Claims
- 1. A writing instrument comprising:
- a pen point;
- a tubular holder having peripheral walls;
- an ink-cartridge containing ink having a first liquid therein, in fluid communication at one end thereof with said pen point disposed within said holder and spaced from said walls so as to define a closed space between said walls and said cartridge surrounding said ink-cartridge;
- a backflow preventing substance filling another end of said ink-cartridge opposite said one end so as to block fluid communication between said space and said ink in said ink-cartridge through said another end;
- a liquid retainer, said retainer being impregnated with a second liquid whose vapor pressure is higher than that of said first liquid in said ink-cartridge and being disposed in, and occupying a portion less than all of, said space, whereby vapor of said second liquid evaporated from said retainer fills said closed space so as to prevent evaporation of said first liquid from said ink;
- a cap removably covering said pen point; and
- an elastic sealing member in said cap removably covering said pen point so as to prevent said first liquid from evaporating from said pen point.
- 2. A writing instrument comprising: a pen point; a tubular holder having peripheral walls; an ink-cartridge containing ink having a first liquid therein, in fluid communication with said pen point disposed within said holder and spaced from said walls so as to define a closed space between said walls and said cartridge surrounding said cartridge; a liquid retainer, said retainer being impregnated with a second liquid whose vapor pressure is higher than that of said first liquid in said ink-cartridge and being disposed in, and occupying a portion less than all of, said space, whereby vapor of said second liquid evaporated from said retainer fills said closed space so as to prevent evaporation of said first liquid from said ink, and a cap removably covering said pen point, said space communicating with the interior of said cap through an opening in said holder adjacent to said pen point that said vapor fills said interior of said cap.
- 3. A writing instrument as in claim 2, wherein said ink-cartridge is air-tightly closed.
- 4. A writing instrument as in claim 2, wherein said liquid retainer is disposed so as to cylindrically enclose the outer periphery of said ink-cartridge.
- 5. A writing instrument as in claim 2, wherein aid holder is transparent and said second liquid impregnating said liquid retainer has a surface tension which is less than 40 dyne/cm at 20.degree. C.
- 6. A writing instrument as in claim 2, wherein said first liquid comprises a first quantity of a solvent and means including a first quantity of vapor pressure reducing substance, for reducing the vapor pressure of said first quantity of solvent, and said second liquid comprises a second quantity of said solvent and means, including a second quantity of said vapor pressure reducing substance, for reducing the vapor pressure of said second quantity of said solvent, the proportion of said second quantity of said vapor pressure reducing substance to said second quantity of said solvent being less than the proportion of said first quantity of said vapor pressure reducing substance to said first quantity of said solvent, whereby the vapor pressure of said second quantity of solvent is greater than that of said first quantity of said solvent.
- 7. A writing instrument as in claim 6, wherein said ink is water based ink, said solvent being water, said vapor pressure reducing substance being a hygroscopic agent.
Priority Claims (2)
Number |
Date |
Country |
Kind |
57-201512[U] |
Dec 1982 |
JPX |
|
58-58306 |
Apr 1983 |
JPX |
|
Parent Case Info
This is a continuation, of now abandoned application Ser. No. 555,001, filed Nov. 21, 1983.
US Referenced Citations (4)
Foreign Referenced Citations (6)
Number |
Date |
Country |
2509978 |
Sep 1976 |
DEX |
887689 |
Aug 1943 |
FRX |
48-26590 |
Aug 1973 |
JPX |
6613097 |
Mar 1967 |
NLX |
16275 |
Jan 1915 |
GBX |
746188 |
Mar 1956 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
555001 |
Nov 1983 |
|