Ink ribbon cartridge having transfer roller with staggered upper and

Abstract

In an ink ribbon cartridge (or cartridge ribbon) in which a length of ink ribbon driven through the cartridge is re-inked by a rotatable foam cylinder or reinker saturated with ink, an improved transfer roller is provided for transferring ink from the reinker onto the surface of the ink ribbon as the ink ribbon is advanced past the transfer roller. The transfer roller is of generally cylindrical shape and is provided with a plurality of elongated raised ridges or teeth on the outer surface thereof. The teeth present a surface area which transfers a desired amount of ink from the reinker to the ink ribbon as the ink ribbon rotates the transfer roller, and thereby the reinker. At the same time, positive engagement of the transfer roller with the ink ribbon and the reinker is enhanced, for the given surface area presented by the teeth, by offsetting or staggering a lower arrangement of the teeth relative to an upper arrangement thereof on the outer surface of the transfer roller. The elongated teeth extend along substantially the entire length of either an upper or a lower portion of the transfer roller, are generally equally spaced around the outer circumference or periphery of the transfer roller and are generally parallel with the central axis of the transfer roller. The offset or staggered configuration of the teeth locates each of the teeth of the upper arrangement approximately equidistantly between a pair of teeth of the lower arrangement.