Serial printing device

Claim 2

A serial printing device for teleprinters and data processing systems in general, having a paper carrier, a type carrier, a carriage mounting one of said carriers, a reversible stepping motor, and means permanently connecting said motor with said carriage to transversely move said carriage in one of the two opposite directions along a printing line, and comprising : an electronic register having a portion settable according to the transverse position required of said carriage, an electronic counter for constantly indicating the current position of said carriage, said counter having a capacity corresponding to the number of positions that can be occupied by said carriage along the printing line, a comparison circuit to compare the contents of said portion of said register with the contents of said counter, a pulse generator for generating pulses at a predetermined frequency, direction control means controlled by said comparison circuit for selecting the direction of movement of said carriage, first circuit means connecting said pulse generator with said stepping motor and controlled by said comparison circuit for causing said motor to be driven in the selected direction a number of steps corresponding to the pulses generated until said comparison circuit determines equality between the contents of said portion of said register and the contents of said counter, and second circuit means connecting said pulse generator with said counter and controlled by said comparison circuit for causing said counter to count said pulses according to the selected direction, whereby said counter constantly indicates the current position of said carriage.

Claim 3

The device of claim 1, wherein said motor is provided with a number of windings activatable in sequences, and said direction control means comprise a sequential counter having a capacity equal to said number, and Having two inputs to count said pulses, the pulses entering a first of said inputs generating signals at a number of outputs which in predetermined combinations activate said windings in a sequence producing a rotation of said motor in one direction, while the pulses entering the second of said inputs generate at said outputs signals which in other combinations activate said windings in another sequence producing a rotation of said motor in the opposite direction, said control means causing said pulses to enter one or the other of said inputs according to whether the contents of said register is lower or higher than that of said counter.

Claim 4

The device of claim 1, comprising means for effecting synchronization between the position of the carriage and said counter comprising a sensor for sensing the passage of said carriage through a predetermined position, zeroizing means controlled by said sensor when sensing said predetermined position to zeroize said counter, and manually actuatable means for disabling said comparison circuit and for causing said pulse generator to move said carriage toward said predetermined position, said manually actuatable means being disabled when said sensor senses said predetermined position.

Claim 5

A serial printing device for teleprinters and data processing systems in general, having a stationary frame, a paper platen rotatable on said frame, a type disc formed with a plurality of tongues each one provided with a type protruding from the flat surface thereof, said tongues being of flexible material, said disc being selectively rotatable on a substantially horizontal shaft perpendicular to said platen to locate a predetermined type in front of the printing point, a transversely movable carriage mounting said shaft, a hammer mounted on said carriage and operable to strike against the tongue of the type so located, and a pair of ribbon spools rotatably mounted on a pair of vertical shafts, wherein the improvement comprises: means for removably mounting said disc on said horizontal shaft, an auxiliary frame pivotally mounted on said stationary frame coaxially with the shaft of one of said spools to facilitate the insertion of said paper on said platen or the removal of said disk, said transversely movable carriage being mounted on said auxiliary frame, at least a guide bar being fixed on said auxiliary frame for transversely guiding said carriage, a pair of stepping motors mounted on said auxiliary frame for selectively moving respectively said carriage and said disk, and locking means for locking said auxiliary frame on said stationary frame in a printing position.

Claim 6

A serial printing device for teleprinters and data processing systems in general, having a stationary frame, a paper platen rotatable on said frame, a type disc formed with a plurality of tongues each one provided with a type protruding from the flat surface thereof, said tongues being of flexible material, said disc being selectively rotatable on a substantially horizontal shaft perpendicular to said platen to locate a predetermined type in front of the printing point, a transversely movable carriage mounting said shaft, a hammer mounted on said carriage and operable to strike against the tongue of the type so located, and a pair of ribbon spools rotatably mounted on a pair of vertical shafts, wherein the improvement comprises: means for removably mounting said disc on said horizontal shaft, an auxiliary frame pivotally mounted on said stationary frame coaxially with the shaft of one of said spools to facilitate the insertion of said paper on said platen or the removal of said disk, said transversely movable carriage being mounted on said auxiliary frame, at least a guide bar being fixed on said auxiliary frame for transversely guiding said carriage, a pair of stepping motors mounted on said auxiliary frame for selectively moving respectively said carriage and said disk, and locking means for locking said auxiliary frame on said stationary frame in a printing position.

