Paper No.
`Filed: July 29, 2016
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`
`
`
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`
`
`
`
`
`
`General Electric Company,
`Petitioner
`v.
`
`United Technologies Corporation,
`Patent Owner
`
`
`
`
`
`
`
`
`
`Case No. IPR2016-00952
`Patent No. 9,121,412
`
`
`
`
`
`
`
`PATENT OWNER’S PRELIMINARY RESPONSE
`
`
`
`
`
`

`
`
`
`TABLE OF CONTENTS
`
`
`I.
`
`II.
`
`Introduction ..................................................................................................... 1
`
`Background ..................................................................................................... 3
`
`A.
`
`B.
`
`C.
`
`Patent Owner is a Leading Designer, Developer, and
`Manufacturer of Gas Turbine Engines ................................................. 3
`
`Petitioner Competes with Patent Owner .............................................. 5
`
`The ’412 Patent Describes and Claims an Innovative Geared
`Turbofan Engine ................................................................................... 5
`
`1.
`
`2.
`
`3.
`
`4.
`
`Geared Turbofan Architecture of the ’412 Patent ..................... 5
`
`Propulsor and Propulsor Solidity ............................................... 8
`
`Air Flow and Bypass Flow Pressure Ratio .............................. 10
`
`Benefits of the ’412 Engine Design ......................................... 13
`
`III. Claim Construction ....................................................................................... 14
`
`A.
`
`“pressure ratio . . . with regard to an inlet pressure and an outlet
`pressure of said bypass flow passage” ............................................... 14
`
`1.
`
`2.
`
`Petitioner’s Construction is Inconsistent With the
`Intrinsic Evidence .................................................................... 16
`
`Extrinsic Evidence Demonstrates that “Fan Pressure
`Ratio” and Bypass Flow Passage Pressure Ratio Are Not
`Equivalent ................................................................................ 18
`
`“spool” ................................................................................................ 23
`
`“propulsor” ......................................................................................... 25
`
`B.
`
`C.
`
`IV. The Petition Fails to Meet the Requirements for Instituting an
`Inter Partes Review ...................................................................................... 26
`
`i
`
`

`
`A.
`
`To Focus the Issues Before the Board, Patent Owner Has
`Disclaimed Claims 9 and 10 ............................................................... 26
`
`B. Ground 1: Claims 1, 2, 4, 5, 7, and 8 Are Not Anticipated by
`Davies ................................................................................................. 26
`
`1.
`
`2.
`
`3.
`
`Overview of Davies ................................................................. 26
`
`Davies Does Not Disclose the “Ratio of N/R” Claimed in
`Challenged Claims 1, 2, 4, 5, 7, and 8 ..................................... 28
`
`Davies Does Not Disclose the “Pressure Ratio … of a
`Bypass Flow Passage” Required by Claims 1, 2, 4, 5, 7,
`and 8 ......................................................................................... 31
`
`C. Ground 2: Claims 1, 2, 4, 5, 7, 8, and 11 Are Not Rendered
`Obvious by Davies in View of Knowledge of One of Ordinary
`Skill in the Art .................................................................................... 37
`
`1.
`
`2.
`
`Claims 1, 2, 4, 5, 7, and 8 are Not Obvious Over Davies ........ 38
`
`Claim 11 is Not Obvious Over Davies .................................... 42
`
`D. Ground 3: Claims 5 Is Not Rendered Obvious by Davies in
`View of Middleton ............................................................................. 44
`
`E.
`
`Ground 4: Claims 1, 3, and 4 Are Not Rendered Obvious by
`Schaefer in View of the Knowledge of One of Ordinary Skill in
`the Art ................................................................................................. 45
`
`1.
`
`2.
`
`Overview of Schaefer .............................................................. 45
`
`Schaefer Does Not Render Obvious the Challenged
`Claims ...................................................................................... 46
`
`F.
`
`Grounds 1-4: The Petition Fails to Establish that Davies or
`Schaefer Discloses the Claimed Spool ............................................... 50
`
`1.
`
`2.
`
`Davies Fails to Disclose the Claimed Spool ............................ 50
`
`Schaefer Also Fails to Disclose the Claimed Spool and
`Gear Arrangement .................................................................... 53
`
`V.
`
`Conclusion .................................................................................................... 55
`
`ii
`
`

