US4522525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Writing instrument having a needle slidably mounted in a tubular tip
Assignee: Pentel Co Ltd
•
Filing: 1983-06-23
•
Granted: 1985-06-11
•
Expires: 2003-06-23
Abstract
Abstract A writing instrument has a tubular tip and a needle longitudinally mounted within the tubular tip for enhancing the flow of ink towards a writing point of the tubular tip. The writing instrument has a mechanism which provides a smooth flow of ink without forming an air ring or bubble in the passage of the ink.
Inventors
- 👤 Sigeru Saito
- 👤 Takahiko Shimizu
- 👤 Takasi Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:33
CPC Classifications
B; B43; B43K; B43K8/00; B43K8/16; B43K8/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
201 words
In a writing instrument comprising a cylindrical casing having therein an ink reservoir, a tubular writing tip, a cylindrical holder for holding said tip, ink feed means disposed between said cylindrical holder and said ink reservoir for feeding ink in said ink reservoir towards said tip, a needle longitudinally slidably positioned within said tip and normally projecting outwardly from one end of said tip and operable to be depressed when writing force is applied to said tip to forcibly retract said needle within said tip, and a weight element connected to said needle for facilitating the longitudinal movement of said needle within said tip, the improvement comprising: projection means for limiting the displacement of the weight element rearwardly towards said ink reservoir, said projection means comprising at least one projection formed on and extending inwardly from an inner surface of said casing at a position to be abutted by said weight element, said projection extending longitudinally axially of said casing; and channel means for feeding ink in said reservoir towards said ink feed means even when said weight element is in abutment with said projection means, said channel means including at least one slit in said casing adjacent said projection means.
Claim 2
Dependent Claim
201 words
In a writing instrument comprising a cylindrical casing having therein an ink reservoir, a tubular writing tip, a cylindrical holder for holding said tip, ink feed means disposed between said cylindrical holder and said ink reservoir for feeding ink in said ink reservoir towards said tip, a needle longitudinally slidably positioned within said tip and normally projecting outwardly from one end of said tip and operable to be depressed when writing force is applied to said tip to forcibly retract said needle within said tip, and a weight element connected to said needle for facilitating the longitudinal movement of said needle within said tip, the improvement comprising: projection means for limiting the displacement of the weight element rearwardly towards said ink reservoir, said projection means comprising at least one projection formed on and extending inwardly from an inner surface of said casing at a position to be abutted by said weight element, said projection extending longitudinally axially of said casing; and channel means for feeding ink in said reservoir towards said ink feed means even when said weight element is in abutment with said projection means, said channel means including at least one slit in said casing adjacent said projection means.
Claim 3
Dependent Claim
24 words
A writing instrument according to claim 1, in which said ink feed means comprises a tubular structure having a plurality annular grooves for ink.
Claim 4
Dependent Claim
35 words
The writing instrument according to claim 1, wherein said ink feed means is press-fitted at a first end thereof to said cylindrical holder and at a second end thereof to a portion of said casing.
Claim 5
Dependent Claim
37 words
The writing instrument according to claim 3, wherein the engagement force between said portion of said casing and said ink feed means is smaller than the engagement force between said cylindrical holder and said ink feed means.
Claim 6
Dependent Claim
157 words
In a writing instrument comprising a cylindrical casing having therein an ink reservoir, a tubular writing tip, a cylindrical holder for holding said tip, ink feed means disposed between said cylindrical holder and said ink reservoir for feeding ink in said ink reservoir towards said tip, a needle longitudinally slidably positioned within said tip and normally projecting outwardly from one end of said tip and operable to be depressed when writing force is applied to said tip, and a weight element connected to said needle for facilitating the longitudinal movement of said needle within said tip, the improvement wherein: said weight element comprises a tubular member extending towards said ink reservoir and having a bore; said needle is inserted into said bore of said tubular member and projects outwardly from a first end thereof; and said needle is connected to a second end of said tubular member directed toward said reservoir and away from said tip holder.
Claim 7
Dependent Claim
157 words
In a writing instrument comprising a cylindrical casing having therein an ink reservoir, a tubular writing tip, a cylindrical holder for holding said tip, ink feed means disposed between said cylindrical holder and said ink reservoir for feeding ink in said ink reservoir towards said tip, a needle longitudinally slidably positioned within said tip and normally projecting outwardly from one end of said tip and operable to be depressed when writing force is applied to said tip, and a weight element connected to said needle for facilitating the longitudinal movement of said needle within said tip, the improvement wherein: said weight element comprises a tubular member extending towards said ink reservoir and having a bore; said needle is inserted into said bore of said tubular member and projects outwardly from a first end thereof; and said needle is connected to a second end of said tubular member directed toward said reservoir and away from said tip holder.
Claim 8
Dependent Claim
19 words
A writing instrument according to claim 5, wherein said second end of said tubular member has a reduced diameter.
Claim 9
Dependent Claim
35 words
The writing instrument according to claim 5, wherein said ink feed means is press-fitted at a first end thereof to said cylindrical holder and at a second end thereof to a portion of said casing.
Claim 10
Dependent Claim
168 words
In a writing instrument comprising a cylindrical casing having therein an ink reservoir, a tubular writing tip, a cylindrical holder for holding said tip, ink feed means disposed between said cylindrical holder and said ink reservoir for feeding ink in said ink reservoir towards said tip, a needle longitudinally slidably positioned within said tip and normally projecting outwardly from one end of said tip and operable to be depressed when writing force is applied to said tip, and a weight element connected to said needle for facilitating the longitudinal movement of said needle within said tip, the improvement wherein: said weight element comprises an elongated member having at a first end thereof adjacent said tip and spaced from said ink reservoir, a first tapered portion defining a relatively small space with an inner surface of said cylindrical holder, and a second tapered portion extending generally at right angles relative to said first tapered portion and defining a relatively large space with the inner surface of said cylindrical holder.
Claim 11
Dependent Claim
168 words
In a writing instrument comprising a cylindrical casing having therein an ink reservoir, a tubular writing tip, a cylindrical holder for holding said tip, ink feed means disposed between said cylindrical holder and said ink reservoir for feeding ink in said ink reservoir towards said tip, a needle longitudinally slidably positioned within said tip and normally projecting outwardly from one end of said tip and operable to be depressed when writing force is applied to said tip, and a weight element connected to said needle for facilitating the longitudinal movement of said needle within said tip, the improvement wherein: said weight element comprises an elongated member having at a first end thereof adjacent said tip and spaced from said ink reservoir, a first tapered portion defining a relatively small space with an inner surface of said cylindrical holder, and a second tapered portion extending generally at right angles relative to said first tapered portion and defining a relatively large space with the inner surface of said cylindrical holder.
Claim 12
Dependent Claim
16 words
The writing instrument according to claim 8, wherein said second tapered portion comprises a planar surface.
Claim 13
Dependent Claim
14 words
The writing instrument according to claim 8, wherein said second tapered portion is curved.
Claim 14
Dependent Claim
35 words
The writing instrument according to claim 8, wherein said ink feed means is press-fitted at a first end thereof to said cylindrical holder and at a second end thereof to a portion of said casing.
References Cited (Backward Citations)
US243364A
Cited
US2029152A
Cited
US3459486A
Cited
DE1561871A1
Cited
US3580689A
Cited
US3561881A
Cited
US3938899A
Cited
US4364684A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |