> by an auxiliary roller B<2>. The amount of the sensitizer strip exposed beneath the screen is read on a graduated disk K prevented from rotating by a stop K<1>, the whole or part of the strip in the focal plane being covered as the handle is at the zero mark K<1> or other mark on the disk E. The screen and strip winding means may be interlocked by a pinion H<1> fast to the spindle of the strip roller B', and a loose pinion H which may be locked to the handle by a plunger G<3> on the handle and holes H<2> in the pinion corresponding to the graduations on the disk K. In operation, the plunger G<3> is withdrawn from the pinion H, and the handle G<2> is rotated till the desired amount of film is uncovered by the screen, as indicated at K. The plunger G<3> is then engaged with the pinion H, the rollers being thereby connected and held by friction, or by ratchet and pawl, or by friction brake if necessary. After exposure, the screen and strip are unwound till the handle stops against the mark K<1>, and the exposed portion of the film cut off. To give ready access to the spool B, the roller E and guide E<1> are supported on arms L hinged to the body at L<1> and fixed in the working position by stops L' and turn-buttons or the like if desired. Stops L<2> are provided to locate the arms in the horizontal position. The handle B<3> may be omitted, the handle G<3> serving to wind both blind and film.