Mitsubishi Pencil Company, Limited

Yoshiharu Namiki

Hisami Tamano

Yusuke Nakamura

Kazuhiko Furukawa

Atsushi Nakashima

Kazuhiko Takanashi

Toshimi Kamitani

Tooru Nakajima

Satoru Banzai

Yosuke Setagawa

Hitoshi Kino

Yoshihiro Manta

Takanori Suzuki

Provided is a knock type writing instrument provided with a simple mechanism allowing a stable fretting operation or the like. A knock type writing instrumentis provided with: a shaft cylinder; a refillarranged inside the shaft cylinder; a springbiasing the refillbackward; an operation partpressed forward against a biasing force of the springin a knocking operation; and a main rotor, and is switchable between a writing state and a non-writing state with the knocking operation. The knock type writing instrumentis further provided with: a knock locking membermovable forward and backward inside the shaft cylinderdue to gravity; and a locking partprovided on a side of the shaft cylinderand capable of being locked with the knock locking member. When a front end of the shaft cylinderis directed upward, the knock locking membermoves backward to be locked with the locking partto prevent forward movement of the operation part

Knock type writing instrument

Provided is a writing instrument suited to ballpoint pens, marking pens and the like in which a flow pressure of an ink applied to a pen tip is controlled to a fixed level to prevent an ink direct flow phenomenon reverse flow phenomenon. The above writing instrument comprises a pen tip disposed at a front part of an ink tank, an ink received in the ink tank, a follower filled at a rear part of the ink, and a capillary porous member provided with a capillary force, which is arranged at a space part between a rear part of the follower and a rear end part of the ink tank in a state in which the follower is filled, wherein the pen tip is sealed when a cap is put on the writing instrument.

Writing instrument

A slide body () is arranged in a cut-away portion of a holder () under a clip () so as to not hinder writing or portability, and a safety mechanism is constituted so as to be engaged with the clip (). Due to functions of a knock rod cam () of a knock rod () and a knock cam () of a rotor (), further, the rotor () is rotated and moved forward responsive to each knocking operation, a refill () is brought to a writing position and a holding position alternately responsive to each knocking operation due to a cam mechanism provided in the inner wall of an inner cylinder () and a reactive force of a spring (). A slide body cam () provided on the slide body () is incorporated in a portion of the cam mechanism so that the knock type writing instrument thrusts the pen point out, by one knock even after the safety operation.

Upon depressing a knock rod in a state of writing of FIG.A, a cam protuberanceof a rotor turns rightward to assume a position shown in FIG.B. Upon removing a finger, the cam protuberanceturns sliding on a tilted surface, arrives at a position shown in FIG.C through a first vertical motion (distance d) and, further, arrives at a position shown in FIG.D through a second vertical motion (distance e). Here, a tilted surface of cam protuberancecomes in collision with a tilted surface of an inner cylinder camtwice, and shocks are transmitted to a refillBy forming a step between the front half and the rear half of the tilted surface of the inner cylinder camhowever, a distance of vertical motion of the cam protuberanceeach time is shortened to decrease the shock of collision imparted to the refill each time.

Knock-type writing instrument having a shock-relaxing device

Growing community of inventors

Yokohama, Japan

Yoshiharu Namiki