Patent ID: 7146881

Claim:
A wrench, comprising: a drive head; a drive member mounted in an inner wall of the drive head; a plurality of locking teeth defined in an outer wall of the drive head and the drive member; an urging block mounted in a driving recess in the inner wall of the drive head and a direction control knob pivotably mounted on the drive head and connected to the urging block for rotating the urging block, and two locking devices mounted in the driving recess and located beside the drive member, the urging block located between the two locking devices so that the urging block presses one of the locking devices by operating the direction control knob, each of two locking devices including two independent driving blocks laminating each other, each of the two driving blocks formed with a locking end and a positioning portion, the locking end engageable with the locking teeth, the locking ends of the two driving blocks are respectively engaged with the locking teeth at different time.