Abstract: A method and associated apparatus for quickly and accurately advancing paper between the platen and printing mechanism on a line-by-line basis in a high speed printer for printing lines of text including a platen and a printing mechanism disposed adjacent the platen.

Abstract: A method of operating an impact printer having a printhead normally intended to create letter quality characters during one pass across the printing medium at a carriage speed at least three times slower than the carriage speed at which the printer creates draft quality characters wherein the method of operation produces letter quality characters at least 50% faster than the prior art method of operation. To accomplish the throughput increase, the printer is operated in the same faster draft speed for the printing of both draft and letter quality characters. Letter quality characters, however, are created in two passes and the printing medium is not advanced to a next row position until after the two passes. During the first pass, the carriage is moved across the printing medium while printing one of each pair of horizontally close adjacent dots includes in the vertical strokes of the characters comprising a row of characters and a portion of other dots included in the row of characters.

Abstract: In a serial printer wherein a bi-directionally operating motor with a shaft drives a carriage in an oscillatory motion between two end points, an improvement for minimizing the time for direction reversal of the carriage. There is a ballistic rebound device for transferring energy of the moving motor and carriage in one direction into a resilient member and for retransmitting energy absorbed by the resilient member back into the motor and carriage in a direction opposite the one direction. There is also an electrically operated clutch for selectively coupling the ballistic rebound device to the shaft of the motor. Sensing apparatus is provided for sensing the position of the carriage with respect to the two ends.

Abstract: An improvement to a dot matrix printer of the shuttle variety wherein a printhead is oscillated from side to side within a printer base. The shuttle is disposed within a ballistic energy transfer device mounted for oscillating movement from side to side in the opposite direction to the instantaneous movement of the shuttle. A rebound spring is operably connected to exert a rebounding force against the shuttle to aid it in reversing direction. Also, a centering spring is operably connected for exerting a centering force against the ballistic energy transfer device. A linear motor is connected for driving the shuttle back and forth in an oscillating motion with respect to the ballistic energy transfer device. Optionally, the linear motor is connected for driving the ballistic energy transfer device back and forth in an oscillating motion with respect to the printer base. The turnaround time of the shuttle is adjusted by adjusting the span of the shuttle or the spring constant of the rebound spring.

Abstract: A method and associated apparatus for quickly and accurately advancing paper between the platen and printing mechanism on a line-by-line basis in a high speed printer for printing lines of text including a platen and a printing mechanism disposed adjacent the platen.

Abstract: In a serial printer wherein a bi-directionally operating motor drives a carriage in an oscillatory motion between two end points, an improvement for minimizing the time for direction reversal of the carriage. There is a ballistic rebound device for transferring energy of the moving carriage in one direction into a resilient member and for retransmitting energy absorbed by the resilient member back into the carriage in a direction opposite the one direction. There is also an electrically operated brake for selectively coupling the ballistic rebound device to the carriage. Sensing apparatus is provided for sensing the position of the carriage with respect to the two ends.

Abstract: A high speed print pin driver for a dot matrix printer. A U-shaped core having a pair of parallel spaced legs is formed of a plurality of laminations of silicon iron. A rectangular magnetic field-forming coil is on one of the legs. A magnetic flux plate of silicon iron is disposed across the open end of the U of the core between the legs, the flux plate being attached to the other of the legs and in close-spaced adjacent relationship to the one of the legs. The top surface of the flux plate over the other leg is slightly longitudinally beveled and the flux plate has a bore therethrough over the one of the legs and longitudinally aligned therewith. A longitudinal spring-metal beam is disposed along the flux plate, being attached on one end to the beveled top surface and extending out over the flux plate on the other end. The beam includes an armature piece of magnetically attractable material disposed within the bore in the flux plate.

Abstract: A dot matrix print head utilizing a print pin carrying spring beam mounted as a cantilever with an armature mounted thereon over a solenoid housing with a spring member overlying a portion of the beam to resist motion of the beam past its rest position on rebound following a printing stroke.

Abstract: A dot matrix print head includes a solenoid and a spring assembly for driving a print pin, with a positioning means for holding the assemblies in a predetermined relation. The solenoid assembly preferably has a first positioning means adjacent its upper surface and a second positioning means preferably forms a part of the spring assembly. The first and second positioning means are preferably circumferential and the second means is preferably adapted to engage the first positioning means around more than 180.degree. of arc thereof and is expandable to permit sliding engagement with the first positioning means so as to hold the spring assembly locked onto the solenoid assembly. Preferably a molded stiffening rib is carried by the spring assembly and extends from the armature to the pin-carrying tip of the spring assembly. The molded pin support is formed integrally with the stiffening rib and permits rotation of the end of the pin in the support.

Abstract: The method of assembling a dot matrix print pin driving spring in relation to a solenoid having an axial hole, the spring carrying a cylindrical armature and the hole being designed for receiving the cylindrical armature, the solenoid being carried by a housing, positioning a plastic sheet adjacent the hole, with an edge of the plastic sheet overlying the hole, inserting the armature into the hole thereby partially drawing the plastic sheet into the hole so that it engages more than 180.degree. of circumference of the armature to center the armature in the hole.