tractor A device for moving continuous stationery through a printer and maintaining good registration relative to the page boundaries. The technique by which this is achieved is known as tractor feed. The tractors are used in pairs and consist of loops of light chain or bands on which are mounted pegs (also known as pintles or sprockets) that engage with holes that have been punched along both edges of the stationery. The tractors are usually driven by a d.c. servo or stepper motor that is controlled by the printer electronics. In high-speed printers there may be pairs of tractors above and below the print line but in lower-speed devices there is usually only one pair and friction is relied upon to keep the paper tensioned. In printers for transaction documents the tractors are arranged immediately below the print line so that the document may be torn off close to the last line of print.

trac·tor / ˈtraktər/ • n. a powerful motor vehicle with large rear wheels, used chiefly on farms for hauling equipment and trailers. ∎  a short truck consisting of the driver's cab, designed to pull a large trailer.

tractor Four-wheeled or tracked vehicle for moving and operating heavy implements. Tractors are used mostly in farming and construction. The first tractors were built in the 1870s. Modern tractors have petrol or diesel engines, and can haul and power a wide range of implements, including hay balers, crop sprayers, and mowing machines.