Prosecution Insights
Last updated: April 19, 2026
Application No. 16/497,864

A VAPOUR COMPRESSION SYSTEM WITH A SUCTION LINE LIQUID SEPARATOR

Non-Final OA §103§112
Filed
Sep 26, 2019
Examiner
FURDGE, LARRY L
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Danfoss A/S
OA Round
7 (Non-Final)
62%
Grant Probability
Moderate
7-8
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 §112
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 was filed in this application after a decision by the Patent Trial and Appeal Board, but before the filing of a Notice of Appeal to the Court of Appeals for the Federal Circuit or the commencement of a civil action. 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examination under 37 CFR 1.114 and the fee set forth in 37 CFR 1.17(e) has been timely paid, the appeal has been withdrawn pursuant to 37 CFR 1.114 and prosecution in this application has been reopened pursuant to 37 CFR 1.114. Applicant’s submission filed on 12/4/2025 has been entered. Information Disclosure Statement The information disclosure statement (IDS) submitted on 10/3/2023 was filed after the mailing date of the application. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Claim Objections Claim 8 is objected to because of the following informalities: Regarding Claim 8, the claim recites “…in in the case that the liquid level in the liquid separating device.” Please amend the claim to recite - - in the case that the liquid level in the liquid separating device - - for correctness. Appropriate correction is required. Claim Rejections - 35 USC § 112 § 112 1st statement The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 8-19, 21 and 22 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Regarding Claims 8-19, 21 and 22, the claims are drawn to a method of operating a vapour compression system, where one skilled in the art would recognize that such operation is typically executed by a controller in conjunction with inputs from various sensors. However, the disclosure is silent to the structure that actually performs the control function. As per MPEP 2111.01 Plain Meaning and MPEP 2173.01 Interpreting the Claims, under a broadest reasonable interpretation, words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. In this instance, word “operating” is defined as “…relating to the way a machine, vehicle, device, etc., functions or is used and controlled.” Thus, the amendment to the claim where the word “controlling” is replaced with the word “operating” does not move the interpretation of the claim beyond “A method for controlling.” One skilled in the art would recognize that interpreting the word “operating” as being similar in scope to the word “controlling” is consistent with the specifications. Lastly, the disclosure recites in at least 0001, 0006, 0007. 0008, 0033 and 0051 “…A method for controlling a vapour compression system.” Thus, Applicant amendment to the claims 8 and 22 may be construed as new matter. Therefore, the claim fails the written description requirement and is rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph. Regarding Claims 8 and 22, the recitation of “…in the case that the liquid level in the liquid separating device is not above a predefined threshold level, flowing refrigerant from the evaporator(s) to the liquid separating device and flowing refrigerant from the liquid outlet of the liquid separating device to the secondary inlet of the ejector,” is not described in the specifications such that one skilled in the art would recognize Applicant’s possession of the claimed subject matter. For example, the disclosure is silent to receiving “in the case that the liquid level in the liquid separating device is not above a predefined threshold level, flowing refrigerant from…the liquid outlet of the liquid separating device to the secondary inlet of the ejector.” Thus, the disclosure does not support the amended language. Therefore, the claim fails the written description requirement and is rejected under 35 U.S.C. 112(a) or pre-AlA 35 U.S.C. 112, first paragraph. § 112 2nd statement The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 8-19, 21 and 22 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Regarding Claims 8-19, 21 and 22, because the claims are drawn to a method of operating a vapour compression system and the structure that actually performs the operating function not being disclosed, renders the claim unclear in light of the 112-1st rejection above. In particular, the lack of sufficient structure to perform operating of the vapour compression system i.e. adjusting operating parameters does not necessarily provide one skilled in the art the ability to ascertain the metes and bounds of the particular claims. As