Prosecution Insights
Last updated: October 25, 2026
Application No. 18/570,352

RECUPERATOR BURNER WITH A RECUPERATOR FOR GUIDING COUNTER-FLOWING FLUIDS

Final Rejection §102§103
Filed
Dec 14, 2023
Priority
Jun 18, 2021 — EU PCT/EP2021/066647 +1 more
Examiner
LAU, JASON
Art Unit
3762
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Kueppers Solutions GmbH
OA Round
2 (Final)
54%
Grant Probability
Moderate
3-4
OA Rounds
6m
Est. Remaining
70%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allowance Rate
501 granted / 926 resolved
-15.9% vs TC avg
Strong +16% interview lift
Without
With
+15.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
55 currently pending
Career history
983
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
66.1%
+26.1% vs TC avg
§102
16.1%
-23.9% vs TC avg
§112
14.1%
-25.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 926 resolved cases

Office Action

§102 §103
DETAILED ACTION Claim Interpretation The following is a quotation of 35 U.S.C. 112(f): (f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph: An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof. Such claim limitation(s) is/are: “a space separating system into the flow pot for a transition of the at least one flow channel into the input or the output”, as recited in claim 5, and the corresponding structure described in the specification is a wall 21 If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. 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, 7-9, 12, 14, 18, 19 are rejected under 35 U.S.C. 102a1 as being anticipated by Wunning (US 4877396 A). Regarding claim 1, Wunning discloses a recuperator burner comprising a recuperator, which has two separate flow systems provided for guiding counter-flowing fluids (abstract), each system comprising at least one flow channel being open on both sides (Figs. 2-4), and the at least two fluids entering/leaving via intake inputs and offtake outputs at opposite ends of the burner inlet and burner outlet (col. 7, lines 44- col. 8, line 2), and one of the fluids is set up by a combustion air to be preheated and the other by an exhaust gas of the burner (abstract), wherein the recuperator comprises a one-piece heat transfer body (there is a single integrated unit 4), wherein the respective at least one flow channel of the two flow systems (9, 10) is formed in the heat transfer body, and wherein the jacket-shaped outer wall section of the heat transfer body forms, at the burner inlet (end proximate the casing 15), a flow pot (15+17+ portion of body 4 behind the wall 16) with an integral connection (i.e., it forms a single operational unit) to the inlet for combustion air (26) to be preheated and to the outlet (20) for the burner's exhaust gas. Regarding claim 7, Wunning discloses the recuperator burner according to claim 1, wherein the at least one flow channel (9, 10) of each of the two flow systems is divided into a plurality of partial flow channels for guiding counter-flowing fluids. Regarding claim 8, Wunning discloses the recuperator burner according to claim 7, whereinthe partial flow channels of one and/or the other flow channel can be fluidically connected by channel wall openings (upstream openings into channel 10 for receiving air flow). Regarding claim 9, Wunning discloses the recuperator burner according to claim 1, wherein the at least one flow channel (9, 10) in each case has a number of lined-up tube sections (Fig. 4: a section along the radial direction) as at least one flow-through channel, and the tube sections being formed from minimal surface elements (square-like wall elements) and the tube sections being connected in a continuous manner. Regarding claim 12, Wunning discloses the recuperator burner according to claim 1, wherein the at least one third and/or fourth flow system (there are a plurality of flow systems 9, 10; each channel 9, 10 can be a flow system), each with at least one flow channel open on both sides for at least one third and/or fourth fluid (the third and fourth fluids are the same as the first and second fluids), is integrated into the heat transfer body. Regarding claim 14, Wunning discloses the recuperator burner according to claim 1, wherein the heat transfer body has a flow-through inner body section (13) which can be positioned extending into the flow pot, as a result of which the latter can be directly flowed against laterally with combustion air to be preheated. Regarding claim 18, Wunning discloses the recuperator burner according to claim 1, wherein the heat transfer body is formed from a ceramic and/or metallic material (col. 7, lines 1-6). Regarding claim 19, Wunning discloses the recuperator burner according to claim 1, wherein the recuperator is designed as a ceramic recuperator (4; col. 7, lines 1-6) which is monolithic. 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. Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wunning (US 4877396 A) in view of Chen (CN 111238034 A). Regarding claim 2, Wunning discloses the recuperator burner according to claim 1, except wherein the flow pot is defined by an outer wall section having a wall tapering, which forms a bulbous extension of the heat transfer body having shoulder sections for the integrally connection of necks for the input for combustion air to be preheated and the output for exhaust gas from the burner. However, Chen teaches a stove comprising a flow pot defined by an outer wall section having a wall tapering (Fig. 1 shows a top bulbous flow pot), which forms a bulbous extension of the heat transfer body (portion beneath the flow pot) having shoulder sections (rounded sections below element 1) for the integrally connection of necks (2-2, 2-3, 1) for the input for combustion air to be preheated. It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Wunning wherein the flow pot is defined by an outer wall section having a wall tapering, which forms a bulbous extension of the heat transfer body having shoulder sections for the integrally connection of necks for the input for combustion air to be preheated and the output for exhaust gas from the burner. The motivation to combine is so that the flow pot can be attached to the metallic outer wall (Wunning, 16) in any rotational orientation, so that the necks (Wunning; 20, 26, 37) can be oriented for ease of connection with the exhaust, air, and fuel lines Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wunning (US 4877396 A) in view of Murray (US 20120196237 A1). Regarding claim 20, Wunning discloses the recuperator burner according to claim 18, except wherein the ceramic is made of a non-oxide and/or oxide ceramic material, in particular (note: the limitations following “in particular” are examined to be optional) silicon-infiltrated, reaction-bonded silicon carbide (RBSiC), silicon-infiltrated, reaction- bonded silicon carbide/boron carbide (RBSiC/B4C), silicon-infiltrated silicon carbide (RBSiC), silicon nitride-bonded silicon carbide (NSiC), pressureless sintered silicon carbide (SSiC), recrystallized silicon carbide (RSiC), aluminium oxide, silicate-bonded silicon carbide, zirconium oxide. However, Murray teaches a ceramic burner made of a non-oxide and/or oxide ceramic material (para. 51). It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Wunning wherein the ceramic is made of a non-oxide and/or oxide ceramic material, since these are suitable temperature-resistant ceramic materials for the ceramic recuperator of Wunning. Allowable Subject Matter Claims 21-30 are allowed. Response to Arguments Applicant asserts the following: PNG media_image1.png 220 629 media_image1.png Greyscale Examiner’s response: A one-piece heat transfer body is examined to mean that the body is a single joined functional structure, as opposed to a system that is made up of disparate pieces that are separated in space. Applicant asserts the following: PNG media_image2.png 166 628 media_image2.png Greyscale Examiner’s response: Wunning discloses wherein the input (26) for the combustion air and the output (20) for the exhaust gas are structurally and functionally integrated with the flow pot (15+17). Moreover, the jacket-shaped outer wall section (outer wall of body 4) forms part of the flow pot structure. Applicant asserts the following: PNG media_image3.png 186 625 media_image3.png Greyscale Examiner’s response: The portion of the body 4 located behind the wall 16 forms part of the flow pot. Applicant asserts the following: PNG media_image4.png 79 628 media_image4.png Greyscale Examiner’s response: The Office Action explains how Wunning reads on the limitations in amended claim 1. 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 JASON LAU whose telephone number is (571)270-7644. The examiner can normally be reached Mon-Fri 8:00-5:00. 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. /JASON LAU/Primary Examiner, Art Unit 3762
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Prosecution Timeline

Dec 14, 2023
Application Filed
Jun 22, 2026
Non-Final Rejection mailed — §102, §103
Sep 14, 2026
Response Filed
Sep 28, 2026
Final Rejection mailed — §102, §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

3-4
Expected OA Rounds
54%
Grant Probability
70%
With Interview (+15.9%)
3y 4m (~6m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 926 resolved cases by this examiner. Grant probability derived from career allowance rate.

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