Abstract: A new high strength steel alloy characterized by having high DC magnetic saturation, ultra high tensile, yield and fatigue strengths that is particularly suited for use as a hammerspring in hammerbanks in impact printers and for other applications where magnetic alloys are used and high mechanical strength is desirable. The alloy is formed of the following composition in weight percent: about 20% to about 35% Co; about 2% to about 6.0% Ni; about 0.0 to about 0.15% C; about 0.75% to about 3% Mo; 0% to about 3.0% Cr; 0% to about 2% Mu; 0% to about 0.02% Si; 0% to about 0.003% P; 0% to about 0.001% S; 0% to about 0.005% 02+N2;with the balance comprised of Fe. A process for making the alloy includes homogenizing preferably at a temperature of 2150° F. for 24 hours, and solution treating at a temperature in the range of about 1500° F. to about 1700° F. under a vacuum or inert gas protective atmosphere; air-cooling; and precipitation aging at a temperature in the range of about 800° F.

Abstract: A thermal printer having a source of print media, a source of print ribbon, a rotatable platen, and a print head in associated placement with the platen over which print ribbon and media pass for printing purposes. A pivotally connected ribbon support is placed before and/or after the passage of the ribbon over the print head for pivotal movement across the width of the print ribbon. The support can be a roller, and support can be combined for contact with the ribbon on surfaces opposite from each other. A drive for the print ribbon can move the print ribbon by a motor connected to the source and collecting spindle based upon the Back EMF of at least one motor.

Abstract: A line printer with a hammerbank having print hammers with printing tips and a ribbon supported for impact by the tips for printing on media and a metal platen for supporting the media. An elastomer on the metal platen supports the media and has a layer of material harder than the elastomer extending inwardly from its surface which receives the impacts of the hammer tips. The harder material can be particles extending inwardly randomly from the surface of the elastomer of a ceramic having a sphericity exceeding 0.50 up to 35 percent of the thickness of the elastomer, and in the range of 20 microns to 400 microns in size.

Abstract: A paper stacker for use with a printer which prints connected sheets that are to be stacked in a folded relationship having a surface for receiving the paper with a frame surrounding the paper that is raised in relationship to the paper in order to maintain paper within the confines of the frame as the frame moves upwardly. The frame is balanced by a constant force spring, and is indexed by optical sensors. The frame includes two adjustable fences for variously sized paper which adjustably moves with paddles to press the paper edges downwardly in the stack. Pinch rollers for driving the paper include low inertia drive rollers formed of a relatively low density plastic material with a pair of idler rollers. To improve stacking, ironing tractor idler rollers iron the tractor perforations, and chains orient the catenary stacking movement.

Abstract: A new high strength steel alloy characterized by having high DC magnetic saturation, ultra high tensile, yield and fatigue strengths that is particularly suited for use as a hammerspring in hammerbanks in impact printers and for other applications where magnetic alloys are used and high mechanical strength is desirable. The alloy is formed of the following composition in weight percent: about 20% to about 35% Co; about 2% to about 6.0% Ni; about 0.0 to about 0.15% C; about 0.75% to about 3% Mo; 0% to about 3.0% Cr; 0% to about 2% Mn; 0% to about 0.02% Si; 0% to about 0.003% P; 0% to about 0.001% S; 0% to about 0.005% O.sub.2 +N.sub.2 ; with the balance comprised of Fe.A process for making the alloy includes homogenizing preferably at a temperature of 2150.degree. F. for 24 hours, and solution treating at a temperature in the range of about 1500.degree. F. to about 1700.degree. F. under a vacuum or inert gas protective atmosphere; air-cooling; and precipitation aging at a temperature in the range of about 800.

Abstract: A clean print ribbon feed system and method for a printer having a ribbon with two non-inked clean hands portions wound around a pair of spools is disclosed. Detection of the spool having greater angular velocity and lesser angular velocity determines the direction of feed. The spool having greater angular velocity winds and takes up the print ribbon. The non-inked portion can be formed as a conductive plastic and is initially wound on each spool. Detection of the non-inked portion of the ribbon takes place by two electrical contactors. The determination of the angular velocity of the spools determines the amount of print ribbon on one of the spools so that the spool having the lesser ribbon can be driven as a take-up spool to provide proper directional drive for winding the clean hands portion and the inked portion which follows.