`
`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`Crocs, Inc. v. ITC,
`598 F.3d 1294 (Fed Cir. 2010) ........................................................................... 41
`
`Cuozzo Speed Techs., LLC v. Lee,
`136 S.Ct. 2131 (U.S. 2016) ................................................................................. 14
`
`Gen. Elec. Co. v. United Tech. Corp.,
`IPR2016-00531, Paper 7 (P.T.A.B. June 30, 2016) .......................................... 20
`
`Gen. Elec. Co. v. United Tech. Corp.,
`IPR2016-00533, Paper 7 (P.T.A.B. June 30, 2016) .......................................... 20
`
`HP Inc. v. Memjet Technology Ltd,
`IPR2016-00356, Paper 7 (P.T.A.B. June 16, 2016) .......................................... 51
`
`In re Kahn,
`441 F.3d 977 (Fed. Cir. 2006) ...................................................................... 38, 41
`
`KSR Int’l Co. v. Teleflex Inc.,
`127 S.Ct. 1727 (2007) ................................................................................... 38, 41
`
`Microsoft Corp. v. Proxyconn, Inc.,
`789 F.3d 1292 (Fed. Cir. 2015) .......................................................................... 14
`
`Net MoneyIN, Inc. v. Verisign, Inc.,
`545 F.3d 1359 (Fed. Cir. 2008) .......................................................................... 32
`
`In re Zletz,
`893 F.2d 319 (Fed. Cir. 1989) ............................................................................ 14
`
`Statutes
`
`35 U.S.C. § 102 .................................................................................................. 26, 32
`
`35 U.S.C. § 103(a) ............................................................................................. 37, 44
`
`iii
`
`

`
`Regulation
`
`37 C.F.R. § 42.100(b) .............................................................................................. 14
`
`
`
`iv
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`

`
`Introduction
`
`I.
`U.S. Patent No. 9,121,412 (“the ’412 patent”) discloses and claims an
`
`innovative gas turbine engine design that addresses the “complex and elusive task”
`
`of “identifying and changing appropriate design factors” to reduce propulsive
`
`losses and enhance propulsive efficiency. (’412 patent at 1:27-31.) The ’412
`
`patent provides specific ranges for propulsor blade counts, propulsor solidities,
`
`ratios of blade count-to-solidity, and bypass flow passage pressure ratios. These
`
`features are enabled in part by the claimed engine architecture. The gear assembly
`
`positioned between the spool and propulsor enables the propulsor to run at a
`
`different speed than the spool. The claimed features collectively result in a better
`
`engine with enhanced propulsive efficiency and a “reduction of performance
`
`debits.” (Id. at 4:9-21.)
`
`All of Petitioner’s unpatentability grounds rest on the erroneous notion that
`
`the “pressure ratio . . . with regard to an inlet pressure and an outlet pressure of
`
`said bypass flow passage” of claims 1-8 is equivalent to a “fan pressure ratio.” It is
`
`not. The fan is only one of many structures located in a bypass flow passage, and
`
`the additional structures cause further pressure losses before and after the fan, thus
`
`altering the bypass flow passage pressure ratio. As publications from experts in
`
`the field make clear, the resulting pressure change across the entire bypass flow
`
`passage can be significantly greater than the pressure change across the fan alone.
`
`1
`
`

