Patent ID: 7497444

Claim:
A chuck device in which a rotary sleeve is rotated so that a plurality of jaws inserted into a hole provided in a tip end of a body is slidingly opened and closed to thereby clamp a tool by the jaws, characterized in that ratchet teeth forming an annular shape are provided in the body, an annular rotary member threadedly engaged with the jaws and rotated together with the rotary sleeve is fitted around the body inside of the rotary sleeve, a retainer spring member detachably engaging with the ratchet teeth is disposed outside of the ratchet teeth, the retainer spring member is provided so as to rotate a circumference of the ratchet teeth in accordance with the rotation of the rotary member, the retainer spring member is mounted on the rotary member by a concave and convex engagement means, furthermore, a holding portion for holding a condition that the ratchet teeth and the retainer spring member are engaged with each other and a condition that a disengagement between the ratchet teeth and the retainer spring member is released and the ratchet teeth are formed of a harder member than the body, and having a strip shape to be wrapped around the circumferential surface of the body, said harder member is a discrete member from the body.