A drill ring for a cylindrical core drill bit is disclosed. The drill ring includes at least two ring segments which are constructed from a sintered powder mixture and diamond particles. The diamond particles are arranged on ablation tracks in a plane perpendicular to the cylinder axis and the ring segments are connected to each other on their lateral edges.

A method for producing a drill ring for a core drill bit is disclosed. The method includes constructing at least two green parts from encapsulated diamond particles, the diamond particles being covered by a powder mixture. The green parts are formed into ring segments under the effect of pressure and the ring segments are annularly assembled and sintered under temperature action to form a continuous drill ring.

There is provided a drill bit for cutting tiles comprising a hollow body portion bearing an annular cutting surface at one end and a wax plug located within the hollow body portion, wherein an internal wall of the hollow body portion has at least one region of reduced thickness so as to provide one or more channels along which melted wax can flow to reach cutting surface. The channels can be provided by an offset central passage within body portion, or as elongate grooves around the internal wall of the hollow body portion. The channels can be helical grooves.

One example of the present disclosure relates to a coupon. The coupon includes a first surface with a first circular channel and a second surface opposite and parallel to the first surface. The second surface is spaced a distance D0 from the first surface and includes a second circular channel concentric with the first circular channel. The coupon also includes a toroidal portion between the first circular channel and the second circular channel. The toroidal portion includes a rectangular sectional portion.

A rotary tool comprises a cylindrical sleeve including an opening formed in an outer circumferential surface thereof providing fluid communication between a hollow interior of the sleeve and an environment surrounding the sleeve. The sleeve includes an axially extending flow passage formed therein terminating in a first fluid outlet formed in an open end of the sleeve disposed adjacent a cutting element of the rotary tool. The fluid outlet is configured to deliver a flow of a fluid toward the workpiece to cause chips formed during the machining operation to be directed away from the workpiece and out of the hollow interior of the sleeve through the opening formed in the outer circumferential surface thereof.

A medical drill bit comprises an accommodating slot disposed concavely on a main body of the medical drill bit, a separate board disposed in the accommodating slot to separate the accommodating slot into a first slot and a second slot, and a lid engaging with the separate board and covering the accommodating slot. The lid and the separate board do not rotate with the main body when the main body in rotation. The accommodating uses to fill with cooling liquid which able to be pumped out from the accommodating slot, and fresh cooling liquid is able to inject into the accommodating slot for cooling the drill bit in rotation.

The invention concerns a drilling device (1) and a method for drilling holes in a stack of material (100). The drilling device is provided with clamping means (23, 26) for clamping the material, a hollow drill (10) with an internal channel and a drive (3) for the hollow drill. The drilling device is further provided with connecting means (4) for cooling means, that are arranged for conducting gas through the internal channel, and suction means (51) for suctioning drilling debris. The drilling shaft is provided with a cut out, that runs in longitudinal direction along the drill shaft and forms a discharge channel for the drilling debris.

The invention also concerns a machine for machining and assembling window coverings, such as pleated blinds, comprising one or more drilling devices according to the invention.

A rotary cutting tool is provided having a body and a fluid passage. The body has a shank portion and a cutting portion. The body extends lengthwise along a central axis between a shank end and a cutting end. The cutting portion includes a fluted section and a plurality of teeth extending axially outwardly from the fluted section at the cutting end. The fluted section includes a plurality of flutes disposed within an exterior surface of the fluted section. The cutting portion includes an internal cavity disposed within the fluted section and open to the cutting end. The internal cavity is defined by an interior wall surface. The cutting portion includes a plurality of channels disposed within the interior wall surface and open to the internal cavity. The fluid passage extends through the shank portion to the internal cavity.

A rotary cutting tool having a lengthwise extending central axis is provided. The tool includes a shank portion and a cutting portion. The cutting portion is connected to the shank portion, and includes a fluted section and a plurality of teeth. The fluted section includes a plurality of flutes disposed within an exterior surface of the fluted section. The cutting portion includes an internal cavity disposed within the fluted section and open to a cutting end. Each tooth includes a front side surface, an exterior side surface, an interior side surface, and an axial end surface. The front side surface intersects with the axial end surface to form an axial end cutting edge that extends radially between an outer radial tip and an inner radial tip, and the outer radial tip is disposed axially outside of the inner radial tip.

A rotary cutting tool cutting insert is provided that includes front, aft, exterior, and interior side surfaces, an axial end surface, and a base surface. The exterior side surface intersects with the front side surface. The interior side surface intersects with the front side surface. The axial end side surface intersects with the front side surface at an axial end cutting edge, with the exterior side surface at a first outer axial edge, and with the interior side surface at a second outer axial edge. The base surface intersects the front, exterior, and interior side surfaces and the aft surface. The base surface intersects the front side surface at an inner edge. An outer radial tip is disposed at a first heightwise distance from an inner edge, and an inner radial tip is disposed at a second heightwise distance from the inner edge.