Abstract: A print wheel cartridge for a serial printer. The cartridge includes a spring designed to lock the print wheel in the cartridge. The spring automatically releases the print wheel when the cartridge is inserted into the printer.

Abstract: An improved printer for accommodating and printing upon, a broad range of record medium thicknesses, including multi-part forms, while maintaining high print quality. The printer includes a platen and a pair of guide rails having a fixed relationship to one another, and an adjustable marking module supported for movement along the guide rails. An adjustment mechanism for adjusting the clearance between the platen and the marking module includes a toggle bracket for allowing the front of the module to pivot about the guide rail closest to the platen and for allowing the rear of the module to be moved relative to the furthest guide rail.

Abstract: A feed arrangement for transporting a record carrier around and in intimate contact with a printing platen in a printer. The feed arrangement includes a rotatable guiding member in the form of a paddle wheel having a number of resilient blades mounted in interference relationship to the platen. The guiding member serves to capture the leading edge of the record carrier and redirect it toward and then urge it into intimate contact with the platen.

Abstract: A clip for attaching printing unit guide rails to a printing apparatus guide rail support member. The clip is held to the print frame by spring tension between a spring foot and a guide rail retainer. The guide rail is held in place in the clip by spring tension between a leaf spring and the guide rail retainer.