Abstract: A print hammer mechanism for use in an impact printer such as a band printer or other printer which has printing elements which are impacted to make impressions on paper or other record medium. The hammer of the mechanism is impacted by dual armatures in forward motion toward the paper and return motion away from the paper so that the hammer is positively driven and does not depend upon the bounce back of the hammer from the paper or need a return spring on the hammer. This reduces the time for each hammer stroke and increases printing speed (characters per second). The armatures are normally decoupled from the hammmer and strike the hammer only after accelerating sufficiently to transfer sufficient speed to the hammer upon impact therewith. Springs are used to bias the hammer to a home position in the return direction and to maintain the armatures against a stop spaced from the hammer so that the armatures are normally decoupled from the hammer.

Abstract: Printing apparatus which provides full font character and dot matrix printing with an endless band having full font printing elements and dot printing elements spaced successively on the band. In order to provide the proper spacing of the characters, either formed with the full font elements or the dot matrix elements and to provide for graphics printing capabilities, a plurality of hammers are movably mounted on a shuttle which reciprocates along the print line. A plurality of fixed armatures selectively impact the hammers as they are moved. Predetermined, incremental hammer movements provide standard, compressed or expanded horizontal character and/or dot spacing.

Abstract: An impact dot matrix print head has a body with a coil frame assembly and a nose piece on the rear of which the coil frame assembly is mounted. The nose piece has guides for print wires which are maintained in sliding relationship by a linear slot guide at the front end of the nose piece. Armatures are freely disposed at one end on the frame and at the other end on the rear ends of the print wires. An end cap which bears on the frame assembly has a plurality of posts which extend through holes in each of the armatures and holes in spider springs which bear against the end cap and against the armatures where they bear against and pivot on the frame whereby to provide for ease of assembly and low friction guidance of the armatures and the spider springs which retain them.

Abstract: A printer has a horizontal platen for supporting paper and a print head which moves horizontally opposite thereto during indexing operations and is driven toward the platen for character printing. The print head is mounted on a carriage bearing block acting as a linear bearing and having a passageway of complex cross-section resulting from the superimposition of a square and a circle. A controllably rotatable carriage shaft passes through the passageway of the block.