Mitsubishi Pencil Company, Limited

Mitsubishi Pencil Kabushiki Kaisha

Yukinori Sawa

Takahiro Osada

Kazuhiro Ami

Masahiro Suzuki

Toshimi Kamitani

Tooru Nakajima

Akira Fukai

Kouichi Hirano

Atsushi Iwasa

To provide a writing instrument capable of further improving durability of a writing nib without impairing writing performance even when writing is performed with a heavy writing load. A writing instrument A having a writing part formed of at least a writing nibmade of a porous body and a retainermade of a hard material, in which the protrusion amount of the distal end of the writing nibfrom the retaineris 0.65 mm or more and 1.05 mm or less and/or 40% or more and 65% or less of the thickness of the writing nib

Writing instrument

An applicator cap is closed on the front side and opening on the rear side, covering an applying part provided in the front end of a barrel cylinder of an applicator, from the rear-side opening, and detachably fitted on the barrel cylinder so as to be able to seal and keep the surrounding space of the applying part airtight, and includes a holding portion formed such that the middle part of the cap with respect to the axial direction is smaller in outside diameter than the front end with respect to the axial direction.

Valved applicator

An applicator which includes a rear barrel; an ink occlusion elementaccommodated in rear barrel; an ink occlusion element receiveropposing the front end part of ink occlusion element; a see-through front barrelfitted to the opening of rear barrel, a detection tubeinserted in front barrelfor flowing ink from ink occlusion element; a joint coresupported by detection tubeand flowing out ink from ink occlusion element; and a pen coresupported by detection tubeand disposed on the opposite side of joint corewith a detection spacefrom joint core. Detection tube, joint coreand pen coreare formed into an integral structure. It is possible to exactly grasp the ink end state in a visual manner, based on the presence/absence of ink in detection spaceof detection tube

Applicator

A capless writing instrument (), wherein a writing element () is arranged inside a barrel cylinder () so that a pen point () of the writing element () can come out and retract through a front end opening of the barrel cylinder (), is characterized in that an inner cap () formed of rubber or elastic resin is provided at the front end opening of the barrel cylinder (), and the inner cap () is composed of: a closing portion () disposed on the pen point projecting side with respect to the axial direction of the barrel cylinder for closing the front end opening and having a slit () for allowing the pen point () to project and retract; and forward projected portions () that are projected from the outer periphery of the closing portion () toward the front end opening, and the inner cap is fitted inside the barrel cylinder so that, in the slit () closed state, force which is directed approximately perpendicular to the slit surfaces will act inward from the outer periphery of the forward projected portions ().

Capless writing instrument

A writing instrument equipped with an exchangeable inner pen filled with an ink containing a solvent having a vapor pressure of 1 to 50 mm Hg (20&deg; C.) in a writing instrument main body which is a barrel part, wherein the inner pen described above has a pen tip comprising a fiber feeder or a plastic feeder, and the above pen tip is coated with a substance having a vaporization-inhibiting action in an amount of 0.01 to 20% by weight in terms of a weight ratio based on the pen tip. It is more effective to further add a substance having a vaporization-inhibiting action to the ink. The substance having a vaporization-inhibiting action includes glycerin derivatives, polyoxyethylenesorbit fatty acid esters, alkyl phosphates, waxes and lecithin.

Writing utensil

In a capless writing instrument with its writing element arranged in the barrel cylinder so that a writing point of the writing element can come out and retract through a front-end opening of the barrel cylinder, an inner cap having a dome-like convex portion projected frontwards is arranged at the front-end part of the barrel cylinder, and the inner cap is formed of rubber or elastic resin, a slit-forming groove having a thin-film portion at the depressed bottom of the slit is formed from a position at the root of the dome-like inner cap to the opposite position at the root intersecting the substantially center of the convex portion.

Growing community of inventors

Gunma, Japan

Yukinori Sawa