Claim 7

The device of claim 4, wherein said motor is provided with a number of windings activatable in sequences, and wherein said direction control means comprise a sequential counter having a capacity equal to said number, and having two inputs to count said pulses and a number of outputs connected to said windings, the pulses entering a first of said inputs generating signals on said outputs in a predetermined sequence producing a rotation of said motor in one direction, while the pulses entering the second of said inputs generate signals on said outputs in another sequence producing a rotation of said motor in the opposite direction, said control means causing said pulses to enter one or the other of said inputs according to the selected direction of shortest route.

Claim 8

A serial printing device for teleprinters and data processing systems in general, having a type carrier carrying a plurality of types, means for rotatably mounting said type carrier to bring said types individually to a printing point upon being selectively rotated, a reversible stepping motor, and means permanently connecting said motor with said type carrier to rotate said type carrier in one of two opposite directions, and comprising: a register having a portion settable according to the angular position required of said carrier, a first counter for indicating the current angular position of saiD carrier, said counter having a capacity equal to the number of angular positions of said carrier, a comparison circuit adapted to compare the contents of said portion of said register with the contents of said counter, a first pulse generator for generating pulses at a predetermined frequency, another pulse generator for generating other pulses at a frequency substantially higher than the frequency of the first pulse generator, another counter having a capacity equal to the number of angular positions of said type carrier, said other counter being adapted to generate a first signal when it is loaded with less than half the pulses for which it has the capacity and a second signal when it is in the full state, means controlled by said comparison circuit when no coincidence is determined for causing a number of pulses from said other generator equal to said capacity to simultaneously enter said counters without driving said motor, a bistable element for so controlling said direction control means as to bring the type to be printed to said printing point through the shortest route, means controlled by said first signal in coincidence with a coincidence signal of said comparison circuit generated when it determines that said contents are equal to drive said bistable element, and control means controlled by said comparison circuit for causing said counter to count said pulses according to the selected direction and for causing said motor to be driven in the selected direction by said pulses till said comparison circuit determines equality between the contents of said portion of said register and the contents of said counter.

Claim 9

A serial printing device for teleprinters and data processing systems in general, having a type carrier carrying a plurality of types, means for rotatably mounting said type carrier to bring said types individually to a printing point upon being selectively rotated, a reversible stepping motor, and means permanently connecting said motor with said type carrier to rotate said type carrier in one of two opposite directions, and comprising: a register having a portion settable according to the angular position required of said carrier, a first counter for indicating the current angular position of saiD carrier, said counter having a capacity equal to the number of angular positions of said carrier, a comparison circuit adapted to compare the contents of said portion of said register with the contents of said counter, a first pulse generator for generating pulses at a predetermined frequency, another pulse generator for generating other pulses at a frequency substantially higher than the frequency of the first pulse generator, another counter having a capacity equal to the number of angular positions of said type carrier, said other counter being adapted to generate a first signal when it is loaded with less than half the pulses for which it has the capacity and a second signal when it is in the full state, means controlled by said comparison circuit when no coincidence is determined for causing a number of pulses from said other generator equal to said capacity to simultaneously enter said counters without driving said motor, a bistable element for so controlling said direction control means as to bring the type to be printed to said printing point through the shortest route, means controlled by said first signal in coincidence with a coincidence signal of said comparison circuit generated when it determines that said contents are equal to drive said bistable element, and control means controlled by said comparison circuit for causing said counter to count said pulses according to the selected direction and for causing said motor to be driven in the selected direction by said pulses till said comparison circuit determines equality between the contents of said portion of said register and the contents of said counter.

