An improved mechanism for advancing and guid
ing an inked ribbon having a predetermined width and
an indeterminate length, past a printing position includ
ing a crown roller having an axis and a smooth surface
of revolution about the axis having a major diameter
and a minor diameter with two end ?anges spaced a
distance apart substantially greater than the width of
the ribbon, wherein the improvement comprises:
the major diameter of the crown roller located closer
to one ?ange than the other ?ange;
the major diameter of the crown roller located, with
respect to the printing position, to print with a new ribbon principally nearer a ?rst ribbon edge nearer
the other ?ange of the crown roller; and
suf?cient spacing between the major diameter of the crown roller and the other ?ange of the crown
roller to accommodate the ribbon as the ribbon
migrates toward the other ?ange with wear and
stretching so as to bring into the printing position a
portion of the ribbon located nearer the one ?ange
of the crown roller.
3. An improved mechanism according to claim .2
wherein the crown roller is positioned with the center
line of the printing position between the major diameter
of the crown roller and the other ?ange of the crown
roller.