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 .
Drawings
The drawings were received on 10/28/2025. These drawings are accepted.
Claim Objections
Claim 14 is objected to because of the following informalities: term “each of the mixing tubes” is believed to be in error for - - each of the plurality of mixing tubes - -
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 7 and 13 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claim 7, the recitation “wherein the reduced diameter wall surface extends along the central axis line of the mixing tube from an upstream position at a downstream end portion of the strut to a downstream position at the tip opening of the fuel nozzle” contains new matter because:
i) claim 4, which claim 7 depends, directs to the embodiment of Fig. 5, which requires the second fuel injection unit is a strut surface hole, and claim 7 as claimed directs to the embodiment of Fig. 6, i.e., claim 7 claims a mixing tube of Fig. 5 has a reduced diameter surface 33b of Fig. 6;
ii) however, the specification does NOT disclose the embodiments of Figs. 5-6 are compatible to each other, and thus, claim 7 contains new matter.
Regarding claim 13, the recitation “wherein the second fuel injection unit has a wall surface hole configured to inject the second fuel into the mixing tube from the inner wall surface of the mixing tube” contains new matter because:
i) claim 4, which claim 13 depends, directs to the embodiment of Fig. 5, which requires the second fuel injection unit is a strut surface hole, and claim 13 directs to the embodiments of Figs. 3 and 6, i.e., claim 13 claims a second fuel injection unit has a strut surface hole of Fig. 5 and a mixing tube wall surface hole of Figs. 3 and 6;
ii) however, the specification does NOT disclose the embodiments of Figs. 3 and 5-6 are compatible to each other, and thus, claim 13 contains new matter.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 6-7 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.
Regarding claim 6 and its dependent, the recitation “an upstream wall surface … extending in a downstream direction with a uniform inner diameter, …, and a downstream wall surface … extending toward the downstream end surface of the combustor plate with a uniform inner diameter smaller than an inner diameter of the upstream wall surface” is unclear whether term “an inner diameter” refers to the previously claimed uniform inner diameter; or a different inner diameter of the upstream wall surface.
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.
Claims 2, 4-5, 14-15, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over HELLAT 20240060644 in view of Chen 7107772.
Regarding claim 4, HELLAT teaches the invention as claimed: A combustor (Fig. 3) comprising:
a combustor plate (1 in Fig. 3) having an upstream end surface (11) and a downstream end surface (12), and including a mixing tube (43) extending to penetrate an upstream end surface (11) and a downstream end surface (12, see Fig. 3) and having an upstream end (inlet 40) at the upstream end surface (11) into which air (4) is to be introduced (see Figs. 2-3 and [0078]);
a first fuel injection unit (comprising nozzle 62 in Fig. 2 and strut in annotated Fig. 3) configured to inject first fuel (one of the hydrogen and natural gas in plenum 32, see Fig. 3 and [0088]) along a central axis line (annotated Fig. 3) of the mixing tube (43) from inside the mixing tube (30, see Fig. 3); and
a second fuel injection unit (comprising hole 51) configured to inject second fuel (another one of the hydrogen and natural gas in plenum 31, see Fig. 3 and [0088]) into the mixing tube (43) from a radial outer side of the central axis line of the mixing tube (because hole 51 is on the wall of the mixing tube 43, see Fig. 3);
wherein the first fuel injection unit includes:
a fuel nozzle (62) extending along the central axis line (annotated Fig. 3) of the mixing tube (43) inside the mixing tube (43, see Fig. 3), and having a tip opening (annotated Fig. 3) for injecting the first fuel (from plenum 32) to an end portion (where the outlet of the mixing tube 43 is, see annotated Fig. 3) on a downstream side (see annotated Fig. 3) of the mixing tube (43),
a strut (annotated Fig. 3) extending in a radial direction with respect to the central axis line (annotated Fig. 3) of the mixing tube (43) between the fuel nozzle (62) and an inner wall surface (annotated Fig. 3) of the mixing tube (43) so as to connect the fuel nozzle (62) and the inner wall surface (annotated Fig. 3) of the mixing tube (43) to each other (see Figs. 2-3), and
a fuel introduction portion (132, Fig. 2) configured to introduce the first fuel (from plenum 32) into the fuel nozzle (62) through an inside of the strut (see Fig. 2), and
wherein the second fuel injection unit has a surface hole (51) located on a mixing tube wall surface (see Fig. 3) and configured to inject the second fuel (from plenum 31) into the mixing tube (43) from the inner wall surface (annotated Fig. 3) of the mixing tube (43, see Fig. 3).
