BLACKBOARD ERASER USING VACUUM CLEANER

摘要

PROBLEM TO BE SOLVED: To prevent adverse effect to health and to make cleaning work easy by eliminating the powder of chalk. SOLUTION: The powder of the chalk is prevented from flying and a blackboard can be cleanly erased by using the suction force of a vacuum cleaner connecting a blackboard eraser 2 to the vacuum cleaner 1. COPYRIGHT: (C)2007,JPO&INPIT