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 .
Response to Amendment
This Office action is responsive to the amendment filed 6/11/2026 for application 18848777.
Claims 2-3, 8-9, 11-12, 14, & 16-18 are canceled by Applicant. Claims 1, 4-7, 10, 13, 15, & 19-20 remain pending.
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.
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.
Claims 1, 4-7, 10, 13, 15, & 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Ethier 20150322857 in view of Lawson 20110036092.
Regarding Independent Claim 1, Ethier teaches a firing apparatus (Figs. 1, 3) to control flow of fuel gas to a nozzle of a burner or a nozzle manifold for the firing of a gas turbine (fuel nozzle of combustor in which 319 is located), the firing apparatus comprising:
an inlet (first end of dashed line at 318 connected to fuel tank) connectable to a fuel gas source;
an outlet (at connection to combustor) for supplying a controlled amount of fuel gas to the nozzle or the nozzle manifold;
a shutoff valve (323) for selectively allowing fuel gas flow from the fuel source to the outlet;
a fuel line (fuel line between 323 and the three branches in Fig. 3) having a first end (first end at 323) connected to the shutoff valve;
a first fuel flow path coupled to a second end of the fuel line and to the outlet (extending from second end of the fuel line, the second end being at the branching point of the three branches in Fig. 3, to the outlet at the combustor), the first fuel flow path comprising a first valve (327) and a second valve (valve indicated at 322 in Fig. 1) disposed in series (327 and valve at 322 are in series);
a second flow path coupled to the first fuel flow path at a first location upstream of the first valve and a second location downstream, the second fuel flow path comprising an orifice (flow path with orifice 324 is connected to the first fuel flow path at locations upstream and downstream of 327),
wherein the second fuel flow path has a flow rate that is less than the flow rate of the first fuel flow path (second fuel flow path with orifice 324 has flow rate of 0.25 g/s whereas first fuel flow path with valve 327 has flow rate of 5 g/s; para. [0084]), and
wherein the first valve and the second valve are configured to assume:
a first operating state in which fuel gas flows through the second fuel flow path to the second valve and then to the nozzle or to the nozzle manifold of the gas turbine (327 can be closed and then fuel will be routed through the second fuel flow path to the valve at 322); and
a second operating state in which fuel gas flows through the first valve and the second valve and then to the nozzle or to the nozzle manifold of the gas turbine over start-up, operation, and shutdown conditions (327 can be opened and then fuel will flow through 327 and 322 and then to the combustor over any desired operations).
Ethier fails to teach the shutoff valves arranged to form a double block and bleed system.
Lawson teaches a system with a flow path for receiving fuel gas (126 receives fuel gas 122), the flow path comprising a pair of shutoff valves (VS4-11, VSR-11) and a vent valve coupled between the pair of shutoff valves (vent valve VA13-20 between VS4-11, VSR-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Ethier’s system to include shutoff valves arranged to form a double block and bleed system, as taught by Lawson, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Ethier’s shutoff valve versus the claimed shutoff valves arranged to form a double block and bleed system, as taught by Lawson), b) the substituted components and their functions were known in the art (Ethier’s arrangement of valves and Lawson’s arrangement of valves were both known to be useful for providing shutoff functions in fuel supplies for gas turbine engines), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Ethier’s valve arrangement or Lawson’s valve arrangement could have been used to predictably provide valves for stopping fuel flow). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B).
Regarding Dependent Claim 4, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier further teaches the second valve is a metering valve (valve at 322 in Fig. 1 is a metering valve inasmuch as it permits fuel to be metered and is capable of opening/closing to control fuel flow).
Regarding Dependent Claim 5, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier further teaches the second valve is opened in the first operating state (valve at 322 in Fig. 2 is capable of being open in the first operating state).
Regarding Dependent Claim 6, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier further teaches the first valve is closed in the first operating state (327 is capable of being closed in the first operating state).
Regarding Dependent Claim 7, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier further teaches the orifice member is sized to prevent passage of an amount of fuel that can cause excess fueling (the claimed orifice member is no different structurally than Ethier’s orifice and thus Ethier’s orifice is capable of the claimed function; para. [0084]).
Regarding Dependent Claim 10, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier further teaches the second valve comprises a shutoff valve (valve at 322 in Fig. 1 is a shutoff valve inasmuch as it is capable of shutting off fuel flow; para. [0090]).
Regarding Dependent Claim 13, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier in view of Lawson teaches the shutoff valves comprise: a first shutoff valve fluidly connected to the inlet (the replacement of Ethier’s valve with the double block and bleed system includes Lawson’s first shutoff valve which would be fluidly connected to the inlet); a second shutoff valve fluidly connected between the first shutoff valve and the first valve (the replacement of Ethier’s valve with the double block and bleed system includes Lawson’s second shutoff valve which would be fluidly connected between the first shutoff valve and the first valve); and wherein a vent valve is coupled between the first shutoff valve and the second shutoff valve (the replacement of Ethier’s valve with the double block and bleed system includes Lawson’s vent valve coupled between the first shutoff valve and the second shutoff valve).
