International Business Machines Corporation

William D Thorne

William A Patterson

Douglas Stuart Brown

Robert A Sebrosky

David M Sedgwick

Gerald Carl Sienkiewicz

George Coleman Matuck

Norman F Cole

The present invention relates to an assembly of electromagnetic actuators for the hammers of an impact printer arranged side by side and extending along a line. Each actuator comprises a first stator part formed with at least one pole piece, a second stator part formed with at least one pole piece and positioned relative to the first stator part so that the pole pieces are spaced apart so as to form a gap therebetween. A single coil is associated with one of the stator parts. Each actuator also includes an armature member formed with a body of non-magnetizable material, at least one armature element of magnetizable material and a hammer head. The armature member is supported between the stator parts so that the armature element is located adjacent to the gap. Energization of the coil causes the generation of a flux which passes across the gap and through the armature element tending to move the armature element into the gap and to cause the hammer head to move into a print position. According to the invention the components of adjacent actuators are complementary in shape so that projecting components of each actuator engage in recessed components of the adjacent actuators whereby the overall length of the assembly along the line is less than the sum of the overall widths of the individual actuators.

Electromagnetic hammer actuator for impact printer

A printer of the type including a platen, a bank of hammers extending in a straight line along and spaced from the platen and a continuous metal band of magnetizable material on which are mounted a plurality of print elements is provided with drive means for moving the band between the platen and the hammer bank and control means for controlling the movement of the band so that the print elements on the band move along the line of hammers. The band drive means includes a drive wheel located near one end of the hammer bank and means for forcing the band into close contact with the peripheral surface of the drive wheel. The means for forcing the band into close contact with the peripheral surface of the drive wheel can be a permanent magnet member located on the surface of the drive wheel. The band movement control means includes guide means for guiding the band so that it extends along the hammer bank and permanent magnet means adapted to force the band into close contact with the guide means. The guide means can be a fixed guide member located near the end of the hammer bank remote from the drive wheel and the permanent magnet means can be a permanent magnet member located on the surface of the guide member and adapted to attract the band to the guide member.

Printer having drive and control system for metal band holding print

A printer of the type including a platen, a bank of hammers extending in a straight line and spaced from the platen, a metal band on which are mounted print elements and drive means for moving the band between the platen and the hammer bank is provided with means for controlling the movement of the band. This band movement control means includes a guide surface extending along the hammer bank and bearing means located adjacent to one edge of the guide surface and including at least one bearing surface extending perpendicular to the guide surface. The control means also includes a permanent magnet means located adjacent to the guide surface and the bearing means and adapted to attract one surface of the band to the guide surface and one edge of the band to the bearing surface. The permanent magnet means comprises a plurality of elongated parallel sided permanent magnet members each magnetized so as to exhibit a pole of one polarity on one elongate surface and a pole of the opposite polarity on the opposite elongate surface. The elongated permanent magnet members are positioned side by side in parallel lines so that the exposed elongate surfaces of adjacent members exhibit poles of opposite polarity. The elongated permanent members are located on the guide surface so that the parallel lines are inclined at an angle to the direction of movement of the band past the surface, towards the bearing surface.

A dot matrix printer is described in which the dots are formed by impact at an intersection between a raised ridge on a platen and a vertical ridge or bar font member. A moving belt carries a plurality of individually mounted vertical bar segments. The bar segments are each mounted on a flexible finger and can be deflected out of the path of the moving belt by impact from a print hammer mechanism. The vertical bars may be caused thusly to individually impact against a platen arranged parallel to the line of travel of the fingers. The platen may have a plurality of raised knife-edge ridges on its surface. By appropriate timing of hammer actuations, individual bar elements may be caused to impact against the knife-edge ridges on the platen. If the paper and ribbon are interposed between the bar fingers and the knife-edge ridges, a mark in the shape of the intersectional area between the bar and the knife-edge ridge can be made. If the knife-edge ridges are angled with respect to the direction of travel of paper, continuously moving paper and associated transport mechanisms may be advantageously employed. By appropriate timing of the hammer firings, together with angling of the knife-edge ridges on the platen and selection of paper translation velocity, a linear array of dots may be produced in a single row. Various other arrays of dots in succeeding rows can similarly be generated to build up desired character shapes or patterns. The mechanism reduces or eliminates the shadow printing problem inherent in intersectional printers of the type involved and enables equivalent throughput to be obtained with continuously moving paper with reduced peak power requirements.

