DETAILED ACTION
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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 03/12/2026 has been entered.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1, 2, 4, 6, 8, 13-18 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 1, 17, “the corresponding phase parameter at the second monitoring location” lacks proper antecedent basis.
Claim 4th paragraph from the end: “and operating the fuel system based on the phase parameter” is indefinite as it is unclear if this is using one or both of “phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location” -- note these are not necessarily the same phase parameter at the different locations. See also claim 17, last paragraph for analogous issues.
Furthermore, subsequent use of “when the phase parameter is indicative that the fuel at the second monitoring location” does not use the same language as the previously “corresponding phase parameter” and analogous recitations – see e.g. rest of claim 1, 17 as well as claim 13.
Claim Rejections - 35 USC § 103
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.
Claim(s) 1, 2, 4, 6, 8, 13, 16, 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Miller et al (2023/0366353) in view of Miller et al (2022/0403783) and either Kunizawa et al (2022/0298745) or Palmer (2023/0092811). Miller et al ‘353 [e.g. Fig. 3] teach An operating method for an aircraft powerplant, comprising: directing fuel in a first fuel circuit from a fuel source 210 towards a fuel injector 174 in a combustion section of the aircraft powerplant, wherein a fuel system 200 for the aircraft powerplant includes the fuel source, the first fuel circuit and the fuel injector, and the fuel system is configured to fluidly couple the fuel source to the fuel injector through the first fuel circuit; heating the fuel with a first fuel heater 221, wherein the first fuel heater is disposed downstream of the fuel source 210 along the first fuel circuit; and operating the fuel system based on the phase parameter, the fuel system operated in a first mode where the phase of the fuel being in a gaseous phase [223 off], and the fuel system operated in a second mode where the phase being in a liquid phase or a mixed phase with a first portion of the fuel in the liquid phase and a second portion of the fuel in the gaseous phase [223 on, see ¶ 0043 which teaches 223 is operated when 221 is insufficient to reach the desired temperature]; wherein the fuel system further includes a second fuel heater 223 and the first fuel heater 221 along the first fuel circuit; wherein during the first mode, the fuel system directs the fuel from the first fuel circuit to the fuel injector; and wherein during the second mode [223 on], the fuel system further heats the fuel using the second fuel heater 223 prior to directing the fuel from the first fuel circuit to the fuel injector 174. (2) wherein the fuel comprises hydrogen fuel. (4) wherein the second fuel heater 223 is non-operational during the first mode [¶ 0043]. (6) wherein the second fuel heater 223 does not heat the fuel directed from the fuel source to the fuel injector during the first mode [¶ 0043]. (8) wherein the first fuel heater comprises a heat exchanger 221 which transfers heat energy from combustion products to be exhausted from the aircraft powerplant into the fuel [¶ 0032 teaches the heat exchanger may be in the turbine section or exhaust section for the waste heat source for e.g. 225]. (16) wherein the aircraft powerplant comprises a turbine engine. (17) An operating method for an aircraft powerplant, comprising: directing fuel in a liquid phase from a fuel source into a fuel delivery circuit 200, wherein a fuel system for the aircraft powerplant includes the fuel source 210, the fuel delivery circuit 200, a primary fuel heater 221, a secondary fuel heater 223 and a fuel injector 174, and wherein the fuel injector 174 is disposed in a combustion section of the aircraft powerplant; heating the fuel in the fuel delivery circuit using the primary fuel heater 221 to change the fuel into a gaseous phase or into a mixed phase with a first portion of the fuel in the liquid phase and a second portion of the fuel in the gaseous phase; and operating the fuel system based on the phase, the fuel system delivering the fuel to the fuel injector 174 when the phase of the fuel is in the gaseous phase, and the fuel system further heating the fuel with the secondary fuel heater 223 when the phase of the fuel is in the mixed phase such that the fuel in the mixed phase changes into the gaseous phase for subsequent delivery to the fuel injector 174; wherein the secondary fuel heater 223 is arranged downstream of the primary fuel heater 221. Miller et ‘353 specifically teach
“[0043] The secondary vaporizer 223 of this embodiment is a combination start-up and trim vaporizer that may used to heat the liquid hydrogen fuel flowing through the fuel delivery assembly 202 when the main vaporizer 221 is not sufficient to heat the hydrogen fuel. During start-up of the engine 100, for example, the engine 100 may not be in a thermally stable condition, and the secondary vaporizer 223 is used during start-up (or prior to start-up) to heat the hydrogen fuel instead of the main vaporizer 221. In this example, the secondary vaporizer 223 operates as a start-up vaporizer. In another example, the main vaporizer 221 may not be heating the hydrogen fuel to the desired temperature and, thus, the secondary vaporizer 223 operates as a trim vaporizer to add supplemental heat to the hydrogen fuel and heat the hydrogen fuel to the desired temperature. Such a condition may occur when, for example, the heat provided by the primary heat source 225 to the main vaporizer 221 is not sufficient to heat the hydrogen fuel to the desired temperature.”
