Patent ID: 8051747
Filing Date: 2011-11-08
Classification: B25B

Abstract:
1. A one-way ratchet wrench comprising a wrench body, a ratchet wheel, a pawl, an anchor, an elastic element, a cover and a clip ring, wherein: the acting end of the wrench body is provided with a circular first receiving recess, a smaller-diameter pressing edge is disposed on the bottom surface of the first receiving recess, one side of the first receiving recess is provided with a curved second receiving recess which is communicated with the first receiving recess, the diameter of the second receiving recess is smaller than that of the first receiving recess, the center of the curve of the second receiving recess is located in the first receiving recess, the center of the circle of the first receiving recess is at a distance from that of the second receiving recess, the top and bottom of the second receiving recess are closed respectively, a bevel groove is disposed on the periphery on one side of the second receiving recess of the wrench body, the bevel groove is circular hole shaped but not through-going, and the longitudinal axis of the bevel groove intersects the center of the circle of the first receiving recess and has an included angle with respect to the axis of the wrench body which is from ten to twenty-five degrees; the ratchet wheel is pivotally disposed in the first receiving recess and provided with a sleeve portion, and engaging teeth are circularly arranged around an outer periphery of the ratchet wheel which presses against the pressing edge of the wrench body; one side of the pawl is provided with pawl teeth for engaging with the engaging teeth of the ratchet wheel, one side of the pawl presses against a wall of the second receiving recess of the wrench body, and the other side of the pawl is provided with a pressing surface; the anchor is received in the bevel groove of the wrench body and projects into the second receiving recess, the anchor does not contact with the engaging teeth of the ratchet wheel, and the axis of the anchor intersects the center of the circle of the first receiving recess and has an included angle with respect to the axis of the wrench body which is the same as the included angle between the axis of the bevel groove and the center of the circle of the first receiving recess; one end of the elastic element presses against the pressing surface of the pawl, the other end of the elastic element presses against the anchor, the elastic force of the elastic element allows the pawl teeth of the pawl to engage with the engaging teeth of the ratchet wheel, the anchor is received at a tilt angle in the bevel groove, the closer to the first receiving recess the opening defined by the anchor and the pawl goes, the smaller the opening is, and the elastic element is propped between the pawl and the anchor without disengagement such that the elastic element is positioned within the second receiving recess; the cover is hollow and annular and is annularly provided with a groove, the cover is mounted on the first receiving recess of the wrench body and presses against engaging teeth; and the clip ring is mounted between a clip groove of the wrench body and the groove of the cover, the cover and the ratchet wheel are thereby mounted in the first receiving recess of the wrench body such that the cover and the ratchet wheel would not disengage from the first receiving recess of the wrench body during rotation.