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US 5,071,267 AGranted
Actuation magnet for a printing stylus of a matrix printer
AssigneeU.S. Philips Corporation
InventorBernd E. H. Aldefeld
Life of this patent
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AssigneeU.S. Philips Corporation
InventorBernd E. H. Aldefeld
Estimating the term…
The invention relates to an actuation magnet for a printing stylus (11) of a matrix printer, in which an armature (12) of the plunger type connected to the printing stylus (11) is guided in the cylindrical inner space of two soft-magnetic pole pieces (6,7) enclosed by a direct current energizing coil (14), the space between these pole sleeves (6,7) being bridged by a spacer element (17), which consists of a material, whose magnetic conductance or permeance is considerably smaller than that of the material of the pole sleeves (6,7). The movement force exerted on the soft-magnetic armature (12) is increased in that the distance between the ends of a yoke (13) is bridged by a permanent magnet (17), whose pole faces engage the free ends of the yoke (13), and in that the energization of the energizing coil (14) produces a magnetic flux, which has a sense opposite to a magnetic flux of the permanent magnet (17) through the yoke (13).
An actuation magnet for a printing stylus of a matrix printer including an armature of the plunger type connected to said printing stylus, two cylindrical soft magnetic poles sleeves, a direct current energizing coil around said pole sleeves, a space between said pole sleeves, a spacer element in said space, said spacer element comprising a material with a permeance which is considerably lower than that of the material of he pole sleeves, said spacer element being an annular permanent magnet and energizing means energizing said coil to produce a magnetic flux of opposite direction to the magnetic flux of the permanent magnet, said permanent magnet having arranged coaxially within it an annular layer of a non-magnetic material.
Dependencies are inferred from the claim text.