Abstract: Apparatus for precisely positioning the various work stations (e.g., image-forming, cleaning and image-transfer stations) of an electrophotographic printer/copier relative to the outer surface of a rotating drum, e.g., an image-forming drum or an image-transfer drum. Such apparatus comprises a pair of drum-support members, each having associated reference surface features adapted to mate with complimentary reference surface features on the individual work stations. Preferably, the placement of the reference surface features of the drum-support members are factory set to account for any idiosyncrasies (e.g., run-out) of a drum supported by such members.

Abstract: A protective enclosure for an image-recording drum of the type used in electrophotographic printer/copiers comprises a pair of spaced guides that serve to slidably support the drum within the enclosure. Such guides, when aligned with similar drum guides located within a printer/copier frame, enable the drum to be transferred from the enclosure to the copier/printer by merely sliding the drum from one pair of drum guides to the other. A mounting mechanism operates to couple the drum enclosure with the printer/copier frame to properly align the respective drum guides. By virtue of the invention, the image-recording drum can be installed in copier/printer without physically contacting the drum's delicate photosensitive surface, thereby eliminating any image artifacts that may arise from inadvertent scratching or marring of the drum surface during installation.