In other words, Miller et al ‘353 already suggest the knowledge of the temperatures and phase parameter of the first / primary and second / secondary fuel heaters would be desirable so as to know when to determine when to turn on the second fuel heater 223 on and off for the supplementary heating.
Miller et al ‘353 do not explicitly teach monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location at the first fuel heater, and at a corresponding second monitoring location between the first fuel heater and the fuel injector, wherein the phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location; and operating the fuel system based on the phase parameter, the fuel system operated in a first mode where the phase parameter is indicative of the fuel at the second monitoring location being in a gaseous phase, and the fuel system operated in a second mode where the phase parameter is indicative of the fuel at the second monitoring location being in a liquid phase or a mixed phase with a first portion of the fuel in the liquid phase and a second portion of the fuel in the gaseous phase at the second monitoring location; second fuel heater arranged between the second monitoring location and the first fuel heater along the first fuel circuit; (13) continued monitoring of the phase parameter during the operating of the fuel system in the second mode; and switching from the second mode to the first mode once the phase parameter is indicative of the fuel at the second monitoring location being in the gaseous phase; (17) determining a phase parameter of the fuel within the fuel delivery circuit at a first monitoring location at the primary fuel heater, and at a second monitoring location downstream of the primary fuel heater, wherein the phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location; and operating the fuel system based on the phase parameter, the fuel system delivering the fuel to the fuel injector when the phase parameter is indicative that the fuel at the second monitoring location is in the gaseous phase, and the fuel system further heating the fuel with the secondary fuel heater when the phase parameter is indicative that the fuel at the second monitoring location is in the mixed phase such that the fuel in the mixed phase changes into the gaseous phase for subsequent delivery to the fuel injector; the secondary fuel heater is arranged … upstream of the second monitoring location.
Miller et al ‘783 teach monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location [104, see annotations 80 and adjacent first heater 98, see ¶ 0040-0041], and at a second monitoring location 104 [see annotations, e.g. between 90 and 100] between the first fuel heater [first of 98] and the fuel injector, wherein the phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location 104 [see annotations]; and operating the fuel system based on the phase parameter, the fuel system operated in a first mode where the phase parameter is indicative of the fuel at the second monitoring location 104 [see annotations] being in a gaseous phase, and the fuel system operated in a second mode where the phase parameter is indicative of the fuel at the second monitoring location 104 [see annotations] being in a liquid phase or a mixed phase with a first portion of the fuel in the liquid phase and a second portion of the fuel in the gaseous phase at the second monitoring location 104 [see annotations]; wherein the fuel system further includes a second fuel heater [last of multiple heat exchangers 98] arranged between the second monitoring location [see annotations] and the first fuel heater [first of multiple heat exchangers 98] along the first fuel circuit; (13) continued monitoring of the phase parameter during the operating of the fuel system in the second mode; and switching from the second mode to the first mode once the phase parameter is indicative of the fuel at the second monitoring location being in the gaseous phase [note fuel is desired to be gaseous for combustion, ¶ 0061]; (17) determining a phase parameter of the fuel within the fuel delivery circuit at a first monitoring location [additional sensor 104, see ¶ 0040-0041], and at a second monitoring location downstream of the primary fuel heater, wherein the phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location 104 [between 90 and 100]; and operating the fuel system based on the phase parameter, the fuel system delivering the fuel to the fuel injector when the phase parameter is indicative that the fuel at the second monitoring location 104 [between 90 and 100] is in the gaseous phase, and the fuel system further heating the fuel with the secondary fuel heater when the phase parameter is indicative that the fuel at the second monitoring location is in the mixed phase such that the fuel in the mixed phase changes into the gaseous phase for subsequent delivery to the fuel injector; wherein the secondary fuel heater [second 90] is arranged downstream of the primary fuel heater [first 90] and upstream of the second monitoring location 104 [see annotations]. As Miller ‘783 teach the first monitoring location is adjacent the first fuel heater and the second monitoring location is downstream of the thermal management system 90, which includes multiple (first, second or primary, secondary) heat exchangers, the monitoring locations are analogous to that disclosed since the knowledge of the fuel phase / state at the second monitoring location, prior to fuel injection, allows the controller to utilize the sensed parameters, including the pressures and temperatures, determine the fuel state/phase [¶ 0066-0068] and then control the heating of the heat exchangers 90, 98 to control the fuel state [¶ 0066-0068].
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It would have been obvious to one of ordinary skill in the art to obvious to employ monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location, and at a corresponding second monitoring location between the first fuel heater and the fuel injector, i.e. adding the second monitoring location downstream the second fuel heater / secondary fuel heater arranged … upstream of the second monitoring location / second fuel heater arranged between the second monitoring location and the first fuel heater, specifically by:
monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location, and at a corresponding second monitoring location between the first fuel heater and the fuel injector, wherein the phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location; and operating the fuel system based on the phase parameter, the fuel system operated in a first mode where the phase parameter is indicative of the fuel at the second monitoring location being in a gaseous phase, and the fuel system operated in a second mode where the phase parameter is indicative of the fuel at the second monitoring location being in a liquid phase or a mixed phase with a first portion of the fuel in the liquid phase and a second portion of the fuel in the gaseous phase at the second monitoring location; a second fuel heater arranged between the second monitoring location and the first fuel heater along the first fuel circuit wherein the second fuel heater is arranged between the second monitoring location and the first fuel heater along the first fuel circuit; (13) continued monitoring of the phase parameter during the operating of the fuel system in the second mode; and switching from the second mode to the first mode once the phase parameter is indicative of the fuel at the second monitoring location being in the gaseous phase; (17) determining a phase parameter of the fuel within the fuel delivery circuit at a first monitoring location 104 [see annotations], and at a second monitoring location 104 [see annotations] downstream of the primary fuel heater, wherein the phase parameter at the first monitoring location supplements the phase parameter at the second monitoring location; and operating the fuel system based on the phase parameter, the fuel system delivering the fuel to the fuel injector when the phase parameter is indicative that the fuel at the second monitoring location is in the gaseous phase, and the fuel system further heating the fuel with the secondary fuel heater when the phase parameter is indicative that the fuel at the second monitoring location is in the mixed phase such that the fuel in the mixed phase changes into the gaseous phase for subsequent delivery to the fuel injector; the secondary fuel heater is arranged … upstream of the second monitoring location,
as taught by Miller et al ‘783, because using a phase between the first fuel heater and the fuel injector for the second monitoring location, secondary fuel heater is arranged … upstream of the second monitoring location / second fuel heater arranged between the second monitoring location and the first fuel heater, are the typical location used in the art so that the fuel phase / condition is known before combustion by the fuel injectors in order to facilitate controlling the fuel heaters based on the desired phase of the fuel prior to entering the fuel injector / combustor [see ¶ 0066-0068]. Note that the first monitoring location 104 of Miller ‘783 is upstream and adjacent the first fuel heater rather than at the first / primary heater. Kunizawa et al teach [Fig. 3] monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location 44B at the first / primary fuel heater [vaporizer 39] and teaches the benefit of monitoring the phase parameter at the fuel heater 39 allows knowing if the fuel is vaporized from the first / primary fuel heater. Kunizawa et al can also be regarded as broadly teaching the monitoring location is between each fuel heater 39 and the fuel injector 37 so that the outlet conditions of the vaporizer [gas vs liquid] are known, if multiple fuel heaters in series were used as is done in Miller et al ‘353. Alternately, Palmer [Fig. 6] teaches monitoring a phase parameter [temperature 644] of the fuel within the first fuel circuit at a first monitoring location 644 at the first fuel heater [vaporizer / recuperator 501] and teaches the benefit of monitoring the phase parameter at the first / primary fuel heater 39 allows knowing if the