`
`None of Petitioner’s references takes the entire bypass flow passage into account,
`
`nor discloses what the pressure ratio is across the entire bypass flow passage.
`
`Grounds 1-3 of Petitioner’s four unpatentability grounds ignore the “0.83”
`
`blade solidity value expressly disclosed in Davies as a “main feature” of its
`
`engine.1 Petitioner does this without explanation and for good reason. The stated
`
`solidity value for Davies’ engine falls outside the propulsor solidity ranges claimed
`
`in the ’412 patent. To assert Davies as prior art, therefore, Petitioner derives
`
`solidity based on undocumented assumptions and approximate fan diameter and
`
`fan tip chord values that Davies reports solely “[t]o illustrate the magnitude of the
`
`problem” of blade retention. (See GE-1005.009, emphasis added.) The discussion
`
`is unrelated to blade solidity and involves forces not requiring the precision that a
`
`solidity calculation would require.2 Petitioner never explains why it ignores
`
`Davies’ specifically reported solidity value, and more importantly, provides no
`
`
`1 “Solidity” numerically expresses how much the propulsor blades block the flow
`
`of air (i.e., how “solid” the collection of blades appears to be from a fluid flow
`
`perspective). (’412 patent at 3:24-26; UTC-2006.056.)
`
`2 Blade retention “results in the need to provide a restraint of about 40 tons,” a
`
`figure so large that rounding or approximations in its calculation do not change the
`
`“magnitude” of the result. (GE-1005.009-.010, emphasis added.)
`
`2
`
`

`
`reason and no factual basis for one of ordinary skill to disregard the reported value
`
`in favor of Petitioner’s different, derived value based on approximations. There is
`
`no good explanation, and Petitioner’s decision to ignore the stated solidity value
`
`undermines every Davies-based ground, including Grounds 1-3.
`
`Each ground suffers from additional deficiencies. Petitioner fails to explain
`
`why Davies would have been modified to achieve the claimed bypass flow passage
`
`pressure ratio ranges when Davies teaches away from them (Ground 2). In
`
`addition, Petitioner erroneously construes “spool” to mean only a “shaft” when
`
`the ’412 patent expressly defines a shaft as merely one component of a spool
`
`(Grounds 1-4). Petitioner fails to demonstrate that certain documents qualify as
`
`prior art (Grounds 2 and 4).
`
`In light of these deficiencies and others described in this Preliminary
`
`Response, Petitioner has not demonstrated a reasonable likelihood that it would
`
`prevail on any challenged claim of the ’412 patent. Patent Owner respectfully
`
`requests that the Board deny institution.
`
`II. Background
`Patent Owner is a Leading Designer, Developer, and
`A.
`Manufacturer of Gas Turbine Engines
`
`Patent Owner, United Technologies Corporation (“UTC”), has spent twenty
`
`years and over $10 billion dollars researching, designing, and optimizing gear-
`
`driven, high bypass turbofan engines. (UTC-2001.001.) This work culminated in
`
`3
`
`

`
`the recent introduction of a family of commercial engines that are quieter, cleaner,
`
`and 16% more efficient than the previous generation of gas turbine engines.
`
`(UTC-2002.004, .006.)
`
`While the benefits of a successful geared turbofan engine are enormous, the
`
`challenges to introducing a gear system into a large, complex, high bypass engine
`
`are significant. UTC overcame these significant challenges, and its high bypass
`
`geared turbofan engines began operating on commercial airlines for the first time
`
`in January 2016. This was a pioneering event. No other engine manufacturer has
`
`introduced a high bypass geared turbofan engine. The ’412 patent reflects several
`
`elements of UTC’s groundbreaking work that allow for a dramatically more
`
`efficient commercial engine.
`
`Petitioner argued publicly for years that UTC’s development of a geared
`
`turbofan was “simply a bad idea,” was full of risk, and ultimately would have a
`
`“serious negative impact on reliability.” (UTC-2003.001; UTC-2004.003; UTC-
`
`2005.003.) Petitioner essentially told the marketplace that it could not be done.
`
`These public expressions of skepticism by Petitioner are strong evidence against
`
`obviousness. Only now, after UTC has successfully developed the geared turbofan
`
`and patented many of the enabling innovative ideas like those disclosed in the ’412
`
`patent, Petitioner has filed numerous IPR petitions against UTC, claiming that
`
`UTC’s geared turbofan technology was obvious all along. Petitioner’s belated
`
`4
`
`

