Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This application is a continuation of application 18/337615 now patent 12098679.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02/23/2026 has been entered.
Claims 1-20 are currently being examined.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-9 and 12-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hoke et al. 20130199200 in view of Cayre et al. FR 3032010A1 (citations are from attached English translation), Gord et al. 20180252868 and NPL 2012 Sadeghbeigi Fluid Catalytic Cracking Handbook.
Regarding independent claim 1, Hoke teaches a method of operating a gas turbine engine (Fig. 1), the gas turbine engine comprising a staged combustor (56 Fig. 2; combustor 56 has 10 duplex nozzles and 6 simplex nozzles per paras. 41-42, such that 56 is a staged combustor in light of instant specification page 27 lines 6-10) comprising an arrangement of fuel spray nozzles (86 Fig. 3; para. 41) in which fuel flow is biased to a subset of the fuel spray nozzles (duplex nozzles 86D; per para. 50 overall (primary plus secondary) fuel flow to the duplex nozzles 86D is increased, i.e., biased to duplex nozzles 86D, in relation to the simplex nozzles 86S) adjacent one or more ignitors (duplex nozzles 86D are adjacent igniters 124 per para. 49) during a procedure (as described in para. 50, at low power conditions, valve 116 is closed and there is increased fuel flow to the duplex nozzles 86D versus to the simplex nozzles 86S), the method comprises providing fuel to the combustor (para. 41 describes the multiple of nozzles 86 (sixteen shown in Fig. 3) are arranged to supply fuel to the combustor 56).
Hoke teaches location arrangement of the duplex nozzles 86D facilitates starting (para. 0043) and although low power can be interpreted as little or no power such as during a starting procedure or a re-light, i.e., reignition, procedure, Hoke does not explicitly teach the procedure at low power conditions is a re-light procedure and Hoke is silent on the fuel having an aromatic content of 10% or lower by volume, and one or more of iso-alkanes and cyclo-alkanes.
Cayre teaches a gas turbine engine (page 2 para. 2 describes an aircraft engine with compressors, a combustor, and turbines, i.e., a gas turbine engine) comprising a combustor (Fig. 1) which comprises an arrangement of fuel spray nozzles (14 Fig. 3) and one or more ignitors (spark plug 128 Fig. 3, i.e., ignitor, page 3 para. 2), and
a controller (30 Fig. 3; page 3 para. 1) which biases fuel flow to a subset of the fuel spray nozzles (a small number of fuel spray nozzles 14 each with respective valve 23 in respective supply pipe 15 in Fig. 3; page 3 para. 2) adjacent the one or more ignitors (per page 3 para. 2, the small number of fuel spray nozzles are preferably adjacent to ignitor 128 as shown in Fig. 3)
during a re-light procedure (page 2 para. 1 and page 3 para. 2 describe when a re-ignition, i.e., re-light, of the combustion chamber is necessary, a valve 28 in Fig. 3 is controlled by controller 30 so as to open the auxiliary circuit and to inject emergency fuel from an auxiliary tank 25 into the fuel spray nozzles concerned which are the two fuel spray nozzles 14 with respective valves 23; each pressure relief valve 23 automatically closes the main supply circuit when the auxiliary circuit is used; the outlet duct 126 comprises a calibrated section 127 Fig. 3 which adjusts the delivery rate of the emergency fuel to the two fuel spray nozzles close to the ignitor 128 Fig. 3 of the combustion chamber, and which are also fed in normal service by the main circuit line),
the fuel having an aromatic content of 10% or lower by volume (per page 3 para. 1, fuel in auxiliary tank 25 is more easily flammable to favor reignition, i.e., re-light, and per page 3 para. 3 the fuel may be propane, butane or hydrogen, each of which has zero aromatic content which is 10% or lower by volume as claimed).
Propane, butane, and hydrogen each have zero aromatic content as evidenced by Sadeghbeigi since an aromatic was a compound that must contain at least one benzene ring (page 1 of chapter FCC Feed Characterization) and propane, butane, and hydrogen each do not contain at least one benzene ring.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the invention of Hoke to bias fuel flow to the subset of the fuel spray nozzles during a re-light procedure and to supply the subset of the fuel spray nozzles with fuel having an aromatic content of 10% or lower by volume as taught by Cayre to deliver emergency fuel when fuel supplying the combustion chamber may not be able to ignite under certain circumstances, in particular low pressures or low temperatures at altitude, after a shutdown of the combustion chamber (Cayre page 1 Description para. 1), and having the emergency fuel be propane, butane or hydrogen which was more flammable and had no aromatic content, which is 10% or lower by volume to enable successful ignition and force a re-light (Cayre Abstract).
