US3828296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheathed electric heater elements
Assignee: Huntington Alloys Corp
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Filing: 1973-01-18
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Granted: 1974-08-06
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Expires: 1993-01-18
Abstract
Abstract Sheathed electric heater elements wherein the sheathing is made of an alloy including specially proportioned amounts of nickel (about 15 percent to about 23 percent), chromium (about 17 percent to about 23 percent), silicon (about 0.3 percent to about 1.5 percent) and cerium (an effective amount up to about 0.05 percent) to assure high oxidation resistance and good corrosion resistance.
Inventors
- 👤 H Eiselstein
- 👤 J Hosier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:23
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; H; H01; H01C; H01C1/00; H01C1/02; H01C1/028
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
23 words
The sheathed electric heater element of claim 1 wherein the alloy of which the sheath is composed contains at least 0.01 percent cerium.
Claim 2
Dependent Claim
24 words
The sheathed electric heater element of claim 1 wherein the alloy of which the sheath is composed contains no more than 1 percent manganese.
Claim 3
Dependent Claim
50 words
The sheathed electric heater element of claim 1 wherein the alloy of which the sheath is composed contains from 18 percent to 22.5 percent nickel, from 19 percent to 22 percent chromium, from about 0.6 percent to about 1.1 percent silicon and from 0.015 percent to about 0.04 percent cerium.
Claim 4
Dependent Claim
27 words
The sheathed electric heater element of claim 2 wherein the alloy of which the sheath is composed contains about 20 percent nickel and about 20 percent chromium.
Claim 5
Dependent Claim
27 words
The sheathed electric heater element of claim 3 wherein the alloy of which the sheath is composed contains about 20 percent nickel and about 20 percent chromium.
Claim 6
Dependent Claim
35 words
The sheathed electric heater element of claim 1 wherein the alloy of which the sheath is composed contains about 20 percent nickel, about 20 percent chromium, about 0.6 percent silicon and about 0.02 percent cerium.
Claim 7
Dependent Claim
195 words
A sheathed electric heater element in which an electric resistance conductor is enclosed within a tubular metal sheath and supported in spaced, insulated relation thereto, the sheath being composed of an oxidation and corrosion resistant alloy consisting essentially, in per cent by weight, of from about 8 percent to about 23 percent nickel, from about 17 percent to about 23 percent chromium, from about 0.3 percent to about 1.5 percent silicon, from a small but effective amount of cerium up to about 0.05 percent to improve oxidation and corrosion resistance, up to about 2 percent manganese, up to about 0.15 percent carbon, up to about 0.5 percent aluminum, up to about 0.5 percent titanium, up to about 0.015 percent sulfur and the balance essentially iron, said alloy being characterized by exhibiting high resistance to cyclic oxidation resulting from balancing the constituents of the alloy within the ranges stated according to the following formula: 1178 - 9986 (% ce) - 1085 (% Si) - 49.78 (% Cr) + 3965 (% Si X % Ce) + 304.5 (% Cr X % Ce) + 44.84 (% Si X % Cr) +16.65 (% Mn/(% Si + % Ce)) 60.
Claim 8
Dependent Claim
21 words
An electric heater element as in claim 8 wherein the alloy of the sheath contains at least about 0.01 percent cerium.
References Cited (Backward Citations)
US3369209A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |