Title of Invention

AN INTERNAL COMBUSTION ENGINE WITH EXHAUST GAS RECIRCULATION SYSTEM

Abstract An engine including an exhaust system operable to convey exhaust gases from the engine. A turbocharger is in fluid communication with the exhaust system. A diesel particulate filter, disposed in fluid communication with the exhaust system and located in downstream relation to the turbocharger, operates to substantially remove particulate matter from within the exhaust gases. An exhaust gas recirculation passage, disposed in upstream relation from the turbocharger and diesel particulate filter, operates to communicate a portion of the exhaust gases to an air-to- air heat exchanger, which operates to cool the portion of the exhaust gases. An exhaust gas recirculation valve operates to selectively and variably communicate the portion of the exhaust gases to an inlet air duct of an intake system. An engine cover defines an opening operable to communicate ambient air to the air-to-air heat exchanger to promote the cooling of the portion of the exhaust gases.
Full Text GP-307205-PTE-CD
1
EXHAUST GAS RECIRCULATION SYSTEM FOR
AN INTERNAL COMBUSTION ENGINE
TECHNICAL FIELD
[0001] The present invention relates to exhaust gas recirculation systems for
internal combustion engines.
BACKGROUND OF THE INVENTION
[0002] Oxides of nitrogen, or NOx, is one of the components in internal
combustion engine emissions. A common method for reducing NOx is through the
recirculation of a fraction of engine exhaust gases back into the air inlet of the
engine to be combined with the incoming air charge. This process is often called
charge dilution or exhaust gas recirculation (EGR). By introducing a combination
of fresh inlet air and exhaust gases into the engine, the heat absorbing capacity of
the air charge is increased and the overall oxygen content of the air charge is
decreased. Increasing the heat absorbing capacity of the air charge suppresses or
reduces engine combustion temperature, thereby inhibiting NOx formation.
Decreasing the oxygen content of the air charge decreases NOx formation by
reducing the availability of one of its constituent elements.
[0003] EGR typically involves recirculation of exhaust gases through an
EGR passage between an engine exhaust conduit and an engine fresh air intake
passage. A valve within the EGR passage, the EGR valve, is controlled to vary a
restriction within the EGR passage to regulate the flow of exhaust gases
therethrough. When EGR is not required, the EGR valve is driven to a full
restriction (closed) position. When EGR is required, the EGR valve is driven to an
open position through application of a position control signal to the EGR valve. The
degree of opening of the EGR valve varies with the magnitude of the position
control signal.

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[0004] Typically, the exhaust gases within the EGR passage are cooled,
prior to mixing the exhaust gases with the fresh inlet air, by passing the exhaust
gases through a heat exchanger. A typical heat exchanger for this application will
facilitate the transfer of heat energy from the exhaust gases to a liquid cooling
medium, such as the engine coolant. This type of heat exchanger is commonly
referred to as an air-to-water heat exchanger.
SUMMARY OF THE INVENTION
[0005] An engine defining at least one cylinder bore is provided having an
exhaust system operable to convey exhaust gases away from the at least one cylinder
bore and an intake system operable to convey intake air to the at least one cylinder
bore. Also provided is at least one turbocharger, such as a variable geometry
turbocharger, in fluid communication with the exhaust system and operable to
pressurize at least a portion of the intake system. Additionally, a diesel particulate
filter operates to substantially remove particulate matter from within the exhaust
gases. The diesel particulate filter is disposed in fluid communication with the
exhaust system and located in downstream relation to the turbocharger. An exhaust
gas recirculation passage is disposed upstream from the turbocharger and diesel
particulate filter and operates to communicate a portion of the exhaust gases to an
air-to-air heat exchanger. The air-to-air heat exchanger is operable to cool the
portion of the exhaust gases. An exhaust gas recirculation valve operates to
selectively and variably communicate the portion of the exhaust gases to an inlet air
duct of the intake system. Additionally, a vehicular hood member or engine cover
is provided, which defines an opening operable to communicate ambient air to the
air-to-air heat exchanger to promote the cooling of the portion of the exhaust gases.

