Abstract: In the print band timing system described herein, the bipolar pulse generated in a sensor by the passage of a print band timing mark is applied to a discriminating circuit which compares the pulse signal with a voltage level substantially equal to the nominal d.c. level of the sensor signal. Hystereis is provided in one direction only so that the nominal zero crossing is precisely determined in a time position relationship.

Abstract: A ribbon feed mechanism for a bi-directional printer that produces a constant relative ribbon to print-head velocity. The invention produces the constant relative velocity by coupling the ribbon to the print-head through a reciprocating shuttle, which moves in an opposite direction to and at one-half the speed of the print-head. As the shuttle reciprocates it engages the ribbon such that a constant length is maintained between the ribbon supply and the print-head and between the print-head and the ribbon take-up. The ribbon is taken up at a constant speed. By this method, the relative ribbon to print-head speed is fixed at the ribbon take-up speed.

Abstract: In the high speed impact printer disclosed herein, the effects of magnetic interaction between adjacent magnetic actuators is offset or compensated for by providing a programmable delay in the energization of each magnet, the value of the delay being programmed as a predetermined function of the pattern of energization of physically adjacent coils.

Abstract: The high speed print pin actuator disclosed herein is constructed as two sub-assemblies, a U-shaped fixed magnet structure and an armature sub-assembly. One leg of the U-shaped structure constitutes a coil core and the other includes a permanent magnet and a keeper plate, the ends of the keeper and the core being finished to a common plane. The armature assembly includes a flux return bridge structure which extends from the keeper to a region adjacent the end of the coil core and which is bifurcated to receive an armature which is selectively attracted to the coil core. The armature is carried on a spring which is, in turn, mounted on the bridge structure. With the spring in a deflected position, the armature is finished to a common surface with the portion of the bridge which mates with the magnet structure. Accordingly, assembly of the armature sub-assembly with the U-shaped fixed magnet structure is facilitated and accurate parallelism of the armature and pole piece is provided.

Abstract: The slaved ramp voltage generator disclosed herein facilitates the writing of characters by a servo controlled stylus carried on a moving carriage. The carriage is driven at a selectable speed and the drive system generates pulse signals at a rate which is proportional to carriage speed. A digital counter is advanced by these pulse signals and the digital value held by the counter is converted to an analog voltage which varies in proportion to displacement of the carriage. This carriage displacement voltage is summed with a vector-defining position voltage to obtain a control voltage which drives the stylus servo mechanism to effect writing with respect to a moving frame of reference.

Abstract: In the dot matrix printer disclosed herein, a multicolor ribbon is shifted to bring different colored stripes in alignment with the nosepiece of a dot matrix printhead by means of cup-like ribbon guide members journaled on either side of the nosepiece. Each guide member provides, in its periphery, an arcuate slot through which the ribbon can freely slide as the printhead traverses. A stepping motor is coupled to the guide members for rotating them so as to selectively bring a stripe of desired color into operative position.

Abstract: A recording or printing device which will print bidirectionally in both the left to right and right to left directions by use of an ink jet head travelling horizontally with respect to a printing medium. A carriage carries the ink jet head and an image is formed by ink droplets from the ink jet head. To compensate for relative horizontal displacement of the ink droplets caused by the horizontal travel of the head and carriage, tilting compensating structure is provided for parallel electrostatic deflection plates. The deflection plates are mounted on a pivotable structure upon the traverse carriage and because of the bias effect of a pair of springs and a slide block will tilt in the correct direction to provide the needed compensation of the ink droplets. Mechanical limit stops on a slide bar determine the amount of tilt for more than one speed of carriage traverse, and changeable limit stop structure permits the limit stops to be changed for a second, a third or more speed of carriage movement.

Abstract: Disclosed is a free-flight hammer, impact-printing apparatus including a shifting hammer bank having a plurality of interchangeable hammer modules. Each hammer module includes a plurality of individual linear motion, slidable hammers which are mounted in a side by side relationship in a hammer housing. Each hammer housing also includes a hammer-return spring mounted adjacent a hammer for causing the hammer to return to a set position. The hammers are caused to strike a moving record medium by a plurality of interchangeable actuator modules which each include an actuator assembly. Each actuator assembly comprises a stator housed in a stator housing, a solenoid assembly and an armature. The solenoid assembly is mounted between the stator and the armature. The armature actuates pushrods, which are slidably mounted in the stator housing, in order to cause a hammer to strike.

Abstract: The high speed print pin actuator disclosed herein is constructed as two sub-assemblies, a U-shaped fixed magnet structure and an armature sub-assembly. One leg of the U-shaped structure constitutes a coil core and the other includes a permanent magnet and a keeper plate, the ends of the keeper and the core being finished to a common plane. The armature assembly includes a flux return bridge structure which extends from the keeper to a region adjacent the end of the coil core and which is bifurcated to receive an armature which is selectively attracted to the coil core. The armature is carried on a spring which is, in turn, mounted on the bridge structure. With the spring in a deflected position, the armature is finished to a common surface with the portion of the bridge which mates with the magnet structure. Accordingly, assembly of the armature sub-assembly with the U-shaped fixed magnet structure is facilitated and accurate parallelism of the armature and pole piece is provided.

