Roller wrench

A roller wrench comprising:

• a body with a head, a circular chamber being disposed in the head;
• a driving member being a regular polygonal component with a plurality of sides, the driving member being installed in the chamber of the head and capable of rotating in the chamber;
• a plurality of rollers with a quantity the same as a quantity of the sides of the driving member, the rollers being installed in the chamber and respectively located between the sides of the driving member and a peripheral wall of the chamber;
• and
• a reversing knob rotatably installed on the head, the reversing knob being capable of driving the rollers to move in the chamber, so that each of the rollers moving between one edge and another edge of each of the sides of the driving member;
• wherein:
• each of the sides of the driving member has a central area, a concave latching surface is respectively provided on two sides of the central area, each of the latching surfaces has an inner side connected to the central area and an outer side away from the central area, a concave state of each of the latching surfaces is gradually concaved inwardly from the inner side to the outer side;
• an included angle with a small degree is formed between each of the latching surfaces and the central area of each of the sides;
• when each of the rollers is located on one edge of each of the sides, a peripheral surface of the roller contacts with the latching surface and the peripheral wall of the chamber, so that the body, the rollers and the driving member are latched with one another.