Abstract: A graphic recorder convertible for use with multiple width strip chart paper. A rotatable main drum carries sets of sprocket teeth for transporting strip charts along an information transfer head. At least one set of sprocket teeth is formed by separable sprocket sections which are detachably mounted about a recess in the drum for use with a strip chart of one width. Filler inserts are mounted in the recess in place of the separable sprockets for use with a chart of another width. Means is provided for positioning the separable sprocket teeth in precise angular agreement with the other sets of sprocket teeth. Compensator means is provided for ensuring angular agreement of the teeth on one sprocket section with the teeth on the other section.

Abstract: A graphic recorder for use in recording information on a strip chart. The recorder includes a housing having a pair of rollers mounted at opposite ends of an opening across which the strip chart moves. Radially outwardly extending pins are mounted at opposite ends of each of the rollers for registering with and engaging positioning holes formed along the edges of the strip chart. Drive apparatus is provided for reversibly turning the rollers conjointly to move the strip chart along an X-axis. Apparatus is provided for creating a partial vacuum in a chamber within the housing so as to tension the portion of the strip chart suspended between the rollers along a curved path for properly positioning the chart with respect to the pins on the rollers. A recording head is mounted on the cover of the housing for movement along a Y-axis for marking the strip chart.