Regarding Dependent Claim 15, Ethier in view of Lawson teaches the invention as claimed and as discussed above for claim 1, and Ethier further teaches a gas turbine (Fig. 1), comprising: a burner for burning fuel (combustor in which 319 is positioned); a nozzle manifold having one or more nozzles (since the claimed manifold only requires one nozzle, this could simply be the portion of the fuel line between the valve at 322 and the nozzle at the combustor – and the combustor would necessarily include a nozzle, i.e. any outlet structure for injecting fuel into the combustor) for injecting fuel into the burner; and the firing apparatus according to claim 1 (see the rejection of claim 1 above).
Regarding Independent Claim 19, Ethier teaches a system (Figs. 1 & 3), comprising:
a gas turbine (Fig. 1) comprising a nozzle manifold (multiple nozzles are not recited, thus the manifold can simply be a portion of a supply line to the nozzle itself, which is between valve at 322 and the combustor in which 319 is positioned); and
a firing apparatus coupled to the nozzle manifold, the firing apparatus comprising:
a first flow path for receiving fuel gas (from fuel tank to 323), the first flow path comprising a shutoff valve (323); and
a second flow path interposed between the first flow path and the nozzle manifold and arranged to receive fuel gas flow downstream of the shutoff valve (from 323 to 322), the second flow path comprising a first branch with a first valve and a second valve (with valve 327 and the valve at 322) and a second branch with a fixed orifice (branch with orifice 324), the second branch coupled to the first branch at a first location upstream of the first valve and at a second location downstream of the first valve (second branch coupled to the first branch at respective points upstream and downstream of 327),
wherein operation of the firing apparatus causes the first valve and the second valve to assume:
a first operating state in which fuel gas flows through the second branch into the second valve and then to the nozzle manifold of the gas turbine (327 can be closed and fuel will then flow through the second branch into the valve at 322 and then to the nozzle manifold discussed above), or
a second operating state in which fuel gas flows through the first branch and the second branch and then to the nozzle manifold over start-up, operation, and shutdown conditions of the gas turbine (327 can be opened and fuel will then flow through the first branch and the second branch and then to the nozzle manifold discussed above over any desired operation).
Ethier fails to teach a pair of shutoff valves and a vent valve coupled between the pair of shutoff valves.
Lawson teaches a system with a flow path for receiving fuel gas (126 receives fuel gas 122), the flow path comprising a pair of shutoff valves (VS4-11, VSR-11) and a vent valve coupled between the pair of shutoff valves (vent valve VA13-20 between VS4-11, VSR-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Ethier’s system to include a pair of shutoff valves and a vent valve coupled between the pair of shutoff valves, as taught by Lawson, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Ethier’s shutoff valve versus the claimed pair of shutoff valves and a vent valve coupled between the pair of shutoff valves, as taught by Lawson), b) the substituted components and their functions were known in the art (Ethier’s arrangement of valves and Lawson’s arrangement of valves were both known to be useful for providing shutoff functions in fuel supplies for gas turbine engines), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Ethier’s valve arrangement or Lawson’s valve arrangement could have been used to predictably provide valves for stopping fuel flow). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B).
Regarding Independent Claim 20, Ethier teaches a method (para. [0084]), comprising:
on a gas turbine (Figs. 1, 3) comprising a nozzle manifold (multiple nozzles are not recited, thus the manifold can simply be a portion of a supply line to the nozzle itself, which is between valve at 322 and the combustor in which 319 is positioned),
regulating a flow of fuel gas through a first flow path using a shutoff valve (323 regulates gaseous fuel; paras. [0084] & [0093]);
receiving the flow of fuel gas at a second flow path downstream of the pair of shutoff valves (flow path from 323 to 322), the second flow path comprising a first branch comprising a first valve and a second valve (327 and valve at 322) and a second branch comprising a fixed orifice (branch with orifice 324), the second branch coupled to the first branch at a first location upstream of the first valve and at a second location downstream of the first valve (second branch coupled to the first branch at respective points upstream and downstream of 327); and
regulating a flow of fuel gas through the second flow path (as follows) by:
operating the first valve and the second valve in a first operating state to cause fuel gas flow to bypass the first valve through the second branch to the nozzle manifold of the gas turbine (initially, fuel passes through 324 to the nozzle manifold discussed above; para. [0084]); or
operating the first valve and the second valve in a second operating state to cause fuel gas flow through the first branch and the second branch to the nozzle manifold during start-up, operation, and shutdown conditions of the gas turbine (during operation, 327 and the valve at 322 are opened to cause fuel to flow through 324 and 327/322; para. [0084]).
Ethier fails to teach a pair of shutoff valves.
Lawson teaches a system with a flow path for receiving fuel gas (126 receives fuel gas 122), the flow path comprising a pair of shutoff valves (VS4-11, VSR-11) and a vent valve coupled between the pair of shutoff valves (vent valve VA13-20 between VS4-11, VSR-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Ethier’s system to include a pair of shutoff valves, as taught by Lawson, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Ethier’s shutoff valve versus the claimed pair of shutoff valves, as taught by Lawson), b) the substituted components and their functions were known in the art (Ethier’s arrangement of valves and Lawson’s arrangement of valves were both known to be useful for providing shutoff functions in fuel supplies for gas turbine engines), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Ethier’s valve arrangement or Lawson’s valve arrangement could have been used to predictably provide valves for stopping fuel flow). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B).