Bar band intersectional matrix printer

Described, is a printing mechanism allowing full exploitation of the potential of dot matrix printing. Dot forming elements are mounted on a carrier for transport past an array of hammers located in front of media to be marked upon. The dots or carrier are impacted by the hammers to form dots on the medium. By appropriate control of motion of the printing medium and timing of the hammer impacts, a dot may be formed anywhere on the surface of the medium. This allows unlimited character font set generation as well as special character printing for enlarged font, miniaturized font, fast rough draft copy printing, the printing of ascenders and descenders for characters and for condensed or compacted printing. In addition, the mechanism permits an all points available graphics generation system and full control for variable vertical spacing of printed elements and of variable horizontal spacing of the printed elements. Variable print element shapes, grey tone graphics printing and multi-color additive or subtractive color processes are also facilitated.

Band and hammer dot matrix printer

Described, is a printing mechanism allowing full exploitation of the potential of dot matrix printing. Dot forming elements are mounted on a carrier for transport past an array of hammers located in front of media to be marked upon. The dots or carrier are impacted by the hammers to form dots on the medium. By appropriate control of motion of the printing medium and timing of the hammer impacts, a dot may be formed anywhere on the surface of the medium. This allows unlimited character font set generation as well as special character printing for enlarged font, miniaturized font, fast rough draft copy printing, the printing of ascenders and descenders for characters and for condensed or compacted printing. In addition, the mechanism permits an all points available graphics generation system and full control for variable vertical spacing of printed elements and of variable horizontal spacing of the printed elements. Variable print element shapes, grey tone graphics printing and multi-color additive or subtractive color processes are also facilitated. To improve the throughput speed, a reversible motor is used for driving the dot element carrier and a plurality of dot font sizes and shapes are provided on the carrier. By selection of the required font size and shape and by comparison with the presently known position of the carrier, the quickest access to the next desired dot font for any given hammer can be achieved.

Oscillatory band and hammer dot matrix printer

An improved print hammer and actuator mechanism therefor are described. The hammer mechanism comprises a solenoid plunger and push wire or push rod which is directly affixed to one end of the hammer. The opposite end of the hammer is flexibly or pivotably mounted by a spring. The spring is rigidly affixed to the bottom portion of the hammer. It is flexed or twisted to enable the hammer top portion to be deflected. A shock absorbing connector connects the push wire to the print hammer. The position of the solenoid plunger can be adjusted by adjustable abutments at either end of its throw. This adjusts the flight time and the impact force, as well as the relative rest position of the hammer face, since the push wire is firmly connected to both the plunger and to the top of the hammer mechanism. The shock absorbing connector between the end of the push wire and the hammer mechanism controls the amount of force applied at impact.

Spring mounted torsionally rigid print hammer mechanism

Hammers impact dot front elements on a moving band and drive them into a printing medium. The pitch between two dot font elements is assigned to two adjacent hammers in this invention. An electronic control is used so that adjacent hammers cannot be fired simultaneously. Hammers in a bank are divided into two groups with members of each group alternating on a one for one basis along the hammer bank. Hammers which are fired in a group will all be operating on the same relative dot position in their space in the line of print being formed. With prior dot band hammers, additional spacing is allowed between dots on the band to avoid the problem of nipping and crashing of the anvil elements on the back of the dot band into extended faces of adjacent print hammers. This has created a small gap in which no dots can be created. The present invention also provides a means for automatically selecting large or small dots for printing if the print band has large and small size dot font elements alternated serially on it. It is only necessary to choose firing the hammers of the first group or the second group first in order to select large dots or small dots for printing.

Multiplexed hammer dot band matrix printer

Disclosed is an improved form of a mosaic printer of the bar helix type. The helical raised threads on the printer drum instead of being continuous are broken into segments which are offset axially on the drum. This produces a significant increase in throughput by reducing waiting time for the drum to rotate a section of continuous thread into alignment with a hammer at the start of a new helical pattern.

Segmented drum bar helix printer

For typewriters, disk printers or similar moveable print element devices, a carrier is provided to move the print element. The carrier acts by cooperation between a lead screw, mounted in stationary supports in a nonrotating fixture, and rotatable nut members supported in the print element carrier and threadedly engaging the lead screw. A motor is provided for rotating the nuts and the motor is arranged so that the rotor of the motor, the nuts and the lead screw are arranged in concentric fashion so that the motor, nuts and carrier assembly ride back and forth on the fixed lead screw, depending upon the direction of rotation of the motor.

Linear motion drive apparatus for a printer carriage

A ribbon cartridge for an endless loop inked ribbon suitable for use with a wire matrix printer, for example, is disclosed in which the cartridge includes elongated guide members to confine the path of the loop of ribbon outside of the cartridge to a predetermined path and to allow for insertion of the cartridge into a using machine without the necessity of threading inky ribbon through fixed guides on the machinery.

Growing community of inventors

Wake Forest, NC, United States of America

William D Thorne