Hoke in view of Cayre is silent regarding the fuel having one or more of iso-alkanes and cyclo-alkanes.
Gord teaches isobutane is commonly used in IC internal combustion devices per [0041]. Isobutane was an iso-alkane and did not contain a benzene ring such that isobutane had zero aromatic content which is 10% or lower by volume as claimed.
The selection of a known material based on its suitability for its intended use was an obvious extension of prior art teachings, In re Leshin, 227 F.2d 197, 125 USPQ 416 (CCPA 1960), MPEP 2144.07.
It would have been obvious to one of ordinary skill in the art, prior to the effective filing date of the claimed invention, to modify the invention of Hoke in view of Cayre to have the fuel provided to the combustor include isobutane since isobutane was known as a suitable fuel used for internal combustion engines such as gas turbine engines.
Regarding independent claim 12, Hoke teaches a gas turbine engine (Fig. 1) for an aircraft (para. 2), comprising:
a staged combustor (56 Fig. 2; combustor 56 has 10 duplex nozzles and 6 simplex nozzles per paras. 41-42, such that 56 is a staged combustor in light of instant specification page 27 lines 6-10) comprising an arrangement of fuel spray nozzles (86 Fig. 3; para. 41) and one or more ignitors (124 Fig. 3 para. 49); and
a controller (120 Fig. 6 para. 46-47) configured to bias fuel flow to a subset of the fuel spray nozzles (duplex nozzles 86D; per para. 50 overall (primary plus secondary) fuel flow to the duplex nozzles 86D is increased, i.e., biased to duplex nozzles 86D, in relation to the simplex nozzles 86S) adjacent the one or more ignitors (duplex nozzles 86D are adjacent igniters 124 per para. 49) during a procedure (as described in para. 50, at low power conditions, valve 116 is closed and there is increased fuel flow to the duplex nozzles 86D versus to the simplex nozzles 86S).
Hoke teaches location of the duplex nozzles 86D facilitates starting (para. 0043) and although low power can be interpreted as little or no power such as during a starting procedure or a re-light, i.e., reignition, procedure, Hoke does not explicitly teach the procedure at low power conditions is a re-light procedure and Hoke is silent on the fuel having an aromatic content of 10% or lower by volume, and one or more of iso-alkanes and cyclo-alkanes.
Cayre teaches a gas turbine engine (page 2 para. 2 describes an aircraft engine with compressors, a combustor, and turbines, i.e., a gas turbine engine) comprising a combustor (Fig. 1) which comprises an arrangement of fuel spray nozzles (14 Fig. 3) and one or more ignitors (spark plug 128 Fig. 3, i.e., ignitor, page 3 para. 2), and a controller (30 Fig. 3; page 3 para. 1) which biases fuel flow to a subset of the fuel spray nozzles (a small number of fuel spray nozzles 14 each with respective valve 23 in respective supply pipe 15 in Fig. 3; page 3 para. 2) adjacent the one or more ignitors (per page 3 para. 2, the small number of fuel spray nozzles are preferably adjacent to ignitor 128 as shown in Fig. 3)
during a re-light procedure (page 2 para. 1 and page 3 para. 2 describe when a re-ignition, i.e., re-light, of the combustion chamber is necessary, a valve 28 in Fig. 3 is controlled by controller 30 so as to open the auxiliary circuit and to inject emergency fuel from an auxiliary tank 25 into the fuel spray nozzles concerned which are the two fuel spray nozzles 14 with respective valves 23; each pressure relief valve 23 automatically closes the main supply circuit when the auxiliary circuit is used; the outlet duct 126 comprises a calibrated section 127 Fig. 3 which adjusts the delivery rate of the emergency fuel to the two fuel spray nozzles close to the ignitor 128 Fig. 3 of the combustion chamber, and which are also fed in normal service by the main circuit line),
the fuel having an aromatic content of 10% or lower by volume (per page 3 para. 1, fuel in auxiliary tank 25 is more easily flammable to favor reignition, i.e., re-light, and per page 3 para. 3 the fuel may be propane, butane or hydrogen, each of which has zero aromatic content which is 10% or lower by volume as claimed).
Propane, butane, and hydrogen each had zero aromatic content as evidenced by Sadeghbeigi since an aromatic was a compound that must contain at least one benzene ring (page 1 of chapter FCC Feed Characterization) and propane, butane, and hydrogen each did not contain at least one benzene ring.
It would have been obvious to one of ordinary skill in the art, prior to the effective filing date of the claimed invention, to modify the invention of Hoke to bias fuel flow to the subset of the fuel spray nozzles during a re-light procedure and to supply the subset of the fuel spray nozzles with fuel having an aromatic content of 10% or lower by volume as taught by Cayre to deliver emergency fuel when fuel supplying the combustion chamber may not be able to ignite under certain circumstances, in particular low pressures or low temperatures at altitude, after a shutdown of the combustion chamber (Cayre page 1 Description para. 1), and having the emergency fuel be propane, butane or hydrogen which is more flammable and has no aromatic content, which is 10% or lower by volume to enable successful ignition and force a re-light (Cayre Abstract).
Hoke in view of Cayre is silent regarding the fuel having one or more of iso-alkanes and cyclo-alkanes.
Gord teaches isobutane was commonly used in IC internal combustion devices per [0041]. Isobutane was an iso-alkane and did not contain a benzene ring such that isobutane had zero aromatic content which is 10% or lower by volume as claimed.
The selection of a known material based on its suitability for its intended use was an obvious extension of prior art teachings, In re Leshin, 227 F.2d 197, 125 USPQ 416 (CCPA 1960), MPEP 2144.07.
It would have been obvious to one of ordinary skill in the art, prior to the effective filing date of the claimed invention, to modify the invention of Hoke in view of Cayre to have the fuel provided to the combustor include isobutane since isobutane was known as a suitable fuel used for internal combustion engines such as gas turbine engines.
Regarding claims 2 and 13, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and teaches (claim 2) the fuel (claim 13) providing the fuel having an aromatic content of 5% or lower by volume (isobutane has no aromatic content which is 5% or lower by volume as claimed).
Regarding claims 3 and 14, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and teaches (claim 3) the fuel (claim 14) providing the fuel having an aromatic content of 1% or lower by volume (isobutane has no aromatic content which is 1% or lower by volume as claimed).
Regarding claims 4 and 15, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and Hoke further teaches wherein a number of fuel spray nozzles is between 14 and 22 (there are 16 fuel spray nozzles 86 in Fig. 3, para. 43; 16 is between 14 and 22) and/or a number of fuel spray nozzles per unit engine core size is 2 to 6.
Regarding claim 5, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and Hoke further teaches wherein the subset of fuel spray nozzles comprises at least one half of a total number of fuel spray nozzles (there are 10 duplex nozzles 86D which is at least half of 16).
Regarding claim 6, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above in claim 5 but is silent as discussed so far wherein the subset of fuel spray nozzles comprises at least two thirds of the total number of fuel spray nozzles which is essentially a range of two thirds to 100% of the total number of fuel spray nozzles.
Hoke teaches 10 of 16 fuel spray nozzles are duplex nozzles to which fuel is biased which is 5/8 of the total number of fuel spray nozzles which is close to the claimed at least 2/3. Per MPEP 2144.05 I.: “a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties.").
In addition, since in the instant application specification, Applicant does not provide any advantage or unpredictable effect of the subset comprising at least two thirds of the total number of fuel spray nozzles versus the subset comprising at least one half of the total number of fuel spray nozzles, having the subset comprise slightly less than two thirds of the total number of fuel spray nozzles would predictably achieve the same benefit as having two thirds the total number.
Therefore, the claimed range of the subset of fuel spray nozzles comprising at least two thirds of the total number of fuel spray nozzles would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention over the invention of Hoke in view of Cayre, Gord and Sadeghbeigi.
Regarding claim 7, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and Hoke further teaches wherein the arrangement of fuel spray nozzles comprises duplex nozzles (86D Fig. 3 para. 43) and single flow nozzles (86S Fig. 3 para. 43; 86S has a single secondary flow jet 102 in Fig. 5, not a primary flow jet 100 and secondary flow jet 102 like duplex nozzles 86D).
Regarding claim 8, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above in claim 7 and wherein the subset of fuel spray nozzles comprises the duplex nozzles (as cited in claim 1, subset of fuel spray nozzles comprises duplex nozzles 86D) and the remaining fuel spray nozzles comprise the single flow nozzles (fuel spray nozzles other than duplex nozzles 86D are single flow nozzles 86S in Fig. 3).