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HELLAT does not teach said second fuel injection unit has a surface hole configured to inject said second fuel into said mixing tube from a surface of said strut.
However, Chen teaches a second fuel injection unit (49, Fig. 4 and col. 4, ll. 18-28) configured to inject a second fuel (the fuel injected from fuel injection hole 50) into a mixing tube (40), and wherein the second fuel injection unit (49) has a surface hole (50) located in a strut (44) and configured to inject the second fuel into the mixing tube (40) from a surface of the strut (44), which is an alternative to a surface hole located on a mixing tube wall in order to provide premixed flame (per col. 4, ll. 17-27, the fuel injection hole 50 may be provided on the wall of the mixing tube 40 or in the strut 44).
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify HELLAT by relocating HELLAT’s surface hole of the second fuel injection unit from HELLAT’s mixing tube wall to HELLAT’s strut as taught by Chen because it is noted that a simple substitution of one known element, in this case, injecting fuel from a wall surface as taught by HELLAT and Chen, for another, in this case, injecting fuel from a strut surface as taught by Chen, to obtain predictable results, in this case, providing fuel for premixing combustion, was an obvious extension of prior art teachings, MPEP 2141 III(B).
Regarding claim 2, HELLAT in view of Chen as discussed above teaches the second fuel injection unit has a surface hole on the strut.
HELLAT further teaches wherein the first fuel injection unit (comprising 62 and strut, see Figs. 2-3) is configured to inject the first fuel (from plenum 32) from a downstream side position (where nozzle tip is) in the mixing tube (43) relative to a position of the strut (see annotated Fig. 3 in claim 4), and the strut is where the second fuel injection unit, i.e., the surface hole on the strut, located at as taught by HELLAT in view of Chen as discussed above.
Regarding claim 5, HELLAT in view of Chen teaches the invention as claimed and as discussed above.
HELLAT in view of Chen as discussed so far does not teach wherein the strut has a wing shape with an upstream end portion thereof set as a leading edge and a downstream end portion thereof set as a trailing edge.
However, Chen further teaches wherein the strut (44) has a wing shape (per col. 3, l. 63 to col. 4, l. 4, 44 are swirler vanes that inherit to have a wing shape) with an upstream end portion thereof set as a leading edge (annotated Fig. 4) and a downstream end portion thereof set as a trailing edge (annotated Fig. 4).
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It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the strut of HELLAT in view of Chen to be strut as taught by Chen in order to promote mixing of the fuel and air to reduce NOx and provide flame stability (Chen, col. 3, l. 63 to col. 4, l. 3).
Regarding claim 14, HELLAT in view of Chen teaches as discussed above teaches the second fuel injection unit has a surface hole on the strut.
HELLAT further teaches wherein the mixing tube (43) of the combustor plate (1 in Fig. 3) is one of a plurality of mixing tubes (see Fig. 3), and each of the mixing tubes (each 43s) includes a respective first fuel injection unit (comprising nozzle 62, see Fig. 3) and a respective second fuel injection unit (comprising hole 51).
Regarding claim 15, HELLAT in view of Chen teaches the invention as claimed and as discussed above.
HELLAT further teaches further comprising the first fuel (the fuel in plenum 32) and the second fuel (the fuel in plenum 31), wherein the first fuel is more reactive than the second fuel (the first fuel is one of hydrogen and natural gas and the second fuel is another one of hydrogen and natural gas, wherein hydrogen is more reactive than natural gas and is preferred to be injected by nozzle 62 to form a diffusion flame, see [0088, 0004-0005, and 0082]).
Regarding claim 17, HELLAT in view of Chen teaches the invention as claimed and as discussed above.
HELLAT further teaches a gas turbine ([0078]) comprising: a compressor (the compressor per [0078]) configured to generate compressed air (inherit by the teaching of compressor); the combustor (Fig. 3) configured to generate a combustion gas (produced in combustion space 3, Fig. 3 and [0078]) by burning a premixed gas (generated in tube 43) generated by mixing the compressed air (4, Fig. 2) from the compressor with at least one of the first fuel (from plenum 32) and the second fuel (from plenum 31); and a turbine driven by the combustion gas from the combustor ([0078]).
Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over HELLAT 20240060644 in view of Chen 7107772, and in further view of Zuo 20110197587.
Regarding claim 6, HELLAT in view of Chen teaches the invention as claimed and as discussed above.
