Controlling structure for a unidirectional ratchet wrench

A controlling structure for a unidirectional ratchet wrench comprising:

• a driving head of an unidirectional ratchet wrench, and the driving head including a receiving cavity defined in a front end thereof and a groove formed in a rear end thereof and communicating with the receiving cavity;
• the receiving cavity having a driving member received therein, and the driving member having a toothed portion arranged around an outer wall thereof;
• the groove having a retaining block received therein, and the retaining block having a plurality of locking teeth formed on a front end thereof so as to engage with the toothed portion of the driving member;
• the retaining block having a slot defined therein or a tab extending outwardly therefrom so as to retain with the elastic member;
• wherein the elastic member has a fitting segment, a curved section, and an abutting segment, the fitting segment is fitted into the slot of the retaining block or is retained with the tab, the curved section extends outwardly from the fitting segment and becomes curved, and the abutting segment connects with the curved section and abuts against the groove.