Other

R. C. Sanders Technology Systems, Inc.

John P Conant

Royden C Sanders

John L Forsyth

Michael I Lerer

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. Finally, logic connected to the sensing device is provided for removing a drive voltage from the motor and connecting the ballistic rebound device to the motor shaft at points with respect to the end points which will cause the carriage to stop motion in one direction at a desired position with respect to the end points and for applying a drive voltage to the motor and disconnecting the ballistic rebound device from the motor shaft at points with respect to the end points which will cause the carriage to stop and accelerate to a maximum velocity in a direction opposite the one direction in a minimum amount of time.

Serial printer carriage drive with ballistic rebound reversal

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. Linear encoders are provided to determine the shuttle position as the shuttle moves back and forth.

High speed shuttle printer

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. Finally, logic connected to the sensing device is provided for removing a drive voltage from the motor and connecting the ballistic rebound device to the carriage at points with respect to the end points which wil cause the carriage to stop motion in one direction at a desired position with respect to the end points and for applying a drive voltage to the motor and disconnecting the ballistic rebound device from the motor shaft at points with respect to the end points which will cause the carriage to stop and accelerate to a maximum velocity in a direction opposite the one direction in a minimum amount of time. One version employs a single brake carried by the carriage and another employs a pair of brakes disposed adjacent respective ends of carriage movement.

The printing apparatus disclosed herein generates alphanumeric characters of high quality, using a multi-pin printing head capable of forming discrete dots or pels, by controlling the actuation of the printing head with a timing resolution which is an order of magnitude finer than the nominal dot diameter so that a line smoothness for slanted or curved lines is obtained which is greater than that obtainable by a uniform matrix. The printing head is repeatedly traversed or scanned across the paper to provide essentially parallel lines of scan separated vertically by a distance which is a submultiple of the vertical spacing of the pins so that overlapping dots may be provided in the vertical dimension. By these means the apparatus facilitates the formation of smooth lines of essentially arbitrary slope or curvature.

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Milford, NH, United States of America

John P Conant