Conical NIB and writing instrument using the same

摘要

A nib piece with high roundness is obtained in the following manner: in the forming of the nib piece, a punched hole is formed in a base portion of a punched plate which is to be bent; the base portion of the punched plate is bent and shaped into a tubular structure; a pipe member which is aligned with and accommodated in the tubular body, is disposed in an inner portion of the base portion of the punched plate having been bent; and the punched plate is shaped to obtain a structure to wrap an outer periphery of the pipe member. The punched plate includes an engageable joint portion, such as a protrusion and a recess, which engage each other and form a hooked edge when the punched plate is bent into a cylindrical form.

主权项

1. A conical nib manufactured by bending and shaping a punched plate into a tubular form, the conical nib comprising:
a nib piece which includes a tubular base portion, formed into a hollow conical body gradually tapering from a lengthwise direction middle portion to a tip thereof, the tip being a hemispherical writing tip, the conical body being provided with multiple narrow gaps at equal intervals which gaps extending from the writing tip to the rear in the same direction as an axial center and along the conical body so that the conical body is divided into multiple combtooth-shaped pieces, and a base end of each combtooth-shaped piece is connected to the tubular base portion; and an ink relay core which is provided inside the nib piece and extends to reach an inner surface of a tip of the conical body of the nib piece, wherein a protrusion which protrudes from one side toward another side of a joint edge of the base portion of the bent and shaped nib piece and a recess which is formed to receive the protrusion at another side of the joint edge are formed at the joint edges, the protrusion engaging the recess to form a hooked edge so as to prevent displacement of the nib piece from the tip to the rear.