Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.