Browse Prior Art Database

Dynamic Determination of Print Hammer Face Location

IP.com Disclosure Number: IPCOM000102747D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 56K

Publishing Venue

IBM

Related People

Logan, TD: AUTHOR

Abstract

Disclosed is a method for dynamically determining the actual location of a printer hammer face with respect to its nominal design location, within 0.0001 inch. The actual location must be known, in the present embodiment, in order to check the hammer face alignment and verify the dynamic performance of the hammer assembly.

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This is the abbreviated version, containing approximately 63% of the total text.

Dynamic Determination of Print Hammer Face Location

      Disclosed is a method for dynamically determining the actual
location of a printer hammer face with respect to its nominal design
location, within 0.0001 inch. The actual location must be known, in
the present embodiment, in order to check the hammer face alignment
and verify the dynamic performance of the hammer assembly.

      The basis for this procedure is determination of the hammer
"zero flight gap". This is accomplished by placement of a "load
cell", capable of measuring print hammer impact force, in front of
the hammer, and repeatedly firing the hammer. The load cell to hammer
face gap is changed and the hammer is again repeatedly fired. The
hammer flight time is measured for each load cell position. This
procedure is iterated, under computer control, until the load cell
just touches the hammer face in the hammer's rest position. This is
the "zero flight gap" position.  Flight time is defined as the time
from hammer coil energization to the time when the impact force
measured by the load cell reaches a specified level.

      In the present embodiment the load cell is initially located
approximately 0.003 inch from the nominal position of the hammer
face.  The load cell is moved towards the hammer face in 0.0005-inch
increments, and the flight time is measured at each location. The
flight time decreases with each 0.0005-inch step until the load cell
touches the hammer face. At this point, since...