Coating implements with material supply – Material flows through porous tool – Wick feed from within reservoir to tool
Reexamination Certificate
2000-10-31
2002-06-04
Huson, Gregory L. (Department: 3751)
Coating implements with material supply
Material flows through porous tool
Wick feed from within reservoir to tool
C401S223000, C401S225000, C401S227000, C401S229000, C401S230000, C401S241000
Reexamination Certificate
active
06398442
ABSTRACT:
TECHNICAL FIELD
The present invention relates to improvement of a writing implement such as a ball point pen or a felt-tip pen having a pen point serving as a writing point, the improvement being made to a free-ink type collector type writing implement comprising an ink tank for directly storing an ink, a collector which is a vane type regulating member with a plurality of vanes utilizing a capillary phenomenon, for regulating the interior pressure and means for guiding the ink from the ink tank to the pen point.
BACKGROUND ART
In conventionally known oil-based ball point pens, for the purpose of decreasing the incidences of forward leaking which is a leakage of an ink from a pen point and back leaking which would occur in the condition that the ball point pen is turned upside down and cause staining of clothes or disable writing, an ink having a high viscosity ranging from about 3,000 to 10,000 mPa S is generally used and the capillary force is increased by making the ink tank thinner so as to prevent the ink from moving, thereby preventing occurrence of the above-mentioned leakage, however, with these measures, the problems of heavy writing sensation, blobbing, unevenness of drawing lines, light density and the like arise.
Furthermore, a so-called reservoir type pen in which a reservoir of a fiber bunch is immersed with an ink having a low viscosity of several mPa S, thereby allowing the ink to be guided to the pen point via an ink guiding feed, however this type of pen also involves the problems that consumption of the ink cannot be recognized, and that though an intense drawing line is obtained in the initial stage because the flow amount of the ink is large, the intensity of the drawing line gradually decreases because the flow amount of the ink gradually decreases due to repeated writing. Conduction of the ink from the reservoir can be improved by making a setting to weaken the capillary force of the reservoir, however, this measure also involves the problems with regard to blowing out of the ink that the incidence of blowing-out, the situation that the ink leaks from the reservoir in response to a shock of dropping to stain cloths is increased, and on the other hand, when the capillary force of the reservoir is increased, the flow amount of the ink significantly drops as the writing is repeated, so that the intensity of the drawing line becomes significantly low in the latter stage of lifetime even though the ink remains sufficiently.
For the purpose of solving the above-mentioned problems associated with the oil-based ball point pen and the reservoir type writing implement, a so-called collector type ink direct-storage type writing implement (hereinafter, referred to as “collector type writing implement”) is known in which a mechanism used in a fountain pen is applied by disposing an ink tank for directly storing the ink in a rearward position, and regulating the air replacement interior pressure at the time of writing by a collector having a plurality of vane-type grooves. The collector type writing implement has an advantage that the flow amount of the ink is as large as or larger than that in the initial stage of the reservoir type writing implement, making it possible to write with an intense drawing line until the final writing without gradual decrease in the flow amount of the ink even if pen pressure is not applied, however, since it is necessary to make the ink storage amount larger than that of the oil-based ball point pen, the diameter of the ink tank is made large and generally about 1 to 3 cc of ink is stored.
In the conventional collector type writing implement, when the atmospheric pressure of the outside air is changed, the internal pressure is regulated by movement of the ink into the collector, thereby preventing the ink from leaking from the tip of the pen point. In order to prevent volatilization of the ink, it is general to provide a cap which seals the airhole and the pen point concurrently utilizing an undercut, however this measure has a certain problem that as a result of change in the internal pressure of the cap due to attachment/removal of the cap, the ink gradually fills the collector and finally flows out of the collector via the air hole when exceeding a limit of retaining capability, which phenomenon is known as a pumping phenomenon.
In addition, the above mechanism has a problem that as a result of repeated cycles of heating and cooling, or repeated cycles of reduced pressure and high pressure in an airplane, high- or, low-atmospheric pressure, difference in altitude and the like, the blowing out phenomenon occurs similarly. The pumping phenomenon can be dealt by, for instance, adopting a movable inner cylinder into the cap. Meanwhile, in order to solve the problem of blowing out caused by repeated cycles of addition and reduction of the pressure in atmospheric pressure, measures to increase the maximum ink retaining capability of the collector (increase the diameter and length) or to decrease the size of the ink tank have been suggested. However, in the case of currently commercially available products which adapt the above measures, the following problems arise: size of a barrel cylinder is increased to cause a problem regarding appearance; the amount of the ink is decreased to shorten the lifetime, which degrades the cost performance; the collector is made excessively longer and thus the height of the ink head toward the pen point becomes large so that forward leakage is likely to occur; and furthermore, when the above problems are addressed by the ink, it is necessary to use an ink which has extremely low wettability, consequently writing performance must be sacrificed.
Furthermore, in the collector type writing implement, it is possible to keep the intense drawing line until the ink is completely consumed, so that there arises a problem that when the ink runs out during use of the pen, the user meets inconvenience such that writing suddenly becomes no longer possible. Meanwhile, request for improvement of the final writing performance is also proposed as follows: to begin with, the state that ink being almost run out from the tank can be visually recognized from the outside; then, from this point of time, the flow amount of the ink gradually decreases and the writing condition in which the drawing line is visible even if the intensity thereof is weak, that is, during almost all of the lifetime of the pen, a desirable writing performance of free-ink condition is assured; and from the point of the time when the ink within the tank runs out, the performance similar to that of the final writing stage of the reservoir type pen can be assured (that is, normal letter writing can be conducted without any problems, though the drawing line is more or less light and ink starving occurs when a fast writing may be performed).
The main object of the present invention is to improve the widely available collector type writing implement, and to concurrently solve the problem that the significant disadvantage of staining clothes of the consumer due to the repeated up and down cycle of the pressure in the airplane, the problem that there is a request of realizing slim appearance for the collector type writing implement which tends to be thick and the problem of final writing performance which suddenly disables writing when the ink runs out, while satisfying the excellent writing performance possessed by the conventional collector type writing implement, by satisfying the request for reliably improving accident preventing properties of the writing implement, such as preventing property of ink leakage caused by up and down of the atmospheric pressure due to attachment/removal of the cap during use, and blowing-out preventing property during storage of long period in stores.
DISCLOSURE OF INVENTION
The present invention for solving the above-mentioned problems will be summarized as follows.
The first aspect of the present invention is a so-called collector type writing implement comprising: a pen point having a writing point at a tip end thereof; an ink
Darby & Darby
Huson Gregory L.
Mitsubishi Pencil Kabushiki Kaishaki
Prunner Kathleen J.
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