Prosecution Insights
Last updated: April 19, 2026
Application No. 18/072,915

FUEL CELL SYSTEM AND METHOD FOR STOPPING POWER GENERATION IN FUEL CELL SYSTEM

Final Rejection §103
Filed
Dec 01, 2022
Examiner
THOMAS, BRENT C
Art Unit
1724
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Honda Motor Co. Ltd.
OA Round
2 (Final)
50%
Grant Probability
Moderate
3-4
OA Rounds
3y 10m
To Grant
76%
With Interview

Examiner Intelligence

Grants 50% of resolved cases
50%
Career Allow Rate
215 granted / 434 resolved
-15.5% vs TC avg
Strong +26% interview lift
Without
With
+26.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
25 currently pending
Career history
459
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
66.0%
+26.0% vs TC avg
§102
18.6%
-21.4% vs TC avg
§112
9.3%
-30.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 434 resolved cases

Office Action

§103
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 Arguments Applicant’s arguments, see pages 10-12, filed 9/17/2025, with respect to the rejection(s) of amended claim(s) 1, 3-4, and 8 under Fukawa and Fukawa in view of Imamura have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Fukawa in view of Takasu (US 2015/0075885 A1, hereafter Takasu) as necessitated by the claim amendments. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim(s) 1-4 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fukawa (JP 2021-052479 A, hereafter Fukawa) in view of Takasu (US 2015/0075885 A1, hereafter Takasu). With regard to claim 1, With regard to claim 1, Fukawa teaches a fuel cell system provided in a moving body, the fuel cell system comprising: a fuel cell stack (fuel cell 10) [0026]; a cathode supply path (air supply passage 111) through which an oxygen-containing gas is supplied to the fuel cell stack [0038, 0045]; an air pump (compressor 51) configured to supply the oxygen-containing gas to the cathode supply path [0038, 0045]; a stop valve (on-off valve 121) provided between the air pump and the fuel cell stack in the cathode supply path [0045-0046, fig. 2]; a discharge path (112 a-c) through which the oxygen containing gas discharged from the fuel cell stack is discharged to an outside of the fuel cell system [0047-0048]; a cathode bypass passage (bypass path 113) through which the oxygen containing gas supplied to the fuel cell stack flows from an upstream side of the stop valve to the discharge [0051, fig. 2]; a bypass valve (on off valve 123) provided in in the cathode bypass passage between the cathode supply path and the discharge path [0054, fig. 2]; and one or more processors that execute computer-executable instructions stored in a memory (control device 100 with central processing unit and memory), wherein the one or more processors execute the computer-executable instructions to cause the fuel cell system to execute a first control of stopping power generation to the fuel cell stack by closing the stop valve during power generation of the fuel cell stack (during regenerative power consumption control), and a second control of discarding surplus electric power generated in the moving body (regenerative) by driving the air pump by the surplus electric power [0060, 0084-0087], wherein, when starting to execute the first control and the second control, if a closed state of the stop valve is detected, the one or more processors cause the fuel cell system to drive the air pump in a predetermined state [0084-0087, 111]. Fukawa does not explicitly teach that the fuel cell system increases a power of an air pump to use surplus power generated in a fuel cell stack or reducing a voltage command of the fuel cell stack. However, in the same field of endeavor, Takasu teaches using excess fuel cell power to drive a compressor and teaches reducing a voltage command of the fuel cell stack to a predetermined voltage [0042, 0044]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to use the method of Takasu of using excess fuel cell power to drive a compressor and reducing a voltage command of the fuel cell stack to a predetermined voltage with the control device of Fukawa for the benefits of converting excess power to air pressure and preventing degradation of the fuel cell [Takasu 0042, 0044]. With regard to claim 2, Fukawa teaches the surplus electric power includes electric power generated by an external device other than the fuel cell stack (regenerative power of motor 30), and when executing the first control and the second control the one or more processors cause the fuel cell system to change a driving state of the air pump in accordance with a power generation state of the external device (regenerative power excessive for battery 20) [0018, 0034, 0080-0084, 0133]. With regard to claims 3-4, Fukawa teaches a control device (control device 100) that is capable of changing the driving state of an air pump (compressor 51) [0060, 0084-0087] but does not explicitly teach the control device is capable of changing the output of a fuel cell stack based on a voltage value. However, in the same field of endeavor, Takasu teaches using excess fuel cell power to drive a compressor and teaches reducing a voltage command of the fuel cell stack to a predetermined voltage [0042, 0044]. Takasu further teaches the reduced voltage may cause surplus power (large output) and teaches using the air compressor to convert the surplus power into pressure energy [0042-0045]. Therefore, Fukawa modified by Takasu would be capable of performing the claimed functions. It would have been obvious to one of ordinary skill in the art at the time the invention was made to use the method of Takasu of using excess fuel cell power to drive a compressor and reducing a voltage command of the fuel cell stack to a predetermined voltage with the control device of Fukawa for the benefits of converting excess power to air pressure and preventing degradation of the fuel cell [Takasu 0042, 0044]. Claims