GP-307205-PTE-CD
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[0006] An auxiliary fan may be provided that operates to provide a pressure
differential across the air-to-air heat exchanger, thereby drawing ambient air across
the air-to-air heat exchanger. The air-to-air heat exchanger may be removably
mounted with respect to the engine and may include a shroud or duct such that
ambient air is directed through the air-to-air heat exchanger and onto at least a
portion of the engine. The engine may be placed in a vehicle having a body
structure. The body structure may contain a plurality of vents to provide a pressure
differential such that the mass flow rate of ambient air across the air-to-air heat
exchanger is increased.
[0007] The above features and advantages and other features and advantages
of the present invention are readily apparent from the following detailed description
of the best modes for carrying out the invention when taken in connection with the
accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
[0008] Figure 1 is a schematic diagrammatic representation of a partial vehicle
having an engine and incorporating the various aspects of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] Referring to Figure 1, there is shown schematically a vehicle, generally
indicated at 10, having a body structure 12 (shown as dashed lines), an internal
combustion engine 14, and a portion of a vehicular hood member or engine cover 16.
The internal combustion engine 14 may be a compression ignited or a spark ignited
combustion type engine, both of which are known to those skilled in the art. For
discussion herein, the internal combustion engine 14 operates in a compression
ignited or diesel mode of operation. The internal combustion engine 14 has a cylinder
case 18 with a generally V-type configuration. In a V-type configuration, a first and a
second bank of cylinder bores 20A and 20B, respectively, of the cylinder case 18 are

GP-307205-PTE-CD
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disposed with an included angle of less than 180 degrees relative to one another.
Those skilled in the art will recognize that each of the first and second banks of
cylinder bores 20A and 20B may each contain one or a plurality of cylinder bores
22A and 22B, shown in phantom. A first and second cylinder head 24A and 24B are
mounted with respect to the first and second bank of cylinder bores 20A and 20B,
respectively.
[0010] Each of the first and second cylinder heads 24A and 24B define
respective exhaust ports 26A and 26B through which exhaust gases or products of
combustion 27 are selectively evacuated from the respective cylinder bores 22A and
22B. The exhaust ports 26A and 26B communicate exhaust gases 27 to a respective
one of a first and second integral exhaust manifold 28A and 28B, each defined within
the first and second cylinder head 24A and 24B, respectively. The first and second
integral exhaust manifolds 28A and 28B are formed integrally with the respective first
and second cylinder head 24A and 24B, thereby obviating the need for fasteners and
gaskets typically needed for exhaust manifold attachment. Since the integrated
exhaust manifolds 28A and 28B are formed integrally with the cylinder heads 24A
and 24B, respectively, the potential exhaust gas leak paths during operation of the
internal combustion engine 14 are reduced.
[0011] The first and second integral exhaust manifolds 28A and 28B arc
positioned on the internal combustion engine 14 such that they discharge exhaust
gases 27 in an inboard configuration, i.e. the first and second integral exhaust
manifolds 28A and 28B are substantially adjacent to an inboard region or generally
V-shaped cavity 30. The inboard discharge configuration is beneficial in that the
packaging requirement of the engine 14 may be reduced. The integral exhaust
manifolds 28A and 28B may discharge in any orientation within the general area
defined by the generally V-shaped cavity 30 while remaining within the scope of that
which is claimed. A respective first and second discharge conduit or pipe 32A and
32B are in fluid communication with the first and second integral exhaust manifolds
28A and 28B, respectively.