fuel is vaporized from the first fuel heater 501 [note line 605 is a gaseous fuel line ¶ 0135]. It would have been further have been obvious to one of ordinary skill in the art to employ monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location at the first fuel heater, and determining a phase parameter of the fuel within the fuel delivery circuit at a first monitoring location at the first / primary fuel heater, rather than immediately upstream thereof, as taught by either Kunizawa et al or Palmer, in order to know the phase conditions at the outlet of the first heater to determine if sufficient vaporization / temperature was reached by the first fuel heater, which is consistent with the requirements of Miller ‘353 and teachings of Miller ‘783. Note that Miller ‘783 teaches using multiple sensors throughout the fuel flow path [including upstream the first fuel heater] to supplement the phase parameter at the second monitoring location [downstream the second fuel heater] to know the phase parameter at different locations within the fuel system and in order to know the phase conditions at the outlet of the first heater to determine if sufficient vaporization / temperature was reached by the first fuel heater, which is consistent with the requirements of Miller et al ‘353. Accordingly, by applying the teachings of either Kunizawa et al or Palmer of monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location at the first fuel heater, vs upstream the first fuel heater, this is an alternative position well known in the art that indicates the phase / temperature conditions at the first fuel heater and indicates what phase conditions have been reached at the first fuel heater. It would have been obvious to employ wherein the phase parameter at the first monitoring location [of the first / primary fuel heater of Kunizawa et al or Palmer- teach the phase parameter at the first monitoring location allows for knowledge of the flow at the exit of the vaporizer] to supplement the phase parameter at the second monitoring location, as taught by Miller ‘783, noting that the Miller ‘783 teaches using multiple sensors throughout the fuel flow path [including upstream the second fuel heater] to supplement the phase parameter at the second monitoring location to know the phase parameter at different locations within the fuel system and in order to know the phase conditions at the outlet of the first heater to determine if sufficient vaporization / temperature was reached by the first fuel heater, which is consistent with the requirements of Miller et al ‘353 when to turn on and off the second fuel heater to have sufficient vaporization / temperature for combustion.
In combination, the above prior art [abbreviated M ’353, M’783, K or P] teach: (1) … heating the fuel with a first fuel heater [M ‘353], wherein the first fuel heater is disposed downstream of the fuel source along the first fuel circuit [M ‘353]; monitoring a phase parameter of the fuel within the first fuel circuit at a first monitoring location [M’783] at the first fuel heater K or P], and at a second monitoring location [M ‘783] between the first fuel heater and the fuel injector [of M ‘353], wherein the phase parameter at the first monitoring location [from K] supplements the phase parameter at the second monitoring location [M ‘783]; and operating the fuel system based on the phase parameter, the fuel system operated in a first mode [M’353] where the phase parameter is indicative of the fuel at the second monitoring location being in a gaseous phase [M ‘783], and the fuel system operated in a second mode [M ‘353 teaches using the secondary fuel heater to achieve the desired temperature (of vaporization)] where the phase parameter is indicative of the fuel at the second monitoring location [M ‘783] being in a liquid phase or a mixed phase with a first portion of the fuel in the liquid phase and a second portion of the fuel in the gaseous phase at the second monitoring location [M ‘783]; wherein the fuel system further includes a second fuel heater [of M ‘353] arranged between the second monitoring location [M ‘783] and the first fuel heater [of M ‘353] along the first fuel circuit; wherein during the first mode, the fuel system directs the fuel from the first fuel circuit to the fuel injector; and wherein during the second mode, the fuel system further heats the fuel using the second fuel heater [of M ‘353] prior to directing the fuel from the first fuel circuit to the fuel injector [of M ‘353].
