US5431012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for monitoring the performance of automotive catalysts
Assignee: Ford Global Technologies LLC
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Filing: 1994-07-05
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Granted: 1995-07-11
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Expires: 2014-07-05
Abstract
Abstract This invention is directed to a system for monitoring the efficiency of a catalyst employed to convert exhaust gases containing carbon monoxide, hydrocarbons and nitrogen oxides, e.g., those generated by an internal combustion engine such as in an automobile. The system comprises a thin-film resistive device and an electrical circuit connected to said thin-film resistive device capable of determining a change in the electrical resistance of a electrically conductive material provided in the device, the electrical resistance being subject to change during conversion of said exhaust gases over the catalyst.
Inventors
- 👤 Chaitanya K. Narula
- 👤 Andrew A. Adamczyk, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:13
CPC Classifications
F; F01; F01N; F01N11/00; F01N11/002; F01N2550/00; F01N2550/02; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
111 words
A system useful to monitor the efficiency of a catalyst employed to convert exhaust gases containing carbon monoxide, hydrocarbons and nitrogen oxides, which system comprises: a thin-film resistive device comprising an electrically insulating substrate, a thin layer of an electrically conductive material selected from the group consisting of carbides, nitrides, silicides, and metal oxides applied on a surface of the substrate, a washcoat carried on a surface of the electrically conductive material, and a catalyst carried on a surface of the washcoat; and an electrical circuit connected to said thin-film resistive device for determining a change in the electrical resistance of said electrically conductive material during conversion of said exhaust gases.
Claim 2
Independent Claim
111 words
A system useful to monitor the efficiency of a catalyst employed to convert exhaust gases containing carbon monoxide, hydrocarbons and nitrogen oxides, which system comprises: a thin-film resistive device comprising an electrically insulating substrate, a thin layer of an electrically conductive material selected from the group consisting of carbides, nitrides, silicides, and metal oxides applied on a surface of the substrate, a washcoat carried on a surface of the electrically conductive material, and a catalyst carried on a surface of the washcoat; and an electrical circuit connected to said thin-film resistive device for determining a change in the electrical resistance of said electrically conductive material during conversion of said exhaust gases.
Claim 3
Dependent Claim
25 words
The system according to claim 1, wherein said metal oxides are selected from the group consisting of fluorine-doped tin oxide and tin oxide-doped indium oxide.
Claim 4
Dependent Claim
19 words
The system according to claim 2, wherein said electrically conductive material is less than about 5000 angstroms in thickness.
Claim 5
Dependent Claim
19 words
The system according to claim 1, wherein said washcoat is selected from the group of alumina and titanium oxide.
Claim 6
Dependent Claim
19 words
The system according to claim 4, wherein said washcoat further comprises stabilizers selected from barium oxide and cerium oxide.
Claim 7
Dependent Claim
17 words
The system according to claim 1, wherein said catalyst is selected from noble metals and mixtures thereof.
Claim 8
Dependent Claim
21 words
The system according to claim 1, wherein said device is employed within a exhaust gas system for an internal combustion engine.
Claim 9
Dependent Claim
21 words
The system according to claim 7, wherein said device is employed within a catalytic converter employed within the exhaust gas system.
Claim 10
Dependent Claim
24 words
The system according to claim 8, wherein said catalytic converter employs catalyst material therein substantially of the type of catalyst employed in said device.
Claim 11
Dependent Claim
15 words
The system according to claim 1, wherein said electrical circuit includes an electronic engine control.
Claim 12
Dependent Claim
27 words
The system according to claim 1, wherein the area covered by said electrically conductive material is located substantially below the area of the catalyst in said device.
Claim 13
Dependent Claim
19 words
The system according to claim 8, wherein said device is provided integrated into a portion of said catalytic converter.
Claim 14
Dependent Claim
23 words
The system according to claim 1, wherein said washcoat and said catalyst are applied together as a mixture onto said electrically conductive material.
References Cited (Backward Citations)
US3882451A
Cited
DE2643739A1
Cited
US4319451A
Cited
WO1989000439A1
Cited
EP0236659A1
Cited
US4656829A
Cited
US4729220A
Cited
US5060473A
Cited
US5255511A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-10 | 1999-01-09 | 1999-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-10 | 2003-01-09 | 2003-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-10 | 2007-01-09 | 2007-07-11 | $7700.00 | Window Closed / Lapsed |