A chuck assembly includes a chuck body rotatable about an axis, a plurality of jaws each received within a slot of the chuck body for co-rotation with the chuck body about the axis, a wedge engageable with an outer surface of each jaw, a pusher coupled to the plurality of jaws to bias the plurality of jaws in a forward direction into engagement with the wedge, and a tightening sleeve threadably coupled to the chuck body for relative rotation with the chuck body. The tightening sleeve includes a clamping surface engageable with the wedge for inwardly displacing the plurality of jaws in a radial direction, causing the plurality of jaws to secure a tool bit received within the chuck assembly, in response to rotation of the tightening sleeve relative to the chuck body in a tightening direction.

A chuck assembly includes a chuck body rotatable about an axis, a plurality of jaws each received within a slot of the chuck body for co-rotation with the chuck body about the axis, a wedge engageable with an outer surface of each jaw, a pusher coupled to the plurality of jaws to bias the plurality of jaws in a forward direction into engagement with the wedge, and a tightening sleeve threadably coupled to the chuck body for relative rotation with the chuck body. The tightening sleeve includes a clamping surface engageable with the wedge for inwardly displacing the plurality of jaws in a radial direction, causing the plurality of jaws to secure a tool bit received within the chuck assembly, in response to rotation of the tightening sleeve relative to the chuck body in a tightening direction.

A method of operating a power tool chuck assembly includes inserting a tool bit within a central bore of a chuck body, displacing a plurality of jaws with the tool bit from an extended position to a retracted position, displacing the jaws from the retracted position toward the extended position with a spring, rotating a tightening sleeve about a rotational axis in a tightening direction, thereby imparting an axial displacement to the tightening sleeve relative to the chuck body, inwardly displacing a plurality of clamping nuts in a radial direction in response to engagement between a wedge defined on the tightening sleeve and the clamping nuts, causing respective threads on the clamping nuts and the jaws to engage, and applying a clamping force on the tool bit with the jaws in response to continued rotation of the tightening sleeve in the tightening direction.

A method of operating a power tool chuck assembly includes inserting a tool bit within a central bore of a chuck body, displacing a plurality of jaws with the tool bit from an extended position to a retracted position, displacing the jaws from the retracted position toward the extended position with a spring, rotating a tightening sleeve about a rotational axis in a tightening direction, thereby imparting an axial displacement to the tightening sleeve relative to the chuck body, inwardly displacing a plurality of clamping nuts in a radial direction in response to engagement between a wedge defined on the tightening sleeve and the clamping nuts, causing respective threads on the clamping nuts and the jaws to engage, and applying a clamping force on the tool bit with the jaws in response to continued rotation of the tightening sleeve in the tightening direction.

A chuck assembly, for use with a rotary power tool, includes a chuck body rotatable about an axis, a plurality of jaws supported by the chuck body for relative movement therewith between a retracted position for permitting insertion of a tool bit within the chuck body and an extended position for clamping the tool bit, a plurality of clamping nuts surrounding the chuck body and having interior threads engageable with corresponding threads on the respective jaws, a tightening sleeve surrounding and threadably engaged with the chuck body for relative rotation therewith, and a wedge defined on the tightening sleeve for selective engagement with the clamping nuts for inwardly displacing the clamping nuts, causing the respective threads on the clamping nuts and jaws to engage, in response to rotation of the tightening sleeve relative to the chuck body in a tightening direction.

A clamping device for clamping a fastener, includes a clamping jaw, a first biasing member for biasing the clamping jaw, a clamping body having a central axis, a driving assembly for driving the clamping jaw to clamp the fastener, and a second member which can be driven by the first member to move axially relative to the clamping body so as to push the clamping jaw to clamp the fastener. The clamping body is formed with a notch for receiving the clamping jaw and the driving assembly is supported on the clamping body and includes a first member which can rotate and move axially relative to the clamping body. The installation structures between the clamping body, the driving assembly and the clamping jaw may be designed to be more compact so that the clamping device has a smaller size.