directed to apparatus must be distinguished from the prior art in terms of structure rather than function. In re Danly, 263 F.2d 844, 847, 120 USPQ 528, 531 (CCPA 1959). See also MPEP § 2114. The manner of operating the device does not differentiate an apparatus claim from the prior art. A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987). With regard to claim 8, Fukawa teaches a method for stopping power generation of a fuel cell system provided in a moving body, wherein the system includes: a fuel cell stack (fuel cell 10) [0026]; a cathode supply path (air supply passage 111) through which an oxygen-containing gas is supplied to the fuel cell stack [0038, 0045]; an air pump (compressor 51) configured to supply the oxygen-containing gas to the cathode supply path [0038, 0045]; and a stop valve (on-off valve 121l) provided between the air pump and the fuel cell stack in the cathode supply path [0045-0046, fig. 2]; a discharge path (112 a-c) through which the oxygen containing gas discharged from the fuel cell stack is discharged to an outside of the fuel cell system [0047-0048]; a cathode bypass passage (bypass path 113) through which the oxygen containing gas supplied to the fuel cell stack flows from an upstream side of the stop valve to the discharge [0051, fig. 2]; a bypass valve (on off valve 123) provided in in the cathode bypass passage between the cathode supply path and the discharge path [0054, fig. 2]; and the method comprising causing the stop valve to be closed during power generation of the fuel cell stack (starting regenerative power consumption control) [0060, 0084-0087], detecting a closed state of the stop valve after the stop valve is closed (via controller 100) [0084-0085]; and driving the air pump in a predetermined state by surplus electric power generated in the moving body (regenerative power) after the closed state of the stop valve is detected [0084-0085, 0137-0138]. Fukawa does not explicitly teach that the fuel cell system increases a power of an air pump to use surplus power generated in a fuel cell stack or reducing a voltage command of the fuel cell stack. However, in the same field of endeavor, Takasu teaches using excess fuel cell power to drive a compressor and teaches reducing a voltage command of the fuel cell stack to a predetermined voltage [0042, 0044]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to use the method of Takasu of using excess fuel cell power to drive a compressor and reducing a voltage command of the fuel cell stack to a predetermined voltage with the method of Fukawa for the benefits of converting excess power to air pressure and preventing degradation of the fuel cell [Takasu 0042, 0044]. Claim(s) 5-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fukawa and Takasu as applied to claims 1-4 and 8 above, and further in view of Ojima et al. (US 2005/0130000 A1, hereafter Ojima). With regard to claims 5-6, Fukawa does not explicitly teach a flow rate detection device or a controller capable of opening a valve in response to a flow rate detection device. However, in the same field of endeavor, Ojima teaches a fuel cell system with a control unit that receives signals from an air flow rate detection sensor and controls the operation of components including a compressor and valve [0057]. It would have been obvious to one of ordinary skill in the art to use the flow rate sensor and control system configured to control components including compressors and valves based on the signals from the sensor of Ojima with the fuel cell system of Fukawa for the benefit of being able to supply air to the fuel cell at a predetermined pressure [Ojima 0053, 0057]. When used with the controller and flow sensor configuration of Ojima the fuel cell system of modified Fukawa would be capable of performing the claimed functions. With regard to claim 7, Fukawa does not explicitly teach a flow rate detection device or a controller capable of opening a valve in response to a flow rate detection device. However, in the same field of endeavor, Ojima teaches a fuel cell system with a control unit that receives signals from an air flow rate detection sensor and controls the operation of components including a compressor and valve [0057]. It would have been obvious to one of ordinary skill in the art to use the flow rate sensor and control system configured to control components including compressors and valves based on the signals from the sensor of Ojima with the fuel cell system of Fukawa for the benefit of being able to supply air to the fuel cell at a predetermined pressure [Ojima 0053, 0057]. When used with the controller and flow sensor configuration of Ojima the fuel cell system of modified Fukawa would be capable of performing the claimed functions. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRENT C THOMAS whose telephone number is (571)270-7737. The examiner can normally be reached Flexible schedule, typical hours 11-7 M-F. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Miriam Stagg can be reached at (571)270-5256. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /BRENT C THOMAS/Examiner, Art Unit 1724 /STEWART A FRASER/ Primary Examiner, Art Unit 1724
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Prosecution Timeline

Dec 01, 2022
Application Filed
Jun 13, 2025
Non-Final Rejection — §103
Sep 12, 2025
Applicant Interview (Telephonic)
Sep 12, 2025
Examiner Interview Summary
Sep 17, 2025
Response Filed
Dec 23, 2025
Final Rejection — §103
Mar 11, 2026
Interview Requested
Mar 17, 2026
Applicant Interview (Telephonic)
Mar 17, 2026
Examiner Interview Summary

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
50%
Grant Probability
76%
With Interview (+26.4%)
3y 10m
Median Time to Grant
Moderate
PTA Risk
Based on 434 resolved cases by this examiner. Grant probability derived from career allow rate.

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