US3886785A
Expired / Lapsed
US
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Gas sensor and method of manufacture
Assignee: Ford Motor Co
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Filing: 1973-08-31
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Granted: 1975-06-03
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Expires: 1993-08-31
Abstract
Abstract A gas sensor, and its method of manufacture, particularly useful as an exhaust gas sensor for an internal combustion engine air/fuel ratio system, is disclosed. The sensor is comprised of a sintered ceramic body of transition metal oxide, such as titania, and includes a pair of spacedapart electrodes. As the partial pressure of oxygen in the gas being sensed varies in response to variations in the inlet air/fuel mixture ratio, the resistance of the ceramic material varies, The active portion of the sensor body is a substantially uniform body of porous ceramic material having a density of less than about 85 percent of theoretical density and a modulus of rupture in excess of 11,000 psi. The sensor is fabricated from a very pure transition metal oxide powder having a very fine and highly uniform particle size. The transitional metal oxide is selected so that the operating temperature of the resulting device is less than about 75 percent and preferably less than about 50 percent of the melting temperature of the metal oxide.
Inventors
- 👤 Henry L Stadler
- 👤 Tseng-Ying Tien
- 👤 Michael J Esper
- 👤 Donald J Romine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:10
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/1454; F02D41/1455; G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; F02D2700/00; F02D2700/09
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
88 words
A sensor for sensing the partial pressure of oxygen comprising: a porous, sintered ceramic sensor body having a modulus of rupture greater than about 11,000 psi; a pair of electrodes embedded in said body and spaced apart so that at lease a portion of the sensor body is interposed between said electrodes; and electrical means connected to said pair of electrodes for responding to changes in the inter-electrode resistance; said porous sensor body being comprised of ceramic material having a density less than about 85% of theoretical density.
Claim 2
Dependent Claim
88 words
A sensor for sensing the partial pressure of oxygen comprising: a porous, sintered ceramic sensor body having a modulus of rupture greater than about 11,000 psi; a pair of electrodes embedded in said body and spaced apart so that at lease a portion of the sensor body is interposed between said electrodes; and electrical means connected to said pair of electrodes for responding to changes in the inter-electrode resistance; said porous sensor body being comprised of ceramic material having a density less than about 85% of theoretical density.
Claim 3
Dependent Claim
88 words
A sensor for sensing the partial pressure of oxygen comprising: a porous, sintered ceramic sensor body having a modulus of rupture greater than about 11,000 psi; a pair of electrodes embedded in said body and spaced apart so that at lease a portion of the sensor body is interposed between said electrodes; and electrical means connected to said pair of electrodes for responding to changes in the inter-electrode resistance; said porous sensor body being comprised of ceramic material having a density less than about 85% of theoretical density.
Claim 4
Dependent Claim
88 words
A sensor for sensing the partial pressure of oxygen comprising: a porous, sintered ceramic sensor body having a modulus of rupture greater than about 11,000 psi; a pair of electrodes embedded in said body and spaced apart so that at lease a portion of the sensor body is interposed between said electrodes; and electrical means connected to said pair of electrodes for responding to changes in the inter-electrode resistance; said porous sensor body being comprised of ceramic material having a density less than about 85% of theoretical density.
Claim 5
Dependent Claim
26 words
The sensor of claim 1 wherein said porous sensor body is comprised of ceramic material having a density greater than about 72 percent of theoretical density.
Claim 6
Dependent Claim
102 words
A sensor for sensing the partial pressure of oxygen comprising: a porous, sintered ceramic sensor body having a modulus of rupture greater than about 11,000 psi; a pair of electrodes embedded in said body and spaced apart so that at lease a portion of the sensor body is interposed between said electrodes; and electrical means connected to said pair of electrodes for responding to changes in the inter-electrode resistance; said sensor body being comprised of matured powder material having a purity of at least 99.5 percent and a powder particle size which is less than about 20 microns in equivalent spherical diameter.
Claim 7
Dependent Claim
102 words
A sensor for sensing the partial pressure of oxygen comprising: a porous, sintered ceramic sensor body having a modulus of rupture greater than about 11,000 psi; a pair of electrodes embedded in said body and spaced apart so that at lease a portion of the sensor body is interposed between said electrodes; and electrical means connected to said pair of electrodes for responding to changes in the inter-electrode resistance; said sensor body being comprised of matured powder material having a purity of at least 99.5 percent and a powder particle size which is less than about 20 microns in equivalent spherical diameter.
Claim 8
Dependent Claim
84 words
In a gas sensor for sensing the partial pressure of oxygen in a gas of the type having a pair of electrodes embedded in a substantially solid ceramic body, the improvement wherein said ceramic body is porous, is exposable to the gas and said ceramic body has a density less than about 85 percent of theoretical density, an open pore diameter of from about 0.4 microns to about 0.7 microns and an open pore volume of from about 0.04 cc/gm to about 0.1 cc/gm.
Claim 9
Dependent Claim
84 words
In a gas sensor for sensing the partial pressure of oxygen in a gas of the type having a pair of electrodes embedded in a substantially solid ceramic body, the improvement wherein said ceramic body is porous, is exposable to the gas and said ceramic body has a density less than about 85 percent of theoretical density, an open pore diameter of from about 0.4 microns to about 0.7 microns and an open pore volume of from about 0.04 cc/gm to about 0.1 cc/gm.
Claim 10
Dependent Claim
20 words
The sensor of claim 4 wherein said porous ceramic body has a density greater than about 72 percent of theoretical.
Claim 11
Dependent Claim
25 words
The sensor of claim 5 wherein said porous ceramic body is comprised of titania and has a modulus of rupture greater than about 11,000 psi.
Claim 12
Dependent Claim
25 words
The sensor of claim 5 wherein said porous ceramic body consists essentially of titania and has a modulus of rupture greater than about 11,000 psi.
Claim 13
Dependent Claim
29 words
The sensor of claim 4 wherein said sensor body is comprised of matured particles of a transition metal oxide powder, the powder being comprised of 100 percent-20 micron particle.
Claim 14
Dependent Claim
24 words
The sensor of claim 8 wherein at least about 90 percent of the particles of the powder are sized between 10 and 0.5 microns.
Claim 15
Dependent Claim
23 words
The sensor of claim 8 wherein at least about 75 percent of the particles of the powder are smaller than about 5 microns.
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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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |