US3438730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of disintegrating sintered hard carbide masses
Assignee: Individual
•
Filing: 1966-11-14
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Granted: 1969-04-15
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Expires: 1986-11-14
Abstract
No abstract record available.
Inventors
- 👤 Warren M Shwayder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:17
CPC Classifications
C; C22; C22C; C22C3/00; C09; C09K; C09K3/00; C09K3/14; C09K3/1409; C22B; C22B34/00; C22B34/30; C22B34/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
A METHOD OF DISINTEGRATING SINTERED HARD CARBIDE MASSES FORMED OF HARD CARBIDE PARTICLES, SUCH AS TUNGSTEN CARBIDE, TITANIUM CARBIDE AND TANTALUM CARBIDE, CEMENTED BY COBALT, COMPRISING IMMERSING SUCH MASSES IN A RELATIVELY WEAK PHOSPHORIC ACID AT RELATIVELY LOW TEMPERATURE, SUCH AS IN THE RANGE OF SLIGHTLY ABOVE ROOM TEMPERATURE, THEREBY CAUSING THE COBALT TO DISSOLVE IN SAID ACID AND FREEING THE PARTICLES IN ESSENTIALLY THERI ORIGINAL, PRE-SINTERED SIZES, FROM THE MASSES AND CAUSING THE PARTICLES TO SUSPEND IN THE ACID; AND THEREAFTER MECHANICALLY SEPARATING THE PARTICLES FROMT THE ACID, SUCH AS BY CENTRIFUGING OR FILTERING.
Claim 2
Independent Claim
95 words
A METHOD OF DISINTEGRATING SINTERED HARD CARBIDE MASSES FORMED OF HARD CARBIDE PARTICLES, SUCH AS TUNGSTEN CARBIDE, TITANIUM CARBIDE AND TANTALUM CARBIDE, CEMENTED BY COBALT, COMPRISING IMMERSING SUCH MASSES IN A RELATIVELY WEAK PHOSPHORIC ACID AT RELATIVELY LOW TEMPERATURE, SUCH AS IN THE RANGE OF SLIGHTLY ABOVE ROOM TEMPERATURE, THEREBY CAUSING THE COBALT TO DISSOLVE IN SAID ACID AND FREEING THE PARTICLES IN ESSENTIALLY THERI ORIGINAL, PRE-SINTERED SIZES, FROM THE MASSES AND CAUSING THE PARTICLES TO SUSPEND IN THE ACID; AND THEREAFTER MECHANICALLY SEPARATING THE PARTICLES FROMT THE ACID, SUCH AS BY CENTRIFUGING OR FILTERING.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-04-14 | 1972-10-14 | 1973-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-04-14 | 1976-10-14 | 1977-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-04-14 | 1980-10-14 | 1981-04-15 | $7700.00 | Window Closed / Lapsed |