per MPEP 2111.01 Plain Meaning and MPEP 2173.01 Interpreting the Claims, under a broadest reasonable interpretation, words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. In this instance, word “operating” is defined as “…relating to the way a machine, vehicle, device, etc., functions or is used and controlled.” Thus, the amendment to the claim where the word “controlling” is replaced with the word “operating” does not move the interpretation of the claim beyond “A method for controlling.” One skilled in the art would recognize that interpreting the word “operating” as being similar in scope to the word “controlling” is consistent with the specifications. Also, the disclosure recites in at least 0001, 0006, 0007. 0008, 0033 and 0051 “…A method for controlling a vapour compression system.” Thus, Applicant amendment to the claims 8 and 22 may be construed as new matter as stated above or at minimum the amendments may conflict with the disclosure. See MPEP 2173.03 Correspondence Between Specification and Claims. Lastly, the recitation of “…in the case that the liquid level in the liquid separating device is not above a predefined threshold level, flowing refrigerant from the evaporator(s) to the liquid separating device and flowing refrigerant from the liquid outlet of the liquid separating device to the secondary inlet of the ejector,” not having adequate support in the disclosure creates an indefiniteness issue. “A claim, although clear on its face, may also be indefinite when a conflict or inconsistency between the claimed subject matter and the specification disclosure renders the scope of the claim uncertain as inconsistency with the specification disclosure or prior art teachings may make an otherwise definite claim take on an unreasonable degree of uncertainty. See MPEP 2173.03 Correspondence Between Specification and Claims. Therefore, the claim is indefinite and is rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. 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. Claims 8-13, 15-18, 21 and 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Girotto (EP2718642B1) and Taguchi (EP0217605A2) in view of Minami et al. (US9689589). Regarding Claims 8, 21 and 22, as best understood, Girotto teaches a method for operating a vapour compression system [0006; fig 2], the vapour compression system comprising a compressor unit [1], a heat rejecting heat exchanger [2], an ejector [14], a receiver [5], at least one expansion device [6] and at least one evaporator [7] arranged in a refrigerant path [fig 3], the vapour compression system further comprising a liquid separating device [8] arranged in a suction line of the vapour compression system [0014; 0016; 0028; fig 2] and a liquid level sensor [22] arranged in the liquid separating device [0042] and the liquid separating device comprising a gaseous outlet [at least the outlet to the suction inlet of compressor 1] connected to an inlet of the compressor unit [1] and a liquid outlet [at least the outlet from the lower end of device 8 to the inlet of injector 14] connected to and in open fluid communication with a secondary inlet [15] of the ejector [14; 0038; by inspection at fig. 2]; monitoring a liquid level in the liquid separating device by means of the liquid level sensor [0038; 0042]. in the case that the liquid level in the liquid separating device [8] is not above a predefined threshold level, flowing refrigerant from the evaporator(s) [7] to the liquid separating device and flowing refrigerant from the liquid outlet of the liquid separating device to the secondary inlet [15] of the ejector [0017; 0018; where the predefined threshold level can be the height of the liquid outlet located below a predefined maximum level]. Girotto does not explicitly teach the steps of: in the case that the liquid level in the liquid separating device is above a predefined threshold level, adjusting a control parameter of the vapour compression system in order to decrease a flow rate of liquid refrigerant from the evaporator(s) to the liquid separating device by, for at least some of the evaporator(s), selecting a positive setpoint for a superheat value and/or reducing a maximum allowable opening degree of the expansion device(s) based on a superheat value of refrigerant associated with said evaporators, thereby preventing said evaporator(s) from being operated in a flooded state. However, Taguchi teaches an air conditioner having a compressor unit [10], a heat rejecting heat exchanger [20], an expansion device [21] and an evaporator [22] arranged in a refrigerant path and a liquid separating device [23; 0008; fig 2] having a liquid level sensor [24] arranged in the liquid separating device [0010], and the steps of: - monitoring a