A cutting tool (10) in which a cutting insert (14) is retained by a retaining screw (18). The cutting insert comprises a rear surface (32) and a lower surface (28) being generally v-shaped.

Cutting tool and cutting insert therefor

A semiconductor memory device comprises a plurality of memory cells each having a source terminal and a drain terminal and a ferroelectric capacitor having a first terminal connected to the source terminal, wherein the plurality of memory cells are connected in series, and one or more selected transistors connected to at least one terminal of the series connected memory cells to constitute a memory cell block, the memory cell block having one terminal connected to a bitline and another terminal connected to a plate electrode, and wherein two memory cell blocks, which are respectively connected to two bit lines forming a bit line pair and also connected to the same word line, are respectively connected to a first plate electrode and a second plate electrode.

Semiconductor memory device and various systems mounting them

A ball end mill is disclosed which includes a tool body having an axis of rotation therethrough and having a forward end portion, and a cutting edge provided on the forward end portion of the tool body and having an arcuate shape as viewed in a direction opposite to the direction of rotation of the tool body. The cutting edge is comprised of a radially inner portion disposed adjacent to the axis of rotation of the tool body and extending radially inwardly of the tool body in a direction opposite to the direction of rotation of the tool body, and a radially outer portion extending from the inner portion radially outwardly and axially rearwardly of the tool body. Each of the inner and outer portions of the cutting edge is formed of a two-layered composite sintered complex having a base layer of cemented carbide and an upper layer of sintered super hardened compact disposed on the base layer and containing cubic boron nitride, diamond or the like. The composite sintered complex defining the outer portion of the cutting edge is arranged such that the upper layer is directed in the direction of rotation of the tool body while the composite sintered complex defining the inner portion of the cutting edge is arranged such that the upper layer is directed forwardly of the tool body.

Ball end mill

A rotatable cutting bit for penetrating an earth formation wherein the rotatable cutting bit includes an elongate bit body having a forward end and a rearward end. The bit body further defines a peripheral surface. The bit body has a first cutting insert affixed thereto at the axially forward end thereof. The first cutting insert has a first leading cutting edge and a first side clearance cutting edge. The first cutting insert is attached to the bit body so that the first side clearance cutting edge radially extends past the peripheral surface of the bit body so as to engage the earth formation.

Rotatable cutting bit assembly with cutting inserts

A rotary cutting tool or end mill (10, 110) is provided, the tool (10, 110) comprising a plurality of pairs of diametrically-opposed, symmetrical, helical flutes (30, 32, 34) formed in a cutting portion (24) of the tool body (20), wherein the index angle (γ, e) between at least one pair of adjacent helical flutes (30, 32, 34) in at least one radial plane along the axial length of the flutes (30, 32, 34), a plurality of peripheral cutting edges (40, 42, 44), wherein at least one of the peripheral cutting edges (40, 42, 44) has a radial rake angle (α, β, δ, λ, ρ, σ, ψ, ω) different from radial rake angle (α, β, δ, λ, ρ, σ, ψ, ω) of a peripheral cutting edge (40, 42, 44) of a different helical flute (30, 32, 34).

Rotary Cutting Tool

An end mill comprises an end mill body and a throw-away tip mounted on a forward end of the end mill body so as to be spaced from an axis thereof. A core receiving recess is formed at a center of a forward end face of the end mill body and has a size equal to or greater than a distance between the throw-away tip and the axis of the end mill body. The throw-away tip has an end cutting edge formed by a cutting edge ridge located adjacent the forward end of the end mill body and extending from an outer peripheral side of the end mill body toward an inner peripheral side thereof, and outer and inner peripheral cutting edges respectively formed by cutting edge ridges respectively extending from outer and inner peripheral ends of the end cutting edge toward a rearward end of the end mill body. The end mill body may mount at least two throw-away tips disposed symmetrically with respect to the axis thereof.

End mill with throw-away tip

A cutter insert of the indexable type for a rotary cutter includes a body of a plate of a generally circular shape and having three notches of a V-shape formed in a circumferential face of the body in equally circumferentially spaced relation, each V-shaped notch being defined by a pair of first and second opposed walls. A front face of the body cooperates with the circumferential face, interrupted by the three V-shaped notches, to define three arcuate convex cutting edges each having a leading and a trialing end. A marginal portion of the front face disposed adjacent to and extending along each cutting edge serves as a rake surface for the cutting edge, the rake surface being recessed adjacent to the first wall of the V-shaped notch so as to slope toward a rear face of the body toward the first wall to provide a convex portion extending between the front face and the first wall. The first wall of each V-shaped notch, intersecting a respective one of the cutting edges at the leading edge thereof, is sloping toward the trailing end of the adjacent cutting edge at the second wall of the notch and is inclined with respect to a plane disposed perpendicular to the front face and passing through a center of a circle along which the one cutting edge extends and the leading end of the one cutting edge disposed at the first wall.

Indexable cutter insert

In a face milling cutter, a plurality of cutter inserts are detachably mounted to an outer periphery of a forward end portion of a cutter body. The cutter inserts are arranged in peripherally spaced relation to each other about a rotary axis of the cutter body. Each of the cutter inserts has opposite faces one of which, first face being generally in the form of an octagon having eight ridgelines or a hexagon having six ridgelines, which are formed respectively into cutting edges. Each pair of adjacent cutting edges as a major edge are intersected with each other at an obtuse angle.

Face milling cutter with cutter inserts

PURPOSE: To easily discharge cutting chips by forming a tilt surface of tilting a face of a main cutting edge so as to gradually approach a lower surface side in a direction of separating from a subcutting edge along a lengthwise direction of the main cutting edge also tilting the rake surface so as to gradually approach the lower surface side in a direction of crossing with the main cutting edge. CONSTITUTION: In an upper surface 14, a rake face 22 of a main cutting edge 16 is formed in almost the same width in its lengthwise direction to be tilted (tilt angle β) so as to approach (distance to lower surface 13 shortened) gradually a lower surface side along a lengthwise direction of the main cutting edge 16 from a side of a subcutting edge 18, also to be tilted (rake angle α) so as to approach (distance to lower surface shortened) gradually the lower surface side in a central direction (through hole direction) of separating from the main cutting edge 16. In a throwaway tip, by the rake face 22 of the main cutting edge 16, sharpness is improved by increasing the rake angle α, and cutting chip dischargeability is improved by providing the tilt angle β. COPYRIGHT: (C)1996,JPO

Tatsuo Arai

Papers

Ball end mill

End mill with throw-away tip

Indexable cutter insert

Face milling cutter with cutter inserts

Throwaway tip and throwaway type cutter