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
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 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 of this title, 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.
Claims 1, 4, 6-7 and 9-13 are rejected under pre-AlA 35 U.S.C. 103 as being unpatentable over JUNG et al. (DE 4140625) in view of KATO et al. (US 2021/0207859).
In regards to claim 1, JUNG discloses a method for controlling a fill level (Figs. 1-2) of an oil separator (separating device 3) for a cooling circuit (refrigerant circuit; Figs. 1-2), comprising: connecting a controllable valve (valve 4) downstream of an outlet of the oil separator (3) through which oil is fed into an oil collecting container (crankcase of the compressor 1; par. 10), wherein, after the valve (4) is opened, measuring a first temperature (temperature T at a first temperature sensor T1) by a temperature measuring device (temperature sensor T1) arranged in a line between the controllable valve (4) and the oil collecting container (crankcase of the compressor 1), specifying a limit value (a predetermined limit value) for at least one parameter (T) that is characteristic of a change in the first temperature (T at sensor T1), and closing the controllable valve (4) as soon as the at least one parameter exceeds the specified limit value (a predetermined limit value is reached, valve 4 is closed; par. 11) characterized in that the oil separator (3) is connected downstream of a compressor (a compressor 1) on an outlet side of the outlet (as can be seen in Fig. 1), but fails to explicitly teach that a starting temperature is determined and a difference between a current temperature and the starting temperature is used as a characteristic variable.
KATO teaches an apparatus wherein that a starting temperature (defines temperatures T2, T3 and T4 as initial temperatures; par. 84) is determined (via temperature sensors 34, 44 and 54) dynamically at a time of opening the controllable valve and a difference between a current temperature and the starting temperature (difference between the above-described initial temperature and the detected current temperature; par. 85) is used as the at least one parameter (refer to par. 85).
It would have been obvious to a person skilled in the art before the effective filing date of the claimed invention to modify the method of JUNG such that a starting temperature is determined and a difference between a current temperature and the starting temperature is used as a characteristic variable as taught by KATO in order to ensure heat absorption from the heat medium while preventing freezing of the heat medium (par. 7 of KATO).
In regards to claim 4, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 1. Further, JUNG teaches wherein the compressor (1) of the cooling circuit is supplied with the oil from the oil collecting container (crankcase of the compressor 1) by means of a regulation of an oil level in the compressor (1).
In regards to claim 6, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 1. Further, JUNG teaches wherein furthermore a second temperature (T1) is measured (via T1) in a region upstream of the controllable valve (4) and the difference between the first (T2) and the second (T1) temperature is used as a characteristic parameter.
In regards to claim 7, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 6. Further, JUNG teaches wherein the second temperature (T1) is measured in a line (a line 7) between the oil separator (3) and the controllable valve (4).
In regards to claim 9, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 1. Further, JUNG teaches wherein the opening of the controllable valve (4) is carried out cyclically (Valve 4 opens periodically at predetermined time intervals; pars. 6 and 10).
In regards to claim 10, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 9. Further, JUNG teaches wherein a cycle length (predetermined time intervals or a predetermined limit value; pars. 10-11) is determined as a function of a capacity of the compressor (refer to par. 11).
In regards to claim 11, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 1. Further, JUNG teaches in which a minimum and/or a maximum time for opening the controllable valve (4) is predetermined (refer to par. 10).
In regards to claim 12, JUNG discloses a system (Figs. 1-2), comprising an oil separator (separating device 3) and an oil collecting container (crankcase of the compressor 1; par. 10) connected downstream on an outlet side via a controllable valve (valve 4), a number of temperature measuring devices (a first temperature sensor T1, a second temperature sensor T2) and a control device (controller 5), adapted for carrying out a method for controlling a fill level (Figs. 1-2) of the oil separator (3), the system comprising: a controllable valve (4) connected downstream of an outlet of the oil separator (3) through which oil is fed into the oil collecting container (par. 10), wherein, after the controllable valve (4) is opened, a first temperature(temperature T at a first temperature sensor T1) is measured by a temperature measuring device (first temperature sensor T1) arranged in a line between the controllable valve (4) and the oil collecting container, a limit value (a predetermined limit value) is specified for at least one parameter (T) that is characteristic of a change in the first temperature (T at sensor T1), and the controllable valve (4) is closed as soon as the at least one parameter exceeds the limit value (a predetermined limit value is reached, valve 4 is closed; par. 11), characterized in that the oil separator (2) is connected downstream of a compressor (a compressor 1) on an outlet side of the outlet (as can be seen in Fig. 1), but fails to explicitly teach that a starting temperature is determined dynamically at a time of opening the controllable valve and a difference between a current temperature and the starting temperature is used as the at least one parameter and a difference between a current temperature and the starting temperature is used as the at least one parameter.
