(under subclass 342) Device wherein the advancing means comprises a roller about which the web or sheet is wound and a second roller from which the material is unwound, the viewing locus being in the path of travel of the web or sheet between the two rollers.
SEE OR SEARCH THIS CLASS, SUBCLASS:
518+, for a changeable exhibitor including double-reel-and-web means for moving a charactered web or sheet so as to bring a particular portion thereof into view.
SEE OR SEARCH CLASS
242, Winding, Tensioning, or Guiding,
324+, for winding and unwinding a convertible information carrier such a magnetic tape or image film, and subclasses 538+ for a convolute winding machine with both a coiled take-up and supply.
