US3779816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making mold for forming objects
Assignee: GNB Inc
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Filing: 1971-08-26
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Granted: 1973-12-18
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Expires: 1991-08-26
Abstract
Abstract A mold for forming objects such as battery grids includes a cavity having a titanium layer with an adherent titanium oxide layer integrally formed thereon. The oxide layer is formed by heating the titanium layer under controlled oxidizing conditions to provide an oxide layer of a specified thickness which is tenaciously adherent to the unoxidized titanium.
Inventors
- 👤 G Mao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:11
CPC Classifications
B; B22; B22C; B22C23/00; B22C23/02; B22C3/00; B22D; B22D17/00; B22D17/20; B22D17/22; B22D17/2209
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
55 words
The method of claim 1 wherein the titanium layer is first heated to a temperature in the range of about 1400* to 1500*F., is then partially cooled to a temperature and for a time sufficient to improve the adhesion of the oxide layer to the unoxidized titanium and is thereafter cooled to substantially ambient temperatures.
Claim 2
Dependent Claim
16 words
The method of claim 1 wherein the heating step is carried out in a partial vacuum.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the oxidizing atmosphere comprises a minor amount of molecular oxygen with an inert gas.
Claim 4
Dependent Claim
36 words
The method of claim 1 wherein the temperature of the titanium is raised at a rate of from about 100* to 200*F. /hr. and is cooled at a rate of from about 100* to 400*F. /hr.
Claim 5
Independent Claim
137 words
A method of making a mold for forming objects from a fluid, the mold having at least a surface of titanium of at least commercial purity with a definite depth and defining a cavity in the shape of the object to be formed, which comprises heating in an oxidizing atmosphere the titanium surface to raise the titanium to a temperature in the range of from about 1200* to 1500*F. and to hold it for a time sufficient to oxidize the titanium surface to form an oxide layer which is adherent to the unoxidized Titanium and with a thickness at least sufficient to provide the necessary heat-insulating properties for the forming of the object and thereafter cooling the mold, the heating and cooling being carried out at rates controlled to substantially avoid thermal shock in the oxide layer.
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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |