Prosecution Insights
Last updated: April 17, 2026
Application No. 17/839,021

Heat Reclaimer for Stoves

Final Rejection §103
Filed
Jun 13, 2022
Examiner
JONES, LOGAN P
Art Unit
3762
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
unknown
OA Round
4 (Final)
42%
Grant Probability
Moderate
5-6
OA Rounds
3y 6m
To Grant
72%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
215 granted / 511 resolved
-27.9% vs TC avg
Strong +30% interview lift
Without
With
+30.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 6m
Avg Prosecution
66 currently pending
Career history
577
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
57.0%
+17.0% vs TC avg
§102
19.4%
-20.6% vs TC avg
§112
20.0%
-20.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 511 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 . DETAILED ACTION Response to Arguments Applicant’s arguments with respect to the claims 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. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 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 the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 9 and 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Yeager (US 2468909 A), hereinafter Yeager, in view of Landon (US 20070221200 A1), hereinafter Landon, and further in view of Alex (US 20040026073 A1), hereinafter Alex. Regarding claims 9, 6, 7, Yeager discloses a heat reclaimer (“air heater 32 is of cylindrical form, and includes a central pipe 33 in spaced concentric relation to the cylindrical outer surface, which pipe 33 is mounted between spaced portions 35 and 36 of the flue pipe by means of brackets or straps 37, 38” column 3, line 28) for a free-standing wood-burning stove (When reading the preamble in the context of the entire claim, the recitation “of a free-standing wood-burning stove” is not limiting because the body of the claim describes a complete invention and the language recited solely in the preamble does not provide any distinct definition of any of the claimed invention’s limitations. Thus, the preamble of the claim(s) is not considered a limitation and is of no significance to claim construction. See Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1305, 51 USPQ2d 1161, 1165 (Fed. Cir. 1999). See MPEP § 2111.02. Furthermore, a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. In this instance, the heat reclaimer of Yeager is “an auxiliary air heater which may be readily installed to cooperate with an existing heating arrangement for providing additional heat from the waste flue gases” (column 1, line 9) and could be mounted between two sections of an exhaust-gas-conveying flue of a free-standing wood-burning stove), the heat reclaimer comprising: a reclaimer flue having a flue cover (“the cylindrical outer surface” column 3, line 29) and an inside-surface member parallel to exhaust-gas flow, the reclaimer flue defining a cross-sectional area shaped to increase the surface area of the inside-surface member of the reclaimer flue which is exposed to exhaust gas by extending the inside-surface member of the reclaimer flue into the exhaust gas flow (“The pipe 33 is preferably provided with longitudinally disposed central metal fins 48” column 3, line 51), the reclaimer flue configured to be mounted between two sections of an exhaust-gas-conveying flue of the stove (“pipe 33 is mounted between spaced portions 35 and 36 of the flue pipe by means of brackets or straps 37, 38” column 3, line 30); and a heat-exchange assembly adjacent to and in contact with the reclaimer flue on one side thereof (“As shown in Figs. 5 and 6, a plurality of semicircular baffles 46 are provided which are spaced apart as illustrated, whereby the cool air from the fan casing is forced into the auxiliary air heater 32, and around the hot flue gas pipe 33 in a tortuous helical path, to exit, through an outlet pipe 41 which is preferably secured to and made integral with the upper surface of the auxiliary air heater 32. The pipe 33 is preferably provided with longitudinally disposed central metal fins 48 which, quickly absorb and transfer heat to the outer shell of the pipe for more effective heat transfer from the hot flue gases to the air to be heated” column 3, line 43), one portion of the heat-exchange assembly including an inside-surface portion of the reclaimer flue on the opposite side of the inside-surface member of the reclaimer flue, the inside-surface member of the reclaimer flue thereby separating the exhaust gas from the heat-exchange assembly (The inside surface of 33), the heat-exchange assembly also including: a fan for moving ambient air (“A fan similar to the fan 20 of Fig. 2, is mounted in the fan housing 39, and is driven by an electric motor 44” column 3, line 37); a chamber through which the fan drives the ambient air, the chamber defining a primary airflow direction (“cool air from the fan casing is forced into the auxiliary air heater 32, and around the hot flue gas pipe 33” column 3, line 45); and a