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[0012] The internal combustion engine 14 also includes a turbocharger 34
defining a restriction and positioned within the generally V-shaped cavity 30. The
turbo charger 34 includes a turbine housing 36 into which the first and second
discharge pipes 32A and 32B communicate exhaust gases 27. Those skilled in the art
will recognize that the first and second discharge pipes 32A and 32B may be
eliminated by incorporating the first and second discharge pipes 32A and 32B into the
turbine housing 36. The heat, noise, and kinetic energy of the exhaust gases 27 cause
a turbine blade 38, shown in phantom, to spin or rotate within the turbine housing 36.
In the preferred embodiment, the turbocharger 34 is a variable geometry type
turbocharger. When the useful energy is removed by the turbocharger 34. the exhaust
gases 27 are communicated to a discharge pipe 40. The discharge pipe 40
communicates the exhaust gases 27 to a diesel particulate filter, or DPI7 42. The DPF
42 defines a restriction, which contains a separation medium that operates to capture
particulate matter, such as soot, contained within the exhaust gases 27. A DPI"
discharge pipe 44 communicates exhaust gases 27 to the remainder of the vehicular
exhaust system, not shown. The inboard configuration of the first and second
integral exhaust manifolds 28A and 28B permit the length of the first and second
discharge pipes 32A and 32B to be minimized. By minimizing the length of the first
and second discharge pipes 32A and 32B, the energy of the exhaust gases 27 may be
retained to rotate the turbine blade 38. This heat energy would otherwise be lost to
the atmosphere through heat transfer. Those skilled in the art will recognize that the
present invention may incorporate a single turbocharger 34, twin turbochargers, or
staged turbochargers.
[0013] The turbine blade 38 is rigidly connected, through a shaft 46, to a
compressor blade 48 for unitary rotation therewith. The rotating compressor blade 48
cooperates with a compressor housing 50 to induct air at generally atmospheric
pressure through an inlet air duct 52 and subsequently compress the air. The
pressurized air is communicated to a compressor outlet duct 54, which is in
communication with a heat exchanger 56. The heat exchanger 56 operates to transfer

GP-307205-PTE-CD
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heat energy from the pressurized air to increase the operating efficiency of the engine
14. The heat exchanger 56 subsequently communicates the cooled pressurized air to a
first and second intake manifold 58A and 58B, respectively. The first and second
intake manifolds 58A and 58B distributes the air to one of a plurality of intake ports
60A and 60B defined by each of the first and second cylinder heads 24A and 24B.
The intake ports 60A and 60B selectively introduce air to a respective one of the
plurality of cylinder bores 22A and 22B where the air, along with a fuel charge, is
subsequently combusted in a known fashion.
[0014] An exhaust gas recirculation (EGR) passage 62 is provided in upstream
relation to the turbo charger 34 and DPF 42. The EGR passage may be provided in
one or both of the first and second discharge pipes 32A and 32B, or one or both of the
first and second integral exhaust manifolds 28A and 28B. The EGR passage 62
communicates a fraction or portion 63 of the exhaust gases 27 flowing to the
turbocharger 34 for communication to a heat exchanger 64. In the preferred
embodiment of the present invention, the heat exchanger 64 is an air-to-air type. An
air-to-air type of heat exchanger facilitates the transfer of heat energy from one
gaseous fluid, in this case the portion 63 of the exhaust gases 27, to another relatively
cooler gaseous fluid, in this case ambient air. The engine cover 16 defines a port or
opening 66 operable to allow ambient air to pass through the heat exchanger 64 to
cool the portion 63 of the exhaust gases 27 contained therein. A seal 68, such as an
elastomeric perimeter seal, is provided to direct the ambient air into the heat
exchanger 64. As the speed of the vehicle 10 increases above a threshold value, the
"ram air" effect will force the ambient air though the heat exchanger 64 to effect
cooling of the portion 63 of the exhaust gases 27 contained therein. However, when
the vehicle 10 is operated below the threshold speed, an auxiliary fan 70 is provided
to provide the necessary pressure differential to draw the ambient air though the heat
exchanger. The auxiliary fan 70 is preferably electrically driven.

