Wire matrix print head.

摘要

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, the ends of which at the rear of the nose piece are in a circular array and are in a linear array and are maintained in sliding relationship by a linear slot guide at the front end of the nose piece so as to facilitate high quality high impact printing. An array of solenoidal coils and armatures complementary to the array of print wires at the rear end of the nose piece are located in the frame assembly. The 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 caps 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. The springs may also be located with respect to the pivot so that they oppose the force of return springs on the print wires and partially balance such force to improve magnetic actuation of the armatures to help increase the printing speed of the head. Another end cap at the front of the frame assembly and the rear end cap are joined together by press fitting into posts to clamp the frame assembly into assembled relationship. A printed circuit board may be attached to the outside of the front end cap facing the front end of the nose piece. The coils are connected to energizing circuits for the print head by leads therefrom which extend through holes in the front end cap and are connected to the printed circuit board.