`
`legal argument of unpatentability lacks credibility given its previous real-world
`
`admission of novelty.
`
`Petitioner Competes with Patent Owner
`
`B.
`General Electric Company (“GE” or “Petitioner”)
`
`is a diversified
`
`manufacturing company. Petitioner’s subsidiary, GE Aviation, manufactures and
`
`sells aircraft engines in competition with Pratt & Whitney.
`
`C. The ’412 Patent Describes and Claims an Innovative
`Geared Turbofan Engine
`
`The ’412 patent discloses and claims an improved gas turbine engine
`
`“having a geared turbo fan architecture that is designed to efficiently operate with a
`
`high bypass ratio and a low pressure ratio.” (GE-1001.004, 1:14-17.) Gas turbine
`
`engines include many components relating to the fan and bypass flow passage
`
`capable of contributing to propulsive losses. (GE-2006.006.) As explained in the
`
`’412 patent, “[a]lthough some basic principles behind such losses are understood,
`
`identifying and changing appropriate design factors to reduce such losses for a
`
`given engine architecture has proven to be a complex and elusive task.” (GE-
`
`1001.004, 1:27-31.) The ’412 patent identifies and claims combinations of engine
`
`features that provide lower losses and improved propulsive efficiency.
`
`1. Geared Turbofan Architecture of the ’412 Patent
`As illustrated in the annotated version of Figure 1 below, the ’412 patent
`
`discloses a turbofan engine that includes low pressure and high pressure
`
`5
`
`

`
`compressors, which compress the air entering the engine (’412 patent at 2:43-48); a
`
`combustor, which mixes the air with fuel and combusts it (id.); and high and low
`
`pressure turbines, which are rotated by the hot, expanding gas emerging from the
`
`combustor (id.). After performing work in the turbines, the combusted air then
`
`passes out the rear of the engine through an outlet or nozzle. (Id. at 2:49-51.)
`
`
`
`(Id. at .002, Fig. 1 (annotations added by Patent Owner).)
`
`
`
`The engine’s compressors and turbines connect to form assemblies called
`
`“spools,” highlighted in the annotated figure below, that permit the turbines to
`
`drive the compressors. (Id. at 2:25-41.)
`
`6
`
`

`
`
`
`
`
`,._
`
`-_
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`
`A “high spool 32 includes an outer shaft 50 that is coupled with a high pressure
`
`compressor 52 and a high pressure turbine 54.” (Id. at 2:35-37.) And a “low spool
`
`generally includes an inner shaft 40 that is coupled with a propulsor 42, a low
`
`pressure compressor 44 and a low pressure turbine. (Id. at 2:25-34.)
`
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`
`(of high spool)
`
`(of low spool)
`
`
`
`The engine claims of the ’4l2 patent recite a geared turbofan arrangement,
`
`in which a spool drives a gear assembly, which, in turn, drives a propulsor.
`
`(Id. at
`
`4:44-46.) This claimed spool is the low spool described in the ’412 specification,
`
`shaded in blue above.
`
`2.
`
`Propulsor and Propulsor Solidity
`
`The propulsor of the ’412 patent may comprise a fan with multiple blades
`
`arranged radially around a rotor. As shown below, each propulsor blade includes a
`
`root and a tip. (Id. at 3:2—5.)
`
`

`
`
`
`The ’412 patent discloses a design parameter called “solidity,” which defines
`
`how much the blades block the flow of air (i.e., how “solid” the collection of
`
`blades appear to be from a fluid flow perspective).
`
`(Id. at 3:24-26; UTC-
`
`2006.056_) The patent defines solidity as
`
`Solidity is an important design
`
`Variable because modifying a fan’s solidity can affect the engine’s performance,
`
`efficiency, and weight. GJTC-2006.056; GE-1005.007-.008 (identifying solidity as
`
`one of the “main features” of Davies’ design)_)
`
`Solidity is a fimction of the propulsor’s chord dimension (“CD” in Fig. 2
`
`above) and circumferential pitch (“CP” in Fig. 2 above). (See ’412 patent at Fig. 2,
`
`3:24-26.) The chord dimension is a length that extends between the leading edge
`
`and the trailing edge, and the circumferential pitch is equivalent to the arc distance
`
`between the tips of neighboring propulsor blades.
`
`(Id. at 3:5-10-) The solidity
`
`

