Patent US4606887A successfully refreshed from Google Patents.
US4606887A
Expired / Lapsed
US
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Cobalt alloys for the production of dental prothesis
Assignee: Evonik Operations GmbH
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Filing: 1984-05-25
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Granted: 1986-08-19
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Expires: 2004-05-25
Abstract
Abstract As replacements for noble metal containing alloys fused to porcelain in dental prosthetics there are needed alloys based on cobalt-chromium-tungsten which have a hardness of less than 300 (HV 5), can be veneered faced with known dental ceramics without problems and can be worked without problem with the customary working techniques. Such alloys contain in addition to 42-69.5 weight % cobalt, 10-35 weight % chromium, and 5-25 weight % tungsten, 2-10 weight % iron, 1-4 weight % aluminum, 0-5 weight % rhenium, and 0-2 weight % titanium, whereby the sum of the content oc chromium, tungsten, and rhenium is between 27.5 and 45 weight % and the sum of aluminum and titanium is below 5 weight %.
Inventors
- 👤 Jurgen Hausselt
- 👤 Dieter Kaufmann
- 👤 Udo Englisch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:00
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/07; A; A61; A61K; A61K6/00; A61K6/80; A61K6/84; A61K6/842
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
84 words
A cobalt alloy suitable for the production of fixed and removable dental constructions consisting essentially of 50 to 65 weight % cobalt, 15-22 weight % chromium, and 5-15 weight % tungsten, 3-7 weight % iron, 1-3 weight % aluminum, 0-5 weight % rhenium, and 0-2 weight % titanium, whereby the sum of the contents of chromium, tungsten, and rhenium is at least 27.5 weight % and at most 45 weight % and the sum of titanium and aluminum is at most 5 weight %.
Claim 2
Dependent Claim
84 words
A cobalt alloy suitable for the production of fixed and removable dental constructions consisting essentially of 50 to 65 weight % cobalt, 15-22 weight % chromium, and 5-15 weight % tungsten, 3-7 weight % iron, 1-3 weight % aluminum, 0-5 weight % rhenium, and 0-2 weight % titanium, whereby the sum of the contents of chromium, tungsten, and rhenium is at least 27.5 weight % and at most 45 weight % and the sum of titanium and aluminum is at most 5 weight %.
Claim 3
Dependent Claim
12 words
A cobalt alloy according to claim 1 consisting of the stated materials.
Claim 4
Dependent Claim
12 words
A cobalt alloy according to claim 1 containing 0.2-5 weight % rhenium.
Claim 5
Dependent Claim
12 words
A cobalt alloy according to claim 1 containing 0.2-2 weight % titanium.
Claim 6
Dependent Claim
36 words
A cobalt alloy according to claim 1 also including at least one of the elements 0.01-0.2 weight % boron, 0.01-0.2 weight % yttrium, 0.1-2 weight % silicon, 0.1-4 weight % copper, and 0.1-1.5 weight % tin.
Claim 7
Dependent Claim
18 words
A cobalt alloy according to claim 5 which contains not over 40 weight % chromium, tungsten, and rhenium.
Claim 8
Dependent Claim
18 words
A cobalt alloy according to claim 1 which contains not over 40 weight % chromium, tungsten, and rhenium.
Claim 9
Dependent Claim
23 words
A cobalt alloy according to claim 7 wherein the ratio of chromium to tungsten plus rhenium is between about 2:3 and about 2:1.
Claim 10
Dependent Claim
23 words
A cobalt alloy according to claim 6 wherein the ratio of chromium to tungsten plus rhenium is between about 2:3 and about 2:1.
Claim 11
Dependent Claim
23 words
A cobalt alloy according to claim 5 wherein the ratio of chromium to tungsten plus rhenium is between about 2:3 and about 2:1.
Claim 12
Dependent Claim
23 words
A cobalt alloy according to claim 1 wherein the ratio of chromium to tungsten plus rhenium is between about 2:3 and about 2:1.
Claim 13
Dependent Claim
23 words
A cobalt alloy according to claim 9 wherein the ratio of chromium to tungsten plus rhenium is between about 2:3 and about 3:2.
Claim 14
Dependent Claim
22 words
A cobalt alloy according to claim 8 wherein the ratio of chromium to tungsten plus rhenium is between about 2:3 and 3:2.
Claim 15
Dependent Claim
39 words
A cobalt alloy according to claim 13 wherein the content of chromium plug tungsten is at least 30 weight % and at most 40 weight % and the ratio of chromium to tungsten between about 3:4 and about 4:3.
Claim 16
Dependent Claim
39 words
A cobalt alloy according to claim 12 wherein the content of chromium plus tungsten is at least 30 weight % and at most 40 weight % and the ratio of chromium to tungsten between about 3:4 and about 4:3.
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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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |