Ballistic wire matrix print head

摘要

A wire printing head of ballistic type comprises a front guide fixed to a carriage and in which the printing wires are mounted in an axially slidable manner. The electromagnets for actuating the wires have their respective cores mounted inside a tube of non-magnetic material. In order to obtain high heat dissipation, the electromagnet cores and windings are embedded in a resin block which fills the interior of the tube. The exterior of the tube is also provided with a set of cooling fins. The electromagnet armatures are mounted on a rear cover which is connected by a screw to a part of the front guide, which in its turn is housed in a compartment in the resin block. Shims are disposed between the front guide and group of electromagnets, and their number can be varied in order to modify the distance of the ends of the printing wires from the platen.