Prosecution Insights
Last updated: May 29, 2026
Application No. 18/757,606

MULTI-COMPRESSOR REFRIGERATION SYSTEM HAVING A COMMON OIL EQUALIZATION LINE PROVIDED WITH AN OIL PUMPING DEVICE

Non-Final OA §103§112
Filed
Jun 28, 2024
Priority
Jul 06, 2023 — FR 23/07222
Examiner
DELEON, DARIO ANTONIO
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Danfoss Commercial Compressors
OA Round
1 (Non-Final)
63%
Grant Probability
Moderate
1-2
OA Rounds
9m
Est. Remaining
97%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allowance Rate
121 granted / 191 resolved
-6.6% vs TC avg
Strong +33% interview lift
Without
With
+33.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
27 currently pending
Career history
237
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
92.9%
+52.9% vs TC avg
§102
1.7%
-38.3% vs TC avg
§112
4.8%
-35.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 191 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 . Election/Restrictions Applicant’s election without traverse of Species A, claims 1-10, 12, 13, 15-20 and Figures 1-4 in the reply filed on 02/06/2026 is acknowledged. Claims 11 and 14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 02/06/2026. Specification The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification. Claim Interpretation The following is a quotation of 35 U.S.C. 112(f): (f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph: An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked. As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph: (A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function; (B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and (C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function. Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function. Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function. Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are: “an oil level detection device” in claims 1-3 and 16-17. A review of the specification shows that the following appears to be the corresponding structure described in the specification for the 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph limitations: the oil level detection device of each compressor includes an oil level sensor or an oil level switch, as described in paragraph 0045 of the published application. Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof. If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. Claim Rejections - 35 USC § 112 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 9 and 20 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. Claims 9 and 20 recite the phrase “and/or” which renders the claim indefinite. This language is indefinite because it is not clear what is being claimed and what the scope is. No person of the ordinary skill in the art would know what “and/or” means with reasonable certainty. Therefore, the scope is unclear and for purposes of examination, the limitations that follow “and/or” will be considered in the alternative. 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 non-obviousness. Claims 1-2, 13 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Saunders et al (US 20200132346 A1, hereinafter Saunders) in view of Song et al (CN 100516682 C, hereinafter Song), Siegert (US 20130255286 A1, hereinafter Siegert) and Lee et al (US 20170016651 A1, hereinafter Lee). Regarding claim 1, Saunders teaches a multi-compressor refrigeration system (climate-control system 10) comprising a controller (control module 23) configured to control operation of the multi-compressor refrigeration system (as described in paragraph 0110), and a multi-compressor device including: at least three compressors (compressors 12/12/14) which are parallelly coupled (figure 1), each compressor being equipped with a suction fitting (22/22/34), an oil sump (oil sump, paragraphs 0105-0106) and an oil level detection device (monitoring oil level, paragraphs 0105-0106) operatively connected to the controller (paragraphs 0105-0106) and configured to detect an oil level in the respective oil sump (paragraphs 0105-0106), wherein the compressors (compressors 12/12/14) in the multi-compressor device (figure 1) are divided into a first group (figure 1) including at least one compressor (compressor 14) and a second group (figure 1) including at least two compressors (compressor 12/12). Saunders teaches the invention as described above but fail to teach a common suction line configured to fluidly connect the suction fittings of the compressors; a common oil equalization line configured to fluidly connect the oil sumps of the compressors; an oil pumping device located in the common oil equalization line and operatively connected to the controller, the oil pumping device having at least one oil pump. However, Song teaches a common suction line (inlet 35, figure 1) configured to fluidly connect the suction fittings of the compressors (via tank 26, figure 1); a common oil equalization line (lubricating oil pipe 43) configured to fluidly connect the oil sumps of the compressors (as shown on figure 1); an oil pumping device (lubricating oil pump 45a and 45b) located in the common oil equalization line (as shown on figure 1) and operatively connected to the controller (as described in the abstract), the oil pumping device (lubricating oil pump 45a and 45b) having at least one oil pump (lubricating oil pump 45a and 45b). Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the teachings of Saunders to include a common suction line configured to fluidly connect the suction fittings of the compressors; a common oil equalization line configured to fluidly connect the oil sumps of the compressors; an oil pumping device located in the common oil equalization line and operatively connected to the controller, the oil pumping device having at least one oil pump in view of the teachings of Song in order to yield the predictable result of supplying lubricating oil to the compressors. The combined teachings teach the invention as described above but fail to teach wherein one of the first and second groups of compressors is located on a first side of the oil pumping device and the other of the first and second groups of compressors is located on a second side of the oil pumping device, and the multi-compressor device further includes at least one valve located in the common oil equalization line and associated with the second group, the controller being configured to control operation of the oil pumping device and the at least one valve based on outputs from the oil level detection devices. However, Siegert teaches wherein one of the first and second groups of compressors (compressor 10a) is located on a first side of the oil pumping device (left side of pump 12a, figure 1) and the other of the first and second groups of compressors (compressors 10b/10c) is located on a second side of the oil pumping device (right side of 12a, figure 1), and the multi-compressor device further includes at least one valve (valve 14a) located in the common oil equalization line (line 18) and associated with the second group (figure 1), the controller being configured to control operation of the oil pumping device and the at least one valve based on outputs from the oil level detection devices (by selectively opening and closing the respective switchable valves 14a, 14b, 14c the oil compensation between the compressors 10a, 10b, 10c can be selectively controlled in order to equalize the oil levels in the plurality of oil sumps 20a, 20b, 20c, paragraph 0027). Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the teachings of Saunders to include wherein one of the first and second groups of compressors is located on a first side of the oil pumping device and the other of the first and second groups of compressors is located on a second side of the oil pumping device, and the multi-compressor device further includes at least one valve located in the common oil equalization line and associated with the second group, the controller being configured to control operation of the oil pumping device and the at least one valve based on outputs from the oil level detection devices in view of the teachings of Siegert in order to yield the predictable result of in order to avoid an insufficient oil distribution. The combined teachings teach the invention as described above but fail to teach the at least one valve being operatively connected with the controller and being configured to control an oil flow in the common oil equalization line and between the oil pumping device and at least one compressor of the second group. However, Lee teaches the at least one valve (flow path opening/closing valve 73) being operatively connected with the controller (paragraph 0070) and being configured to control an oil flow (paragraph 0029) in the common oil equalization line (lubricant oil circulation flow path 61) and between the oil pumping device (lubricant oil circulation pump 66) and at least one compressor (compressor 10) of the second group. Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the teachings of Saunders to include the at least one valve being operatively connected with the controller and being configured to control an oil flow in the common oil equalization line and between the oil pumping device and at least one compressor of the second group in view of the teachings of Lee in order to yield the predictable result of controlling injection of the lubricant oil by controlling opening/closing of the injection flow path. Further, it is understood, claim 1 includes an intended use recitation, for example “…configured to...”. 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, the combined teachings teach wherein the controller (control module 23 of Saunders) is configured to determine a current amount of oil in each compressor based on outputs from the oil level detection devices (device 54 monitors the lubricant (e.g., oil) level within an oil sump (not shown) of the internal cavity of the second compressor 14. The device 54 may communicate data to the control module 23 that the lubricant level within the second compressor 14 is above or below a predetermined level, paragraph 0105 of Saunders). Further, it is understood, claim 2 includes an intended use recitation, for example “…configured to...”. 