Prosecution Insights
Last updated: April 19, 2026
Application No. 18/439,914

HONEYCOMB STRUCTURE AND HEAT EXCHANGER

Final Rejection §102§103
Filed
Feb 13, 2024
Examiner
LING, FOR K.
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
NGK Insulators Ltd.
OA Round
2 (Final)
54%
Grant Probability
Moderate
3-4
OA Rounds
3y 6m
To Grant
72%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allow Rate
231 granted / 429 resolved
-16.2% vs TC avg
Strong +18% interview lift
Without
With
+18.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 6m
Avg Prosecution
47 currently pending
Career history
476
Total Applications
across all art units

Statute-Specific Performance

§103
50.2%
+10.2% vs TC avg
§102
24.0%
-16.0% vs TC avg
§112
24.5%
-15.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 429 resolved cases

Office Action

§102 §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 § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 1-3 and 5-9 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kawaguchi (US PGPub No. 2019/0277570). Regarding claim 1, Kawaguchi discloses a honeycomb structure (hollow pillar shaped honeycomb structure 8, Figs. 1 and 2) comprising: an inner peripheral wall (6); an outer peripheral wall (7); and partition walls (5a) disposed between the inner peripheral wall and the outer peripheral wall, the partition walls defining a plurality of cells (4) each extending from a first end face (2) to a second end face (3), wherein, in a cross section orthogonal to an extending direction of the cells (Fig. 2), the partition walls comprise one or more first partition walls extending in a radial direction (plurality of the radial extending first partition walls 5a), and wherein the inner peripheral wall and the outer peripheral wall have an average thickness of 0.1 mm or more (see table 1, the outer wall 6 and inner wall 7 each has a thickness of 1.5 mm), and a thickness variation coefficient of 1.0 or less, represented by the following equation (1): the thickness variation coefficient = a standard deviation of the thicknesses of the inner peripheral wall and the outer peripheral wall / an average thickness of the inner peripheral wall and the outer peripheral wall (1) (the outer wall 6 and inner wall 7 have the same thickness. Therefore, a standard deviation of the thicknesses of the outer wall 6 and inner wall 7 is zero. As a result, the equation 1 is also zero which is less than 1 as claimed). Regarding claim 2, Kawaguchi further discloses wherein the partition walls further comprise one or more second partition walls (5b) extending in a circumferential direction in a cross section orthogonal to the extending direction of the cells (see Fig. 2). Regarding claim 3, Kawaguchi further discloses wherein the inner peripheral wall has an inner diameter of 20 to 200 mm (diameter of the hollow region 10 of 52mm, see Example 1, paragraph 0168. The hollow region 10 defines an inner diameter of the inner wall 7), and the outer peripheral wall has an outer diameter of 30 to 300 mm (outer diameter of 70mm in Example 1, paragraph 0168). Regarding claim 5, Kawaguchi further discloses wherein the number of the second partition walls is 50 or less (two second partition walls 5b shown in Fig. 2). Regarding claims 6 and 7, Kawaguchi further discloses wherein the first partition walls and the second partition walls have an average thickness of 0.1 to 1 mm (see table 1, both the first and second partition walls have a thickness of 0.3 mm). Regarding claims 8, Kawaguchi further discloses wherein a length in the extending direction of the cells is 10 to 300 mm (a length of the honeycomb structure in Figs. 1 and 2 is 25mm, Example 1, paragraph 0168). Regarding claims 9, Kawaguchi further discloses a heat exchanger (1) comprising the honeycomb structure (in Figs. 1 and 2) according to claim 1. 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) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kawaguchi (US PGPub No. 2019/0277570) in view of Miyairi (US PGPub No. 2020/0123956). Regarding claim 4, Kawaguchi fails to explicitly disclose wherein the number of the first partition walls is 50 to 1500. Miyairi discloses disclose wherein the number of the first partition walls is 50 to 1500 (paragraph 0072 and Fig. 3, the ceramic cylinder tube 10 may be provided with 50 or more cell columns. Therefore, 50 or more radial first partition walls 13 are provided in the ceramic cylinder tube 10). The number of the first partition walls 5a determines the number of cells 4 and further determines the cell density according to paragraph 0081 in Kawaguchi. The paragraph 0081 further discloses that the cell density may be adjusted as needed depending on applications or the like and increasing the cell density increases the strength of the hollow pillar shaped honeycomb structure 8 itself. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided wherein the number of the first partition walls is 50 to 1500 in Kawaguchi as taught by Miyairi in order to increase strength and increase heat transfer area if the hollow pillar shaped honeycomb structure 8. Response to Arguments Applicant's arguments filed 11/12/2025 have been fully considered but they are not persuasive. In response to applicant’s argument that Kawaguchi fails to disclose the standard deviation of the respective average thickness, it is noted that the features upon which applicant relies upon: the thickness variation of the inner and outer peripheral walls in the honeycomb structure as a result of extruding a green body and further determines the standard deviation (pages 6 and 7 of remarks), are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). The argument implies the standard deviation in microscopic view of the green body or surface roughness, and that causes the thickness variation described in remarks. The argued part of claim 1 is excerpted as follows: “wherein the inner peripheral wall and the outer peripheral wall have an average thickness of 0.1 mm or more, and a thickness variation coefficient of 1.0 or less, represented by the following equation (1): the thickness variation coefficient = a standard deviation of the thicknesses of the inner peripheral wall and the outer peripheral wall / an average thickness of the inner peripheral wall and the outer peripheral wall (1)”. Claim 1 only recites a general average thickness and a standard deviation of the thicknesses of the inner peripheral wall and the outer peripheral wall, without specifying where the thickness is taken or details of the thickness of the inner and outer peripheral walls. Kawaguchi discloses that the outer wall 6 and inner wall 7 have the same thickness of 1.5 mm (in Example 1 of Table 1) more than claimed 0.1 mm. Therefore, an average thickness of the outer wall 6 and inner wall 7 is the same 1.5 mm. A standard deviation of thicknesses of the walls 6 and 7 must be zero because they have the same value, and thus the claimed equation and “a thickness variation coefficient of 1.0 or less”. Conclusion THIS ACTION IS MADE FINAL. 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 FOR K LING whose telephone number is (571)272-8752. The examiner can normally be reached Monday through Friday, 8:30 am to 5 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, Jianying Atkisson can be reached at 571-270-7740. 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. /JIANYING C ATKISSON/Supervisory Patent Examiner, Art Unit 3763 /F.K.L/Examiner, Art Unit 3763
Read full office action

Prosecution Timeline

Feb 13, 2024
Application Filed
Aug 11, 2025
Non-Final Rejection — §102, §103
Nov 12, 2025
Response Filed
Feb 10, 2026
Final Rejection — §102, §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12595969
HEAT EXCHANGER FOR A MOTOR VEHICLE
2y 5m to grant Granted Apr 07, 2026
Patent 12590763
STACKED DISC HEAT EXCHANGER FOR A THERMAL MANAGEMENT MODULE
2y 5m to grant Granted Mar 31, 2026
Patent 12553673
Heat Exchange System for Exchanging Heat with a Formable Material
2y 5m to grant Granted Feb 17, 2026
Patent 12546540
HEAT EXCHANGER
2y 5m to grant Granted Feb 10, 2026
Patent 12516402
BRAZING FOIL, OBJECT AND METHOD FOR BRAZING
2y 5m to grant Granted Jan 06, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
54%
Grant Probability
72%
With Interview (+18.5%)
3y 6m
Median Time to Grant
Moderate
PTA Risk
Based on 429 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month