Abstract: A web loop control system has first and second roller stations and a web loop disposed therebetween. A dancer arm is biased into engagement with the web loop to maintain tension therein. An optical code disk is secured for rotation with the dancer arm and an optical sensing means cooperates with the code disk to generate dancer arm position information which is relayed to the motor control system to maintain a desired web loop length during both drive and stop modes. The invention as applied to a printer for serialized forms utilizes the dancer arm code disc/optical sensing means combination to insure that a between-forms perforation is present at the fuser roller nip when the system is at rest. The serialized form printing system also provides for controlled acceleration and deceleration between operating speed and a dead stop within 3/8 inch of form length. Acceleration and deceleration are closely controlled to prevent jarring or excessive acceleration of the web loop.

Abstract: The ink supply container disclosed herein is adapted for use with a moving carriage printer and controls foaming of a liquid ink in the container by providing, at the top of the container, a well having a sloping floor. Foamed ink is communicated to the well where it is condensed and returns through an opening at the lower end of the floor.

Abstract: A mechanical system for feeding cut sheet paper to a printer from one of several cassettes. A mechanical selector is mounted in each cassette so that it can drive a paper feed roll mounted in that cassette. The cassettes include insert guides which allow each cassette to be replaceably mounted in at least one side rail secured on the printer. The side rail has guides that receive and automatically locate each cassette on the printer with a simple "drop in" engagement. The side rail supports a gear train or an equivalent power transmission arrangement that has a common drive and extends to all of the cassettes. A power input gear of each selector engages an associated gear of the gear train. The selectors each include a combination mechanism that allows the selector to transmit power only after the drive shaft has supplied a programmed pattern of rotations and counter-rotations to the selectors.

Abstract: A dot matrix printer has a dot generator which projects dots through a dot selector and dot deflector towards a recording medium. Dots used for printing are selectively charged by the dot selector and deflected vertically by the dot deflector for printing on the recording medium. The dot generator moves horizontally at a speed S across the recording medium. Dots not used for printing are not charged, not deflected, and are collected in a gutter. A data input designates to the dot selector the character to be printed. A speed selector is operable to select standard speed printing S.sub.1, or high-speed printing S.sub.2. Speed S.sub.2 is equal to some factor Z multiplied by standard speed S.sub.1. If the standard speed printing is selected, the dot selector accesses the standard speed character matrix memory and receives dot position information corresponding to the designated character.

Abstract: A method and apparatus for controlling the velocity of a carriage in a calligraphic type printing apparatus maximizes average velocity across the printing line. The method and apparatus, based upon the present carriage velocity and the maximum future carriage velocities along a predetermined next portion of the printing line, determine the direction of velocity change for the carriage, if any change is needed. Accordingly, the velocity of the carriage is controlled so as to not exceed maximum carriage velocities at various points along the printing line. These maximum carriage velocities are determined by the symbols being printed and in particular by the complexity of the symbols being printed. The method and apparatus can operate either on a demand or on a line-by-line basis.

Abstract: A recoverable ink supply system, comprising both method and apparatus, includes a primary reservoir which is connected by suitable fluid conduit to a prime, or primary, pump. The prime pump transfers the liquid ink from the primary reservoir to an intermediate reservoir at an increased pressure causing a lower pressure condition in the sealed primary reservoir and a higher pressure condition in the sealed intermediate reservoir. Secondary, or metering pumps, receive pressurized ink from the intermediate reservoir after it is filtered at the reservoir outlet, and supply metered, higher pressure ink through combined filter/pressure fluctuation dampers to associated on/off control valves. The control valves permit the flow of the pressurized ink into the print heads wherefrom the ink is discharged at a controlled uniform velocity.

Abstract: A lightweight, inexpensive and yet highly reliable, fully self-contained cartridge for inked ribbons having a drive assembly which "stuffs" the inked ribbon into the ribbon storage region in a full-fan-fold fashion. The storage region is substantially U-shaped and the size of the storage region, coupled with the full-fan-fold configuration of the ribbon provides a significant increased ribbon packing density. The U-shaped storage region substantially surrounds and embraces the print head, making efficient use of the central region of the cartridge.The outfeed end of the ribbon storage region is provided with a pair of posts and terminating projections which are spaced relative to one another so as to accommodate ribbon folds in the spaced regions as the ribbon is being fed to enable the ribbon to be moved across the printing location in a smooth manner.Drive means are provided to assure that the portion of the ribbon being "stuffed" into the storage region retains the full-fan-fold arrangement.

Abstract: A dot matrix impact printer for printing a plurality of colors substantially simultaneously. A print head is comprised of three spaced substantially parallel columns of print wires, each column containing an equal number of print wires. Separate independent ink supply sources are provided immediately adjacent the print head, and ink delivery means carry the ink from an associated supply source to the printing tips of the print wires in an associated column. Each of the ink supply containers contain an ink of a different color. The colors may, for example, be the three primary colors. The ink delivery means incorporate capillary means for delivering ink from the ink supply container to the printing tips by capillary action. Printing dots of different colors in either a partially or a substantially overlapping fashion enables any color to be created from the three primary colors.

Abstract: An ink delivery system employing capillary member for delivering ink from a container directly to the tips of reciprocating print wires for ink transfer to a print receiving medium. Adjustment is provided for regulating the surface contact area between an ink container capillary member and a print head capillary member to regulate ink flow in order to accommodate printing speed and compensate for any factors which may alter ink flow, whether they be to cause more or less rapid ink flow. In a preferred embodiment, the ink container capillary member is moved relative to the print head capillary member. The capillary members are comprised of a porous material. Adjustment of ink flow is simplified through the provision of an easily movable handle arm and cooperating serrated slot for simply and rapidly adjusting the interface between the cooperating capillary members through which interface the ink is caused to flow.