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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/19/2026 has been entered.
Status of Rejections
All previous rejections are maintained.
The previous rejections have been updated in response to the Applicant’s amendments.
Claims 1-4 are pending and under consideration for this Office Action.
Claim Rejections - 35 USC § 112(b)
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.
Claim 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.
Claim 1: The wording of the limitation “when a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure decreases out of a range of threshold values during a predetermined time” is unclear because it appears that it is claiming that a “change in the pressure” is decreasing. If that were that case, it would be indicative of no leakage in the membrane because the pressure change is approaching 0 and the pressure of that side would be steady. Based on a reading of the specification and the rest of the claim, this step is for positively determining a leak is present. In this case, the pressure of the higher-pressure system should decrease because of the leak. Therefore, this limitation will be interpreted as meaning that the higher-pressure path’s pressure decreases out of a range of threshold values during a predetermined time, which would make logical sense if a leak is occurring at the membrane.
Claim 3: Claim 3 has the same issue as claim 1 above.
Any claim(s) dependent on the above claim(s) is/are rejected for its/there dependence.
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 is/are rejected under 35 U.S.C. 103 as being unpatentable over Harada (US 7048839 B2) in view of Yakumaru et al (US 20190276944 A1) and Wakita et al (US 20180166713 A1).
Claim 1: Harada discloses a method of detecting leakage (see e.g. col 25, lines 30-36) in a water electrolyzer (see e.g. abstract), the water electrolyzer having
a water electrolytic cell that has an oxygen-generating electrode disposed on one side thereof across a solid polymer electrolyte membrane and a hydrogen-generating electrode disposed on another side thereof (see e.g. col 11, lines 62-67),
an oxygen-side path that includes piping disposed for oxygen generated at the water electrolytic cell to flow therein (see e.g. col 12, lines 25-32), and
a hydrogen-side path that includes piping disposed for hydrogen generated at the water electrolytic cell to flow therein (see e.g. col 12, lines 33-42),
the method comprising:
closing a valve installed in the oxygen-side path (the valve is closed by default during normal operation, see e.g. connecting paragraph of col 13 and 14), and a valve installed in the hydrogen-side path (see e.g. col 25, lines 30-32);
progressing a water electrolysis reaction at the water electrolytic cell (see e.g. col 13, lines 55-61), and determining leakage in the oxygen-side path and leakage in the hydrogen-side path (see e.g. col 25, lines 30-36).
Harada does not explicitly teach that the leakage in the oxygen-side path and the hydrogen-side path is based on a change in an internal pressure. Harada discloses using gas leak sensors in each path for sensing the concentration of the gases instead (see e.g. col 25, lines 30-36). Yakumaru teaches that pressure gauges can also be used to determine leaks in product flow paths from a water electrolysis cell instead of concentration sensors (see e.g. [0126]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada by using pressure gauges to determine leakage in the oxygen-side path and leakage in the hydrogen-side path as taught in Yakumaru because Yakumaru teaches pressure is a suitable variable to measure to determine said leakages in water electrolysis cells.
Harada does not explicitly teach that following said progressing and determining leakage in the oxygen-side path and leakage in the hydrogen-side path, decreasing a pressure in the oxygen-side path or the hydrogen-side path, thereby making a differential pressure between the oxygen-side path and the hydrogen-side path, and determining leakage from the solid polymer electrolyte membrane when a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure decreases out of a range of threshold values during a predetermined time. However, Harada discusses the importance of ensuring minimum gas mixing to avoid explosive environments (see e.g. col 2, lines 53-61). Wakita teaches a method of water electrolysis (see e.g. [0242]) wherein leakage of hydrogen across the membrane is monitored (see e.g. [0007] and [0009]). The leakage is monitored by decreasing a pressure in the oxygen-side path or the hydrogen-side path, thereby making a differential pressure between the oxygen-side path and the hydrogen-side path (“opens the fourth valve 24 of the purger 23A to form the state where hydrogen is present at one electrode (cathode 11 in this example) of the MEA and hydrogen is not present at the other electrode (anode 12 in this example) of the MEA”, see e.g. [0135]), and determining leakage from the solid polymer electrolyte membrane when a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure decreases out of a range of threshold values during a predetermined time. (see e.g. the increase in cross-over hydrogen would be inversely proportional and also representative to a change in the pressure of the hydrogen-side pressure, [0104]; [0229]; Fig 17).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada by using the method of determining leakage from the solid polymer electrolyte membrane taught in Wakita to ensure that the gas streams have a safe amount of hydrogen or oxygen to prevent explosive environments. Additionally, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada in view of Wakita to perform this step following the said progressing and determining leakage in the oxygen-side path and leakage in the hydrogen-side path because this step needs to be performed when the cell is not being used to electrolyze water (see e.g. [0135] of Wakita).
Claim 2: Harada in view of Yakumaru and Wakita teaches a method of generating hydrogen, the method comprising: generating hydrogen (see e.g. abstract) with periodic leakage detection according to the method defined in claim 1 (see rejection of claim 1 above) in addition to normally generating hydrogen with the water electrolytic cell defined in claim 1 (see e.g. col 13, lines 55-61).
