A tool holder has a holder body, a first clamping member, and a first fastening member. The holder body includes a fixation portion and a mounting portion located rearward of the fixation portion. The fixation portion has a front fixation surface facing in a forward direction, a cylindrical fixation bore opening out to the front fixation surface and extending rearwardly therefrom, and a longitudinally extending primary slot connecting the fixation bore to a fixation envelope surface. The first clamping member occupies a first clamping bore and traverses the primary slot. The first fastening member occupies a first fastening bore which intersects the first clamping bore and opens out to the front fixation surface. The fixation bore has a fixation bore first primary diameter which decreases and increases when the first fastening member is rotated in first fastening and first unfastening directions about the first fastening member axis, respectively.

A rotary cutting tool with a shank and an interchangeable cutting tip, wherein the shank includes a pocket which receives the interchangeable cutting tip via an interference fit. The pocket includes two centering wall portions which, when viewed along a central longitudinal axis, are oriented at a first angle with respect to one another, the first angle being greater than zero. The interchangeable cutting tip is axially displaceable between: an initial position, assumed upon being received in the pocket of the shank; a clamped position, wherein the interchangeable cutting tip is fixedly held with respect to the shank; and a bump-off position, wherein the interchangeable cutting tip is not fixedly held. A holding element holds the interchangeable cutting tip in the clamped position, and a spring assembly which displaces the interchangeable cutting tip between the clamped position and the bump-off position. Other variants and embodiments are broadly contemplated herein.

A cutting insert includes a head portion having a number of cutting edges and a centering pin which is disposed about a central longitudinal axis and which is coupled to, and extends axially away from, the main head portion. The centering pin includes a recess structured to accommodate a portion of a setscrew. The recess includes: a first angled surface disposed generally facing away from a leading end of the centering pin at an acute first angle with respect to the longitudinal axis of the centering pin; and a second angled surface which is positioned opposing the first angled surface at an acute second angle with respect to the longitudinal axis of the centering pin.

A rotary cutting tool includes a tool shank, a replaceable cutting head mounted on the tool shank, a coupling pin, and an actuation member. In one embodiment, the coupling pin has a cylindrical portion with a reduced-diameter portion defined by a pair of angled side walls separated by a bottom surface for cooperating with a non-threaded portion at one end of the actuation member. In another embodiment, the coupling pin has a cylindrical portion with a notch with a pair of side walls for cooperating with a frustoconical member at one end of the actuation member. When assembled, a pair of V-shaped contact surfaces on the cutting head engage a pair of oppositely facing V-shaped contact surfaces on the tool shank to provide stability against the momentum created by cutting forces in two different directions and securely hold the cutting head in place during machining operations.

A cutting insert for a rotary drill tool and a drill tool assembly in which an insert and a support body are coupled via cooperative contact surfaces and a mounting screw. The contact surfaces provide a dual function to axially and rotationally lock the insert at the support body in addition to providing a centring function of the insert.

A self-drilling, self-tapping bone screw is described in which the bone screw has a drill tip free of threads and having a length at least as great as about the thickness of a proximal cortical bone layer, with the drill tip having opposed lands and a helical flute between each of the lands with each of the lands having a cutting edge configured to cut bone as the drill tip is rotated into the bone with the flutes conveying the bone debris away from the drill tip, where a lead thread begins to self-tap internal threads in the proximal cortical bone layer after the drill tip has drilled through the proximal cortical bone layer so as to avoid stripping the threads formed in the bone layer. A method of installation is also disclosed.

A self-drilling, self-tapping bone screw is described in which the bone screw has a drill tip free of threads and having a length at least as great as about the thickness of a proximal cortical bone layer, with the drill tip having opposed lands and a helical flute between each of the lands with each of the lands having a cutting edge configured to cut bone as the drill tip is rotated into the bone with the flutes conveying the bone debris away from the drill tip, where a lead thread begins to self-tap internal threads in the proximal cortical bone layer after the drill tip has drilled through the proximal cortical bone layer so as to avoid stripping the threads formed in the bone layer. A method of installation is also disclosed.

A position adjustment device for adjusting a height of an object to be supported includes: a fixed portion; a movable portion provided to be movable in the height direction relative to the fixed portion and supporting the object to be supported; an expanding and contracting portion coupled to the fixed portion and the movable portion and having formed therein a plurality of cuts extending along a first direction that is orthogonal to the height direction; and an adjustment mechanism configured to adjust expansion and contraction of the expanding and contracting portion. The expanding and contracting portion has a crank shape in which a plurality of the cuts formed on one side in the first direction and a plurality of the cuts formed on the other side in the first direction are alternated along the height direction.

A position adjustment device for adjusting the height of an object to be supported includes: a fixed portion; a movable portion provided to be movable in the height direction relative to the fixed portion and supporting the object to be supported; an expanding and contracting portion coupled to the fixed portion and the movable portion and configured to expand and contract in the height direction; an adjustment mechanism configured to adjust the position of the movable portion in the height direction relative to the fixed portion; and a metal member fixed to the fixed portion and the movable portion.

The present invention relates to a tool bit replaceable rotary cutting tool and a rotary cutting method and a tool bit mounting method thereof and belongs to the field of hole machining in the machining industry. At present, a twist drill for drilling is of an integrated structure, and when service life of a tool bit is exhausted, the whole drill is required to be replaced, so that cost is relatively high. For a tool bit replaceable drilling tool, in a drilling process, radial and axial acting forces on a tool bit are relatively strong and thus may cause the conditions of imprecise drilling caused by radial displacement of the tool bit at a joint and the like, a replaceable structure of the tool bit makes the joint of the tool bit of the drilling tool relatively weak and a design of a chip groove makes a substrate of the drilling tool weaker. According to the tool bit replaceable rotary cutting tool of the present invention, a tool bit is detachably connected with a tool bar, and V-shaped positioning surfaces are adopted for a joint of the tool bit and the tool bar, so that a good tool bit positioning and fixation effect is achieved, and the tool bit is unlikely to deviate; a design with different helical angles is adopted for a chip groove, so that strength of the tool bar is strengthened; due to design of cooling guide grooves, a cooling effect is improved; and the tool bit is easy to mount and dismount.