Abstract: A dot matrix shuttle printer and/or a module therefore uses print wires of different lengths so as to achieve desired close packing of individual print wire actuators and correspondingly close wire-to-wire spacing of the print wires. To help maintain synchronization between the operation of all print wires, the longer ones include hollow sections so as to cause all the print wires to have substantially equal mass in spite of their differing lengths. The longer print wires include a hollow tube of stainless steel. A tip of wear resistant material is fixedly inserted at one end of the tube to effect impact printing.

Abstract: The printer paper feed mechanism disclosed herein operates to transfer a sheet of paper being printed from the printing platen to an output tray above the platen by means of a plurality of resiliently surfaced rolls carried on a shaft which is journaled in arcuate slots in end plates at either end of the platen roll. When the rollers are driven in one direction, the shaft walks along the arcuate slots toward a guide which is overlaid by a sheet of paper being fed from the platen. The rollers drive that piece of paper upwardly away from the platen and into the output tray.

Abstract: A bottom-weighted, free-standing, self-contained, self-supported printer in which the printer is provided with two vertical hoppers in spaced-apart adjacency, with the first hopper to house a supply of cut paper and with the second hopper for paper retrieval in a first in/first out (FIFO) sequence, in which the printer has an exceedingly small footprint so that it may be utilized adjacent the display for a personal computer.

Abstract: A continuous form tractor drive is disposed out of the way and out of sight below the printing platen (which itself may be capable of feeding individual forms to a print station). The mechanical paper handling and printing mechanism is affixed to the upper portion of a hinged housing with the continuous form tractor drive mechanism depending therefrom such that, when rotated upwardly and rearwardly to an opened position, easy access is provided for loading paper into the continuous form paper drive.

Abstract: A printer is provided with a controllable bail located between a print station and a downstream paper tear-off station. Upon occurrence of a first control signal, a printed portion of the paper is advanced to a desired tear-off position adjacent the tear-off station. Thereafter (after a predetermined time delay or after operator switch actuation), the paper is retracted to a new first print line position at the print station. The intermediately located bail is released at least after the leading edge of the paper is retracted thereunder and until sufficient paper is again advanced (e.g. during new printing operations) to ensure that paper is again located between the printing platen and the bail before the bail is re-engaged.

Abstract: An adjustable carriage assembly for a printing device having a print mechanism to be translated along a linear print path. The carriage assembly includes an upper carriage sub-assembly and a lower carriage sub-assembly, the lower carriage sub-assembly having a pair of laterally spaced arm members joined together by a pair of cross members. Each arm member has an open pivot slot and a support ramp portion. A spring coupled between the upper and lower carriage sub-assemblies in the region adjacent the pivot portions provides a spring detent for the upper carriage sub-assembly with respect to the lower carriage sub-assembly in both the first operative position and a second inoperative position. The guide members are adjustable eccentric washers.A cartridge latch is configured to be removably mounted in an aperture formed in a platform on the upper carriage sub-assembly.

Abstract: Detecting the inoperability of a plurality of printing element drivers without printing involving sequentially energizing each of the drivers with a shortened time duration pulse sufficient to produce a signal in indicating operability and/or inoperability but not sufficient to cause printing.

Abstract: A control for a dot matrix shuttle printer executing a sinusoidal velocity traversal across a line on a print medium comprises calculating the instantaneous position locations of the print elements during such traversal by making use of a lookup table. A dot image buffer stores information signals representing an entire line of desired dots to be printed. The calculated positions location information and the information signals are used to cause the desired dots to be printed in spatial sequence across a dot line at desired locations at the appropriate time during shuttle motion.

Abstract: The detected phase difference between a sensed motion velocity signal and an electric motor driving signal is used to drive a phase-locked loop which automatically generates a sinusoidal reference signal having a frequency substantially equal to the instantaneous natural mechanical resonant frequency of the driven mechanism. The sinusoidal reference signal is then combined with the sensed velocity feedback signal to generate the motor driving signal required to maintian resonant driving conditions. Low frequency compensation is also provided in the velocity control loop. The sinusoidal velocity reference signal is initially generated in digital form by counting clock signals which are caused to occur at a rate corresponding to the desired frequency of the sinusoidal reference signal.