liquid level in the liquid separating device by means of the liquid level sensor [0011-0013], and - in the case that the liquid level in the liquid separating device is above a predefined threshold level, adjusting a control parameter of the vapour compression system in order to decrease a flow rate of liquid refrigerant from the evaporator(s) to the liquid separating device by for the evaporator reducing a maximum allowable opening degree of the expansion device(s), thereby preventing said evaporator(s) from being operated in a flooded state [0011-0013]. Taguchi teaches that it is known in the field of endeavor of refrigeration to control the liquid level in a liquid separating device in order to prevent liquid refrigerant from flowing into the compressor [0013]. Therefore, it is a simple mechanical expedient that 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 Girotto to in the case that the liquid level in the liquid separating device is above a predefined threshold level, adjusting a control parameter of the vapour compression system in order to decrease a flow rate of liquid refrigerant from the evaporator(s) to the liquid separating device by, for at least some of the evaporator(s), reducing a maximum allowable opening degree of the expansion device(s), thereby preventing said evaporator(s) from being operated in a flooded state in view of the teachings of Taguchi in order to prevent liquid refrigerant from flowing into the compressor. Lastly, Minami teaches a refrigeration apparatus having a liquid separating device [at least first receiver 80; 0045; fig 1] and in the case that the liquid level in the liquid separating device is above a predefined threshold level [at least level A; 0151; 0152; fig 7], adjusting a control parameter of the vapour compression system in order to decrease a flow rate of liquid refrigerant from the evaporator(s) to the liquid separating device by, for at least some of the evaporator(s), selecting a positive setpoint for a superheat value [0154; where selecting a positive i.e. increased setpoint for a superheat value would necessarily reduce the liquid level in the liquid separating device], thereby preventing said evaporator(s) from being operated in a flooded state [0154; where the superheat value is a superheat value of the evaporator as measured by sensors 75, 71]. Minami teaches that it is known in the field of endeavor of refrigeration to control the liquid level in a liquid separating device in order to suppress the sending of liquid refrigerant to the compressor [0156]. Therefore, it is a simple mechanical expedient that 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 Girotto to in the case that the liquid level in the liquid separating device is above a predefined threshold level, adjusting a control parameter of the vapour compression system in order to decrease a flow rate of liquid refrigerant from the evaporator(s) to the liquid separating device by, for at least some of the evaporator(s), selecting a positive setpoint for a superheat value based on superheat value of refrigerant associated with said evaporators, thereby preventing said evaporator(s) from being operated in a flooded state in view of the teachings of Taguchi in order to suppress the sending of liquid refrigerant to the compressor. Regarding Claim 9, Girotto, as modified, teaches the invention of Claim 8 above and Girotto teaches wherein the step of adjusting a control parameter further comprises adjusting a control parameter of the vapour compression system in order to increase a flow rate of refrigerant from the liquid separating device to the secondary inlet of the ejector [0017; 0018; where a differential pressure of the system is adjusted]. Regarding Claims 10, 11 and 15, Girotto, as modified, teaches the invention above and Girotto teaches wherein the step of adjusting a control parameter [at least a pressure and/or temperature] of the vapour compression system comprises reducing a pressure prevailing inside the receiver [0017; 0018; 0034; where a differential pressure of the system is adjusted]. Regarding Claims 12 and 16, Girotto, as modified, teaches the invention above and Girotto teaches adjusting a control parameter of the vapour compression system by increasing a pressure of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector [0014-0017; where the function is realized by operation of the system]. Regarding Claims 13, 17 and 18, Girotto, as modified, teaches the invention above and Gritto teaches adjusting a control parameter of the vapour compression system by decreasing a pressure prevailing in the suction line of the vapour compression system [0017; 0018; 0034; where a differential pressure of the system is adjusted and a decrease in