KATO teaches an apparatus wherein that a starting temperature (defines temperatures T2, T3 and T4 as initial temperatures; par. 84) is determined (via temperature sensors 34, 44 and 54) dynamically at a time of opening the controllable valve and a difference between a current temperature and the starting temperature (difference between the above-described initial temperature and the detected current temperature; par. 85) is used as the at least one parameter (refer to par. 85).
It would have been obvious to a person skilled in the art before the effective filing date of the claimed invention to modify the method of JUNG such that a starting temperature is determined dynamically at a time of opening the controllable valve and a difference between a current temperature and the starting temperature is used as the at least one parameter and a difference between a current temperature and the starting temperature is used as the at least one parameter as taught by KATO in order to ensure heat absorption from the heat medium while preventing freezing of the heat medium (par. 7 of KATO).
In regards to claim 13, JUNG as modified discloses a cooling circuit (Figs. 1-2) comprising a heat exchanger (condenser 2), wherein a refrigerant line connects the compressor (1) on the outlet side to the heat exchanger (2), further comprising a system according to claim 12.
Claim 8 is rejected under pre-AlA 35 U.S.C. 103 as being unpatentable over JUNG et al. (DE 4140625) in view of KATO et al. (US 2021/0207859), further in view of Renz (US 5894740).
In regards to claim 8, JUNG as modified meets the claim limitations as set forth above in the rejection of claim 7, but fails to explicitly teach wherein a third temperature is further measured in an inlet region of the oil separator, and the third temperature is used in determining the characteristic parameter and/or the limit value.
Renz teaches a refrigerating plant (Figs. 1-2) wherein a third temperature (a temperature sensor 82) is further measured in an inlet region of the oil separator (28), (col.4, lines 53-55), and the third temperature is used in determining the characteristic parameter and/or the limit value (col.4, lines 53-55).
It would have been obvious to a person skilled in the art before the effective filing date of the claimed invention to modify the method of JUNG such that a third temperature to be further measured in an inlet region of the oil separator, and the third temperature is used in determining the characteristic parameter and/or the limit value as taught by Renz in order to recover again the predominant portion of the oil passed to the main stream during compression and to supply this to the compressor (col.3, lines 9-12 of Renz).
Response to Arguments
The drawing objections noted in the previous Office Action were overcome in the communication filed 05/11/2026, and here by withdrawn.
The claim rejections under 35 U.S.C. § 112, second paragraph noted in the previous Office Action were overcome were overcome in the communication filed 05/11/2026, and here by withdrawn.
Applicant's arguments filed 05/11/2026 have been fully considered but they are not persuasive. The reasons are as follows.
Applicant contends that the claim terms "temperature measuring devices" and "control unit" are not subject to § 112(f) treatment because they purportedly connote sufficient structure to a person of ordinary skill in the art, relying primarily on the presumption arising from the absence of the term "means." The Examiner respectfully maintains that § 112(f) applies to at least the term "control unit" and "temperature measuring devices" for the reasons set forth below.
While the Examiner acknowledges the rebuttable presumption articulated in Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015), that presumption is overcome here. The Federal Circuit in Williamson expressly held that the presumption "is not strong" and may be rebutted upon a showing that the claim term fails to recite sufficiently definite structure or recites function without sufficient structure.
The term "control unit," as recited in the claims, does not standing alone convey a sufficiently definite structure to a person of ordinary skill in the art. Rather, it is a generic, nonce term used as a placeholder that is defined entirely by its functional attributes in the claim. The claim does not recite the composition, configuration, or architecture of the "control unit", e.g., whether it is a microprocessor, a relay, an analog controller, or a PLC nor does the specification provide limiting structural details that would differentiate it from any conceivable control mechanism. Accordingly, a POSITA would not understand "control unit" to refer to a specific class of structures, but rather to any structure capable of performing the recited functions. Applicant's reliance on Dyfan, LLC v. Target Corp. and MIT v. Abacus Software is unavailing. In those cases, the claim terms at issue were accompanied by meaningful structural context in the claim language and/or specification that anchored them to recognized structures. Here, by contrast, the specification provides only generic and functional descriptions of the "control unit," and the claim language itself does not constrain the structure of that element beyond the functions it performs. The Examiner acknowledges Applicant's argument that "temperature measuring devices" refers to a recognized class of physical structures such as thermocouples, thermistors, RTDs, and infrared sensors. The Examiner agrees that this term, in context, is more likely to connote sufficient structure and does not press the § 112(f) argument as to that term. Therefore, the § 112(f) rejection is maintained.
Applicant argues that the combination of Jung and Kato fails to render amended claims 1, 4, 6-7, 9-13, 12, and 13 obvious for two principal reasons: (1) Jung does not disclose dynamically determining a starting temperature at the time of valve opening and using the resulting temperature difference as the control parameter; and (2) Kato is in a different technical field and does not remedy this deficiency. The Examiner respectfully disagrees and maintains the § 103 rejections.