GP-307205-PTE-CD
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[0015] A fluid flow shroud or duct 72 is provided on the low pressure side of
the heat exchanger and operate to direct the ambient air over engine components such
as the turbocharger 34 and the first and second integral exhaust manifolds 28A and
28B to provide additional cooling of these components. A plurality of vents 74 may
be mounted within the body structure 12, such as the vehicle fenders, to aid in
producing a pressure differential, thereby providing an increase in the mass flow rate
of ambient air passing through the heat exchanger 64. In the preferred embodiment,
the heat exchanger 64 is removably mounted with respect to the engine 14. Upon
exiting the heat exchanger 64, the cooled portion 63 of the exhaust gases 27 is
selectively and variably introduced into the inlet air duct 52 via an EGR valve 76.
The low pressure condition within the inlet air duct 52 provides a favorable condition
in which to maximize the amount of cooled portion 63 of the exhaust gases 27 that
may be introduced to the engine 14. Additionally, by introducing the cooled portion
63 of the exhaust gases 27 upstream of the compressor housing 50 of the turbocharger
34, an amount of mixing will occur between the cooled the portion 63 of the exhaust
gases 27 and the inlet air prior to being communicated to the engine 14.
[0016] By redirecting the portion 63 of the exhaust gases 27 into the EGR
passage 62 upstream of the turbocharger 34 and the DPF 42, the portion 63 of exhaust
gases 27 are communicated to the heat exchanger 64 at a high pressure since the
turbocharger and DPF 43 each define a flow restriction. Therefore, a greater portion
63 of exhaust gases 27 may be communicated to the inlet air duct 52. Additionally,
the variable geometry nature of the turbocharger 34 enables the amount of restriction
provided by the turbocharger 34 to be varied. This will enable the mass flow rate of
the portion 63 of the exhaust gases 27 to be varied irrespective of the EGR valve 76.
[0017] While the internal combustion engine 10 shown in Figure 1 includes
the turbocharger 34, those skilled in the art will recognize that the turbocharger 34
may or may not be present while remaining within the inventive concept.
Additionally, the intake ports 60A and 60B may be provided on either the inboard
side of the cylinder heads 24A and 24B or the outboard side of the cylinder heads 24A

GP-307205-PTE-CD
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and 24B, as shown in Figure 1. Likewise, the exhaust ports 26A and 26B may be
provided on either the inboard side of the cylinder heads 24A and 24B, as shown in
Figure 1, or the outboard side of the cylinder heads 24 A and 24B.
[0018] While the best modes for carrying out the invention have been
described in detail, those familiar with the art to which this invention relates will
recognize various alternative designs and embodiments for practicing the invention
within the scope of the appended claims.

GP-307205-PTE-CD
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CLAIMS
1. An engine defining at least one cylinder bore, the engine
comprising:
an exhaust system operable to convey exhaust gases from the at
least one cylinder bore, said exhaust system having at least one restriction therein;
an exhaust gas recirculation passage disposed upstream from
said at least one restriction and operable to communicate a portion of said exhaust
gases to an air-to-air heat exchanger;
wherein said air-to-air heat exchanger is operable to cool said
portion of said exhaust gases;
an exhaust gas recirculation valve operable to selectively and
variably communicate said portion of said exhaust gases to an inlet air duct;
an engine cover; and
wherein said engine cover defines an opening operable to
communicate ambient air to said air-to-air heat exchanger to promote the cooling of
said portion of said exhaust gases.
2. The engine of claim 1, further comprising:
an auxiliary fan; and
wherein said auxiliary fan operates to provide a pressure
differential across said air-to-air heat exchanger, thereby drawing ambient air across
said air-to-air heat exchanger.
3. The engine of claim 1, wherein said at least one restriction is
formed by one of a turbocharger and a diesel particulate filter.
4. The engine of claim 3, wherein said turbocharger is a variable
geometry type turbocharger.

GP-307205-PTE-CD
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5. The vehicle of claim 1, wherein said at least one restriction is
formed by a turbocharger; and
wherein said turbocharger has a compressor housing in fluid
communication with said inlet air duct and a compressor outlet duct.
6. The engine of claim 1, wherein said air-to-air heat exchanger is
removably mounted with respect to the engine and wherein said air-to-air heat
exchanger includes a duct such that such that ambient air is directed through said air-
to-air heat exchanger and onto at least a portion of the engine.
7. The engine of claim 1, wherein the engine is placed in a vehicle
having a body structure; and
wherein said body structure contains a plurality of vents to
provide a pressure differential such that the mass flow rate of ambient air across said
air-to-air heat exchanger is increased.
8. An engine defining at least one cylinder bore, the engine
comprising:
an exhaust system operable to convey exhaust gases away from
the at least one cylinder bore and an intake system operable to convey intake air to the
at least one cylinder bore;
at least one turbo charger in fluid communication with said
exhaust system and said intake system, said at least one turbocharger being operable
to pressurize at least a portion of said intake system;
an exhaust gas recirculation passage disposed upstream of said
turbocharger and operable to communicate a portion of said exhaust gases to an air-
to-air heat exchanger;
wherein said air-to-air heat exchanger is operable to cool said
portion of said exhaust gases;

