Prosecution Insights
Last updated: April 19, 2026
Application No. 18/373,992

FREEZER

Non-Final OA §103
Filed
Sep 28, 2023
Examiner
MARTIN, ELIZABETH J
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Karlsruher Institut Fur Technologie
OA Round
3 (Non-Final)
78%
Grant Probability
Favorable
3-4
OA Rounds
2y 7m
To Grant
99%
With Interview

Examiner Intelligence

Grants 78% — above average
78%
Career Allow Rate
729 granted / 930 resolved
+8.4% vs TC avg
Strong +21% interview lift
Without
With
+20.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
28 currently pending
Career history
958
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
47.8%
+7.8% vs TC avg
§102
21.6%
-18.4% vs TC avg
§112
27.3%
-12.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 930 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 . Status This Office Action is in response to the remarks and amendments filed on 1/26/2026. The objection to the drawings have been withdrawn. Claims 1-7, 9-12, 16-19 remain pending for consideration on the merits. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. Claim(s) 1-7, 9, 11-12, 16-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kobayshi et al (US 20110126575) in view of Performance evaluation on an internal auto-cascade refrigeration cycle with mixture refrigerant R290/R600a, Gang et al, Applied Thermal Engineering 75 (2015) 994-1000. Regarding claim 1, Kobayshi teaches a freezer (1), the freezer is an ultra-low temperature ULT device (paragraph 0002) comprising a cooled interior (8) and comprising a wall (4) that surrounds the cooled interior at least in regions, and comprising a refrigeration circuit (2, paragraph 0033) being a single-stage refrigeration circuit (fig. 2) wherein the wall is formed at least in part by a vacuum insulation body (7, paragraph 0035) and in that the refrigeration circuit comprises a refrigerant mixture (mixture, paragraph 0047), where in the single-stage refrigeration circuit comprises a precooler (21) and a compressor (14) but fails to explicitly teach to compress at a pressure ratio of less than or equal to 15 However, Gang teaches the compressor is configured to compress at a pressure ratio of less than or equal to 15 (6.86, 6.07, Table 1) to provide increased evaporation pressure, leading to higher volumetric capacity and better ability to operate at lower external air temperatures. Therefore, it would have been obvious to a person skilled in the art at the time of the invention to modify the freezer of Kobayshi to include the compressor is configured to compress at a pressure ratio of less than or equal to 15 in view of the teachings of Gang to improve overall system performance. Further, it is understood, claim 1 includes an intended use recitation, for example “…to compress...”. The applicant is reminded that a recitation with respect to the manner which a claimed apparatus is intended to be does not differentiate the claimed apparatus from a prior art apparatus satisfying the structural limitations of the claims, as is the case here. While features of an apparatus may be recited either structurally or functionally, the claims are directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. Regarding claim 2, Kobayshi, as modified, teaches that the wall forms part of a housing (fig. 1) of the freezer. Regarding claim 3, Kobayshi, as modified, teaches an inner vacuum insulation panel (7, paragraph 0034) or outer vacuum insulation panel (7, paragraph 0034) is arranged on the wall (fig. 1). Regarding claim 4, Kobayshi teaches, as modified, the refrigeration circuit is configured to cool the cooled interior (paragraph 0050). Regarding claim 5, Kobayshi, as modified, teaches the refrigeration circuit comprises a or exactly one condenser (15) and evaporator (13), and one or exactly one expansion member (18). Regarding claim 6, the combined teachings teach the compressor is configured to compress at a pressure ratio of less than or equal to 10 (6.86, 6.07, Table 1 of Gang). Regarding claim 7, Kobayshi, as modified, teaches the precooler is a microstructure, plate, tube-in-tube, or multi tube-in-tube heat exchanger (fig. 2). Regarding claim 9, Kobayshi, as modified, teaches the refrigerant mixture comprises two or more than two natural hydrocarbons (paragraph 0047) or comprises a binary, tertiary, quaternary, refrigerant mixture of natural hydrocarbons (paragraph 0047). Regarding claim 11, Kobayshi, as modified, teaches the freezer is configured for storing biological material (specimen, paragraph 0002). Regarding claim 12, Kobayshi, as modified, teaches a temperature in the cooled interior is between −150° C. and −36° C (-85 degree C, paragraph 0002, 0050). Regarding claim 17, Kobayshi, as modified, teaches the refrigerant mixture comprises a quaternary or higher-order (>4 component) refrigerant mixture comprising the natural hydrocarbons isobutane, propylene, ethylene and methane (paragraph 0047). Regarding claim 18, Kobayshi, as modified, teaches a temperature in the cooled interior is between −150° C. and −90° C (-85 degree C, paragraph 0002, 0050). Regarding claim 19, Kobayshi, as modified, teaches a temperature in the cooled interior is between −90° C. and −36° C (-85 degree C, paragraph 0002, 0050). Regarding claim 16, the combined teachings the compressor is configured to compress at a pressure ratio of less than or equal to 9 (6.86, 6.07, Table 1 of Gang). Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kobayshi in view of Gang and in further view of Gadhiraju (US 20070181848). Regarding claim 10, the combined teachings teach the invention as described above but fails to explicitly the refrigerant mixture further comprises nitrogen. Gadhiraju teaches the refrigerant mixture further comprises nitrogen (nitrogen, paragraph 0013) to achieve better efficiency or a greater cooling effect or both. Therefore, it would have been obvious to a person skilled in the art at the time of the invention to modify the freezer of Kobayshi to include the refrigerant mixture further comprises nitrogen in view of the teachings of Gadhiraju to achieve better efficiency or a greater cooling effect or both. Response to Arguments Applicant’s arguments with respect to claim(s) 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 ELIZABETH J MARTIN whose telephone number is (571)270-3840. The examiner can normally be reached 8:30-3:00 CT pm M-F. 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. /ELIZABETH J MARTIN/Primary Examiner, Art Unit 3763
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Prosecution Timeline

Sep 28, 2023
Application Filed
Sep 28, 2023
Response after Non-Final Action
Jun 05, 2025
Non-Final Rejection — §103
Oct 10, 2025
Response Filed
Oct 23, 2025
Final Rejection — §103
Jan 26, 2026
Response after Non-Final Action
Feb 09, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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VALVE SET INTEGRATED MODULE, VEHICLE THERMAL MANAGEMENT SYSTEM, AND VEHICLE
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2y 5m to grant Granted Mar 31, 2026
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2y 5m to grant Granted Mar 31, 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
78%
Grant Probability
99%
With Interview (+20.8%)
2y 7m
Median Time to Grant
High
PTA Risk
Based on 930 resolved cases by this examiner. Grant probability derived from career allow rate.

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