Claim 3: Harada discloses a non-transitory computer-readable storage medium with an executable program stored (the system is controlled using a computer, see e.g. col 16, lines 25-26) thereon, the program being for detecting leakage in a water electrolyzer (see e.g. col 25, lines 25-26 and col 30, lines 42-57), the water electrolyzer having
a water electrolytic cell (see e.g. abstract) that has an oxygen-generating electrode disposed on one side thereof across a solid polymer electrolyte membrane and a hydrogen-generating electrode disposed on another side thereof (see e.g. col 11, lines 62-67),
an oxygen-side path that includes piping disposed for oxygen generated at the water electrolytic cell to flow therein (see e.g. col 12, lines 25-32), and
a hydrogen-side path that includes piping disposed for hydrogen generated at the water electrolytic cell to flow therein (see e.g. col 12, lines 33-42),
wherein the program instructs a controller to perform the following:
closing a valve installed in the oxygen-side path (the valve is closed by default during normal operation, see e.g. connecting paragraph of col 13 and 14) and a valve installed in the hydrogen-side path (see e.g. col 25, lines 30-32);
progressing a water electrolysis reaction at the water electrolytic cell (see e.g. col 13, lines 55-61), and determining leakage in the oxygen-side path and leakage in the hydrogen-side path (see e.g. col 25, lines 30-36).
Harada does not explicitly teach that the leakage in the oxygen-side path and the hydrogen-side path is based on a change in an internal pressure. Harada discloses using gas leak sensors in each path for sensing the concentration of the gases instead (see e.g. col 25, lines 30-36). Yakumaru teaches that pressure gauges can also be used to determine leaks in product flow paths from a water electrolysis cell instead of concentration sensors (see e.g. [0126]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada by using pressure gauges to determine leakage in the oxygen-side path and leakage in the hydrogen-side path as taught in Yakumaru because Yakumaru teaches pressure is a suitable variable to measure to determine said leakages in water electrolysis cells.
Harada does not explicitly teach that following said progressing and determining leakage in the oxygen-side path and leakage in the hydrogen-side path, decreasing a pressure in the oxygen-side path or the hydrogen-side path, thereby making a differential pressure between the oxygen-side path and the hydrogen-side path, and determining leakage from the solid polymer electrolyte membrane when a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure decreases out of a range of threshold values during a predetermined time.
Harada discusses the importance of ensuring minimum gas mixing to avoid explosive environments (see e.g. col 2, lines 53-61). Wakita teaches a method of water electrolysis (see e.g. [0242]) wherein leakage of hydrogen across the membrane is monitored (see e.g. [0007] and [0009]). The leakage is monitored by decreasing a pressure in the oxygen-side path or the hydrogen-side path, thereby making a differential pressure between the oxygen-side path and the hydrogen-side path (“opens the fourth valve 24 of the purger 23A to form the state where hydrogen is present at one electrode (cathode 11 in this example) of the MEA and hydrogen is not present at the other electrode (anode 12 in this example) of the MEA”, see e.g. [0135]), and determining leakage from the solid polymer electrolyte membrane when a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure decreases out of a range of threshold values during a predetermined time. (see e.g. the increase in cross-over hydrogen would be inversely proportional and also representative to a change in the pressure of the hydrogen-side pressure, [0104]; [0229]; Fig 17).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the program of Harada by using the method of determining leakage from the solid polymer electrolyte membrane taught in Wakita to ensure that the gas streams have a safe amount of hydrogen or oxygen to prevent explosive environments. Additionally, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada in view of Wakita to perform this step following the said progressing and determining leakage in the oxygen-side path and leakage in the hydrogen-side path because this step needs to be performed when the cell is not being used to electrolyze water (see e.g. [0135] of Wakita).
Claim 4: Harada discloses a water electrolyzer (see e.g. abstract) comprising:
a water electrolytic cell that has an oxygen-generating electrode disposed on one side thereof across a solid polymer electrolyte membrane and a hydrogen-generating electrode disposed on another side thereof (see e.g. col 11, lines 62-67),
an oxygen-side path that includes piping disposed for oxygen generated at the water electrolytic cell to flow therein (see e.g. col 12, lines 25-32);
a hydrogen-side path that includes piping disposed for hydrogen generated at the water electrolytic cell to flow therein (see e.g. col 12, lines 33-42);
a valve arranged in the oxygen-side path (see e.g. connecting paragraph of col 13 and 14);
another valve disposed in the hydrogen-side path (see e.g. col 25, lines 30-32); and
a controller that is electrically connected to the valve and the other valve (see e.g. connecting paragraph of col 13 and 14 and col 25, lines 30-32);
wherein the program for detecting leakage in a water electrolyzer is recorded in the controller see e.g. col 16, lines 25-26), and based on the program, the controller receives signals and transmits signals representing instructions to open and close the valve and the other valve (see e.g. connecting paragraph of col 13 and 14 and col 25, lines 30-32).
