a platen gap adjuster for a printer utilizes a shaft along which the print head carriage slides during printing of each line . the shaft is eccentrically mounted by means of unitary , offset spindles the common axis of which is parallel to but spaced from the shaft axis . by rotating the shaft about the common spindle axis , the carriage and print head will be moved transversely of the shaft , thereby adjusting the gap between the print head and platen without impairing the longitudinal sliding motion of the carriage .