Automatic lead feeding apparatus of automatic drafting machine

In combination;

• an automatic lead feeding apparatus for feeding lead to a pencil lead-carrying writing instrument having a lead feed means for feeding lead and which is used in an automatic drafting machine;
• and
• a writing instrument stocker with a plurality of writing instrument holders thereon for removably holding writing instruments, writing instrument stocker rotating means for rotating the instrument stocker at a side of the drafting machine having said writing instrument stocker is removably mounted thereon, the drafting machine having a line drawing head movable in a direction parallel to a platen for supporting a sheet of drawing medium and operable to mutually exchange writing instruments between the line drawing head and a writing instrument holder of the writing instrument stocker;
• said automatic lead feeding apparatus comprising:
• a unit holder movably mounted at the side of the drafting machine frame for movement toward and away from said writing instrument stocker;
• a writing instrument holding means on said unit holder for removably holding a pencil lead-carrying writing instrument and operable for mutually exchanging a pencil lead-carrying instrument between said writing instrument holding means and a writing instrument holder of the writing instrument stocker;
• a lead feeding reservoir stocker having a plurality of lead reservoirs thereon, each for containing a plurality of writing leads, said lead feeding reservoir stocker being removably mounted on said unit holder above a path of movement of said writing instrument holding means on said unit holder as said unit holder moves toward and away from the writing instrument stocker, and said lead feeding reservoir stocker being movable for moving one lead reservoir at a time above said path;
• a shutter mechanism mounted below said lead feeding reservoir stocker and reciprocally movable so as to cause writing leads contained in a lead reservoir positioned above said path to drop downwardly therefrom one at a time into a pencil lead carrying writing instrument therebelow;
• and
• a lead feed means actuator engagable with a pencil lead-carrying writing instrument held in said writing instrument holding means for actuating the lead feed means thereof for feeding a lead dropped into the lead-carrying writing instrument to a predetermined projected position.