A device for holding and securing a tool, in particular, a drill bit, on a machine tool, for example, a core drill, including an output shaft for transmitting a torque generated in the machine tool to the tool; and a union nut positioned around the output shaft for detachably connecting the output shaft to an attachment end of the tool.

The output shaft includes a locking ring and the union nut includes a washer disk, as well as an attenuator, the washer disk being positioned between the locking ring and the attenuator.

An apparatus in the form of an adapter for forming a connection comprising a first part adapted for coupling with a second part by a quick-release coupling formed by a first projection of the first part having an at least partial dovetail shape and a recess of the second part having an at least partial dovetail shape. An opening in the recess is adapted for receiving the projection in an axial direction. In other embodiments, the adapter is: (1) frictionally enhanced for engaging an internal portion of the drilling element; (2) includes a radial projection elongated in an axial direction for engaging the internal portion of the one drilling element; and/or (3) has a cutter for scoring an internal portion of the one drilling element upon being inserted therein and rotated. An adapter is also disclosed for use with a drill check, including for creating a twist lock connection.

A connecting device may have a tooth-shaped jacket, a locking body internally of the tooth-shaped jacket, a plurality of balls, a spring, and a spring base. The locking body has a rear end with an annular groove and has a neck with a plurality of spherical recesses containing the balls. Radial positioning between the locking body and the tooth-shaped jacket is realized through the balls. The spring is connected between the tooth-shaped jacket and the spring base and axial positioning between the spring base and the locking body is realized through a snap ring in the annular groove.

A tool arrangement and chuck apparatus for quick change of a range of tools; particularly, a quick change chuck adapted to engage various diameter drill bits, tools and tool holders. The tools are rotatable in a chuck or adaptor and have at one end a centering shaft portion having a constant diameter for multiple tool end diameters and shapes, a drive shoulder portion and a lock portion. The chucks have a tool centering arrangement for accommodating the constant diameter centering shaft. The chucks are also described as having tool bit release mechanism operable to disengage the tool from a retention mechanism when a force is applied inwards of the body of the chuck by the user to allow the tool bit to be removed longitudinally from the chuck but also arrange to allow the tool bit to be inserted longitudinally into the chuck without requiring any other user operation.