Printer with interchangeable paper-feed modules

Abstract From the Canadian patent

A data printer having removable and interchange-, able, paper-feed modules such as may embody a tractor or, pin-feed-type paper-feed mechanism. The interchangeable modules each have guide ways which cooperate with and move along complementary guide ways supported by the printer main frame to guide the selected module into place and seat it in a particularly defined position. A mechanical latch locks the seated module to maintain it in place. The paperfeed mechanism of each module is driven by a rotatable member with the power train including a motor-driven worm mounted on the printer and a mating worm-gear carried on the removable paper-feed module. The worm is mounted in an upright …