Abstract: A line printer having a hammerbank for printing on media with print hammers to impact a ribbon to form a dot matrix array having printing tips and permanent magnets for magnetically retaining the hammers. Coils release the hammers by overcoming the magnetism to impact a platen against which the hammer printing tips can strike a ribbon and the underlying media. A cover overlies the hammers having an elongated ridge, and is secured to the hammerbank by threaded members. A print ribbon mask is threadably secured to the cover with openings indexed to openings of the cover to allow the passage of the printing tips.

Abstract: A thermal printer having a supply of media with a rotatable platen on which the media is moved for printing by a thermal printing head. A supply spindle supplies print ribbon from a supply spool mounted thereon, and a take-up spindle takes up the used print ribbon on a take-up spool. The spindles are each driven by a motor and controlled by a controller which detects the Back EMF (BEMF) of the motors, and calculates the velocity of the spindles, spool, and print ribbon to control each motor based on the BEMF. The status of the print ribbon as to low condition, breaks, ribbon full and other monitoring functions can be provided to a remote host computer or other monitoring station.

Abstract: An impact printer and method of printing having a plurality of hammers in side-by-side relationship with pairs of pole pieces in associated relationship with each hammer with a hammer contact end and a distal end removed from the hammer contact. A pair of elongated magnets span the pole pieces at their distal ends and a magnet connection connects the magnets for creating a magnetic circuit through the pole pieces. The pole pieces have reduced adjacent facing areas at their distal ends, and are reduced in cross-section intermediately between their ends. The reduction in area between pole pieces directly reduces the permeance and mutual induction thereby creating greater accuracy of printing by the hammers.

Abstract: A paper stacker for use with a printer which prints connected sheets that are to be stacked in a folded relationship having a surface for receiving the paper with a frame surrounding the paper that is raised in relationship to the paper in order to maintain paper within the confines of the frame as the frame moves upwardly. The frame is balanced by a constant force spring, and is indexed by optical sensors. The frame includes two adjustable fences for variously sized paper which adjustably moves with paddles to press the paper edges downwardly in the stack. Pinch rollers for driving the paper include low inertia drive rollers formed of a relatively low density plastic material with a pair of idler rollers. To improve stacking, ironing tractor idler rollers iron the tractor perforations, and chains orient the catenary stacking movement.

Abstract: A dot matrix printer having a plurality of hammers on a hammerbank with a counterbalance for the hammerbank in adjacent parallel relationship to the hammerbank. The hammerbank and counterbalance are driven by a first crank arm connected to the hammerbank and a second crank arm connected to the counterbalance with looped circular portions having bearing surfaces for moving the crank arms in opposite relationship to each other. A single shaft with two eccentrics, each respectively in the bearing surfaces turns the two crank arms. The crank arms are in close parallel relationship to each other and close proximity to the hammerbank and counterbalance. The single shaft is connected to a motor for driving the hammerbank and counterbalance, and is formed with a stator having coils with a magnetic ring formed as a rotor portion surrounding the stator, and a flywheel surrounding and connected to the magnetic rotor ring.

Abstract: A dot matrix printer having a plurality of hammers forming in part a hammerbank, with a motor for driving the hammerbank, and a controller for releasing the hammers for printing on a print media. A counterbalance is mechanically linked to the hammerbank for balancing it during movement. Lands and grooves are connected for rotation with the motor. A sensor sends pulses corresponding to the lands and grooves for controlling the hammerbank movement. The hammerbank is linked to the position of the lands and grooves as mechanically connected to the motor.

Abstract: A printer with a reciprocally moving hammerbank with a plurality of hammers thereon is disclosed including a magnet for retaining hammers on the hammerbank of the printer from a firing position. A coil overcomes the magnetism of the magnet by a circuit for reversing the magnetic field. At least a portion of the circuit comprises transistor drivers located directly on the hammerbank of the printer.