plurality of heat transfer plates inside the chamber and transverse to the primary airflow direction (“a plurality of semicircular baffles 46” column 3, line 43), the plates defining an airflow passage and having at least an edge in solid-to-solid thermal contact with the inside-surface portion of the reclaimer flue (Figures 5 and 6), thereby heating the ambient air with heat from the exhaust gas while retaining a freely-open exhaust-conveying flue (“The longitudinal fin mounting does not restrict the flow of the flue gases, and facilitates cleaning and brushing of the flue pipe interior” column 3, line 56) and providing a heat reclaimer which safely transfers heat to the space in which it is located (“The principal object of the invention is to provide an improved auxiliary air heater suitable for a domestic heating plant or the like” column 1, line 5). PNG media_image1.png 220 206 media_image1.png Greyscale PNG media_image2.png 324 634 media_image2.png Greyscale Yeager does not disclose: the heat-exchange assembly in contact with the reclaimer flue on only one side thereof; the plates defining airflow openings therethrough, wherein the airflow openings on a plate define a pattern thereon and each plate has the same pattern of openings, wherein the airflow openings in a plate are aligned with the corresponding openings in one of its immediately-adjacent plate. However, Landon teaches the heat-exchange assembly in contact with the reclaimer flue on only one side thereof (The embodiment of figure 2). PNG media_image3.png 698 504 media_image3.png Greyscale PNG media_image4.png 722 468 media_image4.png Greyscale In view of Landon’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include the heat-exchange assembly in contact with the reclaimer flue on only one side thereof as is taught in Landon, in the heat reclaimer disclosed by Yeager because Landon teaches both an embodiment wherein the heat-exchange assembly is in contact with both sides of a reclaimer flue and wherein the heat-exchange assembly is in contact with only one side of a reclaimer flue. Therefore, either arrangement is effective and one may be substituted for another. Furthermore, the one side configuration constitutes a reduction in materials and weight. Yeager, as modified by Landon, does not disclose the plates defining airflow openings therethrough, wherein the airflow openings on a plate define a pattern thereon and each plate has the same pattern of openings, wherein the airflow openings in a plate are aligned with the corresponding openings in one of its immediately-adjacent plate. However, Alex teaches the plates defining airflow openings therethrough, wherein the airflow openings on a plate define a pattern thereon and each plate has the same pattern of openings, wherein the airflow openings in a plate are aligned with the corresponding openings in one of its immediately-adjacent plate (“each of the laminas 3 is formed with a plurality of vents 34 for enhancing airflow” paragraph [0024] and figures 4 and 5). PNG media_image5.png 466 560 media_image5.png Greyscale PNG media_image6.png 442 322 media_image6.png Greyscale In view of the teachings of Alex, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include the plates defining airflow openings therethrough, wherein the airflow openings on a plate define a pattern thereon and each plate has the same pattern of openings, wherein the airflow openings in a plate are aligned with the corresponding openings in one of its immediately-adjacent plate as is taught in Alex, in the heat reclaimer disclosed by Yeager because Alex states that the openings enhance airflow. Therefore, including the openings in the plates of Yeager will improve airflow and thus enhance heat transfer. Regarding claim 5, Yeager, as modified by Landon and Alex, discloses the heat reclaimer of claim 9 wherein the plates are parallel to one another (The plates are parallel in Yeager and Alex). Regarding claim 8, Yeager, as modified by Landon and Alex, discloses the heat reclaimer of claim 9 wherein the plates are substantially perpendicular to the primary airflow direction (Figure 6). Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Yeager, in view of Landon, in view of Alex, and further in view of Gannon (US 2709074 A), hereinafter Gannon. Regarding claim 2, Yeager, as modified by Landon and Alex, discloses the heat reclaimer of claim 9. Yeager, as modified by Landon and Alex, does not disclose wherein the plates are configured as pairs of plates in U-shaped form having a base in thermal contact with the flue inside surface portion and the pair of plates extending from the base. However, Gannon teaches wherein the plates are configured as pairs of plates in U-shaped form (“Each of the fin units is essentially U- shaped in cross section” column 2, line 33) having a base in thermal contact with the pipe inside surface portion (“edges 28 of the recesses will rather closely engage the pipe to maintain good heat transfer relationship” column 