GP-307205-PTE-CD
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an exhaust gas recirculation valve operable to selectively and
variably communicate said portion of said exhaust gases to an inlet air duct of said
intake system;
an engine cover; and
wherein said engine cover defines an opening operable to
communicate ambient air to said air-to-air heat exchanger to promote the cooling of
said portion of said exhaust gases.
9. The engine of claim 8, further comprising a diesel particulate
filter operable to substantially remove particulate matter from within said exhaust
gases, wherein said diesel particulate filter is disposed in fluid communication with
said exhaust system and located downstream of said at least one turbocharger;
10. The engine of claim 8, further comprising:
an auxiliary fan; and
wherein said auxiliary fan operates to provide a pressure
differential across said air-to-air heat exchanger, thereby drawing ambient air across
said air-to-air heat exchanger.
11. The engine of claim 8, wherein each of said at least one
turbocharger has a compressor housing in fluid communication with said inlet air duct
and a compressor outlet duct of said intake system.
12. The engine of claim 8, wherein said at least one turbocharger is
a variable geometry type turbocharger.
13. The engine of claim 8, wherein said air-to-air heat exchanger is
removably mounted with respect to the engine and wherein said air-to-air heat

GP-307205-PTE-CD
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exchanger includes a duct such that such that ambient air is directed through said air-
to-air heat exchanger and onto at least a portion of the engine.
14. The engine of claim 8, wherein the engine is placed in a vehicle
having a body structure; and
wherein said body structure contains a plurality of vents to
provide a pressure differential such that the mass flow rate of ambient air across said
air-to-air heat exchanger is increased.
15. The engine of claim 8 wherein said engine cover is a vehicular
hood member.
16. A vehicle comprising:
an engine defining at least one cylinder bore, wherein said
engine includes:
an exhaust system operable to convey exhaust gases
away from the at least one cylinder bore and an intake system operable to convey
intake air to the at least one cylinder bore;
at least one turbocharger in fluid communication with
said exhaust system and said intake system and operable to pressurize at least a
portion of said intake system;
a diesel particulate filter operable to substantially
remove particulate matter from within said exhaust gases, wherein said diesel
particulate filter is disposed in fluid communication with said exhaust system and
located in downstream relation to said at least one turbocharger;
an exhaust gas recirculation passage disposed
downstream of said diesel particulate filter and operable to communicate a portion of
said exhaust gases to an air-to-air heat exchanger;

GP-307205-PTE-CD
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wherein said air-to-air heat exchanger is operable to
cool said portion of said exhaust gases;
an exhaust gas recirculation valve operable to
selectively and variably communicate said portion of said exhaust gases to an inlet air
duct of said intake system;
a hood member; and
wherein said hood member defines an opening operable to
communicate ambient air to said air-to-air heat exchanger to promote the cooling of
said portion of said exhaust gases.
17. The vehicle of claim 16, further comprising:
an auxiliary fan; and
wherein said auxiliary fan operates to provide a pressure
differential across said air-to-air heat exchanger, thereby drawing ambient air across
said air-to-air heat exchanger.
18. The vehicle of claim 16, wherein each of said at least one
turbocharger has a compressor housing in fluid communication with said inlet air duct
and a compressor outlet duct of said intake system.
19. The vehicle of claim 16, wherein said air-to-air heat exchanger
is removably mounted with respect to said engine and wherein said air-to-air heat
exchanger includes a duct such that such that ambient air is directed through said air-
to-air heat exchanger and onto at least a portion of the engine.
20. The vehicle of claim 16, wherein said body structure contains a
plurality of vents to provide a pressure differential such that the mass flow rate of
ambient air across said air-to-air heat exchanger is increased.