pressure occurs dependent upon the level of refrigerant within component 5]. Claims 14 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Girotto (EP2718642B1), Taguchi (EP0217605A2) and Minami et al. (US9689589) as applied to claim 1 above, and further in view of Nishijima et al. (US2004/0255612). Regarding Claims 14 and 19, Girotto, as modified, teaches the invention above but does not teach adjusting a control parameter of the vapour compression system by increasing a temperature of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector. However, Nishijima teaches a vapor compression refrigerator having a compressor [10], condenser [20], condenser fan [21] and ejector [40; 0030-0032; fig 1] that adjusts a control parameter of the vapour compression system by increasing a temperature of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector [0053]. Nishijima teaches that it is known in the field of endeavor of refrigeration that this arrangement improves the COP of the system [0006]. Therefore, it is a simple mechanical expedient that 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 Girotto to have adjusting a control parameter of the vapour compression system by increasing a temperature of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector in view of the teachings of Nishijima in order to improve the COP of the system. Response to Arguments On pages 6 and 7 of the remarks, the examiner has no comment regarding Applicant’s disagreement with the finding of the Board sustaining 112(a) rejections. With respect to amendments to overcome the 112(a) rejection, the examiners position can be found in the 112(a) section of the Office Action above. On page 7 of the remarks, the examiner has no comment regarding Applicant’s disagreement with the finding of the Board sustaining 112(b) rejections. With respect to amendments to overcome the 112(b) rejection, the examiners position can be found in the 112(b) section of the Office Action above. On pages 7-10 of the remarks, Applicant argues that Girotto (EP2718642B1) as modified by Taguchi (EP0217605A2) and Minami et al. (US9689589) does not teach “…in the case that the liquid level in the liquid separating device is not above a predefined threshold level, flowing refrigerant from the evaporator(s) to the liquid separating device and flowing refrigerant from the liquid outlet of the liquid separating device to the secondary inlet of the ejector.” Applicant’s arguments with respect to claim(s) 8 and 22 have been considered but are moot because the limitations are of first impression and the rejection relies on additional teachings of already used prior art references. On pages 10-11 of the remarks, the examiner has no comment regarding arguments with respect to claims 14 and 19 as the arguments ultimately address arguments asserted above with respect to claim 8. 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
Read full office action

Prosecution Timeline

Sep 26, 2019
Application Filed
Sep 26, 2019
Response after Non-Final Action
Jun 09, 2021
Non-Final Rejection — §103, §112
Sep 15, 2021
Response Filed
Dec 09, 2021
Final Rejection — §103, §112
Jan 31, 2022
Interview Requested
Feb 10, 2022
Applicant Interview (Telephonic)
Feb 11, 2022
Examiner Interview Summary
Feb 18, 2022
Response after Non-Final Action
Mar 31, 2022
Request for Continued Examination
Apr 04, 2022
Response after Non-Final Action
Apr 08, 2022
Interview Requested
Apr 21, 2022
Non-Final Rejection — §103, §112
Jul 25, 2022
Response Filed
Aug 08, 2022
Final Rejection — §103, §112
Oct 12, 2022
Response after Non-Final Action
Oct 12, 2022
Request for Continued Examination
Oct 24, 2022
Response after Non-Final Action
Nov 04, 2022
Non-Final Rejection — §103, §112
Feb 02, 2023
Notice of Allowance
Jun 30, 2023
Request for Continued Examination
Jul 27, 2023
Response after Non-Final Action
Aug 09, 2023
Non-Final Rejection — §103, §112
Oct 03, 2023
Notice of Allowance
Oct 03, 2023
Response after Non-Final Action
Oct 07, 2023
Response after Non-Final Action
Dec 28, 2023
Response after Non-Final Action
Feb 28, 2024
Response after Non-Final Action
Feb 28, 2024
Response after Non-Final Action
Feb 29, 2024
Response after Non-Final Action
Feb 29, 2024
Response after Non-Final Action
Jul 16, 2025
Response after Non-Final Action
Sep 15, 2025
Response after Non-Final Action
Oct 07, 2025
Response after Non-Final Action
Dec 04, 2025
Request for Continued Examination
Dec 20, 2025
Response after Non-Final Action
Jan 13, 2026
Non-Final Rejection — §103, §112 (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

7-8
Expected OA Rounds
62%
Grant Probability
80%
With Interview (+17.9%)
3y 5m
Median Time to Grant
High
PTA Risk
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