Abstract: The inked ribbon cartridge comprises an endless ribbon, an elongated housing for the ribbon, a first laterally extending finger at on end of the housing, a longitudinally slidable arm at the other end of the housing carrying a second finger disposed generally parallel to the first finger. A drive wheel is located behind the ribbon and is rotatable for withdrawing ribbon from the front section and is operative to create folds in the used ribbon and to stuff the folds of ribbon between the drive wheel and the ribbon. A fixedly mounted stripper ring encircles the drive wheel and carries a stripper foot to strip the ribbon from the wheel. At the exit port are three aligned support members with the middle support member being over center with respect to the other two. A leaf spring member is located in contact with all three support members. The ribbon passes between one of the support members and the spring.

Abstract: A ribbon tension control for controlling the tension of ribbon traveling between a rotating supply spool and a rotating take-up spool varies the amount of braking torque applied to the supply spool to hold ribbon tension constant as the distribution of ribbon between the spools changes. A generator rotationally coupled to the supply spool produces braking torque to resist the rotation of the spool when the generator windings are electrically loaded. The loading of the generator is controlled by processing feedback signals emitted by the generator to provide periodic load switching signals. Processing of the feedback signal is accomplished in the exemplary embodiment by a drag lookup table which is addressed by the feedback signal. The drag lookup table produces a duty cycle value which is used to determine the duty cycle of the switching signal, which, in turn, controls the electrical loading of the generator.

Abstract: This disclosure describes a simplified mechanism by which a multitude of ribbon styles may be both transported across a record medium of a data communications printer and shifted band to band to obtain color printing results.

Abstract: The present invention provides a bi-directional drive printer actuator with position feedback control and methods of operation to optimize the performance of impact type printers. By monitoring the position of the print wire, a forward input power pulse can be varied as to magnitude and duration to maintain a desired predetermined velocity of the print wire up until the time of impact. Further, by monitoring position feedback signals generated as the print wire returns to an at-rest position, a reverse input power pulse and forward input power pulse can be modulated for magnitude and duration to maintain a desired rearward velocity of the print wire, and bring the print wire to an at-rest position with a minimum of rebound off a back stop.

Abstract: Refolder for a fan-folded web which automatically adjusts the height of the area in which refolding takes place to accommodate different speeds of movement and volume of fan-folded paper.

Abstract: A dot matrix print head control circuit is capable of selectively requesting and receiving a predetermined set of print head control data from a digital data processor which successively transmits plural sets of such digital data and corresponding data acknowledge pulses in response to a data request signal. The microprocessor is thus enabled to independently control two print wire arrays in a dot matrix print head using identical circuits which are thus more economically formed as LSI chips. Each such identical print head control circuit has a "role determining" circuit which can be initialized such that its associated print head control circuit, although identically constructed, is capable of selecting a predetermined set (e.g. byte) of digital data from among the plural sets (e.g. bytes) of digital data transmitted in succession by the microprocessor. The identical print head control circuits are thus capable of effecting different print functions in response to the selectively received data set.

Abstract: A variable-width friction-feed paper handling apparatus includes a rotatable drive shaft and a stabilizing shaft spaced therefrom and parallel thereto. Two carriage assemblies bridge the drive shaft and stabilizing shaft and are supported thereby and are adapted for sliding movement longitudinally therealong for accommodating varying widths of paper therebetween. Each carriage assembly includes a drive roller coaxial with the drive shaft for rotation thereby and a pivoting gate which rotatably carries a pressure roller, the gate being movable between a loading position accommodating placement of paper between the carriage assemblies and a feeding position wherein the pressure roller is in parallel cooperation with the drive roller frictionally to feed paper therebetween. Over-center springs hold the gate in its two positions and leaf springs resiliently mount the pressure roller. Each carriage assembly carries paper guide device.

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.