Harada does not explicitly teach a pressure gauge that are arranged in the oxygen-side path and another pressure gauge that are disposed in the hydrogen-side path. Harada discloses using gas leak sensors in each path for sensing the concentration of the gases instead (see e.g. col 25, lines 30-36). Yakumaru teaches that pressure gauges can also be used to determine leaks in product flow paths from a water electrolysis cell instead of concentration sensors (see e.g. [0126]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada by using pressure gauges to determine leakage in the oxygen-side path and leakage in the hydrogen-side path as taught in Yakumaru because Yakumaru teaches pressure is a suitable variable to measure to determine said leakages in water electrolysis cells. Based on the combination of Harada with Yakumaru, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to electrically connect the pressure gauges to the controller as well so that they pressure readings can used and processed.
Harada discloses a non-transitory computer-readable storage medium with an executable program stored (the system is controlled using a computer, see e.g. col 16, lines 25-26) thereon, the program being for detecting leakage in a water electrolyzer (see e.g. col 25, lines 25-26 and col 30, lines 42-57), wherein the program instructs a controller to perform the following:
closing a valve installed in the oxygen-side path (the valve is closed by default during normal operation, see e.g. connecting paragraph of col 13 and 14) and a valve installed in the hydrogen-side path (see e.g. col 25, lines 30-32);
progressing a water electrolysis reaction at the water electrolytic cell (see e.g. col 13, lines 55-61), and determining leakage in the oxygen-side path and leakage in the hydrogen-side path (see e.g. col 25, lines 30-36).
Harada does not explicitly teach that the leakage in the oxygen-side path and the hydrogen-side path is based on a change in an internal pressure. Harada discloses using gas leak sensors in each path for sensing the concentration of the gases instead (see e.g. col 25, lines 30-36). Yakumaru teaches that pressure gauges can also be used to determine leaks in product flow paths from a water electrolysis cell instead of concentration sensors (see e.g. [0126]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Harada by using pressure gauges to determine leakage in the oxygen-side path and leakage in the hydrogen-side path as taught in Yakumaru because Yakumaru teaches pressure is a suitable variable to measure to determine said leakages in water electrolysis cells.
Harada does not explicitly teach that following said progressing and determining leakage in the oxygen-side path and leakage in the hydrogen-side path, decreasing a pressure in the oxygen-side path or the hydrogen-side path, thereby making a differential pressure between the oxygen-side path and the hydrogen-side path, and determining leakage from the solid polymer electrolyte membrane based on a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure. However, Harada discusses the importance of ensuring minimum gas mixing to avoid explosive environments (see e.g. col 2, lines 53-61). Wakita teaches a method of water electrolysis (see e.g. [0242]) wherein leakage of hydrogen across the membrane is monitored (see e.g. [0007] and [0009]). The leakage is monitored by decreasing a pressure in the oxygen-side path or the hydrogen-side path, thereby making a differential pressure between the oxygen-side path and the hydrogen-side path (“opens the fourth valve 24 of the purger 23A to form the state where hydrogen is present at one electrode (cathode 11 in this example) of the MEA and hydrogen is not present at the other electrode (anode 12 in this example) of the MEA”, see e.g. [0135]), and determining leakage from the solid polymer electrolyte membrane based on a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure (see e.g. [0136]) and determining leakage from the solid polymer electrolyte membrane when a change in the pressure in the oxygen-side path or the hydrogen-side path having a higher pressure decreases out of a range of threshold values during a predetermined time. (see e.g. the increase in cross-over hydrogen would be inversely proportional and also representative to a change in the pressure of the hydrogen-side pressure, [0104]; [0229]; Fig 17). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the program of Harada by using the steps of determining leakage from the solid polymer electrolyte membrane taught in Wakita to ensure that the gas streams have a safe amount of hydrogen or oxygen to prevent explosive environments. Additionally, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the program of Harada in view of Wakita to perform this step following the said progressing and determining leakage in the oxygen-side path and leakage in the hydrogen-side path because this step needs to be performed when the cell is not being used to electrolyze water (see e.g. [0135] of Wakita).
Response to Arguments
Applicant's arguments filed 02/19/2026 have been fully considered but they are not persuasive.
On page(s) 6, the Applicant argues that Wakita does not teach a pressure difference. This is not considered persuasive. Fig 17 of Wakita shows the measured change of pressure over time in the hydrogen path.
On page(s) 6-7, the Applicant argues that the detector of Wakita is based on the potential of the MEA and not pressure. This is not considered persuasive. First, the potential of the first detector of Wakita is measuring the amount of hydrogen leaking from the membrane and would also be representative of the change in pressure of the hydrogen side. Additionally, Wakita also teaches using a pressure gauge to measure the pressure of the hydrogen side (see e.g. [0229]; Fig 17).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. 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, Luan Van can be reached at 571-272-8521. 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.
/ALEXANDER W KEELING/Primary Examiner, Art Unit 1795
Prosecution Insights