`
`value R is defined as a ratio of chord dimension divided by circumferential pitch.
`
`(Id. at 3:22-25.) The ’412 patent claims specify that the chord dimension is
`
`measured at the tip. (Id. at 4:54-57.)
`
`The ’412 inventors recognized that relating the number of blades in the
`
`propulsor (“N”) with the propulsor’s solidity (“R”), in combination with other
`
`features, could lead to an enhanced engine design. (Id. at 3:38-4:21.) To this end,
`
`the patent defines “N/R” ratios that the inventors found “enhance the propulsive
`
`efficiency of the disclosed engine.” (Id. at 4:9-12.) According to the ’412 patent,
`
`“relatively low speed, relatively large diameter, and the geometry that permits the
`
`disclosed ratios of N/R contribute to the reduction of performance debits, such as
`
`by lowering the speed of the air or fluid that passes over the propulsor blades 74.”
`
`(Id. at 4:17-21.) The ’412 patent claims recite specific ranges of N/R ratios, in
`
`combination with ranges of other parameters. No prior art reference teaches this.
`
`3.
`As the propulsor rotates, it generates pressure and drives air through the
`
`Air Flow and Bypass Flow Pressure Ratio
`
`engine along two primary paths: (1) a core flowpath, where fuel is combusted to
`
`drive the propulsor and to generate a portion of the engine’s thrust, and (2) a
`
`bypass flowpath, where the propulsor generates most of its thrust by forcing air
`
`through a bypass duct and out a nozzle at the rear of the bypass duct. (See, e.g., id.
`
`at .002, Fig. 1 and .005, 3:32-36.)
`
`10
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`
`The portion of air that flows through the bypass flow passage, highlighted in
`
`blue above, interacts with structures in the bypass flow passage downstream of the
`
`fan, which may include fan exit guide vanes, the exhaust duct, nozzle, pylon
`
`mounting structures,
`
`air bleed or
`
`exhaust ports, heat
`
`exchangers,
`
`and
`
`discontinuities between portions of the duct and its components that cause air
`
`leakage in the passage.
`
`(See UTC-2007.006, Fig. 10; GE—1013.006-.007.)
`
`Changing the radial dimension of this annular bypass flow path due to these
`
`structures can have a dramatic effect on pressure.
`
`The ’412 patent discloses an exemplary bypass flow passage that shows
`
`some, but not all, of these structures:
`
`11
`
`

`
`
`
`Structures in the bypass flow passage create pressure losses, reducing the pressure
`
`change measured across the bypass flow path. Depending on engine design, these
`
`pressure losses can be substantial. (See UTC-2007.006, Fig. 10 (disclosing
`
`pressure losses approaching 12%).)
`
`The ’412 patent describes levels of pressure change across the bypass flow
`
`passage B. Importantly, the ’412 patent expressly defines the bypass flow passage
`
`B as extending from inlet 60 to outlet 62. Measuring a pressure differential across
`
`the inlet and outlet of the bypass flow passage B accounts for the pressure increase
`
`created by the fan as well as the pressure losses created by obstructions, structures,
`
`the shape of the bypass flow passage, the nozzle, bleed or exhaust ports, and
`
`discontinuities in the bypass flow passage. These losses are reflected in the ratio,
`
`described and claimed in the ’412 patent, of the pressure at the inlet and pressure at
`
`12
`
`

`
`the outlet of the bypass flow passage (i.e. P2/P1 in the annotated figure above).
`
`(’412 patent at 2:49-55.)
`
`The ’412 patent consistently considers—and expressly claims—the pressure
`
`across the entire bypass flow path, not merely the pressure change associated with
`
`the propulsor. As recognized by art relied upon by Petitioner and its expert, low
`
`fan-pressure ratio fans are sensitive to fan duct pressure loss, requiring careful
`
`design of the fan exit guide vanes, exhaust duct, and nozzle. (GE-1013.006-
`
`.007.) Minimizing fan and pylon interaction is also very important to the pressure
`
`loss in the bypass flow path. (Id. at .007.) The ’412 patent focuses on the pressure
`
`across the entire bypass flow path. It does not claim, discuss, or define a “fan
`
`pressure ratio.”
`
`4.
`To achieve a more efficient engine, the ’412 patent combines a geared
`
`Benefits of the ’412 Engine Design
`
`engine architecture with specific ranges of bypass flow passage pressure ratio,
`
`solidity, fan blade counts, and N/R. (See, e.g., ’412 patent at 1:15-18, 3:34-4:10.)
`
`The gear assembly allows the propulsor to rotate at a different speed than the low
`
`speed spool and, as a result, the propulsor “can be designed with a large diameter
`
`and rotate at a relatively slow speed with regard to the low speed spool.” (Id. at
`
`4:14-17.) The ’412 patent explains that “[a] relatively low speed, relatively large
`
`diameter [fan], and the geometry that permits the disclosed ratios of N/R contribute
`
`13
`
`

`
`to the reduction of performance debits, such as by lowering the speed of the air or
`
`fluid that passes over the propulsor blades.” (Id. at 4:17-21.)
`
`III. Claim Construction
`
`The Petition relies upon incorrect claim constructions.
`
`In inter partes
`
`review, the Board gives claims their “broadest reasonable construction in light of
`
`the specification.” 37 C.F.R. § 42.100(b); Cuozzo Speed Techs., LLC v. Lee, 136
`
`S.Ct. 2131, 2142 (U.S. 2016). However,
`
`in applying the broadest reasonable
`
`interpretation (“BRI”) standard, the words of the claim must be given their plain
`
`meaning consistent with the specification. In re Zletz, 893 F.2d 319, 321-22 (Fed.
`
`Cir. 1989). Moreover, the Board may not “construe claims during IPR so broadly
`
`that
`
`its constructions
`
`are unreasonable under general claim construction
`
`principles.” Microsoft Corp. v. Proxyconn, Inc., 789 F.3d 1292, 1298 (Fed. Cir.
`
`2015) (emphasis in original).
`
`A.
`
`“pressure ratio . . . with regard to an inlet pressure and an
`outlet pressure of said bypass flow passage”
`
`The ratio of the pressure at the inlet of
`
`Substantially equivalent to fan pressure
`
`at the outlet of the bypass flow passage
`
`the bypass flow passage to the pressure
`
`ratio
`
`Claims 1-8 of the ’412 patent require a bypass flow passage having a
`
`“pressure ratio that is between 1.1 and 1.35 with regard to an inlet pressure and an
`
`14
`
`

