Sumitomo Electric Industries, Limited

Jun Maeda

Yoshikatsu Mori

Shigenori Emoto

Kazuo Maeda

Akio Nakamura

Atuhiko Maeta

Syoji Okui

A throwaway insert for a pin mirror cutter in which eight corners can be used and which the cutting performance and machining accuracy can be increased by making positive the axial rake angle of the peripheral cutting edge. Side faces of a negative insert of a parallelogrammic shape are formed by two surfaces connecting to each other at an angle so as to have a first included angle and a second included angle. Further, independent arcuate surfaces are provided at the intersections between the arcuate corner sides of each of the side faces and the top and bottom surfaces and the intersections between the obtuse corner sides and the top and bottom surfaces.

Throwaway insert and pin mirror cutter using the same

A throwaway insert for a ball end mill having an ideal cutting edge shape corresponding to the cutting speeds and loads at different portions of the cutting edges, high in strength and capable of discharging chips smoothly. As viewed in a direction perpendicular to the line connecting noses, each cutting edge forms a convex curve with its nose portion at the lowest level. As viewed in a direction perpendicular to the abovesaid direction, rake faces form symmetrical, downwardly sloping convex accurate surfaces or straight surfaces having a positive rake angle of 5-25.degree.. The wedge angle at the cutting edges is set at 85-65.degree.. Thus, the rake angle will be negative at the noses and positive at other portions. Further, the rake angle increases toward the side where the cutting speed is higher. The thickness of the insert increases toward the side where the load is greater. Since this insert is a modification of a negative insert, i.e. an insert of the type having a side perpendicular to its bottom, it has enough strength. Chips can be discharged smoothly too.

Throwaway insert for ball end mill

A throw-away insert has a cutting edge (12) along its outer periphery and between adjacent noses (11). A concave rake surface (8) is formed which extends directly form the cutting edges (12) toward the center of the insert. A plurality of bosses (10) and a plurality of projections (9) are spaced a predetermined distance from the cutting edges (12) and extend above the rake surface (8). A plurality of lands (5) which are spaced at predetermined intervals (16) from each other are located along the cutting edge (12) and on the rake surface (8).

Throw-away insert

An improved throwaway insert is proposed which has a cutting edge, a land extending along and inside of the cutting edge, a breaker groove extending along and inside of the land, a flat central area enclosed by the breaker groove, and a plurality of semicircular projections arranged in a chip breaker groove at its corners and its straight portions to enable chip to be satisfactorily broken over wide ranges of the depth of cut and the feed. These projections rise from midway of the breaker groove until they become even with the central area enclosed by the breaker groove.

Growing community of inventors

Itami, Japan

Jun Maeda