Printer head for serial dot printer
US4377348A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1981 |
| Grant date | Mar 22, 1983 |
| Priority date | — |
| Expiry date | Mar 16, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A serial printer head is provided which comprises a sandwich structure (1,3,5) of a first circular yoke plate (1), a cylindrical magnet (3) and a ring shaped second yoke plate (5); a plurality of electromagnets (2,4) positioned on the first yoke plate (1) at predetermined angle intervals; an armature-print-needle assembly (7,8,9,10) having a circular resilient spring (7), a plurality of armatures (8) and a plurality of print needles (9) placed on the sandwich structure (1,3,5) so that the sandwich structure (1,3,5), electromagnets (2,4) and the armatures (8) provide first a substantially closed magnetic path; and an adjusting yoke (12) attached to the sandwich structure (1,3,5). The adjusting yoke (12) has the magnetic characteristics that the magnetic reluctance increases as the temperature increases. Although the flux generated by the permanent magnet (3) is changed due to the change of the temperature, that flux change is compensated for by the presence of the adjusting yoke (12).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.