2 results about "Decreased diameter" patented technology

A cutter for a well construction tool has a cutting structure affixed to a substrate, which defines a monotonically decreasing diameter with respect to an axial distance from an interface between the cutting structure and the substrate. A shear surface formed in the cutting structure intersects a surface of the cutting structure between the interface and an apex of the cutting structure, and defines a smaller angle with respect to a reference than the cutting structure proximate the interface and a larger angle with respect to the reference than the cutting structure proximate the apex. The apex is rotationally symmetric about a centerline of the cutting structure in all rotational directions, and a radius of curvature of the apex is at most 75 percent of a diameter of the substrate. A well construction tool includes a tool body with at least one such cutter attached to the tool body.

To provide a technology to reliably mold a cylindrical body with a tapered part by plastic working and to impart compressive residual stress to the cylindrical body even in a high-hardness and difficult-to-process material.SOLUTION: A closed end part of a bottomed cylindrical material is pressed by a punch and stretched while reducing the diameter to form a small diameter cylindrical part, and an opening end is left as it is without reducing the diameter to form a tapered part, thereby generating an intermediate material. Then, the closed end part of the intermediate material is pressed by another punch, and the small diameter cylindrical part is further reduced in diameter and stretched without reducing the diameter of the tapered part. Then, the inner peripheral surface of the tapered part is pressed by still another punch, and the small diameter cylindrical part is further reduced in diameter and stretched without reducing the diameter of the tapered part. Finally, the tapered part is clamped between the punch and a die.SELECTED DRAWING: Figure 1