US4468947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Die
Assignee: Niterra Co Ltd
•
Filing: 1981-12-28
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Granted: 1984-09-04
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Expires: 2001-12-28
Abstract
Abstract A die is described, comprising a die body and a steel case, characterized in that: a die body made of a silicon nitride ceramic or a silicon carbide ceramic is shrink fitted or force fitted into a steel case wherein an optional wide recess may be cut in the inner surface of the bottom of said steel case along a corner where the bottom and the inner wall of said steel case meet.
Inventors
- 👤 Tooru Takeda
- 👤 Masakatsu Hayakawa
- 👤 Yasuo Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:43
CPC Classifications
B; B21; B21C; B21C3/00; B21C3/02; B21C25/00; B21C25/02; B21C25/025; B21C3/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
141 words
A die comprising a die body and a steel case, comprising: a steel case comprising a cavity defined by an inner wall and a bottom wall converging at a corner, a die body made of silicon nitride ceramic or a silicon carbide ceramic shrink fitted or force fitted into the cavity of said steel case, said die body having a side surface and a bottom surface engaging the inner wall and the bottom wall of said steel case, respectively, and a wide recess having a width/depth ratio of from 7.14/1 to 23.33/1 cut in the inner surface of the bottom wall of said steel case along said corner where the bottom and the inner wall of said steel case meet so that a portion of the die body bottom surface is equal to said width of said recess and is unsupported.
Claim 2
Dependent Claim
141 words
A die comprising a die body and a steel case, comprising: a steel case comprising a cavity defined by an inner wall and a bottom wall converging at a corner, a die body made of silicon nitride ceramic or a silicon carbide ceramic shrink fitted or force fitted into the cavity of said steel case, said die body having a side surface and a bottom surface engaging the inner wall and the bottom wall of said steel case, respectively, and a wide recess having a width/depth ratio of from 7.14/1 to 23.33/1 cut in the inner surface of the bottom wall of said steel case along said corner where the bottom and the inner wall of said steel case meet so that a portion of the die body bottom surface is equal to said width of said recess and is unsupported.
Claim 3
Dependent Claim
17 words
A die as in claim 1, wherein the die body is made of a silicon nitride ceramic.
Claim 4
Dependent Claim
17 words
A die as in claim 1, wherein the die body is made of a silicon carbide ceramic.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-04 | 1988-03-05 | 1988-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-04 | 1992-03-05 | 1992-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-04 | 1996-03-05 | 1996-09-04 | $7700.00 | Window Closed / Lapsed |