Claim 10

The device of claim 6, comprising: driving means controlled by said second signal in absence of said coincidence signal for rendering said other pulse generator ineffective, and for causing said first named pulse generator to drive said motor, delay means for delay said coincidence signal to activate said first named pulse generator before said other pulse generator, said driving means rendering ineffective said first named pulse generator when said coincidence signal is generated.

Claim 11

The device of claim 6, wherein said type carrier is formed of a rotatable disc having a plurality of tongues each one provided with a type protruding from the flat surface thereof, said tongues being of flexible material, and comprising: a hammer actuatable when the type to be printed is so located at the printing point to strike against the corresponding tongue, and means controlled by said coincidence signal for actuating said hammer.

Claim 12

The device of claim 4, also comprising: a sensor for sensing the passage of a type of said type carrier through a predetermined position, zeroizing means controlled by said sensor when sensing said passage of the type to send a reset signal to said counter for effecting synchronization between the angular position of said type carrier and said counter, and manually actuatable means for disabling said field indicating means and for causing said pulse generator to rotate said type carrier toward said predetermined position, said manually actuatable means being disabled when said sensor senses said passage of the type.

Claim 13

A serial printing device for teleprinters and data processing systems in general, having a paper carrier, a type carrier carrying a plurality of types, a carriage rotatably mounting said type carrier and transversely movable with respect to said paper carrier, a pair of reversible stepping motors, means permanently connecting a first one of said motors with said carriage to transversely move said carriage in one of two opposite directions in letter spaced positions, a second of said motors being mounted on said carriage, and means permanently connecting said second motor with said type carrier to rotate said carrier in one of two opposite directions, and comprising: a register having a first portion adapted to store a first code combination represenTing the transverse position in which a type is to be printed, and a second portion adapted to store a second code combination representing the type to be printed, a pair of counters, a first one of said counters indicating the current position of said carriage and having a capacity corresponding to the number of said letter spaced positions in a printing line, the other counter indicating the current angular position of said type carrier and having a capacity corresponding to the number of said types, a pair of comparison circuits to compare said code combination with the contents of said counters, a pair of pulse generators associated with said motors for generating pulses at predetermined frequencies corresponding to the requisite speed of said carriage and of said type carrier, field indicating means operable when said carrier is standing to indicate the field presently at the printing point, a pair of direction control means associated with said motors, a first one of said direction control means being controlled by one of said comparison circuits for selecting the direction of movement of said carriage, the other direction control means being jointly controlled by the other of said comparison circuits and by said field indicating means for selecting the direction of rotation of said type carrier, a pair of first control circuits connecting said pulse generators with the corresponding motors and controlled by said comparison circuits for causing the associated motors to be driven to move said carriage and to rotate said type carrier in the selected direction by the pulses generated until each of said comparison circuits determines equality between the contents in the associated portion of the register and the contents in the associated counter, and a pair of second control circuits controlled by said comparison circuits connecting said pulse generators with the associated counters and controlled by said comparison circuits for causing said counters to count said pulses according to the selected directions of movement and of rotation.

