Power driven wrench

A power wrench comprising:

• a handle containing therein motor means operable to rotate a drive shaft extending from a first end of said handle;
• a yoke affixed to said first end of said handle, said yoke having front and rear arms, each of said arms having a bore therethrough, said bores being coaxial with one another, said drive shaft extending into said yoke and terminating in a ball drive member mounted on a radially offset drive stud affixed to said drive shaft, whereby rotation of said drive shaft results in said ball drive member traveling through a circular path;
• a drive rotor journalled for rotational motion in said bores of said arms of said yoke, said drive rotor having a substantially cylindrical body and having a ratchet gear formed on the exterior cylindrical surface of said body, said drive rotor having a first end and a second end, said first end of said drive rotor having drive means for engaging tools adapted to engage said drive means;
• and
• a reciprocatable ratchet head disposed between said arms of said yoke, said ratchet head being generally oblong in shape and having first and second ends, said first end of said ratchet head including a circular bore that encircles said ratchet gear of said drive rotor, said second end of said ratchet head including a semicircular opening in which is positioned said ball drive member, such that rotation of said drive shaft and said ball drive member drive said second end of said ratchet head in reciprocal oscillatory motion and thereby also drive said first end of said ratchet head in reciprocal angular motion about said drive rotor, said ratchet head further including selectively positionable and bidirectional pawl means for engaging said ratchet gear of said drive rotor so as to drive said drive rotor in a desired rotational direction, and said ratchet head further including direction changing means for manually selecting the position of said pawl means.