Wire printing head with unitary return group
US5054942A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1989 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Jun 26, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/235
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A needle or wire printing head comprises a plurality of electromagnets with fixed cores, each with two limbs, which are mounted in a ring within a containment body. Movable armatures are disposed in a radiating array in front of coplanar terminal surfaces of said cores. The movable armatures each have a step configuration for oscillating on the terminal surface of the more outward limb, a surface for closing the magnetic flux which, with the terminal surface of the more inward limb constitutes a main air gap "G" and an end capable in printing of engaging a needle by means of a corresponding limb. A unitary return group accomodates a plurality of coil springs in a prestressed state for restoring the movable armatures. There is also provided a magnetically conductive conveying disc of ferro-magnetic material and comprising a plurality of spokes for closure of the magnetic flux which is common to the armatures and the cores.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.