Prosecution Insights
Last updated: April 19, 2026
Application No. 18/374,425

REFRIGERATION CYCLE APPARATUS

Non-Final OA §103
Filed
Sep 28, 2023
Examiner
FURDGE, LARRY L
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Daikin Industries Ltd.
OA Round
3 (Non-Final)
62%
Grant Probability
Moderate
3-4
OA Rounds
3y 5m
To Grant
80%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allow Rate
469 granted / 755 resolved
-7.9% vs TC avg
Strong +18% interview lift
Without
With
+17.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
41 currently pending
Career history
796
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
51.8%
+11.8% vs TC avg
§102
11.7%
-28.3% vs TC avg
§112
31.1%
-8.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 755 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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 2/13/2026 has been entered. 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)1-3, 10-13, 18 and 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hayes et al. (US4149389) in view of Sonnekalb (DE102008047753B4). Regarding Claim 1, Hayes teaches a refrigeration cycle apparatus fig 1] comprising: a first refrigerant circuit [at least the refrigerant circuit utilizing compressor 1] using a first refrigerant [col 8, line 60 – col 9, line 15] and a second refrigerant circuit [at least the refrigerant circuit utilizing compressor 5] using a second refrigerant [col 8, line 60 – col 9, line 15], a cascade heat exchanger [the assembly of heat exchanger 4b and heat exchange means 6] that exchanges heat between the first refrigerant and the second refrigerant during the dual cycle operation [col 4, lines 22-31]; wherein the refrigeration cycle apparatus enables, in a switchable manner, a dual cycle operation in which the first refrigerant circuit and the second refrigerant circuit are simultaneously operated to exchange heat between the first refrigerant and the second refrigerant [col 5, lines 17-60], and a single cycle operation in which the first refrigerant circuit is operated without operating the second refrigerant circuit to perform a cooling operation or heating operation [col 4, line 52-col 5, line 16]; the cascade heat exchanger includes a first cascade channel through which the first refrigerant flows, and a second cascade channel which is independent of the first cascade channel and through which the second refrigerant flows, the first refrigerant circuit includes a first compressor [1], a first heat exchanger [2], a first expansion valve [3c], and the first cascade channel [at 4b; col 3, line 39-col 4, line 49], the second refrigerant circuit includes a second compressor [5], the second cascade channel [at 6], a second expansion valve [7a], and a second heat exchanger [8; col 3, line 39-col 4, line 49], during the dual cycle operation, the first cascade channel functions as an evaporator of the first refrigerant, the first heat exchanger functions as a radiator of the first refrigerant, the second cascade channel functions as a radiator of the second refrigerant, and the second heat exchanger functions as an evaporator of the second refrigerant [col 5, lines 17-60]; the first refrigerant circuit further includes a third heat exchanger [4a], the cooling operation is enabled in which the third heat exchanger functions as a radiator of the first refrigerant and the first heat exchanger functions as an evaporator of the first refrigerant [col 5, line 61-col 6, line 17], the heating operation is enabled, in which the third heat exchanger functions as an evaporator of the first refrigerant and the first heat exchanger functions as a radiator of the first refrigerant [col 4, line 55-col 5, line 12]. Hayes does not teach where the first refrigerant has a pressure of 1.2 MPa or less at 30°C; and where the second refrigerant has a pressure of 1.5 MPa or more at 30°C and the first refrigerant is R290 and the second refrigerant is carbon dioxide. However, Sonnekalb teaches a refrigeration system having a first refrigerant circuit and a second refrigerant circuit [0001] having where a first refrigerant has a pressure of 1.2 MPa or less at 30°C; and where a second refrigerant has a pressure of 1.5 MPa or more at 30°C and the first refrigerant is R290 and the second refrigerant is carbon dioxide [0045] where one of ordinary skill in the art could have combined the elements as claimed by known methods and that in combination, each element would perform the same function as it did separately and one of ordinary skills would have recognized that the results of the combination were predictable i.e. provide a system that has increased efficiency [0005]. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the assembly of Hayes to have where the first refrigerant has a pressure of 1.2 MPa or less at 30°C; and where the second refrigerant has a pressure of 1.5 MPa or more at 30°C and the first refrigerant is R290 and the second refrigerant is carbon dioxide in view of the teachings of Sonnekalb where the elements could have been combined by known methods with no change in their respective functions, and the combination would have yielded predictable results i.e. provide a system that has increased efficiency. Regarding Claim 2, Hayes, as modified, teaches the invention of claim 1 above and Hayes teaches wherein, during the dual cycle operation, the second refrigerant flowing through the second refrigerant circuit heats the first refrigerant flowing through the first refrigerant circuit to perform the heating operation [col 5, lines 17-60]. Regarding Claim 3, Hayes, as modified, teaches the invention of claim 1 above and Hayes teaches wherein the single cycle operation is performed when a predetermined low-load condition is satisfied [col 4, line 52-col 5, line 16]. Regarding Claim 10, Hayes, as modified, teaches the invention of claim 1 above and Hayes teaches wherein the first refrigerant circuit further includes a switching unit [9] that switches a channel of the