(17) … determining a phase parameter of the fuel within the fuel delivery circuit at a first monitoring location [K or P at the primary fuel heater [M ‘353], and at a second monitoring location [M ‘783] downstream of the primary fuel heater [M ‘353], wherein the phase parameter at the first monitoring location [K or P] supplements the phase parameter at the second monitoring location [M ‘783]; and operating the fuel system based on the phase parameter, the fuel system delivering the fuel to the fuel injector when the phase parameter is indicative that the fuel at the second monitoring location [M ‘783] is in the gaseous phase [M’353], and the fuel system further heating the fuel with the secondary fuel heater [M ‘353 teaches using the secondary fuel heater to achieve the desired temperature (of vaporization)] when the phase parameter is indicative that the fuel at the second monitoring location [M ‘783] is in the mixed phase such that the fuel in the mixed phase changes into the gaseous phase for subsequent delivery to the fuel injector.
Claim(s) 14, 15, 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Miller et al (2023/0366353) in view of Miller et al (2022/0403783) and either Kunizawa et al (2022/0298745) or Palmer (2023/0092811), as applied above, and further in view of Dindar et al (11873768) and for claim 18 further in view of Muldoon et al (2022/0381185). Miller et al do not teach (14) wherein the fuel system further includes a gaseous fuel source; the fuel system fluidly decouples the gaseous fuel source from the fuel injector during the first mode; and the fuel system fluidly couples the gaseous fuel source to the fuel injector during the second mode; (15) directing a portion of the fuel in the gaseous phase from the first fuel circuit into the gaseous fuel source; nor (18) delivering gaseous fuel to the fuel injector from a gaseous fuel source at least while the secondary fuel heater is heating the fuel to change from the mixed phase to the gaseous phase. Dindar et al teach (14) wherein the fuel system further includes a gaseous fuel source 262 in additional to the liquid fuel source 252; the fuel system fluidly decouples 268 the gaseous fuel source from the fuel injector 272 during the first mode [if the amount of gaseous hydrogen produced by the vaporizer 260 is sufficient, then 258, 260 may provide all the vaporized fuel and 268 is decoupled]; and the fuel system fluidly couples 268 the gaseous fuel source 261 to the fuel injector during the second mode [gaseous fuel 261 is added during the second mode when vaporized gases from 260 is insufficient, see paragraph bridging cols. 14-15]; (15) directing a portion of the fuel in the gaseous phase 270, 261 from the first fuel circuit into the gaseous fuel source 262; and (18) delivering gaseous fuel to the fuel injector 272 from a gaseous fuel source 262 at least while the fuel heater 260 is heating the fuel to change from the liquid or mixed phase to the gaseous phase. It would have been obvious to one of ordinary skill in the art to utilize (14) wherein the fuel system further includes a gaseous fuel source; the fuel system fluidly decouples the gaseous fuel source from the fuel injector during the first mode; and the fuel system fluidly couples the gaseous fuel source to the fuel injector during the second mode; (15) directing a portion of the fuel in the gaseous phase from the first fuel circuit into the gaseous fuel source, in the manner taught by Dindar et al, in order to provide gaseous fuel in the first mode which facilitates quicker startup at later times of operation, as this facilitates storing and utilizing the gaseous fuel when desired, including in the second mode. It would have been obvious to one of ordinary skill in the art to employ (18) delivering gaseous fuel to the fuel injector from a gaseous fuel source at least while the secondary fuel heater is heating the fuel to change from the mixed phase to the gaseous phase, as Dindar teaches delivering the gaseous fuel from the gaseous fuel source allows for ensuring sufficient gaseous fuel is delivered according to the desired amounts. As for delivering the gaseous fuel at least while the secondary fuel heater is heating the fuel to change from the mixed phase to the gaseous phase, this is further rendered obvious by Muldoon et al. Muldoon et al teach (18) delivering gaseous fuel 510 to the fuel injector from a gaseous fuel source 510 at least while the fuel heater is heating the fuel to change from the mixed phase to the gaseous phase during start-up [see ¶ 0048, 0063] -- note the fuel heater is heating the liquid fuel to gaseous phase during start-up while the gaseous hydrogen fuel is actually starting the main engine, and note that heating liquid to gaseous phase from an initially liquid phase, will inherently cover a two-phase condition, as both phases will be present at least during some time during such a heating condition and facilitates starting the engine with gaseous hydrogen during a multiplicity of conditions, including flame-out and/or providing redundancy with the main hydrogen starting system [¶ 0063]. It would have been obvious to one of ordinary skill in the art to employ (18) delivering gaseous fuel to the fuel injector from a gaseous fuel source at least while the secondary fuel heater is heating the fuel to change from the mixed phase to the gaseous phase, as taught by Muldoon et al, as the gaseous fuel source is utilized during the start-up condition to enhance starting with hydrogen, including during flame-out conditions and/or to provide redundancy of starting by operating with an available source of gaseous hydrogen during startup.