HELLAT further teaches wherein the inner wall surface (annotated Fig. 3) of the mixing tube (43) includes:
an upstream wall surface (annotated Fig. 3) connected to the upstream end surface (11) of the combustor plate (1, see Fig. 3) and extending in a downstream direction (see annotated Fig. 3) with a uniform inner diameter (see annotated Fig. 3),
a downstream portion wall surface (annotated Fig. 3) connected to a downstream end (where the upstream wall surface and the downstream portion wall surface connects, see annotated Fig. 3) of the upstream wall surface (annotated Fig. 3) and extending toward the downstream end surface (12) of the combustor plate (1, see Fig. 3).
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HELLAT in view of Chen does not teach said downstream portion wall surface comprising: a reduced diameter wall surface connected to said downstream end of said upstream wall surface and having a diameter decreasing in said downstream direction, and
a downstream wall surface connected to a downstream end of the reduced diameter wall surface and extending toward said downstream end surface of said combustor plate with a uniform inner diameter smaller than an inner diameter of said upstream wall surface.
However, Zuo teaches an inner wall surface (the inner surface of tube 902) of a mixing tube (902 in Fig. 9) includes:
a downstream portion wall surface (903, 905, 907, and 909) comprising:
a reduced diameter wall surface (903, 905, and 907) connected to a downstream end (at the dash line between 901 and 903) of an upstream wall surface (901, see Fig. 9) and having a diameter (the diameter of 903 or the diameter of 907) decreasing in a downstream direction (the direction from inlet 901 to outlet 911, see Fig. 9), and
a downstream wall surface (909) connected to a downstream end (at the dash line between 907 and 909) of the reduced diameter wall surface (903, 905, and 907) and extending toward a downstream end surface (where outlet 911 is) with a uniform inner diameter (z’’) smaller than an inner diameter (the uniform inner diameter z) of the upstream wall surface (901, see Fig. 9 and [0030]).
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the downstream portion wall surface of HELLAT in view of Chen to comprise the reduced diameter wall surface and the downstream wall surface as taught by Zuo in order to prevent flash back and reduce downstream pressure losses (Zuo, [0019] and [0026] in right column of p. 2).
Regarding claim 7, HELLAT in view of Chen and Zuo as discussed above teaches the downstream portion wall surface comprising the reduced diameter wall surface.
HELLAT further teaches the downstream portion wall surface (the section marked in annotated Fig. 3) extends along the central axis line (annotated Fig. 3) of the mixing tube (43) from an upstream position (annotated Fig. 3) at a downstream end portion (annotated Fig. 3) of the strut (annotated Fig. 3) to a downstream position (annotated Fig. 3) at the tip opening (annotated Fig. 3) of the fuel nozzle (62).
It is noted that the combination of HELLAT in view of Chen and Zuo read on the claimed limitation of claim 7, see annotated Fig. 3 for demonstration.
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Response to Arguments
Applicant's arguments filed 10/28/2025 have been fully considered.
Examiner does not agree with Applicant’s argument of the amended independent claim 4 directs to the embodiment of Figs. 3 and 5 on pp. 10-11 because the para. [0028 and 0040] pointed by the Applicant disclosed two different embodiments, i.e., the embodiment of Fig. 3 and the embodiment of Fig. 5, and the specification does NOT support said two embodiments are compatible to each other, and thus, claim 7 is rejected under new matters. A similar issue also occurs in claim 13, see rejection above.
Examiner does not agree with Applicant’s argument of Chen does not teach the fuel inlet having a surface hole to inject the fuel from a surface of the strut on pp. 11-12 because:
i) Chen teaches, on col. 4, ll. 18-28, the fuel inlet 50 is an injection hole of the fuel injection unit 49 for premixer flame, and said fuel inlet 50 may be placed on the inner wall surface (on the 40) of the mixing tube or in the strut (vane 44), i.e., the fuel inlet 50 is a surface hole placed on the surface of the strut as claimed in claim 4; and
ii) it is noted, “Mere recognition of latent properties in the prior art does not render nonobvious an otherwise known invention. In re Wiseman, 596 F.2d 1019, 201 USPQ 658 (CCPA 1979)” and “The fact that appellant has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious." Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985)”, MPEP 2145(II). In this case, Examiner provided motivation of the modification of HELLAT in view of Chen (see rejection above), and the combination of HELLAT in view of Chen cannot be rebutted by the latent advantage recognized by the instant application as Applicant argues.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Boardman 6655145 teaches a reduced diameter wall surface of a mixing tube extending from a trailing edge of a vane to a tip opening of a fuel nozzle.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JINGCHEN LIU whose telephone number is (571)272-6639. The examiner can normally be reached 9:30-4:30.
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/JINGCHEN LIU/Examiner, Art Unit 3741 /DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741
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