`
`outlet pressure of said bypass flow passage.” Consistent with this terminology,
`
`Patent Owner refers to this pressure ratio as the “bypass flow passage pressure
`
`ratio.” 3
`
`The parties agree that a bypass flow passage pressure ratio differs from a fan
`
`pressure ratio. Indeed, Petitioner states that the “fan pressure ratio is the pressure
`
`at station 13 [“the fan exit”] divided by the pressure at station 2 [“the fan inlet”]4
`
`(P13/P2),” while “[i]n comparison, the bypass [flow passage] pressure ratio is the
`
`pressure at station 19 [the “outlet of the bypass flow passage”] divided by the
`
`
`3 Petitioner refers to this claim limitation as “bypass pressure ratio.” But such
`
`shorthand risks confusing it with “bypass ratio,” which is a completely different
`
`ratio not involving pressures. The phrase “bypass pressure ratio” also disregards
`
`the
`
`importance of
`
`the “flow passage”
`
`in calculating
`
`the claimed ratio.
`
`Accordingly, Patent Owner instead refers to the claimed ratio more completely as
`
`the “bypass flow passage pressure ratio.”
`
`4 Patent Owner disagrees with Petitioner’s and its expert’s position that the
`
`denominator of the bypass flow passage pressure ratio is to be taken at the fan
`
`inlet. The ’412 patent makes clear it is to be taken at the inlet of the bypass flow
`
`passage, which may be well upstream of the inlet. (’412 patent at 2:49-55, 4:47-
`
`53.)
`
`15
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`pressure at station 2 [“the fan inlet”] (P19/P2).” (Petition at 18.) Despite
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`acknowledging this difference, Petitioner proposes a construction that makes fan
`
`pressure ratio and bypass flow passage pressure ratio synonymous. In the process,
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`Petitioner ignores the claims and specification of the ’412 patent and instead relies
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`on extrinsic evidence. Petitioner’s construction is wrong.
`
`1.
`
`Petitioner’s Construction is Inconsistent With the
`Intrinsic Evidence
`Claim 1 expressly recites “a pressure ratio that is between 1.1 and 1.35 with
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`regard to an inlet pressure and an outlet pressure of said bypass flow passage.”
`
`(’412 patent at 4:50-53, emphasis added.) The ’412 patent specification similarly
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`defines the bypass flow passage pressure ratio with respect to this same inlet and
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`outlet. (’412 patent at 1:42-44; 2:49-55.) It states:
`
`As shown [in Figure 1, reproduced below], the propulsor 42 is
`arranged at an inlet 60 of the bypass flow passage B. Air flow through
`the bypass air passage B exits the engine 20 through an outlet 62 or
`nozzle. For a given design of the propulsor 42, the inlet 60 and the
`outlet 62, the engine 20 define a design pressure ratio with regard to
`an inlet pressure at the inlet 60 and an outlet pressure at the outlet 62
`of the bypass flow passage B.
`
`(Id. at 2:49-55, emphasis added.) Figure 1 shows the described inlet and outlet
`
`locations below.
`
`16
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`36
`
`(’412 patent at Fig. 1 (annotated in green by Patent Owner).)
`
`Ignoring the express language of the ’4l2 claims and specification is
`
`improper.
`
`Petitioner does so here because its references fail to disclose the
`
`claimed features.
`
`Instead, Petitioner finds a separate parameter that is provided in
`
`its references
`
`fan pressure ratio’
`
`and rewrites the claims to cover this different
`
`C‘
`
`3
`
`parameter.
`
`The tenn “fan pressure ratio,” however, is not even mentioned in the ’412
`
`patent despite that it was a known term of art available for the inventors to use.5
`
`The ’412 patent’s inventors were concerned with reducing losses through the
`
`entire bypass flow passage, including not only losses caused by the fan itself, but
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`5 See Petition at 18, describing “fan pressure ratio” is “an operating parameter that
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`is commonly discussed in the technical publications relating to turbofan engines.”
`
`17
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`

`
`also by other structures within the bypass flow passage. There are a number of
`
`other structures in the bypass flow passage, such as fan exit guide vanes, the
`
`exhaust duct, the nozzle, pylon mounting structures, air bleed or exhaust ports, heat
`
`exchangers, and discontinuities between portions of the duct and its components
`
`that cause air leakage in the passage. As its name implies, “fan pressure ratio”
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`specifically addresses only a subset of these components, with a focus on the fan.
`
`(See, e.g., Petition at 18-19, illustrating Petitioner’s view of the difference between
`
`the structures between the measurement points for the fan pressure ratio and the
`
`bypass flow passage pressure ratio.) There is no basis in the four corners of the
`
`’412 patent to conclude that the inventors intended to treat “fan pressure ratio” as
`
`“equivalent” to the bypass flow passage pressure ratio of claim 1. To the contrary,
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`the inventors expressly defined the term in both the specification and in the claims
`
`to encompass much more than just the fan.
`
`2.
`
`Extrinsic Evidence Demonstrates that “Fan Pressure
`Ratio” and Bypass Flow Passage Pressure Ratio Are
`Not Equivalent
`
`With no support in the ’412 patent, Petitioner contends that selected
`
`extrinsic evidence supports its equivalence argument. But Petitioner does not tell
`
`the whole story. As the chart below demonstrates, the total pressure ratio losses
`
`across the entire bypass flow passage can be significant— approaching 12%—
`
`18
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`

