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Semi-open Print Actuator Coil Bobbin

IP.com Disclosure Number: IPCOM000061167D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Wallace, JE: AUTHOR [+2]

Abstract

A semi-open bobbin allows a print actuator coil to be closely wound to the stator to provide good heat transfer and increased winding area as well as protecting the coil from the moving armature.

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Semi-open Print Actuator Coil Bobbin

A semi-open bobbin allows a print actuator coil to be closely wound to the stator to provide good heat transfer and increased winding area as well as protecting the coil from the moving armature.

Print actuators in which the armature partially enters the coil have improved efficiency because more of the magnetic flux flows through the working gap.

A bobbin, of a nonmagnetic material such as nylon, has a thin wall to separate the coil from the stator and armature. The space occupied by the bobbin wall decreases the available winding area and reduces the amount of heat dissipated through the iron as the nylon or similar material acts as a barrier. Eliminating this wall improves the heat dissipation and increases the winding area, but may also result in the moving armature contacting a winding on the open bobbin, resulting in an open winding coil failure.

The figure shows the bobbin 1 constructed so that the part covering the stator 2 is open, while the part covering the entry portion of armature 3 is closed with a barrier 5. This allows increased thickness of the armature without having an interference problem with coil 4, and increases the magnetic f with negligible reduction in winding area. When coil 4 is energized and armature 3 moves, the armature will no longer contact the coil due to the thin nylon barrier 5. When the coil 4 is wound, the initial layer is wound against the stator part 2, which provides good heat dissipati...