Writing tool with core breakage preventing function

Abstract

The present invention provides a writing tool with a core breakage preventing function. When writing, when excessive pen pressure acts on the tip of a core, no matter what pressure is based on the excessive pen pressure, a slider advances and the core can be further protected. On the outer periphery of the main body, a gripping part (4) is provided in a manner capable of moving along the shaft diameter direction and the shaft length direction, and is biased in the backward direction by a backward spring (29). The front end of the gripping part can move along the axial length, and abuts againsta top end abutment piece (22), and a pressing member (30) compresses the backward spring (29) by the top end abutment piece. The slider (6) has a spring support portion (39), and the biasing force ofthe backward spring acts indirectly or directly on a spring support portion (39) so that the slider is biased in the backward direction by the backward spring. When the backward spring is compressed,a moving space is formed between the backward spring and the spring support portion, and the slider uses a forward spring (40) or the weight of the slider to advance along the moving space to protectthe tip of the core.

Description

Technical field [0001] The present invention relates to a writing instrument with a core breaking prevention mechanism that prevents core breaking when the writing pressure is excessively applied. Background technique [0002] Among writing implements such as live pencils, there are known writing implements with an anti-breaking core mechanism: when excessive pen pressure is applied, the core holding portion protruding from the tip of the barrel is advanced to protect the core so that The core does not break (see, for example, Patent Document 1). The writing instrument described in Patent Document 1 has a structure in which when the shaft barrel is tilted under a large pen pressure, the core holding portion is pushed forward by a force applied in the axial diameter direction of the shaft barrel to advance the tip of the core holding portion To the outer periphery of the core and cover the core. At this time, the large pressing force caused by the excessive pen pressure directly...

AI Technical Summary

Problems solved by technology

However, since the mechanical pencil described in Patent Document 2 is configured to distort the grip portion and move the lead delivery unit axially rearward when excessive pen pressure acts, in such a mechanical pencil, the The writing core delivery unit suddenly retreats and the core sinks, the writing operation is interrupted, and it is difficult to use

[0004] In addition, in the mechanical pencil described in Patent Document 3, when the front shaft is skewed with respect to the rear shaft, the lead delivery unit advances. The pressure is used to make the core delivery unit advance directly and push the metal mouth to the paper surface, which may damage the paper surface, etc.

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