Abstract: The present invention is an improved inked ribbon advance and reverse mechanism for use in a multiple print station printing apparatus. The improved inked ribbon advance and reverse mechanism includes a first ribbon spool and a second ribbon spool onto and from which an inked ribbon is wound and unwound, respectively. The improved inked ribbon advance and reverse mechanism also includes a first ratchet wheel and a second ratchet wheel which are axially aligned and fixedly coupled to the first ribbon spool and the second ribbon spool, respectively, so that they rotate together. The second ratchet wheel is disposed in a vertical plane which is parallel with the axis of the rotative drive shaft of the printing apparatus and substantially orthogonal to the plane in which the first ratchet wheel is disposed, and is adjacent, but not contiguous, to the first ratchet wheel.

Abstract: The present invention is a rotatable print head in combination with a multiple print station printing apparatus which includes a movable carrier to which the rotatable carrier is pivotally coupled by an axial rod so that the rotatable print head may rotate substantially an angle of 90.degree., a frame and a driving mechanism which is mechanically coupled to the frame and which drives the movable carrier laterally across the frame in a direction, which is parallel to the axis of rotation of the rotatable print head.

Abstract: The present invention is an improved pawl for use in combination with an inked ribbon advance and reverse mechanism which includes a plate member, a pair of ribbon spools which are disposed on the surface of the plate member and are mechanically coupled thereto so that they can rotate bidirectionally, a pair of ratchet wheels, each having teeth disposed in an opposite direction and each being mechanically coupled to one of the pair of ribbon spools, and a mounting device for mechanically coupling the improved pawl to the plate member. The improved pawl includes an elongated member having a pair of ends, each end having a plurality of teeth which are disposed along the surface of the elongated member that mechanically engages one of the ratchet wheels. The elongated member is pivotally coupled to the mounting device which includes a pivot pin which mechanically couples the elongated member to the mounting device by means of a pair of springs.

Abstract: The present invention is an improved media advancement mechanism for use in combination with a printer that includes a frame, a print head mechanically coupled to the frame and a platen mechanically coupled to the frame so that a print media may pass between it and the print head. The printer also includes a pair of sprockets which are adapted to support the print media and which are mechanically coupled to the frame by a sprocket shaft. The improved media advancement mechanism includes a ratchet wheel which is mechanically coupled to the sprocket shaft in order to provide rotational motion thereto in response to an electrical signal from the printer thereby moving the print media incrementally. The improved media advancement mechanism also includes an adjustment plate pivotally coupled to a sidewall of the frame and a restraining device for restraining the adjustment plate from its pivotal motion.

Abstract: The present invention is a guide for use in combination with a printer which includes a frame and a print head that is mechanically coupled to the frame and that is adapted to travel laterally along the front of the frame. The printer also includes a platen which is mechanically coupled to the frame and which is disposed so that a print medium may travel between the platen and the print head, and a pair of sprockets, each of which has a cylindrical sidewall on which the print medium travels. Each of the sprockets has a disc-shaped hub and is axially coupled to the frame. The media guide includes a pair of integral members each of which is disposed adjacent to one of the sprockets so that the print medium is disposed between the cylindrical sidewall of the sprocket and has a first portion which is mechanically coupled to the disc-shaped hub of the sprocket adjacent to a second portion of the integral member so that each of the sprockets may rotate independently of each of the integral members.

Abstract: There is disclosed an impact device for operation from a source of alternating power and with at least striking member adapted to be electromagnetically actuated to impact against an opposing surface. An electrical gate under the control of a switching circuit and at a given point in time and for a given time duration connects a source of alternating power to the electromagnetic striking member. A source of gate control pulses for rendering the electrical gate conductive and non-conductive is connected through the switching circuit under the direction of a switch control circuit to the electrical gate for selecting which of the gate control pulses are to be connected to the electrical gate.