Prosecution Insights
Last updated: October 02, 2026
Application No. 18/744,144

HYBRID HEAT EXCHANGER

Final Rejection §112
Filed
Jun 14, 2024
Priority
Dec 23, 2020 — provisional 63/129,796 +1 more
Examiner
CIGNA, JACOB JAMES
Art Unit
3726
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Baltimore Aircoil Company Inc.
OA Round
4 (Final)
64%
Grant Probability
Moderate
5-6
OA Rounds
11m
Est. Remaining
96%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allowance Rate
495 granted / 776 resolved
-6.2% vs TC avg
Strong +32% interview lift
Without
With
+32.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
26 currently pending
Career history
801
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
55.0%
+15.0% vs TC avg
§102
18.1%
-21.9% vs TC avg
§112
25.2%
-14.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 776 resolved cases

Office Action

§112
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 . Election/Restrictions Newly amended claim 20 is directed to an invention that is independent or distinct from the invention originally claimed for the following reasons: Claim 20 is amended to recite “each sheath portion having a unitary, one-piece construction.” Applicant argues in the remarks mailed 9 June 2026 that support for the limitation is found in Fig 4 and paragraph 0050. However, there was an election requirement mailed 8 January 2025 which indicated that the species represented by Figs 4, 5, and 6 are distinct and required Applicant to elect one from among them. On 25 February 2025, Applicant elected the species represented by Fig 6. Thus, claim 20 is now directed to the species of Fig 4 which is a non-elected invention. Accordingly, claims 20, 22-24, 28-33, 39-40 are withdrawn from consideration as being directed to a non-elected invention. Claims 27-28 were previously withdrawn and remain withdrawn. See 37 CFR 1.142(b) and MPEP § 821.03. Response to Arguments Applicant argues that claim 20 overcomes the prior art, but claim 20 is withdrawn for being directed to an unelected species. Even though claim 20 is withdrawn, Examiner notes the term “unitary, one piece construction” is potentially indefinite as it is unclear how “one piece” modifies “unitary.” Under the tenets of claim construction, each additional term must add some limitation. Here, it appears that “unitary” and “one piece” are entirely synonymous, but because both limitations are in the claim, there is also the presumption that “one piece” modifies “unitary.” Thus, the inclusion of both “unitary” and “one piece” make the metes and bounds of the claim potentially unclear. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 JACOB JAMES CIGNA whose telephone number is (571)270-5262. The examiner can normally be reached 9am-5pm Monday-Friday. 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, Thomas Hong can be reached at (571) 272-0993. 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. /JACOB J CIGNA/Primary Examiner, Art Unit 3726 1 September 2026
Read full office action

Prosecution Timeline

Show 6 earlier events
Dec 17, 2025
Request for Continued Examination
Feb 11, 2026
Response after Non-Final Action
Mar 09, 2026
Non-Final Rejection mailed — §112
May 29, 2026
Interview Requested
Jun 08, 2026
Applicant Interview (Telephonic)
Jun 09, 2026
Examiner Interview Summary
Jun 09, 2026
Response Filed
Sep 02, 2026
Final Rejection mailed — §112 (current)

Precedent Cases

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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
64%
Grant Probability
96%
With Interview (+32.4%)
3y 2m (~11m remaining)
Median Time to Grant
High
PTA Risk
Based on 776 resolved cases by this examiner. Grant probability derived from career allowance rate.

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