An engine includes a cylinder block including a cylinder hole, a crank shaft as an offset crank, and a connecting rod that connects the piston and the crank shaft. An inclined surface is provided on an entire circumference of a crank-shaft-side opening edge of one end of the cylinder hole. When viewed in the axial direction of the crank shaft, a boundary line between the inclined surface and the cylinder hole extends towards the other end of the cylinder hole as it extends toward an offset side on which the crank shaft is offset from the center axis of the cylinder hole. The offset crank engine has the entire circumference of the crank-shaft-side opening edge of the cylinder hole chamfered without any bad influence on the sliding surface and posture of the piston to avoid interference between the crank-shaft-side opening edge of the cylinder hole and the connecting rod.

A front and back chamfering rotary milling cutter includes a cutter body including an insert pocket and a star-shaped indexable cutting insert releasably retained in the pocket. The cutting insert has star-shaped upper and lower surfaces connected by a peripheral surface intersecting each of the upper and lower surfaces. The cutting insert includes a plurality of circumferentially alternating inner and outer corner portions. A cutting portion is defined by each outer corner portion together with an adjacent first inner corner portion rotationally forward thereof and an adjacent second inner corner portion located rotationally rearward thereof. Each cutting portion includes a front chamfering cutting edge extending from the outer corner portion to the first inner corner portion and a back chamfering cutting edge extending from the outer corner portion to the second inner corner portion.

Various components of an electronic device housing and methods for their assembly are disclosed. The housing can be formed by assembling and connecting two or more different sections together. The sections of the housing may be coupled together using one or more coupling members. The coupling members may be formed using a two-shot molding process in which the first shot forms a structural portion of the coupling members, and the second shot forms cosmetic portions of the coupling members.

A chamfer tool which comprises a tool holder. The tool holder extends along a central axis and comprises a plurality of slot-shaped cutting insert receptacles, each having two opposing lateral abutment surfaces and a base abutment surface arranged between the two lateral abutment surfaces and extending transversely thereto. The chamfer tool further comprises a plurality of cutting inserts, which are fixed in the plurality of cutting insert receptacles in a firmly bonded manner, wherein each of the cutting inserts comprises two opposing lateral surfaces, which abut against or are connected in a firmly bonded manner to the two lateral abutment surfaces of the respective cutting insert receptacle, and a lower surface arranged between the two lateral surfaces and extending transversely thereto, wherein the lower surface abuts against or is connected in a firmly bonded manner to the base abutment surface of the respective cutting insert receptacle. The cutting inserts project out of the first cutting insert receptacles both in an axial direction, which is parallel to the central axis of the tool holder, and transversely to the axial direction. Each of the cutting inserts comprises a main cutting edge which is oriented at a first acute angle to the central axis of the tool holder.

An assembled chamfer mill comprises a tool holder, an extension shaft, and chamfer bits locked to two ends of the extension shaft. The chamfer bits each have upper blades and lower blades for chamfering the edges of a workpiece simultaneously. The length of a shaft body of the extension shaft may be set in various sizes. Depending on the thickness and shape of the workpiece, the shaft body having an appropriate length is selected, so as to control the distance between the two chamfer bits. Another extension shaft may be provided to connect a further chamber bit for chamfering the edges of the workpiece simultaneously.

A milling tool for producing chamfer surfaces at workpieces. It has a cylindrical shaft and a cutting part, which has at least two end cutting edges, which are each located on a cone jacket surface and which run in a spiraled convex manner in the direction of rotation, and which each extend from a radially outer cutting corner to an inner cutting corner on the end side. To broaden the area of application of the milling tool to processes, such as the “ramping” or the linear diagonal plunging, respectively, the circular milling, the spot-drilling, or the waterline milling, the end cutting edges merge at the inner cutting corner into center cutting edges, which are located on a cone jacket surface with a tip angle of above 180°, and which run with a positive chip angle into a region of the milling cutter center located in the milling cutter core.

In a method for creating a through-thread, thread creation means is moved in a screw-in movement in an axial forward direction (VR) through a workpiece from a first workpiece side to a second workpiece side opposite the first workpiece side such that the end face projects out of the workpiece, wherein the thread creation means is moved through the workpiece, in particular along a first line which is a helical line, wherein then, to create at least one countersink, the thread creation means is moved in a countersinking movement, in particular along a second line that differs from the first line, and wherein, for subsequent withdrawal, the thread creation means is moved back through the workpiece in a screw-out movement in the axial backward direction (RR), in particular at least substantially along the first line.

In a tool holding portion of a machining tool, a cartridge is provided so as to be movable forward and backward. A cam accommodated inside a cam accommodation portion rotates while the cam is in abutment against the cartridge to thereby move the cartridge forward and backward. A rod which moves forward and backward inside a tool body along an axis is provided with an abutment portion. The abutment portion abuts against an abutment position of the cam according to the forward and backward movement of the rod to thereby rotate the cam. A restriction mechanism is capable of adjusting the phase of the cam when the abutment portion is apart from the abutment position so that a reference position is reached where the abutment position faces the abutment portion.

Various components of an electronic device housing and methods for their assembly are disclosed. The housing can be formed by assembling and connecting two or more different sections together. The sections of the housing may be coupled together using one or more coupling members. The coupling members may be formed using a two-shot molding process in which the first shot forms a structural portion of the coupling members, and the second shot forms cosmetic portions of the coupling members.

An insert includes a rake angle set corresponding to the hardness of a material to be cut and that can suppress an increase in the material cost even when the strength of a cut edge section is increased. The insert has a polygonal shape and includes a cutting edge portion on at least one side of the polygonal shape. The cutting edge portion includes a rake face having a convex formed on one of opposite surfaces in the thickness direction a flank face having a concave formed on a surface intersecting with the one surface in the thickness direction and a concave cutting edge that is formed between the rake face and the flank face.