Endorser drum having indexable self-aligning print wheels

Abstract

An endorser drum for printing variable data on paper sheets for use in document handling and counting devices. The drum is provided with a plurality of splined pins positioned at spaced intervals adjacent the periphery of the drum. Each splined pin is provided with a gear-like periphery comprised of a plurality of tapered projections extending radially outward from the periphery of the splined pin. An annular-shaped resilient print wheel, having an interior surface whose configuration is substantially complementary to that of each splined pin, is fitted upon the splined pin. The exterior surface of the print wheel is provided with a plurality of raised characters each aligned with an associated one of the grooves provided along the interior surface of the print wheel. Each splined pin is secured to the print drum so as to experience no rotational movement. Each print wheel may be incrementally indexed, i.e., revolved, about its associated splined pin, The resiliency of the print wheel permits the grooves of the interior surface to rise over the corresponding tapered projections of the splined pin upon which it is mounted after which the grooves and projections of the print wheel respectively 'snap' into engagement with the next adjacent tapered projections and grooves of the splined pin to positively and precisely align the next adjacent raised character into the print position.