Patent ID: 7685911

Claim:
A monkey wrench comprising: a handle; a head formed at an end of the handle and formed with a side, a groove in the side and an opening in communication with the groove; a stationary jaw formed on the head and formed with a first nut-contacting face, a second nut-contacting face next to the first nut-contacting face, a bulge on the first nut-contacting face and a recess next to the bulge; a movable jaw movably disposed in the groove and formed with a nut-contacting face and a bulge on the nut-contacting face thereof; and a jaw-moving element disposed in the opening and engaged with the movable jaw so that the jaw-moving element is operable to move the movable jaw relative to the stationary jaw; wherein an angle between the first nut-contacting face of the stationary jaw and an axis of the jaw-moving element is 65 to 85 degrees; wherein in the stationary jaw, a distance between an end of the second nut-contacting face and a line passing an opposite end of the second nut-contacting face and a peak of the bulge of the stationary jaw is no bigger than a largest distance between the jaws; wherein a distance between a peak of the bulge of the movable jaw and the side of the head is 35% to 47% of the largest distance between the jaws to make sure that the bulge of the movable jaw abuts a middle point of a facet of any nut; wherein the peak of the bulge of the stationary jaw and the peak of the bulge of the movable jaw respectively contact two opposite facets of a nut as the monkey wrench secures the nut.