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 13, the combined teachings teach wherein the at least one valve (flow path opening/closing valve 73 of Lee) includes a normally closed solenoid valve (close the injection flow path opening/closing valve, paragraph 0009 of Lee). Regarding claim 16, the combined teachings teach wherein at least one compressor (compressors 12/12/14 of Saunders) of the multi-compressor device (figure 1 of Saunders) comprises at least two oil level detection devices (devices 54/56, paragraphs 0105-0106 of Saunders). Claims 3-8 and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Saunders as modified by Song, Siegert and Lu, as applied to claim 1 above, and in further view of Xu et al (US 9657975 B2, hereinafter Xu). Regarding claim 3, the combined teachings teach the invention as described above but fail to teach wherein the controller is configured to: monitor an oil level in the oil sump of each compressor through the respective oil level detection device; detect a low oil level situation in a respective compressor based on the oil level in said compressor reaching a predetermined low oil level condition; and perform an oil balancing action in response to detecting a low oil level situation, the oil balancing action including controlling operation of the oil pumping device and the at least one valve to transfer oil from the oil sump of at least one compressor for which a low oil level situation has not been detected to the oil sump of the compressor for which a low oil level situation has been detected. However, Xu teaches wherein the controller (control the lowest safety oil level in the oil sump, col 5 lines 34-35) is configured to: monitor an oil level in the oil sump of each compressor (balancing oil levels of the compressors during the running of the compressors, col 5 lines 25-26) through the respective oil level detection device (oil level switch, col 1 line 66 to col 2 lines 1-3); detect a low oil level situation in a respective compressor based on the oil level in said compressor reaching a predetermined low oil level condition (lowest safety oil level herein may be the lowest oil amount for guaranteeing reliable running of the compressors, col 6 lines 11-13); and perform an oil balancing action in response to detecting a low oil level situation (so that when the oil level of the oil-starved compressor is lower than the lowest safety oil level, the oil level switch indicates closing one of the oil-rich compressors. This will ensure that the oil is quickly returned to the oil-starved compressor, col 6 lines 6-11), the oil balancing action including controlling operation of the oil pumping device and the at least one valve to transfer oil from the oil sump of at least one compressor for which a low oil level situation has not been detected to the oil sump of the compressor for which a low oil level situation has been detected (the oil sump of the oil-starved compressor is provided with an oil level switch, so that when the oil level of the oil-starved compressor is lower than the lowest safety oil level, the oil level switch indicates closing one of the oil-rich compressors. This will ensure that the oil is quickly returned to the oil-starved compressor, col 6 lines 4-11). Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the combined teachings to include wherein the controller is configured to: monitor an oil level in the oil sump of each compressor through the respective oil level detection device; detect a low oil level situation in a respective compressor based on the oil level in said compressor reaching a predetermined low oil level condition; and perform an oil balancing action in response to detecting a low oil level situation, the oil balancing action including controlling operation of the oil pumping device and the at least one valve to transfer oil from the oil sump of at least one compressor for which a low oil level situation has not been detected to the oil sump of the compressor for which a low oil level situation has been detected in view of the teachings of Xu in order to yield the predictable result of the oil level of the oil-starved compressor can be restored much more quickly. Further, it is understood, claim 3 includes an intended use recitation, for example “…configured to...”. 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 4, the combined teachings teach wherein the controller (control the lowest safety oil level in the oil sump, col 5 lines 34-35 of Xu) is configured to detect that an excess oil situation in a respective compressor based on the oil level in said compressor reaching a predetermined high oil level condition (compressors with an oil level higher than a standard oil level/height are oil-rich compressors, col 3 lines 26-28 of Xu). Further, it is understood, claim 4 includes an intended use recitation, for example “…configured to...”. 