Abstract: A line printer having a hammerbank with hammers that are held by a permanent magnet and released by electrically driven coils. The temperature of the coils is determined by the relative resistance of the coils to provide an output equivalent to the temperature of said coils. The resistance is determined as a function of the current through the coils or voltage of the coils which is converted from an analog to a digital value. The attendant method of determining temperature of the coils in the hammerbank is by comparing a pre-established current or voltage value based upon a pre-established temperature of the coil with the current passing through the coil during operation of the hammerbank. The comparison of the current passing through the coil during operation with the pre-established current is provided to a controller for controlling the printer in response to the current differential between the currents which is in turn a function of the operating temperature.

Abstract: A dot matrix printer having a plurality of hammers on a hammerbank with a counterbalance for the hammerbank in adjacent parallel relationship to the hammerbank. The hammerbank and counterbalance are driven by a first crank arm connected to the hammerbank and a second crank arm connected to the counterbalance with looped circular portions having bearing surfaces for moving the crank arms in opposite relationship to each other. A single shaft with two eccentrics, each respectively in the bearing surfaces turns the two crank arms. The crank arms are in close parallel relationship to each other and close proximity to the hammerbank and counterbalance. The single shaft is connected to a motor for driving the hammerbank and counterbalance, and is formed with a stator having coils with a magnetic ring formed as a rotor portion surrounding the stator, and a flywheel surrounding and connected to the magnetic rotor ring.

Abstract: A data converting apparatus and process for converting outline representations of a character into its bit mapped form using two buffers one being for the bit mapped form of the character symbol and the other for the chain-code representation of the outline of the character are disclosed. Three steps are utilized in the process. The first step draws the character outline on to the drawing buffer and generates the chain-code representation with flags to indicate contour collisions. The contours are then scanned one more time to add missing flags on the chain-code representation. Finally, the inside part of the contour on the drawing buffer is filled using the chain-code representations of the contour, to provide a filled character.

Abstract: A printer is disclosed of the dot matrix type having a series of hammers with pins that print upon an underlying media, and which are released from magnetic retention by reversing the polarity of a permanent magnet and having electro-mechanical drive circuits and logic circuits. A power supply supplies an output of a voltage level for driving the electro-mechanical circuits connected to a ribbon drive, platen drive, paper feed, shuttle motor, and fans at a given voltage and the hammers at a different voltage. A thermal sensor is connected to a heat sink of the power supply, and to the printer controller to change the rate of printing when pre-established temperatures are sensed.

Abstract: This specification discloses apparatus and a process for printing data on a web of print from data related to a wider web than that to be printed upon. It includes a printer having a paper output of a narrower web than data from the wider web, and the provision of data as to the narrow and wide web width. The apparatus and process establishes the difference between the narrow web width of the printer and the wide web width and calculates the number of pages of narrow web width to be printed thereafter forming a raster output from the difference between the narrow web width and the wide web width to establish the width for printing by the printer.

Abstract: This disclosure sets forth a dot matrix printer having an improved ribbon drive. The ribbon drive is provided by two respective stepper motors. When one stepper motor is in a take-up mode, the second is in a feed mode. The process is reversed proximate the end of the tape as it is unwound. A re-generative mode for the feed motor is provided and a resistance bank varies amounts of drag on the ribbon as it is fed from the feed motor spool. Both motors when in the take-up mode are driven by full H bridge drivers and amplifiers controlled by a micro controller through an address and decode input and output latch. In order to provide for a uniform velocity of the print ribbon the angular velocity of the take up motor is controlled by counting the zero crossings of the feed motor, and then loading it into the micro controller to compare it with a look-up table for purposes of providing a proper speed to the take-up motor and the proper peak drag through the resistance bank to the feed motor.

Abstract: A process and apparatus for welding a tungsten carbide printing tip of a dot matrix printer to a hammerspring by holding the hammerspring in a fixture with a first electrode in adjacent relationship thereto and a second electrode in adjacent relationship to a tungsten carbide printing tip having cobalt and forcing said tungsten carbide printing tip into adjacent relationship with said hammerspring while causing cobalt in said tungsten carbide printing tip to be welded to said hammerspring through a welding current between said first and second electrodes.