Abstract: Wire printing apparatus includes a print head having at least one print wire and associated actuating mechanism and drive circuit. In the drive circuit a capacitor is charged to a predetermined voltage through an inductance and then discharged through the coil of an electromagnet in the actuating mechanism. The current through the coil is arranged to rise and then fall. The circuit permits optimization to maximize the proportion of the energy input to the drive circuit which is transferred to the print wire.

Abstract: A wire matrix printing head moveable along a printing line on a record medium is described in which a ring of wire-selection electromagnets are grouped about the wire guiding arrangement, the electromagnets each having a basic yoke assembly with a pair of limbs each able to support a separate energising coil. The electromagnet armatures are supported by a common frame having a plurality of finger-like structures, one for each armature, on which the armatures are respectively pivoted. The printing wires are spring loaded into their restored positions and abut their respective armatures, which are supported in their respective unoperated positions each by an adjustable resilient backstop. The printing wires are supported in guides so that they are arranged in two columns, both the columnar pitch and the pitch of nominally adjacent wires in the columns being of the order of the wire diameter.

Abstract: A wire printing head is disclosed in which solenoids are arranged in arcuate configuration, the printing wires being connected in line with their respective solenoids. A wire guide is positioned adjacent the printing line and preformed tubes are used to guide the wires from the solenoids to the wire guide. The tubes are located at the end nearest the guide in a tube support member. An intermediate support member is provided to support the tubes, grooves being cut in the intermediate support member for this purpose. The grooves are sufficiently large to enable the tubes to take up their natural positions within their respective grooves, being secured within the grooves by an adhesive material such as synthetic resin. The solenoids are held by clamps in recesses in the head and the recesses radiate from a common point which also serves as the point from which the arc is struck.