Tamperproof protecting construction

A construction for protecting a member such as an adjusting member or fixing member from tampering, said member being proximate to a base, comprising:

• a wall formed generally in the shape of a hollow tube having a cylindrical bore, fixedly attached by one of its ends to said base, and surrounding said member;
• a cup-like plug inserted into said cylindrical bore from the end of said wall remote from said base so as to be wedged therein having a cylindrical side wall tightly contacting the wall surface of said cylindrical bore;
• means for facilitating removal of said plug by a tool comprising a slot formed in said tubular wall for insertion of said tool under said plug, said slot extending along the axial direction thereof from said end remote from said base to a slot bottom at an axial position between said other end of said wall and said base, said slot bottom being closer to said base than is the part of said plug which is closest to said base;
• and
• means for supporting a tip of said tool on the inner surface of said tubular wall at a diametrically opposite point on said wall from said slot.