Multi-functional tool with interchangeable adjustable wrench head unit

A multi-functional tool comprising:

• a tool handle unit including a handle body member having a fitting portion;
• and
• a first tool head unit removably attachable to said handle unit;
• said first head unit having a first fitting member provided to matingly engage said fitting portion of said handle unit so as to removably secure said first head unit to said handle unit;
• wherein said first head unit is an adjustable jaw wrench comprising:
• a head body member defining a stationary jaw;
• a movable jaw reciprocally mounted to said head body member in alignment with said stationary jaw, said movable jaw including a gear rack portion;
• and
• a drive mechanism mounted to said head body member of said first head unit, said drive mechanism being operably coupled to said movable jaw for moving said movable jaw relative to said stationary jaw, said drive mechanism including a worm gear rotatably mounted in said head body, said worm gear engaging said gear rack portion of said movable jaw;
• and
• a first power source selectively driving said drive mechanism;
• said first power source disposed in said handle unit;
• wherein said fitting portion of said tool handle unit includes first and second mating cavities in said handle body member, and wherein said first fitting member of said first head unit includes a first elongated mating post extending from said head body member complementary to and provided to be matingly received in said first mating cavity in said handle body member so as to removably secure said first head unit to said tool handle unit;
• and
• wherein said first elongated post of said first tool head units incorporates at least one detent formed on an outer peripheral surface thereof, and said first mating cavity in said handle body member is provided with at least one locking member releasably engaging said at least one detent to secure said first head unit to said tool handle unit.