An engine including an exhaust system operable to convey exhaust gases
from the engine. A turbocharger is in fluid communication with the exhaust system.
A diesel particulate filter, disposed in fluid communication with the exhaust system
and located in downstream relation to the turbocharger, operates to substantially
remove particulate matter from within the exhaust gases. An exhaust gas
recirculation passage, disposed in upstream relation from the turbocharger and diesel
particulate filter, operates to communicate a portion of the exhaust gases to an air-to-
air heat exchanger, which operates to cool the portion of the exhaust gases. An
exhaust gas recirculation valve operates to selectively and variably communicate the
portion of the exhaust gases to an inlet air duct of an intake system. An engine cover
defines an opening operable to communicate ambient air to the air-to-air heat
exchanger to promote the cooling of the portion of the exhaust gases.

Documents:

01114-kol-2007-abstract.pdf

01114-kol-2007-assignment.pdf

01114-kol-2007-claims.pdf

01114-kol-2007-correspondence others 1.1.pdf

01114-kol-2007-correspondence others 1.2.pdf

01114-kol-2007-correspondence others 1.3.pdf

01114-kol-2007-correspondence others.pdf

01114-kol-2007-description complete.pdf

01114-kol-2007-drawings.pdf

01114-kol-2007-form 1.pdf

01114-kol-2007-form 18.pdf

01114-kol-2007-form 2.pdf

01114-kol-2007-form 3.pdf

01114-kol-2007-form 5.pdf

01114-kol-2007-priority document.pdf

1114-KOL-2007-ABSTRACT 1.1.pdf

1114-KOL-2007-ABSTRACT.pdf

1114-KOL-2007-AMANDED CLAIMS 1.1.pdf

1114-KOL-2007-AMANDED CLAIMS.pdf

1114-KOL-2007-ASSIGNMENT.1.3.pdf

1114-KOL-2007-CORRESPONDENCE 1.6.pdf

1114-KOL-2007-CORRESPONDENCE OTHERS 1.4.pdf

1114-KOL-2007-CORRESPONDENCE-1.5.pdf

1114-KOL-2007-CORRESPONDENCE.1.3.pdf

1114-KOL-2007-CORRESPONDENCE.pdf

1114-KOL-2007-DESCRIPTION (COMPLETE) 1.1.pdf

1114-KOL-2007-DESCRIPTION (COMPLETE).pdf

1114-KOL-2007-DRAWINGS 1.1.pdf

1114-KOL-2007-DRAWINGS.pdf

1114-KOL-2007-EXAMINATION REPORT.1.3.pdf

1114-KOL-2007-FORM 1-1.1.pdf

1114-KOL-2007-FORM 1.pdf

1114-KOL-2007-FORM 18.1.3.pdf

1114-KOL-2007-FORM 2-1.1.pdf

1114-KOL-2007-FORM 2.pdf

1114-KOL-2007-FORM 3.1.3.pdf

1114-KOL-2007-FORM 3.pdf

1114-KOL-2007-GRANTED-ABSTRACT.pdf

1114-KOL-2007-GRANTED-CLAIMS.pdf

1114-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1114-KOL-2007-GRANTED-DRAWINGS.pdf

1114-KOL-2007-GRANTED-FORM 1.pdf

1114-KOL-2007-GRANTED-FORM 2.pdf

1114-KOL-2007-GRANTED-LETTER PATENT.pdf

1114-KOL-2007-GRANTED-SPECIFICATION.pdf

1114-KOL-2007-OTHERS 1.2.pdf

1114-KOL-2007-OTHERS-1.1.pdf

1114-KOL-2007-OTHERS.1.3.pdf

1114-KOL-2007-OTHERS.pdf

1114-KOL-2007-PA.pdf

1114-KOL-2007-PETITION UNDER RULE 137.pdf

1114-KOL-2007-REPLY TO EXAMINATION REPORT.1.3.pdf

1114-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

1114-KOL-2007-TRANSLATED COPY OF PRIORITY DOCUMENT.1.3.pdf


Patent Number 248646
Indian Patent Application Number 1114/KOL/2007
PG Journal Number 31/2011
Publication Date 05-Aug-2011
Grant Date 01-Aug-2011
Date of Filing 13-Aug-2007
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER, DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 CHARLES E. FREESE V 6661 MELDRUM ROAD, IRA TOWNSHIP, MICHIGAN 48023
PCT International Classification Number F02D23/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/561,034 2006-11-17 U.S.A.