Mechanical pencil

A rotational slide type mechanical pencil comprising:

• a hollow axial body composed of first and second bodies, said first and second bodies being rotatable relative to each other;
• a lead case for storage of extra leads disposed within and fixed to said hollow axial body;
• a chuck for firmly clamping a lead during writing, said chuck being rigidly coupled to said lead case;
• a chuck tightening member having a chuck receiving portion for engaging and tightening said chuck, said tightening member being disposed in said first axial body;
• slider means for frictionally gripping said lead, said slider means being movable back and forth through a predetermined distance within said axial body and said slider means being disposed in front of said chuck;
• and a conversion mechanism for converting rotational movement of said second axial body to linear movement of said chuck tightening member whereby rotational movement of said second axial body relative to said first axial body moves said slider means forwardly extending a portion of said slider means from a front opening of said axial hollow body, wherein said hollow body is provided with a hollow space in which said chuck tightening member is movable between a first position and a second position, said chuck tightening member being biased towards said first position, a hollow cylindrical sleeve being provided extending forwardly from a front end of said chuck tightening member, said hollow cylindrical sleeve frictionally retaining said slider means in a front portion thereof, said chuck in said first position being disengaged from said chuck tightening member and said chuck in said second position being engaged with said chuck tightening member, and in said second position, said slider means being fully retractable into said hollow body upon said lead being worn during writing.