Patent ID: 8261635

Claim:
An one-direction ratchet wrench comprising: a driving head comprising: a penetrated first cavity whose inner sidewall has a concaved first annular groove near its top portion and a protruded annular fringe near the bottom portion; a curved second cavity with walls on its top and bottom portions respectively, extended from a sidewall of the first cavity, and a curved convex trough defined on a top of the top wall to communicate with the first annular groove, the center of the curved convex trough is on the same axis as the center of the second cavity, the diameter of the convex trough is less than or equal to the diameter of the second cavity; a pin hole whose top portion links both the second cavity and the convex trough, and bottom portion ends at the top indent of the bottom wall; a ratchet wheel rotatably mounted in the first cavity and held by the annular fringe to avoid falling apart from the wrench, having a plurality of ratchet teeth on its outer periphery and a receptacle at the middle for receiving and driving workpieces, and having a second annular groove at the top portion of its outer periphery for locating the second annular groove itself exactly corresponding to the first annular groove; a pawl moveably located in the second cavity and one of its sides having a plurality of teeth engaged with the ratchet teeth of the ratchet wheel; a pin being inserted in the pin hole; an elastic assembly, placed inside the second cavity, comprising: a first elastic element which has a first end, a second end, a first loop extending through the first end and the second end, and a push element extended outwards from the first end in the opposite direction of the first loop; the elastic push element, employed to hold onto the pin, being stuck against the wall of the second cavity and generating elasticity to make the first elastic element generate a torque relative to the pin; and a second elastic element which also has a first end, a second end and a second loop extending through the first end and the second end; the first end linking with the second end of the first elastic element; the second end being a free end employed to connect with the pawl; the axis of the second loop and the axis of the first loop having a ninety degree angle in between; the second elastic element being effectively connected with the pawl due to the torque from the first elastic element pushing the second elastic element; a C shaped annular hook whose outer periphery is engaged in the first annular groove and inner periphery is engaged in the second annular groove, allowing the ratchet wheel rotatably mounted within the first cavity, and two free ends of the annular hook being extended into the convex trough; and a lid whose shape is in accordance with the contour of the convex trough, and the top of the lid being held and pressed by the two free ends of the annular hook to secure the lid.