Line printer hammer banks

A line printer, comprising:

• a shuttle mechanism;
• and
• a hammer bank coupled to the shuttle mechanism for horizontal reciprocating movement by the shuttle relative to a vertically moveable print medium, wherein the hammer bank comprises:
• a back plate;
• a plurality of elongated pole pieces extending forwardly from a front surface of the back plate, each pole piece having an electrical coil disposed about a circumfery thereof;
• a permanent magnet having a back surface coupled to the front surface of the back plate;
• a shunt fret having a back surface coupled to a font surface of the permanent magnet and defining a plurality of elongated, downwardly extending shunts;
• and
• a hammer fret having a back surface coupled to the front surface of the back plate and defining a plurality of elongated, upwardly extending hammers, each hammer being interdigitated between a pair of adjacent struts and including an elongated spring portion having a hammer head disposed at an upper end thereof, each hammer head having a printing tip projecting forwardly therefrom.

A method for making a hammer bank for a line printer, the method comprising:

• attaching a back end of each of a plurality of elongated pole pieces to a front surface of a back plate such that the pole pieces extend forwardly therefrom and are arranged in a line and disposed generally parallel to one another,
• disposing an electrical coil about a circumfery of each of the pole pieces;
• coupling a back surface of a permanent magnet to the front surface of the back plate;
• coupling a back surface of a shunt fret to a font surface of the permanent magnet, the shunt fret defining a plurality of elongated, downwardly extending shunts;
• and
• coupling a back surface of a hammer fret to the front surface of the back plate, the hammer fret defining a plurality of elongated, upwardly extending hammers, each hammer being interdigitated between a pair of adjacent shunts and including an elongated spring portion having a hammer head disposed at an upper end thereof, each hammer head having a printing tip projecting forwardly therefrom.