Patent ID: 6629697
Filing Date: 2003-10-07
Classification: B23B,Y10T

Abstract:
A chuck apparatus, comprising:a chuck; a power-driven device which selectively places the chuck in an object-hold state thereof in which the chuck holds an object, and an object-release state thereof in which the chuck releases the object, the power-driven device having, as a power source thereof, an electric motor; a frame; and a rotary shaft which is supported by the frame such that the rotary shaft is rotatable about an axis line thereof relative to the frame, wherein the chuck includes a main member which is attached to an end of the rotary shaft so as to be rotated with the rotary shaft, at least one holding member which is supported by the main member such that at least a portion of said one holding member is movable in a radial direction of the main member so as to be selectively placed in the object-hold state and the object-release state, wherein the power-driven device further comprises an axial-direction movable member which is movable in an axial direction of the chuck, a first motion converting device which converts the axial-direction motion of the movable member into the radial-direction motion of at least said portion of said one holding member, a first rotary member which is rotatable about an axis line of the axial-direction movable member and whose axial-direction movement is restricted, and a second motion converting device which converts the rotary motion of the first rotary member into the axial-direction motion of the movable member, wherein the power-driven device further comprises a clutch which is provided between the electric motor and the first rotary member and which is selectively placed in a connected state thereof in which the clutch connects the first rotary member and the electric motor to each other and a disconnected state thereof in which the clutch disconnects the first rotary member and the electric motor from each other, the clutch being usually kept in the disconnected state, and being placed in the connected state when the chuck is switched between the object-hold state and the object-release state, wherein the clutch comprises a first clutch member which is fixedly provided on the first rotary member, a second clutch member which is coaxial with the rotary shaft, is rotatable relative to the rotary shaft, and is movable relative to the rotary shaft in the axial direction of the chuck, and which is moved in said axial direction to be engaged with, and disengaged from, the first clutch member, and wherein the power-driven device further comprises a second rotary member which is supported by the frame such that the second rotary member is rotatable about an axis line thereof relative to the frame and which is engaged with the second clutch member such that the second rotary member is not rotatable relative to the second clutch member and is movable relative to the second clutch member in the axial direction of the chuck, and a rotation transmitting member which transmits the rotation of the electric motor to the second rotary member.