Kotobuki Co., Ltd.

Mitsubishi Pencil Company, Limited

G4 De Mexico Sa De Cv

Takeshi Wakayama

Hidehei Kageyama

Takaaki Nakata

Tadao Odaka

Hiroaki Kondo

Yoshio Noguchi

Mechanical pencil

Writing instrument

A mechanical pencil includes a writing lead, a chuck unit for chucking the writing lead, and a cushion spring configured to elastically support the chuck unit in such a manner that the chuck unit is retractable with a writing pressure. An output of the cushion spring, in response to a cushion stroke, is non-linear, and a slope of a spring constant, in a region where the cushion stroke is relatively small, is smaller than a slope of a spring constant in a region where the cushion stroke is relatively large.

A hand tool includes an outer barrel, an inner barrel housed in the outer barrel, and a rear barrel assembled to the outer barrel and the inner barrel. One of the outer barrel and the inner barrel includes a cam follower protruding in a radial direction of the hand tool, the other of the outer barrel and the inner barrel includes a cam groove engaging with the cam follower, and the cam follower is supported to be movable in a radial direction.

Hand tools, cosmetic devices and writing instruments

Sleeve for a mechanical pencil

Sleeve with cushion spring for mechanical pencil

A writing instrument according to an embodiment of the invention including, a chuck that chucks a writing lead, wherein the chuck includes a first chuck pawl which comes into point contact or line contact with the writing lead to press the writing lead so as to apply first contact stress to the writing lead; and a second chuck pawl which presses the writing lead so as to apply, to the writing lead, second contact stress that is lower than the first contact stress, and the first contact stress is configured such that, when a prescribed impact is applied to the writing lead, a contact portion of the writing lead subjected to the first contact stress fractures and absorbs the prescribed impact.

Growing community of inventors

Kawagoe, Japan

Takeshi Wakayama