Response to Arguments
Applicant's arguments filed 3/12/2026 have been fully considered but they are not persuasive.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, Miller ‘783 teach the first monitoring location is adjacent the first fuel heater and the second monitoring location is downstream of the thermal management system 90, which includes multiple (first, second or primary, secondary) heat exchangers, the monitoring locations are analogous to that disclosed since the knowledge of the fuel phase / state at the second monitoring location, prior to fuel injection, allows the controller to utilize the sensed parameters, including the pressures and temperatures, determine the fuel state/phase [¶ 0066-0068] and then control the heating of the heat exchangers 90, 98 to control the fuel state [¶ 0066-0068]. Miller ‘783 clearly provide a teaching of using the monitoring locations to control the fuel phase, and is consistent with the teachings of Miller ‘353 who desires to do the same thing.
Applicant’s arguments are not persuasive as they misconstrue the references. To arrive at the claimed invention, the combination uses the first and second fuel heaters from Miller 353, and using multiple sensors is taught by Miller ‘783, where the first monitoring location is adjacent the first fuel heater and the second monitoring location is downstream of the thermal management system 90, which includes multiple (first, second or primary, secondary) heat exchangers, the monitoring locations are analogous to that disclosed since the knowledge of the fuel phase / state at the second monitoring location, prior to fuel injection. Making one of the phase monitoring locations at the first / primary fuel heater is taught by either Kunizawa or Palmer, and facilitates determining when the second fuel of Miller ‘353 can be turned on or off.
Miller et ‘353 specifically teaching:
“[0043] The secondary vaporizer 223 of this embodiment is a combination start-up and trim vaporizer that may used to heat the liquid hydrogen fuel flowing through the fuel delivery assembly 202 when the main vaporizer 221 is not sufficient to heat the hydrogen fuel. During start-up of the engine 100, for example, the engine 100 may not be in a thermally stable condition, and the secondary vaporizer 223 is used during start-up (or prior to start-up) to heat the hydrogen fuel instead of the main vaporizer 221. In this example, the secondary vaporizer 223 operates as a start-up vaporizer. In another example, the main vaporizer 221 may not be heating the hydrogen fuel to the desired temperature and, thus, the secondary vaporizer 223 operates as a trim vaporizer to add supplemental heat to the hydrogen fuel and heat the hydrogen fuel to the desired temperature. Such a condition may occur when, for example, the heat provided by the primary heat source 225 to the main vaporizer 221 is not sufficient to heat the hydrogen fuel to the desired temperature.”
As Miller ‘353 requires knowledge of the phase through each of the first vaporizer / heater and second vaporizer/heater to operate to turn the second vaporizer on or off, and the same inventor, Miller ‘783, recognizes that the sensing at multiple monitoring locations is needed for controlling the heaters and the fuel phase prior to fuel injection to regulate control over the plurality of fuel heaters. Furthermore, Kunizawa and Palmer teach using the location of one of the sensors (first) at the first fuel heater, this is an entirely conventional location and obvious so that operation of the first fuel heater phase is known.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Contact Information
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TED KIM whose telephone number is 571-272-4829. The Examiner can be reached on regular business hours before 5:00 pm, Monday to Thursday and every other Friday.
The fax number for the organization where this application is assigned is 571-273-8300.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer, can be reached at 571-272-7118. Alternate inquiries to Technology Center 3700 can be made via 571-272-3700.
Information regarding the status of an application may be obtained from Patent Center https://www.uspto.gov/patents/apply/patent-center. Should you have questions on Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). General inquiries can also be directed to the Inventors Assistance Center whose telephone number is 800-786-9199. Furthermore, a variety of online resources are available at https://www.uspto.gov/patent
/Ted Kim/
Telephone
571-272-4829
Primary Examiner
Fax
571-273-8300
June 24, 2026
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