Serial printer type head - has variable thickness type fingers with set spacing from hammer to avoid ribbon damage

摘要

The serial printer employing type element fingers simplifies the control of hammer impact force to match the length of the imprint character. This avoids damage to ribbon and to document if the same force is applied when printing such characters as M or a comma. Instead of complex electronic control varying the impact force for each character, the type fingers are made of different thickness to maintain a constant spacing between the impact surface of the type finger and the hammer. The printing hammer (2) operates then with a constant force against the type elements (3) of the printing head. The imprint force controlling factor is included in the elements (3) by leaving the impacted side at a constant distance from the printing plane.