Coating implements with material supply – Bifurcate pointed nib tool – Including reservoir and feeder
Reexamination Certificate
1999-12-29
2001-08-21
Walczak, David J. (Department: 3751)
Coating implements with material supply
Bifurcate pointed nib tool
Including reservoir and feeder
C401S231000, C401S224000
Reexamination Certificate
active
06276861
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a writing instrument which can draw fine lines without causing a blur.
2. Prior Art
Writing instruments such as fountain pens make it possible to write with a writing portion by having a structure in which ink in an ink container installed in a penholder is percolated through a bunch of fibers in a pen point receiver which is inserted into a tip end opening portion of the penholder. The ink is supplied from a tip end of the bunch of fibers to the inner surface of the tip end portion of the pen point supported by the pen point receiver. The ink is then introduced to a writing end portion of the pen point through a split formed in the middle of the tip end portion of the pen point.
In such writing instruments structured as mentioned above, the pen point is conventionally formed to curve downwardly from a center of the pen point in its width directions to both edges thereof to make an arc. The pen point is formed to have a venthole at a predetermined length of interval from the writing end portion towards a base end portion of the pen point, and to have a straight split penetrating from the venthole to the center of the writing end portion.
However, according to the above-mentioned pen point, the side fragments of the end portion divided by the split curve with respect to the width directions but they are straight in its longitudinal directions to have a two-dimensional structure. A bend-resistance of the writing end portion against a strength of the pen stroke at the time of writing is inferior. When pressure is exerted on the pen point, both of the side fragments easily warp upwards with the venthole side as a fulcrum; therefore, the split is widened and there arises a problem that the letters and lines become thicker. Therefore, although the conventional pen point may be suitable to write sentences and the like subtly adjusting thickness of letters by changing the strength of the pen stroke, it is difficult to draw an illustration with innumerable fine pieces of hair, for example.
Further, since the writing end portion is easily warped upwards by a strong pen stroke, a gap is made between the writing end portion and the pen point receiver, and letters may blur because a supply of ink from the tip end portion of a bunch of fibers for supplying ink to the pen point becomes insufficient. Furthermore, as the elastic restoration force of the writing end portion is impeded by repeatedly working bend forces at the time of writing, there is a fear that the pen point cannot be used due to a distorted state of the tip end portion of the pen point and the pen point receiver having a gap between them.
Therefore, in order to maintain the elastic restoration force for a long period of time and to resist against such repeated load as a bend force acting on the pen point at a time of writing, it is required to make a thickness of the pen point bigger, in which case it becomes impossible to draw extra fine lines.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a writing instrument having a pen point structure by which a lot of fine lines can be smoothly drawn without causing a blur, and by which distortion and deformation of the pen point are rarely caused due to a strong elastic restoration force.
To achieve the above object, the writing instrument according to this invention comprises a pen point receiver inserted into a tip end opening of a penholder in which an ink container is received. The writing instrument has a pen point having a split of a predetermined length from a writing end portion of the pen point. A base end portion of the pen point is inserted into the tip end opening of the penholder in a state that the pen point is overlapped on the upper surface of the pen point receiver. Then an ink introducing core member is provided in a center of the pen point receiver so that ink may percolate through a base end portion of the ink introducing core member. A tip end portion of the ink introducing core member is tightly contacted with the undersurface of a pen point tip end portion of the pen point. The writing device is characterized in that the tip end portion of the pen point is formed to curve downwardly towards the tip end writing portion with respect to the base end portion of the pen point.
In the above-mentioned writing instrument, it is preferable that the ink introducing core member comprises a bunch of fibers or an elastic porous material and the tip end portion of the core member is compressed elastically with a squeezing pressure between the undersurface of the pen point tip end portion and the upper surface of the tip end portion of the pen point receiver.
Further, it is also preferable that the pen point is made of a thin steel plate having wear resistance and elasticity.
According to the present invention, since the tip end portion of the pen point is formed to curve downwardly to have a three-dimension structure, it may obtain a great bending strength against a bending load loaded at the time of writing. Therefore, even if a writing load is great, the pen point maintains a strong elastic force within a range of an elastic limit. Therefore, it becomes possible to surely carry out a supply of ink by eliminating a blur of the letters or the like without interrupting the supply of ink to the pen point in a state that the undersurface of the tip end portion of the pen point is always in contact with the tip end portion of the ink introducing core member under pressure.
Further, it becomes possible to obtain a great elastic restoration force with respect to a writing load when the pen point is made thin, so that it may provide a pen point structure to draw extra fine lines continuously without causing a blur.
Furthermore, the tip end portion of the pen point is formed to curve downwardly, and a bunch of the fibers or the elastic porous material and tip end portion of the core member are compressed elastically with a squeezing pressure between the undersurface of the pen point tip end portion and the upper surface of the tip end portion of the pen point receiver. Even if the pen point is warped upwards and displaced due to a great writing pressure, the ink introducing core member is restored elastically according to its amount of displacement so as to maintain a state that the core member may always be in contact with the undersurface of the pen point under pressure. As a result, the ink, which is percolated through the ink introducing core member with capillarity, can always be introduced from the tip end portion of the core member to the tip end writing portion through the split of the pen point.
Advantages of this invention are as follows.
A writing instrument of this invention comprises a pen point receiver inserted into a tip end opening of a penholder in which an ink container is received. The pen point has a split of a predetermined length from a writing end portion of the pen point, and a base end portion of the pen is inserted into the tip end opening of the penholder in a state that the pen point is overlapped on the upper surface of the pen point receiver. An ink introducing core member is provided in a center of the pen point receiver so that an ink may percolate through a base end portion of the ink introducing core member. A tip end portion of the ink introducing core member is tightly in contact with the undersurface of a pen point tip end portion of the pen point. The writing device is characterized in that the tip end portion of the pen point is formed to curve downwardly towards the tip end writing portion with respect to the base end portion of the pen point. The tip end portion of the pen point may display a great bending strength against a bending load due to a writing pressure which is caused at the time of writing, and it becomes possible to disperse bending stress to the entire pen point which is curved downwardly without focusing bending stress on a portion of the pen point. The pen point may always repeatedly maintain a restoration force of elast
Greigg Edwin E.
Greigg Ronald E.
Tachikawa Kabushiki Kaisha
Walczak David J.
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