Ruler sleeve for protecting rulers against damage has two plates arranged such that a space for ruler is defined which on one side has insertion slot whereby plates are so connected that they cannot be loosened

摘要

The ruler sleeve (1) has two separate plates (2,3) made up of torsion-resistant material e.g. plastic, wood or metal e.g. aluminum The two plates are arranged in such a way that in between a space is defined which on one side has insertion slot (5) whereby plates are so connected with fastener that they cannot be loosened.