US3802402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal combustion engines
Assignee: Individual
•
Filing: 1972-03-30
•
Granted: 1974-04-09
•
Expires: 1992-03-30
Abstract
Abstract An exhaust gas recirculation system for an internal combustion engine comprises a metering orifice in the exhaust system of the engine opening into a recirculation conduit which leads to the inlet manifold of the engine, a pressure-control valve assembly which controls communication between a location in said conduit immediately downstream of the metering orifice and the inlet manifold in response to changes in pressure at said location such as to maintain said location at substantially atmospheric pressure. The rate of recirculation through said conduit is therefore a substantially constant percentage of the mass airflow rate of the engine. A pressure sensing valve assembly is responsive to a pressure in the engine supply system which indicates certain operating conditions of the engine and automatically closes the valve of the pressure-control valve assembly to prevent exhaust gas circulation under said operation conditions.
Inventors
- 👤 P Swatman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:19
CPC Classifications
F; F02; F02M; F02M26/00; F02M26/13; F02M26/39; F02M26/52; F02M26/55; F02M26/56; F02M26/58; F02M26/59; F02M26/61; F02M26/65; F02M26/66; F02M26/68; F02M2026/001; F02M2026/002; F02M2026/0025
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
146 words
An exhaust gas recirculation system for an internal combustion engine equipped with an inlet manifold and an exhaust system, said recirculation system comprising a metering orifice in said exhaust system opening into a recirculation conduit which leads to said inlet manifold, and a pressure-control valve assembly comprising a pressuresensitive member subjected to atmospheric pressure on one side and to the pressure in said conduit at a location immediately downstream of the exhaust gas metering orifice on its other side, an exhaust-admission valve in said recirculation conduit, and a pneumatic servo connected to operate said exhaustadmission valve in response to movement of said pressure sensitive member and thereby maintain substantially atmospheric pressure at said location whenever said exhaust gas is recirculated, so that said metering orifice governs the rate of recirculation through said conduit as a substantially constant percentage of the mass air-flow rate of the engine.
Claim 2
Dependent Claim
146 words
An exhaust gas recirculation system for an internal combustion engine equipped with an inlet manifold and an exhaust system, said recirculation system comprising a metering orifice in said exhaust system opening into a recirculation conduit which leads to said inlet manifold, and a pressure-control valve assembly comprising a pressuresensitive member subjected to atmospheric pressure on one side and to the pressure in said conduit at a location immediately downstream of the exhaust gas metering orifice on its other side, an exhaust-admission valve in said recirculation conduit, and a pneumatic servo connected to operate said exhaustadmission valve in response to movement of said pressure sensitive member and thereby maintain substantially atmospheric pressure at said location whenever said exhaust gas is recirculated, so that said metering orifice governs the rate of recirculation through said conduit as a substantially constant percentage of the mass air-flow rate of the engine.
Claim 3
Dependent Claim
41 words
An internal combustion engine according to claim 1, in which the exhaust-admission valve is of disc-like form and is operated by a remote valve stem which is so located that it is removed from the influence of the recirculated exhaust gas.
Claim 4
Dependent Claim
51 words
An internal combustion engine according to claim 1, in which the exhaust-admission valve is rigidly connected to the remote valve stem by a hook-like yoke which operates within a chamber that leads from the inlet manifold at a location upstream of that at which the recirculated exhaust gas enters this manifold.
Claim 5
Dependent Claim
58 words
An internal combustion engine according to claim 1, Pg,19 in which the exhaust gas metering orifice is established by an annular seat receiving a reciprocatable plug-like valve which penetrates the orifice and which, whenever it moves, exerts on the surrounding edge of the orifice a rubbing action which ensures maintenance of the original effective area of the orifice.
Claim 6
Dependent Claim
79 words
An internal combustion engine according to claim 1, in which the exhaust-admission valve is of circular form and is rigidly connected to one end of a hollow valve stem which passes, through a sliding pressure seal, into a casing containing three diaphragm-chambers formed by two diaphragms of which one constitutes the pressure-sensitive member and the other constitutes the pneumatic servo; the hollow valve stem extending through the servo-diaphragm into the intermediate diaphragm-chamber, which is in permanent communication with atmosphere.
Claim 7
Dependent Claim
90 words
An internal combustion engine according to claim 5, in which the end of the hollow valve stem remote from the exhaust-admission valve has an orifice which is located within the intermediate diaphragm-chamber and which coacts with a disc-like valve fixed to the pressure-sensitive diaphragm; the valve stem has a second orifice placing its interior in permanent communication with the diaphragm-chamber formed by the servo-diaphragm; and a restrictor is fitted in the valve stem either adjoining the exhaust-admission valve or at a location between that valve and the said second orifice.
Claim 8
Dependent Claim
64 words
An internal combustion engine according to claim 1, in which the servo-diaphragm is spring loaded in the direction to close the exhaust-admission valve, and the relation between the spring-load and the effective area of this diaphragm is such that the exhaust valve is opened when a depression slightly less than that prevailing when the engine is operating at full load acts on the servo-diaphragm.
Claim 9
Dependent Claim
61 words
An exhaust gas recirculation system as claimed in claim 1 which comprises a pressure-sensing valve assembly connected to respond to the depression obtaining at the location of a vacuum-advance drilling in a carburetter supplying said engine and to prevent the pressure-control valve assembly from permitting recirculation when said depression indicates that said engine is idling, overrunning, or operating at full load.
Claim 10
Dependent Claim
34 words
An exhaust gas recirculation system according to claim 8 comprising thermally responsive means connected to prevent said pressure-control valve assembly from permitting recirculation when the temperature of said engine is below about 60* F.
References Cited (Backward Citations)
US22994A
Cited
US2722927A
Cited
US3368345A
Cited
US3491736A
Cited
US3643640A
Cited
US3662722A
Cited
US3641989A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |