Browse Prior Art Database

A Non-Rotating Print Wire in a Wire Matrix Print Head

IP.com Disclosure Number: IPCOM000120945D
Original Publication Date: 1991-Jun-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Downey Jr, HA: AUTHOR [+2]

Abstract

Disclosed is a method to increase the life of a wire-matrix print head by reducing or eliminating rotation of the print wire.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

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A Non-Rotating Print Wire in a Wire Matrix Print Head

Disclosed is a method to increase the life of a wire-matrix print head by reducing or eliminating rotation of the print wire.

Many wire-matrix print heads employ ballistic print wires, each of which is driven by, but not attached to, an electromagnetic actuator. Each wire has a molded plastic end cap, which contacts a return spring acting in the restoring direction, and by the armature of the actuator in the driven direction. The opposite end of the return spring is held in a molded plastic seat that is part of the wire guide. The wire and spring are typically free to rotate, and do so under the continuous excitation of printing. This rotation causes wear.

If instead the spring and print wire are not free to rotate, the wire is drastically reduced in all contact areas: the spring seat, the spring to wire cap contact surface, and the wire cap to armature contact surface. This can be accomplished by many methods:
1) Alter the spring end geometry so that one end engages and locks into the pocket, and the other end engages the wire cap. This can be as simple as a tangential extension of the spring wire on each end, or even a diameter enlargement to engage the spring seat. 2) The pocket and end cap may have features that engage a standard compression spring, such as steps or grooves.

Disclosed anonymously.

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