Abstract: A clip constructed of resilient material slidably engages the door of a paper web drive tractor of a printer. The clip defines two reference edges which are spaced by an amount substantially equivalent to the distance between a type line reference rod and the print line of a print mechanism. The operator aligns a selected type row on the web with the reference rod and slides one reference edge adjacent a mark on the web. The web is moved until the mark is aligned with the other reference edge of the clip and the selected type row is thereby positioned on the print line.

Abstract: A drive shaft of an automatic printer engages tractors which, in turn, pull a paper web across a print mechanism. Located on the drive shaft is a drive shaft position cam which is fixed to the shaft and rotates therewith. Additionally, located upon the drive shaft for limited rotational movement thereon is a second cam. The shape of the second cam is similar to the shape of the first cam and formed integral with the second cam is a frictional surface engaged by the paper. During normal paper drive, the cams are out of registration and rotate in unison. In response to a paper jam condition, the first cam driven by the paper locks and the cams are forced into registration actuating a switch, the plunger of which rides on both of the cams. The switch signal thus serves to interrupt the paper drive mechanism in response to a paper jam condition.

Abstract: An apparatus is described for positioning a paper web with respect to the print mechanism of a high speed printer. The apparatus includes a rod supported by the main frame of the printer and a slide tube is coaxially positionable on the rod. A pair of tractors for driving the web across the print station are carried upon the slide tube. One of the tractors is fixed to one end of the slide tube and the second tractor is positionally adjustable upon the slide tube. A clamp is provided for securing the second tractor to the slide tube after the spacing between the tractors is adjusted in relation to the width of the paper web. The slide tube is positioned to locate the type margin on the web at the desired location and a second clamp secures the slide tube to the rod.