Single shaft sheet advancement mechanism

Claim 1

A single sheet advancement apparatus in combination with an alpha-numeric keyboard wherein the apparatus is used to incrementally advance a copysheet so that the copysheet may be visually scanned by the operator of the keyboard; and, wherein the apparatus consists of: a roller unit consisting of a single elongated roller member having roller axles projecting from both ends, and friction sleeve elements disposed proximate the ends; a transparent roller housing unit comprising: a clear acrylic roller through having an elongated semi-circular configuration; a pair of vertically disposed end plate members connected to said roller through wherein one of said end plate members is provided with an elongated slot that is dimensioned to receive one of said roller axles, whereby said roller housing unit supports said roller member in a floating relationship to accommodate copysheets of different thickness intermediate said roller housing unit and said roller unit; an actuator unit operatively associated with said roller unit and comprising: an indexer assembly; a rotor assembly; and, a pawl assembly connected to one another and to one of the roller axles via a ratchet element, wherein the actuator unit further comprises an elongated actuator member mounted on a pivot element disposed proximate its midpoint and secured to the roller housing unit, wherein the actuator unit is operatively connected to a drive unit via a drive means attached on one end to said pivot element, wherein the drive means has a loop formed on its other end which slidingly engages an elongated force transmitting element disposed on said rotor assembly, wherein said drive unit is operatively associated with said actuator unit for transmitting incremental rotary movement to said roller unit; and, the said indexer assembly comprises: an axle element secured to one of the end plate members; an indexer member rotatably disposed on the axle element, and provided with a stop element; an indexer lever that is disposed generally perpendicular to the roller axle; and, an indexing plate connected to the roller housing unit and provided with a plurality of notches that are dimensioned to receive said indexing lever to vary the position of said stop element within the roller housing unit.