Printer hammerbank with a magnetic shunt
AssigneePrintronix, Inc.
InventorJohn W. Gemmell
Life of this patent
Estimating the term…
Abstract
An impact line printer comprising a print ribbon wound on a pair of spools for traversal in two directions across a plurality of print hammers having tips for impacting the print ribbon to print on a media. A permanent magnet having two pole pieces having pole piece ends in adjacent relationship to the print hammers retains the print hammers until a coil in associated relationship with each pole piece releases the magnetic retention of the hammers. A magnetically permeable extension is longitudinally adjacent each hammer which acts as a magnetic shunt to permit more rapid printing rates and higher impacts. The extensions conduct and shunt magnetic flux from the hammers through the longitudinally adjacent extensions.
Claims36
A line printer comprising:
- a plurality of hammers mounted on a hammerbank having printing tips that impact a print ribbon for printing on a given media;
- a permanent magnet for retaining said hammers;
- an electrical drive for releasing said hammers from retention by said permanent magnet;
- and,
- two magnetically permeable extensions in longitudinal placement on either side of a first one of said hammers and along the same plane as said hammers for shunting flux from said permanent magnet.
A line printer comprising:
- a row of hammers formed on frets mounted on a base;
- a permanent magnet magnetically connected to two pole pieces, each pole piece having an end in adjacent relationship to one of said hammers for pulling back and retaining said hammers against said pole piece ends;
- and,
- two magnetic shunts, one on each side of a first one of said hammers and on the same plane as the row of hammers for shunting flux from said hammers to one of said pole pieces.
An impact line printer comprising:
- a pair of hubs that are driven in a rotational manner;
- a print ribbon wound on a pair of spools mounted on said hubs for traversal in two directions;
- a plurality of print hammers having tips for impacting said print ribbon to print on a media;
- a permanent magnet having two pole pieces with pole piece ends in adjacent relationship to said print hammers for retaining said print hammers;
- a coil in associated relationship with each pole piece for releasing the magnetic retention of said hammers;
- and,
- two magnetically permeable extensions, each adjacent to a first one of the hammers along a longitudinal direction of the print hammers, which act as magnetic shunts.
A magnetic shunt and print hammer system for a line printer comprising:
- a plurality of hammers having printing tips for printing by an ink ribbon;
- a permanent magnet having a pair of pole pieces with pole piece ends in adjacent relationship to said hammers to retain said hammers;
- an electrical drive for releasing said hammers from said permanent magnetism;
- and,
- two magnetically conductive extensions placed on either side of and in longitudinal relationship to a first one of said hammers for shunting a magnetic force between said pole pieces.
A method of printing comprising:
- providing a line printer having a plurality of hammers which impact a ribbon which traverses between two spools;
- retaining said hammers until release by a permanent magnet having two pole pieces with pole piece ends in adjacent relationship to said hammers;
- and,
- conducting and shunting permanent magnetism from said hammers through extensions adjacent to both sides of each of the hammers and along the same plane as said plurality of hammers.
A method of shunting magnetic flux in a line printer comprising:
- providing a plurality of hammers in alignment for printing by impacts against a ribbon;
- retaining said hammers by a permanent magnet until released for impacting said ribbon;
- and,
- shunting magnetic flux in part through extensions located on either side of said hammers and on the same plane as said hammers for a return path of said flux to said permanent magnet through the side of said hammers.
Dependencies are inferred from the claim text.