Mechanical pencil with chuck closing by normal writing grip

A mechanical pencil comprising:

• a hollow pencil body including a front axial sleeve having a generally conically shaped portion and a rear axial sleeve having a generally cylindrical shape;
• a chuck disposed within said pencil body and having a resiliency urging said chuck to open outwardly at a front end thereof, said chuck gripping a lead when tightened;
• a slider including a lead holding member for lightly holding the lead, said slider being slidable at a tip of said front axial sleeve and said slider including a shouldered portion positioned within the front axial sleeve for limiting a range of movement of said slider;
• a generally cylindrical resilient depression member, one end of said depression member being fixed to a portion of said pencil body, said depression member being positioned at a position of the body normally in contact with the writer's fingers during writing with said pencil;
• means for transmitting movement due to deformation of said depression member to said chuck, the deformation of said depression member causing tightening of said chuck about said lead;
• lead casing means disposed in said rear axial sleeve;
• said lead casing means comprising a cylindrical lead casing rigidly coupled to a rear end of said chuck and further comprising a spring for rearwardly biasing said chuck and casing, and said means for transmitting movement comprising a first chuck tightening member surrounding at least a portion of said chuck and a ring member in contact with said tightening member secured to a rear free end portion of said depression member with a front end portion of said tightening member contacting a front outer slanted portion of said chuck so as to transmit movement of said depression member due to its deformation to said chuck whereby said chuck tightening member is advanced to positively grip the chuck;
• and
• an additional lead feeding mechanism, said additional lead feeding mechanism comprising a pushbutton extending outwardly axially from a rear end of said rear axial sleeve for manual depression and a longitudinal rod in contact at one end thereof with the rear end of said chuck tightening member and at the other end thereof with said pushbutton.