Abstract: A dot matrix print head wherein each printing device comprises a pin fitted to one end of the anchor of a respective electromagnet. The electromagnet presents an E-shaped core, the center bar of which forms a first pole piece, and the other two bars of which form the other pole piece coplanar with the first. The anchor consists of a plate having a flat surface designed to rest on the first pole piece and defined by two parallel steps. The first step is located on a portion opposite the end fitted with the pin, and rests on the other pole piece. The other step is adjacent to the aforementioned end, and corresponds with the gap between the center bar and a lateral bar of the core, so as to enable overtravel of the plate and the pin for effecting a ballistic print stroke.

Abstract: A printing head of the type in which the tips of the needles are guided in two parallel rows by a pair of matrices disposed side by side comprises a support which carries a first matrix. The support is fixed to a printing body. The second matrix is carried by a support movable on the printing body so as to move the second matrix in parallel to the first from a position in which the tips of the needles in the two rows are at the same heights, for high-speed printing to the position in which the tips of the needles in one row are located at the heights of the spaces between the tips of the needles in the other row, for high definition printing. The movable support is connected to the printing body by a parallelogram structure in which two parallel sides are constituted by the support and the printing body while two other sides are formed by resiliently-deformable members. A pre-loaded, resilient biasing member maintains the movable support against a first abutment.

Abstract: A dot matrix printing head on which the tips of the printing pins are supported on a matrix, in turn supported on a body designed to travel in the printing plane, in two side by side, parallel offset rows; mainly characterized by the fact that the matrix is supported in idle manner on the supporting body; the printing head presenting means for selectively turning the matrix into two angular positions, in a first of which, the rows of pins are substantially perpendicular to the printing plane for enabling high-definition printing, and in a second of which, both rows of pins are arranged obliquely in relation to the printing plane, and at such an angle that the tips of the pins in both rows are coplanar, thus enabling high-speed printing. (FIGS. 2 and 4).

Abstract: A dot matrix print head of improved type is described the principal characteristic of which lies in the fact that the casing containing the electromagnets actuating the needles is clamped between the needle support body and a cover carrying on its interior the striker elements which, when attracted by the electromagnets, displace the needles; the casing is formed by an extruded metal tube body and by an element of plastics material between which are inserted, in appropriate grooves, stacks of U-shape laminations carrying at one end respective electrical windings constituting the electromagnets.

Abstract: A dot matrix print head is described having an improved type of electromagnetic actuator device for the print needles; the ends of the striker elements which cooperate with one of the poles of the electromagnetic drive for each needle are in fact shaped on the side facing the said pole, in such a way as to be displaced with respect to the point of contact of the striker element on the pole itself, so as to cause between this end and the pole a predetermined clearance capable of compensating possible constructional imprecisions. (FIG. 2).