US 5,899,618 AGranted

Multiplex writing implement

AssigneeMitsubishi Pencil Company, Limited

InventorsSeiichi Kobayashi, Hiroyuki Mutou

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Abstract

A multiplex writing implement of the invention has a multiple number of writing elements, including at least one ball-point pen element which is filled up with a thixotropic water-soluble or low-viscosity oil-based ball-point ink. The ink reserving portion of the ink reservoir of the ball-point pen element is non-flexible and has a relatively large cross-section. A portion for jointing the point assembly with the ink reserving portion is formed so that the element can readily be deflected transversely with respect to the axial direction. The writing tip portions of these writing elements can selectively be projected from and retracted into the barrel front. This multiplex writing implement is able to create line traces with thick line density without causing any blobbing of ink or ink starving. It is also possible to prevent accidental ink leakage. That is, ink can be prevented from staining the barrel cylinder, user's hands, clothes etc., which would be caused by forward leakage of ink or back leakage of ink due to upward writing as well as due to impacts from being dropped or clicked. Still, the multiplex writing implement has a suitable barrel size which meets the demands for portability and high performances of handling.

Claims15

Dependent claims

A multiplex writing implement comprising:

a barrel cylinder;
and a plurality of writing elements incorporated in said barrel cylinder, said multiplex writing implement being characterized in that,
the writing tip portions of said writing elements can selectively be projected from or retracted into the barrel front,
at least one of said plurality of writing elements is a ball-point pen element which comprises:
a point assembly which is composed of a tip ball held in a tip holding portion at the tip end thereof and a spring which is arranged so as to constantly bring said tip ball into sealing contact with the inner brim of said tip holding portion and release the sealed state during writing;
an ink reservoir which is disposed behind said point assembly and is filled up with a thixotropinc water-soluble or low-viscosity oil-based ball-point ink whose viscosity decreases as the tip ball rolls during writing so as to allow smooth distribution of ink;
and an ink follower which consists of a translucent, nondrying greasy material and is disposed at the rear end of the ink so as to move in contact with the ink surface following the consumption of the ink,
the ink reserving portion of said ink reservoir is non-flexible and has a relatively large cross-section, and
a portion for jointing said point assembly with said ink reserving portion is formed so that the point assembly of the writing element can readily be deflected transversely with respect to the ink reserving portion of the writing element.

6 more elements

Dependencies are inferred from the claim text.