first refrigerant, and the switching unit is switched to enable the cooling operation in which the third heat exchanger functions as a radiator of the first refrigerant and the first heat exchanger functions as an evaporator of the first refrigerant and the heating operation in which the third heat exchanger functions as an evaporator of the first refrigerant and the first heat exchanger functions as a radiator of the first refrigerant [col 4, line 52-col 5, line 16; col 5, line 61-col 6, line 17]. Regarding Claim 11, Hayes, as modified, teaches the invention of claim 1 above and Hayes teaches wherein the second heat exchanger [8] exchanges heat between air flowing outside and the second refrigerant flowing inside, the third heat exchanger [4a] exchanges heat between air flowing outside and the first refrigerant flowing inside, and the refrigeration cycle apparatus further comprises a first blowing unit [19] that forms an air flow passing through the second heat exchanger and an air flow passing through the third heat exchanger [col 4, line 52-col 5, line 16; col 5, line 61-col 6, line 17; fig 1]. Regarding Claim 12, Hayes, as modified, teaches the invention of claim 11 above and Hayes teaches wherein the second heat exchanger [8] is located at a position other than leeward of the third heat exchanger [4a] in the air flow [by inspection at fig 1]. Regarding Claim 13, Hayes, as modified, teaches the invention of claim 11 above and Hayes teaches wherein the second heat exchanger [8] and the third heat exchanger [4a] are located away from each other in a direction of the air flow [by inspection at fig 1]. Regarding Claim 18, Hayes, as modified, teaches the invention of claim 2 above and Hayes teaches wherein the single cycle operation is performed when a predetermined low-load condition is satisfied [col 4, line 52-col 5, line 16]. Regarding Claim 21, Hayes, as modified, teaches the invention of claim 1 above and Hayes teaches an outdoor fan [19; col 3, line 61-col 4, line7], wherein the carbon dioxide refrigerant flowing through the second heat exchanger evaporates by exchanging heat with an airflow generated by the outdoor fan during the dual-cycle operation [col 5, lines 17-60; where Sonnekalb teaches carbon dioxide flowing through second heat exchanger]. Claim(s) 14 and 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hayes et al. (US4149389) and Sonnekalb (DE102008047753B4) as applied to claim 1 above, and further in view of Sestito et al. (US2012/0240610). Regarding Claim 14, Hayes, as modified, teaches the invention of claim 1 above but does not teach wherein the second refrigerant circuit further includes a fourth heat exchanger provided between a discharge side of the second compressor and the second cascade channel. However, Sestito teaches a cooling device having at least two cascade cooling stages [0002] wherein a second refrigerant circuit [at least the circuit having compressor 1.1] includes a [fourth] heat exchanger [3] provided between a discharge side of a second compressor [1.1] and a second cascade channel [at least cascade channel of heat exchanger 6; 0020-0026] where one of ordinary skill in the art could have combined the elements as claimed by known methods and that in combination, each element would perform the same function as it did separately and one of ordinary skills would have recognized that the results of the combination were predictable i.e. provide a structure that exchanges heat between two refrigerant circuits and thereby improve the system. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the assembly of Hayes to have wherein the second refrigerant circuit further includes a fourth heat exchanger provided between a discharge side of the second compressor and the second cascade channel in view of the teachings of Sestito where the elements could have been combined by known methods with no change in their respective functions, and the combination would have yielded predictable results i.e. provide a structure that exchanges heat between two refrigerant circuits and thereby improve the system. Regarding Claim 15, Hayes, as modified, teaches the invention of claim 14 above and Sestito teaches wherein a first heat exchanger [4] exchanges heat between air flowing outside and the first refrigerant flowing inside, the [fourth] heat exchanger [3] exchanges heat between air flowing outside and the second refrigerant flowing inside, and the refrigeration cycle apparatus further comprises a [second] blowing unit [5] that forms an air flow passing through both the first heat exchanger and the fourth heat exchanger [0020-0026; fig 1]. Response to Arguments Applicant’s arguments with respect to claim(s) 1 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 LARRY L FURDGE whose telephone number is (313)446-4895. The examiner can normally be reached M-R 6a-3p; F 6a-10a. 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 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. /LARRY L FURDGE/Primary Examiner, Art Unit 3763
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Prosecution Timeline

Sep 28, 2023
Application Filed
May 07, 2025
Non-Final Rejection — §103
Sep 11, 2025
Response Filed
Oct 11, 2025
Final Rejection — §103
Jan 14, 2026
Response after Non-Final Action
Feb 13, 2026
Request for Continued Examination
Mar 05, 2026
Response after Non-Final Action
Mar 17, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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2y 5m to grant Granted Apr 14, 2026
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2y 5m to grant Granted Mar 31, 2026
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2y 5m to grant Granted Mar 24, 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
62%
Grant Probability
80%
With Interview (+17.9%)
3y 5m
Median Time to Grant
High
PTA Risk
Based on 755 resolved cases by this examiner. Grant probability derived from career allow rate.

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