Magnetic Residual As a Backstop for a Flexible Print Hammer
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18
A layer of nonmagnetic material, often called a residual, is placed in series with the magnetic path of a magnetic actuator to provide a minimum gap between a working armature and the magnetic pole piece. The nonmagnetic material provides sufficient gap so that residual magnetism does not provide excessive holding force. This same material can be used as a stop for a flexible print hammer. When the print hammer is actuated, the armature is pulled into contact with the residual and stops. The flexible portion of the hammer continues to travel until it impacts the paper being printed. If the paper being printed is thin, the hammer must travel further and more energy is absorbed in hammer flex.