The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Feb. 07, 1989

Filed:

Sep. 01, 1987
Applicant:
Inventors:

Akiyasu Miyazawa, Toyota, JP;

Mineo Harada, Owariasahi, JP;

Eiji Tajima, Owariasahi, JP;

Takao Abe, Hitachi, JP;

Assignee:

Hitachi, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B41J / ;
U.S. Cl.
CPC ...
400124 ; 101 9305 ;
Abstract

A print head having magnetic members attracted by a permanent magnet while resiliently deflecting resilient members connected to one ends thereof associated with corresponding solenoids adapted to selectively release the associated magnetic members by cancelling the magnetic attracting force of the permanent magnet, so that the magentic member is actuated by the energy stored in the resilient members to drive printing elements into a printing position. To reduce the moment of inertia of the magnetic member, the magnetic pole surface of the permanent magnet or a yoke mounted on the permanent magnet is contacted with one end of the magnetic member to form a fulcrum for the rotation of the magnetic member. The magnetic pole surface of the permanent magnet or yoke on the permanent magnet and at least the fulcrum portion of the magnetic member are provided with hardened wear-resistant layers formed, for example, by plating with nickel, thereby achieving a higher resistance to wear. The wear of the magnetic pole surface of the fulcrum and of the magnetic member are reduced thereby avoiding non-uniformity of the moment of force in the magnetic members, as well as the resilient force in the resilient members, thereby ensuring a high uniformity of the impacting force applied to all printing elements.


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