Applicant has amended claim 1 to expressly recite that "a starting temperature is determined dynamically at the time of opening the controllable valve" and that "a difference between a current temperature and the starting temperature is used as the parameter." Applicant contends that these limitations find no support in either Jung or Kato.
The Examiner acknowledges that Jung does not explicitly disclose the step of capturing a starting temperature at the moment of valve opening. However, the question under § 103 is not whether the exact claim language appears verbatim in the prior art, but whether the claimed subject matter as a whole would have been obvious to a person of ordinary skill in the art at the time of the invention. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007). Jung discloses a refrigeration oil return system utilizing temperature measurements to control a valve. While Jung uses a two-sensor differential (T1 and T2) rather than the claimed single-sensor dynamic baseline approach, the underlying concept of using a temperature difference as a control parameter for valve operation is explicitly disclosed and forms the motivating principle of Jung's invention. The conceptual step from a fixed two-sensor differential to a single-sensor dynamic differential wherein the baseline is captured at the moment of valve actuation is a straightforward design choice that a person of ordinary skill in the art would readily consider.
A person of ordinary skill in the art working with valve control systems would have recognized that using the temperature at valve opening as a dynamic reference point (rather than a fixed second sensor) offers a functionally equivalent and technically predictable approach to achieving the same result: detecting the arrival of refrigerant-laden oil at a downstream sensor. This substitution involves no more than the combination of known elements using known methods to yield predictable results. KSR, 550 U.S. at 416.
Applicant argues that Kato is from a different technical field (hydronic HVAC systems) and that a person of ordinary skill in the art in compressor oil management would have had no reason to consult Kato's frost-prevention control techniques. The Examiner disagrees.
The test for analogous art is whether the reference is either (1) from the same field of endeavor, or (2) reasonably pertinent to the particular problem with which the inventor is involved. In re Bigio, 381 F.3d 1320 (Fed. Cir. 2004). Kato need not be in the identical field of compressor oil return. Rather, it is reasonably pertinent because it addresses the same general problem: determining when to open and close a valve based on a temperature parameter derived from sensor readings in a refrigerant flow system. Both Jung and Kato address valve actuation in fluid-flow systems involving phase-change refrigerants and temperature-driven control logic. The specific application oil return vs. frost prevention does not negate the technical pertinence of Kato's control methodology to the problem faced by the inventors. Moreover, Applicant's characterization of Kato as relying solely on "fixed absolute threshold temperatures" is an oversimplification. As acknowledged by Applicant, paragraph [0084] of Kato discloses storing detected temperatures as "initial temperatures" during first-time operation. While Kato utilizes stored values after initialization, the concept of establishing a temperature reference at a defined operational event and then using temperature differential from that reference is at least suggested by Kato's disclosure. A person of ordinary skill in the art combining the teachings of Jung (temperature differential as a valve control parameter) and Kato (establishing a temperature reference at a defined point in system operation) would have had reason and ability to arrive at the claimed dynamic starting temperature approach.
Applicant does not dispute that a general motivation to improve oil return control in refrigeration systems exists. The Examiner submits that a person of ordinary skill in the art would have been motivated to combine the temperature-differential control concept of Jung with the reference-temperature-at-event concept suggested by Kato in order to: (i) reduce system cost by eliminating the need for a second sensor; (ii) improve reliability by removing dependency on the relative positioning of two discrete sensors; and (iii) achieve adaptive control that compensates for varying initial line temperatures. These are recognized engineering goals that would have driven an ordinarily skilled practitioner toward the claimed approach.
Applicant's arguments regarding the differences between the claimed invention and the prior art are noted but do not establish non-obviousness. Secondary considerations such as long-felt need, commercial success, or teaching away have not been alleged, and the Examiner finds no basis on this record to conclude that the claimed subject matter represents more than the predictable application of known techniques.
Applicant has not advanced specific arguments addressing the rejection of claims 5 and 8 over Jung, Kato, and Renz beyond those made with respect to the base claims. Accordingly, the rejections of claims 5 and 8 are maintained for the same reasons set forth above with respect to the base rejection, and the additional teachings of Renz, which Applicant has not specifically challenged, continue to supply the additional limitations of those dependent claims.
For the foregoing reasons, the rejections under 35 U.S.C. § 112(f) and under 35 U.S.C. § 103 as to claims 1, 4-13 are maintained.
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 MARTHA TADESSE whose telephone number is (571)272-0590. The examiner can normally be reached on 7:30am-5:00pm EST. If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Frantz Jules can be reached on 571-272-6681. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR)system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/M.T/
Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763
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