Ballpoint nibs and ballpoint pens

Abstract

The invention provides a ballpoint pen tip and a ballpoint pen with smooth writing feel. The tip body 2 of the ballpoint pen tip 1 includes: a ball-holding chamber 50 with a contact surface 53a formed on the rear wall of the ball-holding chamber 50; a rear end hole 40, which is set as a from the rear end side toward the distal end side; and, an ink guide hole 60 formed in the center of the abutment surface 53a to communicate the rear end hole 40 with the ball holding chamber 50, and from the abutment surface 53a The angle between the straight line extending from the center of the pen ball 3 to the thinnest part A in the abutting state and the center line of the ballpoint pen tip 1 is 35° or more and 55° or less. The distance between the inner walls of the hole 40 is the shortest, and the distance between the upper edge of the rear end wall and the thinnest part A along the centerline of the pen tip body 2 is 90% or less of the diameter of the pen ball.

Description

technical field [0001] The present invention relates to a ballpoint pen tip and a ballpoint pen including the ballpoint pen tip. Background technique [0002] The nib of the ballpoint pen includes a nib main body, and the nib main body has: a pen ball holding chamber, which holds the pen ball; and an ink guide hole, which is formed in the back end wall of the pen ball holding chamber a center; and a plurality of ink guide grooves extending radially from the ink guide holes. The top part of the pen ball holding chamber is retracted inward, so that a part of the pen ball protrudes from the top edge of the pen tip and holds the pen ball in a freely rotating manner. [0003] Here, the shape of the contact surface at the rear end wall of the pen ball holding chamber is important for writing comfort, and research on the shape of the contact surface is also underway. For example, Patent Document 1 attempts to improve the writing feel by providing a curved contact surface with a c...

AI Technical Summary

Problems solved by technology

[0004] However, according to Patent Document 1, the contact state between the abutting surface at the rear end wall of the ball holding chamber and the ball is not uniform.

In this case, the coefficient of friction between the pen ball and the abutment surface increases, and the writing feel is limited.

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