Regarding claims 9 and 18, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and Hoke further teaches wherein the combustor comprises at least two ignitors (124 Fig. 3; 2 are shown in Fig. 3) and the subset of fuel spray nozzles comprises at least two groups of nozzles (group of 6-D and 7-D, group of 5-D and 4-D in Fig. 3), each group of nozzles adjacent one of the ignitors (each group is adjacent one of ignitors 124 in Fig. 3, also each ignitor 124 is adjacent each group since each ignitor is between the two groups).
Regarding claim 16, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and Hoke further teaches wherein the subset of fuel spray nozzles comprises at least one half of a total number of fuel spray nozzles (there are 10 duplex nozzles 86D which is at least half of 16).
Regarding claim 17, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and Hoke further teaches wherein the arrangement of fuel spray nozzles comprises duplex nozzles (86D Fig. 3 para. 43) and single flow nozzles (86S Fig. 3 para. 43; 86S has a single secondary flow jet 102 in Fig. 5, not a primary flow jet 100 and secondary flow jet 102 like duplex nozzles 86D).
Claim(s) 10 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hoke et al. 20130199200 in view of Cayre et al. FR 3032010A1, Gord et al. 20180252868 and NPL 2012 Sadeghbeigi Fluid Catalytic Cracking Handbook as applied to, respectively, claims 9 and 18 above, and further in view of Venkataramani et al. 5257500.
Regarding claims 10 and 19, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above but is silent as discussed so far wherein the gas turbine engine comprises a plurality of ignitors disposed symmetrically about a circumference of the combustor.
Venkataramani teaches ignition of jet aircraft fuels at high altitudes using plasma jet igniters (col 1 lines 6-8) including during re-lighting the air fuel mixture in the combustor during flame-out conditions (col 3 lines 29-34). Venkataramani teaches a gas turbine engine (per col 2 lines 32-35: Fig. 1 is a combustor dome of a conventional jet engine) comprises a plurality of ignitors (as described in col 3 lines 6-8: although only one ignitor 12 is shown in Fig. 2, another ignitor may be provided diametrically across the combustor dome; as also described in col 3 lines 10-12: several ignitors may be mounted in place of conventional ignitors or in addition to conventional ignitors). Modifying the invention of Hoke in view of Cayre to have additional ignitors respectively positioned diametrically opposite each of the ignitors shown in Fig. 3 of Hoke as taught by Venkataramani results in a plurality of ignitors disposed symmetrically about a circumference of the combustor as claimed since each additional ignitor is 180 degrees apart from a respective ignitor shown in Fig. 3.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the invention of Hoke in view of Cayre, Gord and Sadeghbeigi wherein the gas turbine engine comprises a plurality of ignitors disposed symmetrically about a circumference of the combustor as taught by Venkataramani to provide an ignition system which will reliably relight the jet engine combustor during flight (Venkataramani col 1 lines 17-22) as well as to provide ignitor redundancy for flight safety reasons.
Claim(s) 11 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hoke et al. 20130199200 in view of Cayre et al. FR 3032010A1, Gord et al. 20180252868 and NPL 2012 Sadeghbeigi Fluid Catalytic Cracking Handbook as applied to, respectively, claims 1 and 12 above, and further in view of NPL 2011 Boundy et al. Biomass Energy Data Book: Edition 4.
Regarding claims 11 and 20, Hoke in view of Cayre, Gord and Sadeghbeigi teaches all that is claimed above and teaches wherein:
a) the fuel provided to the combustor has a calorific value of at least 43.5 MJ/kg (isobutane had a heating value, i.e., a calorific value, of 44.862 MJ/kg to 49.096 MJ/kg as evidenced by NPL Boundy in Appendix A which is at least 43.5 MJ/kg as claimed); and/or
b) the gas turbine engine comprises a fuel-oil heat exchanger, and
(claim 11) the method comprises transferring
(claim 20) the controller is arranged to transfer
heat from oil to the fuel before the fuel enters the combustor so as to lower fuel viscosity to 0.58 mm2/s or lower on entry to the combustor at cruise conditions.
Response to Arguments
Applicant's arguments filed 01/16/2026 have been fully considered but are moot as the arguments are regarding the currently amended claims 1 and 12 which require providing fuel to the combustor having one or more of iso-alkanes and cyclo-alkanes. Newly cited prior art Gord et al. 20180252868 is relied on in the current 103 rejections of claims 1 and 12 as teaching the fuel includes isobutane which is an iso-alkane. Applicant does not argue the dependent claims.
Conclusion
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/A.J.H./Examiner, Art Unit 3741
/LORNE E MEADE/Primary Examiner, Art Unit 3741