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`with the duct and nozzle losses being dominant, and generally greater than the
`
`losses of the fan rotor and fan static structure.
`
`
`
`(UTC-2007.006 (recognizing that “nonrotor losses become proportionately more
`
`important as FPR [fan pressure ratio] drops.”) That chart shows nearly a 12% loss
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`for the entire bypass flow passage, while the fan rotor and fan static structure each
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`individually contribute only about 2%. As shown, the ’412 patent’s claimed
`
`bypass flow passage pressure ratio accounts for a far more comprehensive locus of
`
`losses than “fan pressure ratio.”
`
`
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`Ignoring these substantial differences, Petitioner’s expert, Dr. Abhari,
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`suggests that the Willis reference (GE-1011) supports equating the ’412 patent’s
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`bypass flow passage pressure ratio with “fan pressure ratio,” because Willis reports
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`a “bypass stream pressure ratio” with the same “1.27” value as a “fan pressure
`
`19
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`

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`ratio.” (Petition at 19, citing GE-1003.036-37 at ¶ 63, which in turn cites GE-
`
`1011.034, .038.)6 But this numerical similarity cannot mean that Willis’ “bypass
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`stream pressure ratio” is the same as the bypass flow passage pressure ratio of the
`
`’412 patent because the bypass flow passage pressure ratio of the ’412 patent
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`encompasses losses from all the other structures in the bypass flow passage in
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`addition to the fan. If the bypass flow passage pressure ratio was identical to the
`
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`6 For claim construction and in Grounds 2 and 4, Petitioner cites two
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`references—Willis (GE-1011) and Wendus (GE-1016)—as purported evidence of
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`the “knowledge of one of ordinary skill in the art.” (Petition 38, 50-51.) But
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`Petitioner has not established that Willis and Wendus qualify as prior-art printed
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`publications. Although the Board has preliminarily found that Petitioner
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`sufficiently established publication in other proceedings, the Board limited its
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`holdings to the records in those cases and indicated it would revisit the publication
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`issue during the trials. (IPR2016-00531, Paper 7 at 10 (Willis); IPR2016-00533,
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`Paper 7 at 11 (Wendus).) The Board should decline to institute this proceeding for
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`the reasons stated in this Preliminary Response, which do not depend on the prior-
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`art status of Willis or Wendus. But if the Board does institute here, UTC may then
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`demonstrate that Petitioner has not met its burden of proving that Willis and
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`Wendus are prior art.
`
`20
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`

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`“fan pressure ratio” of a fan in the passage (e.g., Willis’ 1.27 value), this would
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`mean the passage is a perfectly efficient duct with no losses whatsoever. This, of
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`course, is impossible.7
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`Petitioner’s reliance on Dr. Abhari’s reference to Wendus (GE-1016) is no
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`better. (Petition at 19, citing GE-1003.036-37 at ¶ 63, which in turn cites GE-
`
`1016.018.) Dr. Abhari relies on the following from Wendus to conclude that
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`Wendus’ bypass duct would have “minimal” pressure losses of “no more than
`
`2%:”
`
`fuel
`specific
`[thrust
`sensitivity of TSFC
`The
`consumption] to fan exit guide vane and fan [bypass]
`
`
`7 Moreover, there is nothing in Willis suggesting that Willis intends its
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`undefined “bypass stream pressure ratio” or “fan pressure ratio” to mean the same
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`thing as the bypass flow passage pressure ratio of the ’412 patent. Willis provides
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`numerous other unexplained pressure ratios relating to the fan or the bypass flow,
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`including a “bypass pressure ratio” (GE-1011.039-.041) and a “Fan Rotor Design-
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`Total Pressure Ratio” (GE-1011.058). Willis says nothing about how any of its
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`parameters are similar to or different from one another, much less to the ’412
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`patent’s claimed “pressure ratio . . . with regard to an inlet pressure and an outlet
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`pressure