Prosecution Insights
Last updated: April 19, 2026
Application No. 18/033,175

BURNER UNIT

Non-Final OA §103
Filed
Apr 21, 2023
Examiner
SHIRSAT, VIVEK K
Art Unit
3762
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Truma Geraetetechnik GmbH & Co. Kg
OA Round
3 (Non-Final)
74%
Grant Probability
Favorable
3-4
OA Rounds
3y 0m
To Grant
99%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allow Rate
781 granted / 1061 resolved
+3.6% vs TC avg
Strong +28% interview lift
Without
With
+28.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
60 currently pending
Career history
1121
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
45.7%
+5.7% vs TC avg
§102
25.2%
-14.8% vs TC avg
§112
23.3%
-16.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1061 resolved cases

Office Action

§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 . Response to Arguments Applicant’s arguments with respect to claim(s) 1-6 and 8 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. Claim(s) 1-6 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Irwin (US 3,886,735) in view of Alber et. al (US 5,993,197). With respect to claim 1 Irwin discloses a burner unit for combusting an air-fuel mixture, comprising: a combustion space [the interior of reference character 3]; a combustion air guide dome [reference character 4]; and a fuel inlet [reference character 15], wherein the fuel inlet opens into the combustion space, wherein the combustion air guide dome is located in the combustion space and has recesses [reference character 28 in Fig. 2], wherein the recesses have a larger width [see annotated Fig. below] on an inside of the combustion air guide dome than on an outside of the combustion air guide dome [see annotated Fig. below], wherein the recesses decrease in width in a radial direction extending outward from the longitudinal axis of the combustion air guide dome [see Fig. 2]. Irwin does not disclose that the recesses are axially oriented slots that extend along a longitudinal axis of the combustion air guide dome. Alber discloses a burner unit for combusting an air fuel mixture, comprising a combustion space [the interior of housing 8, see flame holder 22], a combustion air guide dome [reference character 10], and a fuel inlet [reference character 34], wherein the combustion air guide dome is located in the combustion space and has recesses [reference character 40]. Alber further discloses that the recesses are axially oriented slots that extend along a longitudinal axis of the combustion air guide dome [see Fig. 13]. It would have been obvious to one of ordinary skill in the art at the time of the filing date of the invention to modify the burner unit taught by Irwin by forming the recesses as longitudinal slots, as taught by Alber, because “[t]he longitudinal slots can be manufactured in a markedly simpler manner than hole-like openings in the pipe wall according to the precision casting technology” [column 2 lines 55-58 of Alber]. PNG media_image1.png 255 692 media_image1.png Greyscale With respect to claim 2 Irwin discloses that the recesses taper from the inside to the outside [see Fig. 2]. With respect to claim 3 Irwin discloses that such that the recesses produce a nozzle effect for air directed out of the combustion air guide dome [see column 3 lines 46-62 of Irwin]. With respect to claim 4 the combination of Irwin and Alber disclose that the recesses have a constant profile along the longitudinal axis of the combustion air guide dome [see Fig. 13 of Alber]. With respect to claim 5 Irwin discloses that the combustion air guide dome has a circular cylindrical shape [see Fig. 1]. With respect to claim 6 the combination of Irwin and Alber disclose that the recesses have a common height along the longitudinal axis of the combustion air guide dome [see Fig. 13 of Alber]. With respect to claim 8 the combination of Irwin and Alber disclose that sidewalls of the recesses have an even profile with a constant slope1 [see annotated Fig. of Irwin, below]. PNG media_image2.png 253 662 media_image2.png Greyscale Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to VIVEK K SHIRSAT whose telephone number is (571)272-3722. The examiner can normally be reached M-F 9:00AM-5:20AM. 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, Steven B McAllister can be reached at 571-272-6785. 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. /VIVEK K SHIRSAT/Primary Examiner, Art Unit 3762 1 The examiner notes that the claim only requires that the sidewall of the recesses have an even profile with a constant slope, it does not preclude other profiles and does not require that the even profile with a constant slope extends from the inside of the combustion air guide dome to the outside of the combustion air guide dome.
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Prosecution Timeline

Apr 21, 2023
Application Filed
Jun 21, 2025
Non-Final Rejection — §103
Aug 05, 2025
Response Filed
Nov 13, 2025
Final Rejection — §103
Jan 07, 2026
Response after Non-Final Action
Jan 14, 2026
Request for Continued Examination
Feb 15, 2026
Response after Non-Final Action
Feb 20, 2026
Non-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

3-4
Expected OA Rounds
74%
Grant Probability
99%
With Interview (+28.5%)
3y 0m
Median Time to Grant
High
PTA Risk
Based on 1061 resolved cases by this examiner. Grant probability derived from career allow rate.

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