Prosecution Insights
Last updated: August 16, 2026
Application No. 18/407,526

HEAT EXCHANGER

Final Rejection §103
Filed
Jan 09, 2024
Priority
Feb 07, 2023 — JP 2023-017097
Examiner
TRAN, LEN
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Ngk Insulators Ltd.
OA Round
4 (Final)
13%
Grant Probability
At Risk
5-6
OA Rounds
11m
Est. Remaining
36%
With Interview

Examiner Intelligence

Grants only 13% of cases
13%
Career Allowance Rate
16 granted / 119 resolved
-56.6% vs TC avg
Strong +22% interview lift
Without
With
+22.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 6m
Avg Prosecution
18 currently pending
Career history
136
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
52.9%
+12.9% vs TC avg
§102
21.7%
-18.3% vs TC avg
§112
22.2%
-17.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 119 resolved cases

Office Action

§103
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 Non-Final Office Action is in response to Applicant’s Remarks/Amendments filed within the Pre-Appeal Brief filed on 8 January, 2026. Applicant's request for reconsideration of the finality of the rejection of the last Office action is persuasive and, therefore, the finality of that action is withdrawn. Disposition of Claims Claims 1-10 are 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. Claim(s) 1-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over KAWAGUCHI (US 2019/0204031 A1 – published 4 July, 2019), in view of MIYAIRI (US 2019/0339024 A1 – published 7 November, 2019). As to claim 1, KAWAGUCHI discloses a heat exchanger (20; figure 14-15) comprising: a first flow path through which a first fluid can flow (par. 70; figures 14-15); and a second flow path through which a second fluid can flow (par. 60; figures 14-15), the second flow path having an annular flow path portion (24; par. 71) extending along an axial direction of the first flow path on an outer peripheral side of the first flow path (figure 15, in view of axial extension in figure 14); wherein a honeycomb structure (1; par. 30-31 and 69; figures 14-15) having an outer peripheral wall (8; figures 1-2; par. 31) and partition wall (5a; par. 31 and 33) disposed on an inner side of the outer peripheral wall (figure 1 and 2), the partition walls defining a plurality of cells (4; par. 32) each extending from a first end face (2 or 3) to a second end face (2 or 3), is housed in the first flow path (par. 31 and figures 1-2). However, KAWAGUCHI provides wherein the heat exchanger is used for heat storage (par. 43), but does not disclose wherein a heat storage material is retained in some of the cells of the honeycomb structure. MIYAIRI is within the field of endeavor provided a heat exchanger (abstract) comprising a honeycomb structure (1(20); par. 50) having an outer periphery wall (figure 3) and partition walls (23), with heat storage material (i24i) retained in some of the cells (par. 73). Particularly, MIYAIRI teaches the purpose enables recovery and storage of waste heat that can be used at a later time (par. 132), in an effective manner (par. 5). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MIYAIRI, to include the heat storage material, as claimed, for these reasons. As to claim 2, KAWAGUCHI, as presently modified by MIYAIRI, provides the claimed invention, except the heat storage material is filled in the cells. MIYAIRI further teaches wherein the heat storage material is filled in the cells (figures 3-4; par. 73). Again, MIYAIRI teaches the purpose enables recovery and storage of waste heat that can be used at a later time (par. 132), in an effective manner (par. 5). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MIYAIRI, to include the heat storage material, as claimed, for these reasons. As to claim 3, KAWAGUCHI, as presently modified by MIYAIRI, provides the claimed invention, except the cells filled with the heat storage material are plugged on the first end face side and the second end face side. MIYAIRI further teaches wherein the cells filled with the heat storage material are plugged (via element, 27) on the first end face side (21a or 21b; par. 84; figures 3-4) and the second end face side (21a or 21b; par. 84; figures 3-4). Again, MIYAIRI teaches the purpose enables recovery and storage of waste heat that can be used at a later time (par. 132), in an effective manner (par. 5). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MIYAIRI, to include the cells filled with the heat storage material, as claimed, for these reasons. As to claim 4, KAWAGUCHI, as presently modified by MIYAIRI, provides the claimed invention, except wherein a ratio of the cells having the retained heat storage material to all the cells of the honeycomb structure is 10% or more. MIYAIRI, however, further teaches wherein the ratio of the cells having the retained heat storage material (113 cells as shown in figure 3) to all the cells (144 cells total, wherein 31 cells are without heat storage material, in view of the cells not being plugged, via element 27) of the honeycomb structure is 10% or more (based on the ratio of   n u m b e r   o f   c e l l s   c o n t a i n i n g   h e a t   s t o r a g e   m a t e r i a l t o t a l   n u m b e r   o f   c e l l s = x % 100 %   , which provides the ratio at 78%). Again, MIYAIRI teaches the purpose enables recovery and storage of waste heat that can be used at a later time (par. 132), in an effective manner (par. 5). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MIYAIRI, to include the cells with heat storage material and cells without heat storage material in the ratio, as claimed, for these reasons. As to claim 5, KAWAGUCHI, as presently modified by MIYAIRI, provides the claimed invention, except wherein the heat storage material is a latent heat storage material and/or a sensible heat storage material. MIYAIRI, however, further teaches wherein the heat storage material is a latent heat storage material and/or a sensible heat storage material (par. 97-98). Again, MIYAIRI teaches the purpose enables recovery and storage of waste heat that can be used at a later time (par. 132), in an effective manner (par. 5). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MIYAIRI, to include the heat storage material, as claimed, for these reasons. As to claim 6, KAWAGUCHI, as presently modified by MIYAIRI, further discloses wherein the honeycomb structure further comprises an inner peripheral wall (5a), and the honeycomb structure is a hollow honeycomb structure having the partition walls between the inner peripheral wall and the outer peripheral wall (see annotated figures 2-3). PNG media_image1.png 877 838 media_image1.png Greyscale Annotated Figures 2-3 of KAWAGUCHI Claim(s) 7-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over KAWAGUCHI (US 2019/0204031 A1 – published 4 July, 2019), in view of MIYAIRI (US 2019/0339024 A1 – published 7 November, 2019) and MOSER (US 2014/0041361 A1) As to claim 7, KAWAGUCHI, as presently modified by MIYAIRI, further discloses: wherein the first flow path is branched into two portion (flow into different cells would cause branched flow of the first fluid in the first flow path), wherein the structure is housed in one branched first flow path, and the second flow path is provided on an outer peripheral side of the one branched flow path (figures 14-15). However, KAWAGUCHI does not further disclose wherein the heat exchanger further comprises a valve capable of switching the flow of the first fluid into the one branched first flow path or other branched first flow path. MOSER is within the field of endeavor provided a heat exchanger (22; 22b; par. 84 and 97). MOSER teaches the heat exchanger including a branched flow path (figure 13A-13B) and a valve (716) capable of switching(MPEP § 2114 – II, wherein the limitation is merely a manner of operation of the valve, which MOSER provides full capability thereof, in view of par. 97-98) the flow of the first fluid to the one branched first flow path(figure 13A flow path through at least tubes, 644) or other branched flow first flow path (figure 13B flow path through at least tube, 710). MOSER provides the valve is included to route the fluid based on temperature of the fluid to provide intended heat transfer among different fluids or prevent any further increase in temperature of fluid (par. 92 and 98). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MOSER, to include the valve, as claimed, for these reasons. As to claim 8, KAWAGUCHI, as presently modified by MAYAIRI and MOSER, does not further disclose the requirements of the claim. MOSER, however, further teaches a control unit (par. 75) capable (MPEP § 2114 – II, wherein the BRI of the claim only requires capability of the control unit to perform the claimed function, as it is not specifically “configured” to carry out the control scheme claimed) controlling the valve to a heat recovery mode where heat recovery is performed by switching the flow of the first fluid to the one branched first flow path (figure 13a; par. 97-98), and a non-heat recovery mode where heat recovery is not performed by switching the flow of the first fluid to the other branched first flow path (figures 13b; par. 97-98). MOSER provides the valve, controllable to actuate in a particular manner to shift the flow of the fluid within the heat exchanger (par. 75), is included to route the fluid based on temperature of the fluid to provide intended heat transfer among different fluids or prevent any further increase in temperature of fluid (par. 92 and 98). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MOSER, to include the valve, as claimed, for these reasons. As to claim 9, KAWAGUCHI, as presently modified by MAYAIRI and MOSER, further discloses wherein the first flow path is configured to have a first circulation route in which the first fluid can flow through the cells of the honeycomb structure (figure 1 and annotated figures 2-3, in view of par. 31), and a second circulation route in which the first fluid can flow through the interior of the inner peripheral wall of the honeycomb structure (figure 1 and annotated figures 2-3, in view of par. 31). However, KAWAGUCHI does not further disclose wherein the heat exchanger further comprises a valve capable of switching the flow of the first fluid to the first circulation route or the second circulation rout by controlling the flow of the first fluid in the second circulation route. MOSER is within the field of endeavor provided a heat exchanger (22; 22b; par. 84 and 97). MOSER teaches the heat exchanger including a first circulation route (figure 13A flow path through at least tubes, 644) and a second circulation route (figure 13B flow path through at least tube, 710). More so, MOSER teaches a valve (716) capable of switching(MPEP § 2114 – II, wherein the limitation is merely a manner of operation of the valve, which MOSER provides full capability thereof, in view of par. 97-98) the flow of the first fluid to the first circulation route(figure 13A flow path through at least tubes, 644) or the second circulation route (figure 13B flow path through at least tube, 710) by controlling the flow of the first fluid in the second circulation route (closing off the flow directly into the second circulation route). MOSER provides the valve is included to route the fluid based on temperature of the fluid to provide intended heat transfer among different fluids or prevent any further increase in temperature of fluid (par. 92 and 98). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MOSER, to include the valve, as claimed, for these reasons. As to claim 10, KAWAGUCHI, as presently modified by MAYAIRI and MOSER, does not further disclose the requirements of the claim. MOSER, however, further teaches a control unit (par. 75) capable (MPEP § 2114 – II, wherein the BRI of the claim only requires capability of the control unit to perform the claimed function, as it is not specifically “configured” to carry out the control scheme claimed) controlling the valve to a heat recovery mode where heat recovery is performed by switching the flow of the first fluid to the one branched first flow path (figure 13a; par. 97-98), and a non-heat recovery mode where heat recovery is not performed by switching the flow of the first fluid to the other branched first flow path (figures 13b; par. 97-98). MOSER provides the valve, controllable to actuate in a particular manner to shift the flow of the fluid within the heat exchanger (par. 75), is included to route the fluid based on temperature of the fluid to provide intended heat transfer among different fluids or prevent any further increase in temperature of fluid (par. 92 and 98). Therefore, it would have been obvious to one having ordinary skill within the art, prior to the date the invention was effectively filed, to modify KAWAGUCHI, in view of MOSER, to include the valve, as claimed, for these reasons. Inquiry Any inquiry concerning this communication or earlier communications from the examiner should be directed to Len Tran whose telephone number is (571)272-1184. The examiner can normally be reached Monday-Friday, 8am - 4pm. 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. 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. /LEN TRAN/Supervisory Patent Examiner, Art Unit 3763
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Prosecution Timeline

Show 2 earlier events
Sep 26, 2025
Response Filed
Oct 10, 2025
Final Rejection mailed — §103
Jan 08, 2026
Notice of Allowance
Jan 08, 2026
Response after Non-Final Action
Mar 10, 2026
Response after Non-Final Action
Apr 24, 2026
Non-Final Rejection mailed — §103
Jul 23, 2026
Response Filed
Aug 11, 2026
Final Rejection mailed — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12661676
CLEANING NOZZLE FOR CRYOGENIC FLUID FUELING RECEPTACLE
3y 1m to grant Granted Jun 23, 2026
Patent 12656041
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Patent 12623244
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2y 11m to grant Granted May 12, 2026
Patent 12584693
MICROCHANNEL HEAT EXCHANGER
2y 2m to grant Granted Mar 24, 2026
Patent 12551916
CLEANING RECEPTACLE FOR CRYOGENIC FLUID FUELING NOZZLE
2y 9m to grant Granted Feb 17, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
13%
Grant Probability
36%
With Interview (+22.1%)
3y 6m (~11m remaining)
Median Time to Grant
High
PTA Risk
Based on 119 resolved cases by this examiner. Grant probability derived from career allowance rate.

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