Claim 14

A serial printing device for teleprinters and data processing systems in general, having a paper carrier, a type carrier carrying a plurality of types, a carriage rotatably mounting said type carrier and transversely movable with respect to said paper carrier, a pair of reversible stepping motors, means permanently connecting a first one of said motors with said carriage to transversely move said carriage in one of two opposite directions in letter spaced positions, a second of said motors being mounted on said carriage, and means permanently connecting said second motor with said type carrier to rotate said carrier in one of two opposite directions, and comprising: a register having a first portion adapted to store a first code combination represenTing the transverse position in which a type is to be printed, and a second portion adapted to store a second code combination representing the type to be printed, a pair of counters, a first one of said counters indicating the current position of said carriage and having a capacity corresponding to the number of said letter spaced positions in a printing line, the other counter indicating the current angular position of said type carrier and having a capacity corresponding to the number of said types, a pair of comparison circuits to compare said code combination with the contents of said counters, a pair of pulse generators associated with said motors for generating pulses at predetermined frequencies corresponding to the requisite speed of said carriage and of said type carrier, field indicating means operable when said carrier is standing to indicate the field presently at the printing point, a pair of direction control means associated with said motors, a first one of said direction control means being controlled by one of said comparison circuits for selecting the direction of movement of said carriage, the other direction control means being jointly controlled by the other of said comparison circuits and by said field indicating means for selecting the direction of rotation of said type carrier, a pair of first control circuits connecting said pulse generators with the corresponding motors and controlled by said comparison circuits for causing the associated motors to be driven to move said carriage and to rotate said type carrier in the selected direction by the pulses generated until each of said comparison circuits determines equality between the contents in the associated portion of the register and the contents in the associated counter, and a pair of second control circuits controlled by said comparison circuits connecting said pulse generators with the associated counters and controlled by said comparison circuits for causing said counters to count said pulses according to the selected directions of movement and of rotation.

Claim 15

The device of claim 10 including alphanumeric key responsive means for loading the second portion of said register with a code combination representing the character to be printed and for loading the first portion of said register with a predetermined constant combination, means responsive to said predetermined constant combination for rendering inactive the comparison circuit associated with said first motor, and space means conditionable at the depression of any alphanumeric key for generating a space signal for causing the direction control means associated with said first motor to advance said carriage one letter space.

Claim 16

The device of claim 11, also comprising: a hammer actuatable for printing the selected type, a hammer actuating circuit controlled by the comparison circuit associated with said second motor, said actuating circuit generating a delay signal simultaneously with said hammer actuation, and a delay circuit controlled by said delay signal for causing said space means to generate said space signal after said hammer actuation.

Claim 17

The device of claim 12, wherein the counter associated with said first motor is adapted to generate an end line signal, and comprising means controlled by said end line signal for preventing said delay circuit from so causing said space means to generate said signal.

Claim 18

A serial printing device for teleprinters and data processing systems in general, having a stationary frame, a paper platen rotatable on said frame, a type disc formed with a plurality of tongues each one provided with a type protruding from the flat surface thereof, said tongues being of flexible material, said disc being selectively rotatable on a substantially horizontal shaft perpendicular to said platen to locate a predetermined type in front of the printing point, a transversely movable carriage mounting said shaft, a hammer mounted on said carriage and oPerable to strike against the tongue of the type so located, and a pair of ribbon spools rotatably mounted on a pair of vertical shafts, wherein the improvement comprises: means for removably mounting said disc on said horizontal shaft, an auxiliary frame pivotally mounted on said stationary frame coaxially with the shaft of one of said spools to facilitate the insertion of said paper on said platen or the removal of said disk, at least a guide bar fixed on said auxiliary frame for transversely guiding said carriage, a pair of stepping motors mounted on said auxiliary frame for selectively moving respectively said carriage and said disk, and locking means for locking said auxiliary frame on said stationary frame in a printing position.

Claim 19

A serial printing device for teleprinters and data processing systems in general, having a stationary frame, a paper platen rotatable on said frame, a type disc formed with a plurality of tongues each one provided with a type protruding from the flat surface thereof, said tongues being of flexible material, said disc being selectively rotatable on a substantially horizontal shaft perpendicular to said platen to locate a predetermined type in front of the printing point, a transversely movable carriage mounting said shaft, a hammer mounted on said carriage and oPerable to strike against the tongue of the type so located, and a pair of ribbon spools rotatably mounted on a pair of vertical shafts, wherein the improvement comprises: means for removably mounting said disc on said horizontal shaft, an auxiliary frame pivotally mounted on said stationary frame coaxially with the shaft of one of said spools to facilitate the insertion of said paper on said platen or the removal of said disk, at least a guide bar fixed on said auxiliary frame for transversely guiding said carriage, a pair of stepping motors mounted on said auxiliary frame for selectively moving respectively said carriage and said disk, and locking means for locking said auxiliary frame on said stationary frame in a printing position.