Prosecution Insights
Last updated: April 19, 2026
Application No. 18/114,378

PLANAR ELEMENT FOR FORMING HEAT EXCHANGER

Non-Final OA §103
Filed
Feb 27, 2023
Examiner
BABAA, NAEL N
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Watergen Ltd.
OA Round
3 (Non-Final)
77%
Grant Probability
Favorable
3-4
OA Rounds
2y 10m
To Grant
81%
With Interview

Examiner Intelligence

Grants 77% — above average
77%
Career Allow Rate
410 granted / 534 resolved
+6.8% vs TC avg
Minimal +4% lift
Without
With
+4.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
25 currently pending
Career history
559
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
49.8%
+9.8% vs TC avg
§102
17.4%
-22.6% vs TC avg
§112
31.0%
-9.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 534 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application is being examined under the pre-AIA first to invent provisions. 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 9/22/2025 has been entered. Claim Rejections - 35 USC § 103 The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action: (a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter 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 pre-AIA 35 U.S.C. 103(a) 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 under pre-AIA 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of pre-AIA 35 U.S.C. 103(c) and potential pre-AIA 35 U.S.C. 102(e), (f) or (g) prior art under pre-AIA 35 U.S.C. 103(a). Claim 1 is rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Howard (US 2007/0295027 – previously cited)in view of Tada (US 2007/0266726). Regarding claim 1, Howard teaches a planar element for forming, in combination with other planar elements (see Title, Abstract) assembled in a stack, a heat exchanger (see Fig. 3, paragraph [0028]), said planar element comprising: an inlet region at a first edge of the planar element and an outlet region at a second edge of the planar edge opposed to the first edge; a first array of mutually spaced enhanced counter flow heat exchange (ECFHE) protrusions downstream of said inlet region of said planar element (inlet 16, Fig. 3, outlets 84, 85, with array of protrusions 70/72 at the inlet); and a second array of mutually spaced enhanced counter flow heat exchange (ECFHE) protrusions upstream of said outlet region of said planar element (76, 78, Fig. 3, paragraph [0028]). Howard does not specifically teach a first air flow guiding protrusion at the inlet region and a second air flow guiding protrusion at the outlet region. Tada teaches an air conditioning unit (Tada, Title) which features a heat exchanger (Tada, 15, Fig. 4) and a first air flow guiding protrusion at the inlet region (Tada, 27, Fig. 4) and a second air flow guiding protrusion at the outlet region (Tada, either 31 or 33 read on the limitation, see Fig. 4). It would have been obvious to one of ordinary skill in the art, prior to the effective filing, to provide Howard with the first and second air flow guiding protrusion at the inlet/outlet, as taught by Tada, in order to control the amount of air supplied to the heat exchanger for conditioning. Claims 2-5 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Howard in view of Tada, further in view of Elder (US 2012/0114467). Regarding claim 2, Howard as modified teaches the planar element according to claim 1, but does not teach that each of said mutually spaced protrusions of said first array and/or of said second array has a inlet end and an outlet end that are tapered from a surface of the planar element to an upper surface thereof. Elder teaches a heat exchanger with tapered fins (Elder, Title) wherein the fins (Elder, Fig. 4, see paragraph [0020]) taper from a surface (Elder, 46, Fig. 4) to an upper surface (see Fig. 4, which show the leading edges 74 and 76 taper upward). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Howard with tapered inlet and outlet ends for the first and/or second array of protrusions, as taught by Elder, in order to improve air flow through the fins (Elder, paragraph [0021]). Regarding claim 3, Howard as modified teaches the planar element according to claim 1, but does not teach that the first air flow guiding protrusion creates a narrower opening at the inlet region than inside the inlet region. Elder teaches a heat exchanger with tapered fins (Elder, Title) wherein the fins (Elder, Fig. 4, see paragraph [0020]) taper from a surface (Elder, 46, Fig. 4) to an upper surface (see Fig. 4, which show the leading edges 74 and 76 taper upward). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Howard with tapered inlet and outlet ends for the first and/or second array of protrusions, as taught by Elder, in order to improve air flow through the fins (Elder, paragraph [0021]). Regarding claim 4, Howard as modified teaches the planar element according to claim 1, but does not teach that the second air flow guiding protrusion creates a narrower opening at the outlet region than inside the outlet region. Elder teaches a heat exchanger with tapered fins (Elder, Title) wherein the fins (Elder, Fig. 4, see paragraph [0020]) taper from a surface (Elder, 46, Fig. 4) to an upper surface (see Fig. 4, which show the leading edges 74 and 76 taper upward). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Howard with tapered inlet and outlet ends for the first and/or second array of protrusions, as taught by Elder, in order to improve air flow through the fins (Elder, paragraph [0021]). Regarding claim 5, Howard as modified teaches the planar element according to claim 2, wherein each of the tapered inlet ends and tapered outlet ends of the protrusions has a plane of tapering that intersects with a plain of the planar element (met through the combination). Claim 6 is rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Howard in view of Tada, further in view of Yamanaka (US 4,742,866). Regarding claim 6, Howard as modified teaches the planar element according to claim 1, comprising a planar core element, said planar core element forming, in combination with other planar core elements assembled in a stack (see Howard, paragraph [0009]), but does not teach a cut out region between the first array of mutually spaced ECFHE protrusions and the second array of mutually spaced ECFHE protrusions, said cut out region configured to accommodate a planar core element, said planar core element forming, in combination with other planar core elements assembled in a stack, each corresponding to a respective planar element, a cooling core. Yamanaka teaches a planar element (Yamanaka, col. 1, lines 36-40, Fig. 1C) and a cut out region (Yamanaka, 14, Fig. 1, 7, see col. 6, lines 15-20) between arrays of protrusions (see Fig. 8, 1m, etc), wherein the cutout region accommodates planar elements (Yamanaka, Fig. 7). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Howard as modified with a cutout region with a cooling core, as taught by Yamanaka, in order to provide greater contact surface to increase the rate of heat transfer in the heat exchanger with the cooling core. Response to Arguments Applicant’s arguments with respect to claim(s) 1 and 2 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to NAEL N BABAA whose telephone number is (571)270-3272. The examiner can normally be reached M-F, 9-5 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, Jerry-Daryl Fletcher can be reached at (571)-270-5054. 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. /NAEL N BABAA/ Primary Examiner, Art Unit 3763
Read full office action

Prosecution Timeline

Feb 27, 2023
Application Filed
Nov 25, 2024
Non-Final Rejection — §103
Mar 27, 2025
Response Filed
May 19, 2025
Final Rejection — §103
Sep 22, 2025
Response after Non-Final Action
Nov 20, 2025
Request for Continued Examination
Dec 03, 2025
Response after Non-Final Action
Dec 13, 2025
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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VEHICLE AIR-CONDITIONING DEVICE
2y 5m to grant Granted Apr 14, 2026
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REFRIGERATION CYCLE SYSTEM
2y 5m to grant Granted Apr 14, 2026
Patent 12595941
HEAT PUMP SYSTEM AND CONTROL METHOD THEREOF
2y 5m to grant Granted Apr 07, 2026
Patent 12588768
ARTICLE AND SYSTEM FOR HEATING OR COOLING A SURFACE
2y 5m to grant Granted Mar 31, 2026
Patent 12584667
REFRIGERATION SYSTEM
2y 5m to grant Granted Mar 24, 2026
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
77%
Grant Probability
81%
With Interview (+4.1%)
2y 10m
Median Time to Grant
High
PTA Risk
Based on 534 resolved cases by this examiner. Grant probability derived from career allow rate.

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