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 .
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 3-13, and 15-22 are rejected under 35 U.S.C. 103 as being unpatentable over Kang (US 2006/0144059) in view of Scoccia (US 5,481,884).
As to claim 1, Kang teaches a method of determining a loss of charge of refrigerant in a refrigeration system, the method comprising:
determining a mass flow of refrigerant through a compressor (paragraphs 27-29; note that mr2 is a mass low rate calculated from the volumetric flow rate of the compressor and thus is a mass flow rate through the compressor) of the refrigeration system and a mass flow rate of the refrigerant through an expansion valve of the refrigeration system (paragraph 13);
determining that differential mass flow rate between the compressor mass flow rate and the expansion valve mass flow rate meets a predetermined criteria (paragraph 31-32); and
determining a loss of charge in the system based on the determination that the predetermined criteria are met (paragraphs 32-33).
Kang does not explicitly teach causing a remedial action to be taken based on determining the loss of charge. However, Scoccia teaches causing a remedial action to be taken following determining a loss of refrigerant charge (col. 2, lines 45-55). Therefore it would have been obvious to a person having ordinary skill in the art, before the effective filing date, to modify the method of Kang to include taking a remedial action in response to a low charge determination in the manner as claimed and taught by Scoccia in order to protect the system from malfunction and/or damage.
As to claim 3, Kang discloses the differential mass flow rate as a difference between the compressor mass flow rate mr2 and the expansion valve mass flow rate mr1 (paragraph 32).
As to claims 4-6 Kang does not explicitly teach performing intermediate and principal mass flow determinations as claimed. However, Scoccia teaches that it is known to use two different thresholds for low refrigerant charge determinations, so that the system can provide a service alarm while continuing operation when a moderate charge loss occurs, and shut the system down to prevent damage when a severe charge loss occurs (col. 6, lines 1-38). In light of this teaching, it would have been obvious to a person having ordinary skill in the art, at the time of the invention, to modify Kang to use multiple mass flow rate thresholds and perform intermediate and principal mass flow determinations in the manner as claimed in order to determine the severity of the low charge condition and control system operation accordingly.
As to claim 7, Kang does not explicitly teach determining a loss of charge based on an amount of superheat as claimed. However, Scoccia teaches that it is known to determine a loss of charge based on an amount of superheat exceeding a threshold (col. 6, lines 1-6).
As to claims 8-10, Scoccia teaches performing intermediate and principal superheat determinations as claimed (col. 6, lines 1-38).
As to claim 11, the modified apparatus as discussed above includes determining a loss of charge when both superheat and mass flow determinations are positive.
As to claims 12-13, Kang does not explicitly teach use of the performance characteristics as claimed. However, Official Notice is taken that comparing a degree of subcooling to a threshold to determine abnormal refrigerant system operation is a common and typical feature in the HVAC controls art that would have been obvious to use in conjunction with the method of control of Kang for the purpose of further ensuring proper system operation.
As to claim 15, Scoccia teaches the remedial action comprising issuing an alert and preventing operation of the system (col. 2, lines 50-55).
As to claims 16-18, Scoccia teaches use of a controller 50 with stored instructions to perform the method, and Kang teaches a system comprising a compressor 22, expansion valve 28, a condenser 24, and an evaporator 30.
As to claim 19, Kang does not explicitly teach that the refrigeration system is used in a storage unit as claimed. However, Official Notice is taken that use of such a system in a refrigerator is a common and typical feature of the art and would have been an obvious modification of Kang for the purpose of effectively refrigerating stored goods.
As to claim 20, Kang does not explicitly teach that the refrigeration system is used in a marine vessel as claimed. However, Official Notice is taken that such is a common and typical feature of refrigeration systems and that would have been obvious to use the system of Kang in a marine vessel for the purpose of effectively refrigerating a space within such a vessel.
As to claim 21, Kang teaches that the compressor mass flow rate is determined based on a density of refrigerant entering the compressor (paragraph 29).
As to claim 22, Kang does not explicitly teach use of a low-stage compressor as claimed. However, Official Notice is taken that use of low and high stage compressors is a common and typical feature of a refrigeration circuit that would have been obvious to use in conjunction with the system of Kang for the purpose of providing increased cooling capacity.
Response to Arguments
Applicant’s arguments, see page 11, filed 2/9/2026, with respect to the rejection of claims 1-13 and 16-17 under 35 U.S.C. 101 have been fully considered and are persuasive. Said rejection has been withdrawn.
Applicant's arguments, see pages 11-2 filed with respect to the claim rejections under 35 U.S.C. 102 and 103 have been fully considered but they are not persuasive.
The applicant argues that the Kang reference does not teach or suggest determining a loss of charge based on a difference between a mass flow rate across a compressor and a mass flow rate across an expansion valve. The examiner respectfully disagrees. As set forth in the rejections above, Kang explicitly teaches such an operation (see paragraphs 13 and 31-33). Thus it is maintained that the claimed limitations would have been obvious in view of the cited prior art.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 JONATHAN BRADFORD whose telephone number is (571)270-5199. The examiner can normally be reached Monday-Friday 8:00 - 4:00 ET.
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.
/JONATHAN BRADFORD/ Primary Examiner, Art Unit 3763