US4653950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nonoxide ceramic ball-point pen ball
Assignee: Kyocera Corp
•
Filing: 1985-09-06
•
Granted: 1987-03-31
•
Expires: 2005-09-06
Abstract
Abstract This invention relates to a ball-point pen ball made of nonoxide ceramic and formed into a spherical body whose surface contains voids each having an average pore diameter of less than 75 mu m and more than 0.1 mu m. The ball thus made is not only almost free from "ball sunk", "nonuniformity in writing line thickness", "ball break", etc. but also excellent in affinity with ink and assures steady writing characteristic over a long period of time.
Inventors
- 👤 Haruo Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:42
CPC Classifications
B; B43; B43K; B43K1/00; B43K1/08; B43K1/082
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
45 words
A ball-point pen ball consisting essentially of sintered silicon carbide, the ball having a plurality of surface voids, said voids having an average diameter in the range of 0.1 μm to 75 microns inclusive so as to produce a uniform written line while in use.
Claim 2
Dependent Claim
45 words
A ball-point pen ball consisting essentially of sintered silicon carbide, the ball having a plurality of surface voids, said voids having an average diameter in the range of 0.1 μm to 75 microns inclusive so as to produce a uniform written line while in use.
Claim 3
Dependent Claim
45 words
A ball-point pen ball consisting essentially of sintered silicon carbide, the ball having a plurality of surface voids, said voids having an average diameter in the range of 0.1 μm to 50 μm inclusive, so as to produce a uniform written line while in use.
Claim 4
Dependent Claim
45 words
A ball-point pen ball consisting essentially of sintered silicon carbide, the ball having a plurality of surface voids, said voids having an average diameter in the range of 0.1 μm to 50 μm inclusive, so as to produce a uniform written line while in use.
Claim 5
Dependent Claim
17 words
A ball-point pen ball according to claim 1, wherein the voids are formed by a sintering process.
Claim 6
Dependent Claim
17 words
A ball-point pen ball according to claim 2, wherein the voids are formed by a sintering process.
References Cited (Backward Citations)
CA739725A
Cited
US2847751A
Cited
US3303825A
Cited
US3520630A
Cited
US3746456A
Cited
US3666411A
Cited
US3960581A
Cited
DE3131538A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-30 | 1990-09-29 | 1991-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-30 | 1994-09-29 | 1995-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-30 | 1998-09-29 | 1999-03-31 | $7700.00 | Window Closed / Lapsed |