Prosecution Insights
Last updated: April 19, 2026
Application No. 18/210,835

FUEL CELL STACK

Non-Final OA §103
Filed
Jun 16, 2023
Examiner
REDDY, SATHAVARAM I
Art Unit
1785
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Toyota Boshoku Kabushiki Kaisha
OA Round
1 (Non-Final)
46%
Grant Probability
Moderate
1-2
OA Rounds
4y 2m
To Grant
99%
With Interview

Examiner Intelligence

Grants 46% of resolved cases
46%
Career Allow Rate
274 granted / 602 resolved
-19.5% vs TC avg
Strong +53% interview lift
Without
With
+53.1%
Interview Lift
resolved cases with interview
Typical timeline
4y 2m
Avg Prosecution
79 currently pending
Career history
681
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
53.6%
+13.6% vs TC avg
§102
17.4%
-22.6% vs TC avg
§112
24.3%
-15.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 602 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 . Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Yamaura (US 2011/0081593 A1) in view of Oyama et al (US 2019/0097244 A1). Regarding claim 1, Yamaura disclose a fuel cell stack (Fig. 4 #100; paragraph [0021]) comprising: power generation cells (single cells in fuel cell stack; Fig. 4 #100; paragraph [0025]) configured to generate power using gas (using oxidizing gas from gas distribution chamber; Fig. 4 #100; paragraph [0026]) and stacked in a vertical direction (stacked in z direction in Fig. 4; Fig. 4 #100; paragraph [0021]); and a discharge passage defining member extending in the vertical direction and having an annular cross-sectional shape (space #350 of a generally rectangular parallelepiped space; Fig. 4 #350; paragraph [0025]), wherein each of the power generation cells includes a gas hole (communication hole #115 in Fig. 4 leading air from gas distribution chamber to electrolyte membrane inside each single cell; Fig. 4 #115; paragraph [0026]), the gas holes of the power generation cells defining a gas manifold which extends in the vertical direction and through which the gas flows (oxidizing gas supply manifold #400 in Fig. 4; Fig. 4 #400; paragraph [0026]), part of an upper wall surface of the gas manifold includes a water collection portion configured to collect water from the upper wall surface (protrusion #410 in Fig. 4; Fig. 4 #410; paragraph [0027]), and the discharge passage defining member is located below the water collection portion of the gas manifold (space #350 is below protrusion #410; Fig. 4; paragraphs [0026]-[0027]) and defines a discharge passage out of which the water dropping from the water collection portion is discharged (space #350; Fig. 4 #350; paragraph [0025]). Yamaura does not disclose the fuel cell stack comprising each of the power generation cells including a support frame that supports a membrane electrode assembly and two separators that sandwich the support frame. However, Oyama discloses a power generation cell (Fig. 2 #12; paragraph [0025]) including a support frame (frame shaped resin film; Fig. 2 #28; paragraph [0029]) that supports a membrane electrode assembly (Fig. 2 #28; paragraph [0025]) and two separators that sandwich the support frame (first metal separator #30 and second metal separator #32 sandwich frame shaped resin film #46; Fig. 4 #30 and #32; paragraph [0026]). It would have been obvious to one of ordinary skill in the art to modify the fuel cell stack of Yamaura to substitute each of the single cells of Yamaura with power generation cell having metal separators on both sides of a MEA and sandwiching a frame shaped resin film of Oyama because having the power generation cell where the metal separators have a beaded structure provides suppressed variation of seal surface pressure in bead seals (see paragraph [0006] of Oyama). Claims 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaura (US 2011/0081593 A1) in view of Oyama et al (US 2019/0097244 A1) in further view of Owejan et al (US 2009/0142632 A1). Regarding claim 2, Yamaura and Oyama disclose the fuel cell stack of claim 1 as noted above. Yamaura and Oyama do not disclose the fuel cell stack comprising the water collection portion includes an inclined surface that becomes lower toward the discharge passage defining member. However, Owejan discloses a fuel cell stack comprising the water collection portion includes an inclined surface that becomes lower toward the discharge passage defining member (water management feature #302 may be a wedge #305 and a surface #306 of water management feature #302 is disposed at a slope with respect to insulation layer #300 sufficient for water drawn by the force of gravity to a terminus #304; Fig. 3 #302; paragraphs [0031]-[0032]). It would have been obvious to one of ordinary skill in the art to modify the fuel cell stack of Yamaura and Oyama to substitute the protrusion of Yamaura for the water management feature having a wedge shape of Owejan because having a water management feature with a wedge shape allows for water to drip away from the edges of the fuel cell stack (paragraph [0030] of Owejan). Regarding claim 3, Yamaura and Oyama disclose the fuel cell stack of claim 1 as noted above. Yamaura and Oyama do not disclose the fuel cell stack comprising the water collection portion includes a hydrophilic portion that is more hydrophilic than a portion of the upper wall surface other than the water collection portion. However, Owejan discloses fuel cell stack comprising a water collection portion includes a hydrophilic portion that is more hydrophilic than a portion of the upper wall surface other than the water collection portion (water management feature #302 formed from a material that facilitates the drawing of water away from the fuel cell plates; paragraph [0033]). It would have been obvious to one of ordinary skill in the art to modify the fuel cell stack of Yamaura and Oyama substitute the protrusion of Yamaura for the water management feature having a wedge shape of Owejan because having a water management feature with a wedge shape facilitates the drawing of water away from the fuel cell plates (paragraph [0030] of Owejan). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SATHAVARAM I REDDY whose telephone number is (571)270-7061. The examiner can normally be reached Monday-Friday 9:00 AM-6:00 PM EST. 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, Mark Ruthkosky can be reached at (571)-272-1291. 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. /SATHAVARAM I REDDY/Examiner, Art Unit 1785
Read full office action

Prosecution Timeline

Jun 16, 2023
Application Filed
Mar 05, 2026
Non-Final Rejection — §103 (current)

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

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Prosecution Projections

1-2
Expected OA Rounds
46%
Grant Probability
99%
With Interview (+53.1%)
4y 2m
Median Time to Grant
Low
PTA Risk
Based on 602 resolved cases by this examiner. Grant probability derived from career allow rate.

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