Robot arm coupling apparatus

A coupling apparatus comprising:

• an inner assembly capable of being attached to a drive body;
• an outer assembly to which a component is attached;
• and
• a locking means for locking said inner assembly to said outer assembly;
• said locking means including;
• a piston member slidably supported by said inner assembly, said piston member being slidable between a locking position and an unlocking position;
• a plurality of ball members supported by said inner assembly in a surrounding relationship about said piston member;
• and
• a ball member receiving means formed in said outer assembly for receiving at least a portion of said ball members, said receiving means including an inwardly tapered contact surface;
• wherein said piston member includes a ball member displacement means for displacing said ball members in a radial direction into contact with said contact surface of said receiving means when said piston member is moved to the locking position, said displacement means including a first tapered working surface, a cylindrical contact surface extending axially from a radially inward portion of said first tapered working surface and a second tapered working surface extending inwardly from said cylindrical contact surface, said second tapered working surface having an angle of inclination in the axial direction greater than the angle of inclination in the axial direction of said first tapered working surface.