Response to Arguments
Applicant’s arguments with respect to all claims have been considered and are unpersuasive.
Applicant’s argument (p. 9 of Remarks) that Ethier fails to teach “enforced, state-dependent flow control, but instead merely permits flow through different paths depending on valve positions without any requirement that a particular path governs operation in a defined system state” and that Ethier “does not disclose a system in which distinct operating states actively control which path governs fuel delivery” is unpersuasive. Applicant’s apparatus claims do not cover “enforced, state-dependent flow control” or any kind of active control at all but rather merely require particular states as defined by valve positions. Thus, the prior art, in addition to teaching all the structure of the apparatus claims, merely needs to be capable of assuming the defined states in the same way: by being capable of setting the valves in the same way as is claimed by Applicant. Given that the cited prior art is capable of this, and no particular “control” is actually recited, the recited states do not define over the cited prior art. With respect to the method of claim 20, the rejection clearly identifies where the prior art teaches the specific method steps (in addition to the required structure). Applicant has not provided any specific argument as to how this rejection is in error, other than arguing that the rejection relies on Ethier merely permitting flow through certain fuel paths depending on valve positions, which is not the case for the rejection of the method claim. Rather, the rejection of the method identifies the particular teachings in Ethier in which the active fuel control claimed is taught.
Applicant’s argument (p. 9 of Remarks) that Ethier fails to teach any interaction between the flow paths and a safety isolation system is moot because Ethier is not relied upon for this teaching, Lawson is.
Applicant’s argument (pp. 9-10 of Remarks) that Lawson’s DBB system functions independently of any staged fuel delivery system and is designed for isolation and purging, not modulation of fuel flow and that this confirms “the absence of any teaching or suggestion to combine these disparate systems” is unpersuasive. The fact that Lawson’s DBB system functions independently as an isolation and purging system inherently suggests itself for combination with a fuel system lacking such functions because the isolation and purging is decoupled from the functioning of the rest of the fuel system (in other words, the addition of Lawson’s DBB system would not impede or alter the primary functions of Ethier’s fuel system). Thus, the proposed combination of Ethier with Lawson is reasonable Lawson’s system is complementary to Ethier’s.
Applicant’s argument (p. 10 of Remarks) that the proposed combination of Lawson with Ethier would fundamentally alter the principle of operation of Ethier is unpersuasive. Applicant states that the isolation and venting taught by Lawson would require coordinated effort with Ethier’s system and a substantial redesign of Ethier’s entire architecture. First, as addressed above, Applicant elsewhere (pp. 9-10 of Remarks) argues that Lawson’s system “functions independently of any staged fuel delivery system and is designed for isolation and purging, not modulation of fuel flow.” This conflicts with Applicant’s characterization that the combination of Lawson with Ethier would require a substantial redesign of Ethier and that it would fundamentally alter the principle of operation of Ethier. Either Lawson’s DBB system is independent of staged fuel delivery and has nothing to do with modulation of fuel flow, as argued by Applicant, or Lawson’s DBB system would require substantial coordination with Ethier’s system to such an extent that a substantial redesign of Ethier would be required, also as argued by Applicant. Both cannot be true simultaneously. In fact, Ethier does not teach isolation and purging, and Lawson’s teaching of such using a DBB system would only further bolster the obviousness of combining Ethier with Lawson to provide such functionality rather than suggest non-obviousness. Given that the DBB system in Lawson is, as stated by Applicant, intended for isolation and purging rather than fuel flow modulation during operation, there is very little modification of Ethier required at all other than what one of ordinary skill in the art would have to perform anyway in order to implement such a DBB system (adding valves, programming controllers to control the valves in particular ways under particular circumstances). But there is nothing of record to show that the functionality of Ethier’s system requires a substantial redesign, or any redesign at all, as far as the basic operation of Ethier’s fuel system discussed in the claim rejections above.
In response to applicant's argument (p. 10 of Remarks) 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). In this case, Ethier’s single shutoff valve was known and Lawson’s DBB system was known. Both were known for the capability of shutting off fuel supply to a downstream fuel system. This is not impermissible hindsight. This is merely recognizing, based on the teachings of the prior art itself, what one of ordinary skill in the art already knew and practiced before the effective filing date of the claimed invention. Applicant’s appeal to a “coordinated functional interaction between safety isolation and staged fuel delivery” being absent from both Ethier and Lawson is moot as no such coordinated functional interactions are recited.
Conclusion
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SCOTT J WALTHOUR whose telephone number is (571)272-4999. The examiner can normally be reached Monday-Friday, 10 a.m.-6 p.m. Eastern.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer can be reached at 571-272-7118. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SCOTT J WALTHOUR/Primary Examiner, Art Unit 3741
