Patent ID: 8826557

Claim:
A caliper comprising: a main body having a scale ruler with a predetermined length, a vernier slidably disposed on the scale ruler and reciprocally displaceable along a length of the scale ruler and a restriction section for locking the vernier on the scale ruler without displacement, one side of the scale ruler being marked with a main scale along the length of the scale ruler, one side of the vernier being marked with a subsidiary scale; and a measurement section including a first jaw fixedly connected to one end of the scale ruler and a second jaw disposed on the vernier in alignment with and in parallel to the first jaw, a distance between the first jaw and the second jaw being variable with the displacement of the vernier along the scale ruler, a first measurement end protruding from one side of an end of the first jaw, which side is proximal to the second jaw, a second measurement end protruding from one side of an end of the second jaw, which side is proximal to the first jaw, said caliper being characterized in that the second jaw is pivotally connected to the vernier via a pivot pin and is swingable around the pivot pin between a first position and a second position to change an angle contained between the first and second jaws, the caliper further comprising a locating section disposed on the vernier, the locating section having a restriction body movable between a third position and a fourth position, when the restriction body is positioned in the third position, an abutment end of the restriction body being engaged with one side of the second jaw to restrict the second jaw to the first position, when the restriction body is positioned in the fourth position, the abutment end being disengaged from the second jaw, permitting the second jaw to freely swing between the first and second positions, wherein the second jaw has an elongated jaw body, one end of the jaw body being pivotally connected to the vernier via the pivot pin, a part of an end face of the end of the jaw body being a locating plane face, another part of the end face of the end of the jaw body being a rotary arched face in adjacency to the locating plane face, the pivot pin pivotally connected between the jaw body and the vernier being positioned at a curvature center of the rotary arched face.