Coating implements with material supply – Plural tools including projectable and retractable tool – Selective individual projection by single actuator
Reexamination Certificate
1999-04-30
2001-04-17
Eloshway, Charles R. (Department: 3751)
Coating implements with material supply
Plural tools including projectable and retractable tool
Selective individual projection by single actuator
C401S029000, C401S195000, C401S209000
Reexamination Certificate
active
06217241
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improvement of a multiplex writing implement having a plurality of ball-point pen elements.
2. Description of the Prior Art
In general, there are known multiplex writing implements of rotary, clicking and slider types and the like, which have a plurality of writing elements such as a mechanical pencil, ball-point pen and the like, and selectively allow one of the writing tips to move in and out through the front end thereof.
Meanwhile, conventionally known oil based ball-point pens use an ink having a high viscosity of some thousands of mPa·S or more, hence a considerably large resistance arises when the ball rolls and the ink flows out from the writing point, producing an uncomfortable writing sensation. Further, the pen of this type suffers from problems in that a lesser amount of ink can flow from the writing point during writing and in that blobbing, hence lines drawn can be irregular in parts, the density of the written trace is light and a strong pressure for writing is needed.
As an improvement of the oil based ball-point pen, there has been recently developed a ball-point pen for water based ink which uses an ink having an intermediate viscosity between viscosity of the above water based type and that of the oil based type (ranging from a few mPa·S to some thousands of mPa·S) and hence is called a medium viscosity ink. This ball-point pen uses water based ink having a relatively low viscosity which has so-called thixotropy, that is, a characteristic which lowers the viscosity of ink as the tip ball rolls, so that the ink can smoothly flow out.
As an improvement of oil based ball-point pens, it is possible to consider a ball-point pen which uses an oil based ink having both a low viscosity and an excellent drought resistance.
Because of the less viscosity of ink, any of the above ball-point pens using medium viscosity water based ink or low viscosity oil based ink markedly suffers from the forward leakage problem of ink oozing out from a gap, if any, between the ball point and the tip holder when it is held with its pen tip down, and also suffers from the problem of ink leaking backward when the pen is used with its tip upward or when it receives impacts and the like. When backward or forward leakage of ink occurs, there is a risk of the ink staining clothes and the like. Further, if, while the tip ball and the ball-holder in the point assembly remain in contact with the tapering inner surface of the mouthpiece, the writing tips are made to move in and out repeatedly through the front end opening of the mouthpiece, the inner surface of the mouthpiece is stained with ink, degrading its appearance.
Liquid applicators using a white pigment for correcting character errors etc., are known.
Because the white pigment readily separates from its solvent, applicators of this kind are formed of a flexible container with the ink, a ball, etc. confined therein and the ink and solvent need to be mixed by shaking when it is used. Also the container needs to be pressed on its side part to eject the ink. However, when a reduced amount of ink remains, ink will not be ejected even with strong pressure acting on the side wall of the container, causing user irritation. Further, in order to avoid the applicator's tip drying, the tip is adapted to be sealed with a cap.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to configure a medium viscous, water based or low viscous, oil based ball-point pen element which can maintain its drought resistance of the writing tip and can be left with its sealing cap off, and provide a mechanism for preventing forward and backward ink leakage, in which a plurality of such ball-point pen elements are accommodated in the barrel cylinder so that the writing tips can move in and out smoothly through the front end opening of the mouthpiece. Further, the invention enables the types of the ball-point pen elements to be viewed from outside of the barrel cylinder, and makes it possible to solve the problem of bad appearance, i.e., the problem of the tip ball and tip-ball holder touching the tapering inner surface of the mouthpiece and hence staining the inner surface with ink when the writing tips move in and out through the front end opening of the mouthpiece. Also, the invention makes it further possible to avoid the problem, that is, inducement of ink forward leakage and stain of the inner surface and damage of the ball holder causing degradation of writing performance, all attributed to contact of the tip ball and the ball holder of the point assembly with the inner surface.
Further, the invention makes it possible to provide a convenient multiplex writing implement of which at least one of the ball-point pen elements is an ball-point pen for mistake correction which needs no agitation and is free from the botheration of pressing the container side part.
In order to attain the above objects, the present invention is configured as follows:
The first aspect of the invention resides in a multiplex writing implement having a plurality of ball-point pen elements in the barrel cylinder thereof, in which an ink reservoir thereof is filled with a water based ink having so-called thixotropy, which is a characteristic which lowers the viscosity of ink as the tip ball rolls, allowing outflow of ink, or a low-viscosity oil based ink and which are configured so that the writing tips thereof can selectively move in and out through the front end opening of a mouthpiece of the barrel cylinder, characterized in that at least the front part of the barrel cylinder is formed of a transparent resin molding and the mouthpiece which is opaque and tapered toward the front end is attached to the front of the barrel cylinder.
The second aspect of the invention resides in the multiplex writing implement according to the first feature, wherein longitudinal grooves are formed at required positions on the tapering inner surface of the mouthpiece and the ball holder of the point assembly is loosely inserted in the longitudinal groove when the writing tip moves in and out through the front end opening so that at least the ball holder is kept out of contact with the tapering inner surface.
The third aspect of the invention resides in the multiplex writing implement according to the first feature, wherein a joint for joining the ink reservoir and the point assembly has a projection on the peripheral surface thereof which comes in contact with the tapering inner surface in such a manner that the ball holder is kept out of contact with the tapering inner surface of the mouthpiece when the writing tip moves in and out through the front end opening of the mouthpiece.
The fourth aspect of the invention resides in the multiplex writing implement according to the first feature, wherein the ball-point pen element is configured so that the tip ball is continuously pressed into sealing contact with the inner brim of the ball holder at tip of the point assembly and a follower which is made of a nondrying greasy material and moves following the consumption of the ink as writing proceeds is added at the rear end of the ink.
The fifth aspect of the invention resides in the multiplex writing implement according to the first feature, wherein at least one of the ball-point pen elements is a ball-point pen for mistake correction and the ink is a white pigment ink which includes a white pigment such as titanium oxide, hollow high polymer micro-particles and the like and is compounded so that the pigment is prevented from settling and losing its fluidity.
The sixth aspect of the invention resides in the multiplex writing implement according to the first feature, wherein the ball-point pen element has a valve chamber in which a ball valve is loosely held therein facing the rear end of the point assembly and the rear part of the valve chamber comprises a ball seat with which the ball valve comes into sealing contact to prevent ink from flowing backward and a conduit communicating between the bal
Darby & Darby
Eloshway Charles R.
Mitsubishi Pencil Kabushiki Kaisha
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