Patent ID: 7207573

Claim:
A chuck assembly comprising: a body; a rotary sleeve provided on the body, the rotary sleeve being rotatable; a rotary nut; a jaw which is engaged with the rotary nut, the jaw being movable back and forth to be opened and closed by rotation of the rotary nut rotated together with the rotary sleeve; a ring member disposed to surround the rotary nut; a convex engaging means and a concave engaging means provided between the ring member and the rotary sleeve, such that the ring member and the rotary sleeve are retained and prevented from falling apart from each other by the convex and concave engaging means; and a slotted portion which guides the convex engaging means toward the concave engaging means, such that upon reaching the concave engaging means, the convex engaging means extends into the concave engaging means so as to be held in place, wherein the slotted portion is positioned above the concave engaging means in a state where a tip end of the jaw points downwardly.