Electrical mechanism to influence vibrations to pens and other tracers (Machine-translation by Google Translate, not legally binding)

摘要

Electrical mechanism to influence vibrations to pencils and other tracer instruments, characterized by establishing a spool of antimagnetic material, consisting of a hollow cylinder or cap, on which a coil of copper wire is disposed and which is topped at its ends by two washers. (Machine-translation by Google Translate, not legally binding)