Coating implements with material supply – Material flows through porous tool – Wick feed from within reservoir to tool
Reexamination Certificate
2001-11-15
2003-03-25
Huson, Gregory (Department: 3751)
Coating implements with material supply
Material flows through porous tool
Wick feed from within reservoir to tool
C401S223000, C401S224000, C401S227000, C401S228000, C401S237000, C401S242000
Reexamination Certificate
active
06536976
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a writing instrument with an ink reservoir having an ink retaining portion for temporarily storing ink in accordance with change in the pressure inside the ink tank.
BACKGROUND ART
There are writing instruments having an ink retaining portion in its ink reservoir for temporarily storing ink in accordance with change in the pressure inside the ink tank.
A typical writing instrument, as disclosed in Japanese Utility Model Application Laid-Open Sho No.58-21474 and others, has a temporary ink retaining portion in front of an ink tank. This ink retaining portion is called ‘Jabara (bellows)’ and is formed of a multiple number of disk-like sheet elements arranged at intervals inside the barrel like a comb when sectionally viewed so that ink can be temporarily stored in the gaps between these sheet elements.
In the temporary ink retaining portion used in such a writing instrument, as sectionally shown in
FIG. 1
, the ink retaining portion is comprised of a multiple number of disk-like sheet elements ‘a’ arranged in layers so that the spacing between layered sheet elements ‘a’ will serve as ink retaining grooves. This ink retaining portion is fitted into a barrel cylinder ‘b’ and has a cutout portion ‘d’ formed in the rectangle direction with respect to the center line ‘c’ so as to create an air channel for establishing communication between the ink retaining portion and the outside air. In
FIG. 1
, a reference code ‘e’ designates a common base of multiple sheet elements ‘a’ as sectionally viewed and having a bore allowing an intermediary ink core ‘f’ to fit therein. Designated at ‘g’ is an ink conduit groove (slit) which establishes communication from an unillustrated tank to the ink retaining grooves so as to lead ink.
However, with the above-described conventional ink retaining portion, there have been cases where air replacement might be poor because the size of the cutout (air channel) is not large enough.
Further, when this ink retaining portion is formed by injection molding, the metal die element for molding is thin and sheet-like. Therefore, there has been a fear that the sheet-like metal die elements may give way or break as a result of the pressure arising when the resin is injected and it has been also difficult to produce an ink retaining portion having a large diameter.
The present invention has been devised in view of the above conventional problems and it is therefore an object of the present invention to provide a writing instrument in which a large-diametric ink retaining portion with air grooves small in width and still capable of securing a large enough air channel can be formed so that a sufficient amount of air will be able to be displaced between the ink retaining portion and the outside air.
DISCLOSURE OF THE INVENTION
The present invention has the following configuration in order to solve the above-mentioned problem.
The first aspect of the present invention resides in a writing instrument with an ink retaining portion for temporarily holding ink in accordance with change in the pressure inside the ink tank, comprising: a reservoir formed of sheet elements arranged at intervals in layers, wherein each sheet element is formed with a cutout which is formed to a right angle direction with respect to the center line of the sheet element and has a length equal to or greater than half the radius with one end extended to the periphery.
According to the configuration of the present invention, the following effect can be obtained.
According to the first configuration of the present invention, each sheet element is formed with the cutout which is formed to the right angle direction with respect to the center line of the sheet element and has a length equal to or greater than half the radius with one end extended to the periphery. Therefore, the forming die element of the cutout functions as the supporting bridge across the forming die elements for the grooves between sheet elements of the ink retaining portion, hence even if the cutout die element is large, no deficiency such as the mold yielding will occur when injection molding is performed.
REFERENCES:
patent: 5372445 (1994-12-01), Mutschler
patent: 59-153178 (1984-10-01), None
patent: 1-10236 (1989-03-01), None
patent: 3-31580 (1991-07-01), None
Translated International Preliminary Examination Report dated Feb. 21, 2002.
Burns Doane , Swecker, Mathis LLP
Huson Gregory
Mitsubishi Pencil Kabushiki Kaisha
Prunner Kathleen J.
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