2, line 43) and the pair of plates extending from the base (“fin portions 24 and 25 which are desirably parallel and extend in the same direction from the base portions” column 2, line 35). PNG media_image7.png 258 508 media_image7.png Greyscale PNG media_image8.png 278 217 media_image8.png Greyscale PNG media_image9.png 336 272 media_image9.png Greyscale In view of Gannon’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the plates are configured as pairs of plates in U-shaped form having a base in thermal contact with the pipe inside surface portion and the pair of plates extending from the base as is taught in Gannon, in the heat reclaimer as presently modified because Gannon states “A purpose of the invention is to provide a heat transfer fin construction which can be conveniently assembled on existing or new piping, and which will be easy to apply and easy to remove” (column 1, line 20). Therefore, including the exchanger construction taught by Gannon will simplify application and removal thereof. Regarding claim 3, Yeager, as modified by Landon, Alex, and Gannon, discloses the heat reclaimer of claim 2 wherein the pairs of plates are parallel to one another (The plates are parallel in Yeager, Alex, and Gannon). Regarding claim 4, Yeager, as modified by Landon, Alex, and Gannon, discloses the heat reclaimer of claim 3 wherein the airflow openings in one plate of each pair are aligned with the corresponding openings in the other plate of the pair (As taught by Alex). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Officina San Giorgio Soc. Straneo Incisa (GB 190915628 A) “holes 4 to facilitate the circulation of the surrounding medium through said gills” PNG media_image10.png 288 292 media_image10.png Greyscale Brown (US 3016893 A) “the fin members 21 are provided with perforations 31 which, as shown in FIGURES 2 and 3, provide circumferential paths around the finned tube for the circumferential flow of fluid in the distribution zone and into the outlet 12. Preferably, the openings occupy about half of the total area of the fins but this proportion may be varied considerably. The openings are shown in the drawing as being round, but obviously they can be oval, rectangular or any other convenient shape. This provides adequate passages for the circumferential flow of the fluid and sufficient extended surface area so that heat exchange takes place at a high rate between the fins and the fluid flowing over and through them” (column 3, line 7) Reinke (US 4390060 A) PNG media_image11.png 646 338 media_image11.png Greyscale Parham (US 4509588 A) PNG media_image12.png 318 252 media_image12.png Greyscale PNG media_image13.png 352 332 media_image13.png Greyscale Bidwell (US 4448348 A) “This invention relates to wood burning free-standing fireplaces, stoves and the like, and more particularly, to a forced air flue heater device” column 1, line 4 emphasis added PNG media_image14.png 644 456 media_image14.png Greyscale Murray (US 1382220 A) PNG media_image15.png 410 306 media_image15.png Greyscale Isenberg (US 4187905 A) PNG media_image16.png 436 662 media_image16.png Greyscale Szucs (US 4648443 A) “a flow will start through the openings 24A and 24B as well as through the hole 25 placed in the bending, what draws the boundary layer 27, thus improving heat transfer in a significant degree” column 6, line 42 PNG media_image17.png 696 454 media_image17.png Greyscale Huang (US 11118847 B2) “The first fluid and the second fluid flow in two opposite directions. The second fluid flows along the microchannels of the plurality of fins 2 that expands the outer surface area of the tube 1 and stirs the second fluid, restricting the second fluid to flow reversely through the microchannels along the axis of the finned heat exchanger tube” column 3, line 40 PNG media_image18.png 278 452 media_image18.png Greyscale 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 LOGAN P JONES whose telephone number is (303)297-4309. The examiner can normally be reached Mon-Fri 8:30-5:00 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, Michael Hoang can be reached at (571) 272-6460. 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. /LOGAN P JONES/Examiner, Art Unit 3762 /MICHAEL G HOANG/Supervisory Patent Examiner, Art Unit 3762
Read full office action

Prosecution Timeline

Jun 13, 2022
Application Filed
Oct 28, 2024
Non-Final Rejection — §103
Mar 26, 2025
Response Filed
Apr 04, 2025
Final Rejection — §103
Jul 29, 2025
Request for Continued Examination
Jul 31, 2025
Response after Non-Final Action
Aug 06, 2025
Non-Final Rejection — §103
Nov 07, 2025
Response Filed
Feb 05, 2026
Final Rejection — §103 (current)

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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
42%
Grant Probability
72%
With Interview (+30.4%)
3y 6m
Median Time to Grant
High
PTA Risk
Based on 511 resolved cases by this examiner. Grant probability derived from career allow rate.

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