Patent ID: 6889440

Claim:
A compass for drawing a circle, comprising: a first compass leg with a pointed end or defining a center of a circle; a second compass leg with a drawing instrument end for carrying a drawing instrument; a manipulate portion with which a user transmits a rotational driving force to draw the circle; and a ratchet mechanism provided to the manipulate portion which transmits the rotational driving force only in one direction; wherein the first compass leg and the second compass leg are linked to one another such that a radial distance between the first compass leg point and the second compass leg drawing instrument is adjustable; and wherein the manipulate portion is coupled to the compass legs via the ratchet mechanism, such that when applied with the manipulate portion, the rotational driving force is transmitted to the compass through the ratchet mechanism to cause the second compass leg to rotate about the circle center defined by the first compass leg point.