A cutter holder structure comprises a cutter arbor and a connecting shaft having a tapered section at one end thereof. One end of the tapered section is formed with a first inner screw hole, and another end of the tapered section is formed with a second inner screw hole. The connecting shaft further has a horizontal positioning hole that penetrates through the connecting shaft. Two ends of the positioning hole are formed with cylindrical holes. A reduced hole is defined between the cylindrical holes. A nut has a third inner screw hole at one end and an axial hole at another end. The nut further has a horizontal countersink hole and a horizontal fourth inner screw hole. An eccentric distance is defined between a center of the countersink hole and a center of the fourth inner screw hole. A screw is inserted through the countersink hole and locked into the fourth inner screw hole.

A tool holder used in a machine having a spindle is provided with a connector including a truncated conic part received in the spindle, and a projection extending out of the truncated conic part; a tool mounting member including an axial hole for fastening a tool and a portion of a chuck, and a receptacle for complimentarily receiving the projection; and at least one sleeve formed of a material having a high rigidity, each sleeve including a cavity at one end, the cavity being configured to complimentarily receive the projection, and a protrusion at the other end, the protrusion being configured to complimentarily attach to the receptacle. The connector, the at least one sleeve, and the tool mounting member are secured together.

A tool holder for a machine tool, in particular for a core drilling machine, having a hollow shaft which has, at one end for coupling to the drive of the machine tool, a connector and, at the other end, a receiving opening with a plurality of openings in which locking elements are accommodated which are radially adjustable between a clamping position and an release position for securing a tool accommodated in the receiving opening. A switching sleeve is provided, which is adjustably mounted on the hollow shaft between a first switching position and a second switching position, a first subset of the locking elements being provided in the first switching position for locking the tool in the receiving opening, and a second subset of the locking elements being provided in the second switching position for locking the tool in the receiving opening, while the adjustment of the respective remaining locking elements is deactivated.

A precision securing device is disclosed that comprises a central longitudinal hole to receive a shaft from a first end of the device, a gripping portion around the central hole to fixedly secure an upper part of the shaft, and an adjustment portion around the central hole adjacent the first end. The adjustment portion has a number of lateral adjustment holes opening into the central hole. Each adjustment hole is threaded to receive an adjustment screw into the central hole to contact a lower part of the shaft in the central hole. A first diameter of the central hole at the adjustment portion is larger than a second diameter at the gripping portion. Runout of the shaft is adjustable by adjusting depth of entry of each screw to displace the lower part of the shaft when the upper part has been fixedly secured in the gripping portion.

A chuck includes a mounting part including a conic connection member and a support member in which an end of the connection member is mounted to a predetermined device, and the support member has an axial channel; and a collet partially disposed in the channel and including an axial slit for receipt a portion of a drill bit, longitudinal first gaps on a surface, each first gap having an open end, and first latches each formed between two adjacent first gaps. In response to a force exerted on the first latches, the first latches are flexibly deformed to clamp the drill bit. The mounting part further includes second latches each formed between two adjacent second gaps.

A bit holder is provided including a tool bit receiver body operably configured to receive at least a portion of a tool bit, a retention element configured to retain the tool bit engaged within the tool bit receiver body, a release configured to disengage the retention element enabling removal of the tool bit, a drive element operably coupled to the tool bit receiver body and configured to transfer axial rotation from a driving tool to the tool bit receiver body, and a sleeve disposed around at least a portion of the bit holder and configured such that the tool bit receiver body rotates independent of the axial rotation of at least a portion of the sleeve.

A drill chuck adaptor system including: a drill chuck adaptor tool including a socket body, a lug-receiver, and a threaded-member; as such the drill chuck adaptor system enables the drill chuck adaptor tool for effective use. The drill chuck adaptor tool is defined by the socket body, the lug-receiver, and the threaded-member; the lug-receiver, and the threaded-member extending outwardly from (on) opposing ends of the socket body. The socket body is removably couplable to an impact-driver-tool via a lug of the impact-driver-tool being received by the lug-receiver and the threaded-member is able to be removably coupled to a drill chuck such that the drill chuck is able to be driven via the impact-driver-tool.

A system for securing different first and second drill tools to a drill head including a socket is provided. The system includes a chuck adapted for positioning at least partially within the socket of the drill head, the chuck including a first opening for receiving the first drill tool. An adapter is configured for forming a selective locking engagement within the first opening of the chuck, the adapter including a second opening for receiving the second drill tool. The selective locking engagement may comprise a twist lock engagement, and the adapter may be arranged for receiving a roof bolt. Related methods are also disclosed.

A mandrel assembly includes a mandrel, adapter, and bit coupler. The mandrel includes a shank part axially disposed in the mandrel, an adapter receiver, and a coupler receiver. An internal hole runs axially through the adapter. The coupler includes first and second axial sections, and an axial bit connection hole with a polygonal section proximate to an inner side, and a cylindrical section proximate to an opening. An outer wall of the adapter fits with an inner wall of the adapter receiver. An outer wall of the first section fits with an inner wall of the coupler receiver. An outer wall of the second coupler fits with the internal hole of the adapter. The mandrel transmits torque, via the adapter receiver and coupler receiver, to the adapter and then to a hole saw coupled to the adapter, and to the coupler and then to a bit coupled to the coupler.

A tool bit holder includes an inner sleeve in which a longitudinal bore is defined in which a tool bit is receivable and a detent is engageable with the tool bit for locking the tool bit within the longitudinal bore. An outer sleeve surrounds the inner sleeve and is movable relative to the inner sleeve between a locking position, in which the detent is engaged with the tool bit for locking the tool bit within the longitudinal bore, and a release position, in which the detent may be disengaged from the tool bit to permit removal of the tool bit from the longitudinal bore. A spring is positioned between the inner sleeve and the outer sleeve. The spring biases the outer sleeve toward the locking position