Roller apparatus for a flexible web

A roller apparatus for a flexible web such as a chart, said flexible web being provided on at least one free margin thereof with a rigid, elongated holder element of predetermined cross-sectional dimensions which are substantially greater than the thickness of said flexible webbing material, said roller apparatus comprising:

• rigid, elongated tubular roll means of substantially greater dimensions than said predetermined cross-sectional dimensions of said holder element and including a longitudinal through slot of a cross-sectional dimension smaller than those of said holder element and greater than the thickness of said web, a pair of end caps with one attached to either end of said tubular roll means for rotation therewith and presenting a radial friction drag surface, one of said end caps including a through opening of dimensions at least as great as the cross-sectional dimensions of said holder element and peripherally communicating with said through longitudinal slot for slidably receiving said holder element with said flexible webbing affixed thereto and depending through and below said longitudinal slot, whereby said holder element and said flexible webbing depending therefrom are slidably insertable into the tubular roll means selectively from either right-hand or left-hand margins of said flexible webbing so as to selectively reveal either surface of said flexible webbing with respect to a fixed observer, each end cap having centered shaft means;
• a pair of bracket means receiving said shaft means of adjacent end caps for rotatably mounting said roll means with said brackets for rotation in either direction, whereby said flexible webbing may be rolled upon said roll means in either clockwise or counterclockwise direction;
• adjustable drag means mounted to an adjacent bracket means for imparting a selectable amount of drag on the friction drag surface of the adjacent one of said end caps during rotation of said roll and bi-directional drive means for selectively rotating said roll means relative to said bracket means to effect rolling of the flexible webbing material in either direction upon said roll means.