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 5, the combined teachings teach wherein the oil balancing action includes controlling operation of the oil pumping device and the at least one valve so as to transfer oil from the oil sump of at least one compressor for which an excess oil situation has been detected to the oil sump of the compressor for which a low oil level situation has been detected (the oil sump of the oil-starved compressor is provided with an oil level switch, so that when the oil level of the oil-starved compressor is lower than the lowest safety oil level, the oil level switch indicates closing one of the oil-rich compressors. This will ensure that the oil is quickly returned to the oil-starved compressor, col 6 lines 4-11 of Xu). Regarding claim 6, the combined teachings teach wherein the compressor for which a low oil level situation has been detected is in one of the first and second groups (oil-starved compressor CP1 of Xu), and the balancing action includes operating the oil pumping device and the at least one valve to transfer oil from the oil sump of at least one compressor in the other of the first and second groups for which a low oil level situation has not been detected to the oil sump of the of the compressor having the low oil level situation (the oil sump of the oil-starved compressor is provided with an oil level switch, so that when the oil level of the oil-starved compressor is lower than the lowest safety oil level, the oil level switch indicates closing one of the oil-rich compressors. This will ensure that the oil is quickly returned to the oil-starved compressor, col 6 lines 4-11 of Xu); or wherein one of the first and second groups includes at least one first compressor for which a low oil level situation has been detected and at least one second compressor for which a low oil level situation has not been detected, and the balancing action includes operating the oil pumping device and the at least one valve to transfer oil from the oil sump of the at least one second compressor through a temporary oil vessel to the oil sump of the at least one second compressor, wherein the temporary oil vessel is constituted by the oil sump of at one compressor in the other of the first and second groups. Regarding claim 7, the combined teachings teach wherein the controller (control the lowest safety oil level in the oil sump, col 5 lines 34-35 of Xu) is configured to determine the amount of oil that has to be transferred to a compressor for which a low oil level situation has been detected (the oil sump of the oil-starved compressor is provided with an oil level switch, so that when the oil level of the oil-starved compressor is lower than the lowest safety oil level, the oil level switch indicates closing one of the oil-rich compressors. This will ensure that the oil is quickly returned to the oil-starved compressor. The lowest safety oil level herein may be the lowest oil amount for guaranteeing reliable running of the compressors, col 6 lines 4-13 of Xu) in order to reach a predetermined oil level in said compressor (oil-starved compressor CP1 of Xu). Further, it is understood, claim 7 includes an intended use recitation, for example “…configured to...”. 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 8, the combined teachings teach wherein the controller (control the lowest safety oil level in the oil sump, col 5 lines 34-35 of Xu) is configured to calculate a risk of a low oil level occurrence (when an oil level of the oil-starved compressor is lower than a lowest safety oil level, col 2 lines 2-3 of Xu) in a compressor (oil-starved compressor CP1 of Xu) at a given running condition (the oil-starved compressor and the oil-rich compressor may exist due to a practical running condition, col 3 lines 17-19 of Xu) and to control operation of the oil pumping device (corresponding to lubricant oil circulation pump 66 of Lee, as modified) and the at least one valve (flow path opening/closing valve 73 of Lee) based on that calculation. Further, it is understood, claim 8 includes an intended use recitation, for example “…configured to...”. 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 claims 17-20, it is noted that although the preamble of claims 17-20 is directed towards a method, the structure of the combined teachings discloses all the structure being provided in the method steps, thus the method is also rendered obvious by the combined teachings. If a prior art device, in its normal and usual operation, would necessarily perform the method claimed, then the method claimed will be considered to be anticipated or rendered obvious by the prior art device. When the prior art device is the same as a device described in the specification for carrying out the claimed method, it can be assumed the device will inherently or obviously perform the claimed process. Thus, the method, as claimed, would necessarily result from the normal operation of the apparatus. See MPEP 2112.02. Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Saunders as modified by Song, Siegert, Lu and Xu, as applied to claim 8 above, and in further view of Yang et al (CN 107339826 A, hereinafter Yang). Regarding claim 9, the combined teachings teach the invention as described above but fail to teach wherein the controller is configured to control the oil pumping device and the at least one valve to deliver more oil to a compressor that has a high risk of a low oil level occurrence or to control the oil pumping device and the at least one valve block the transfer of oil from a compressor that has a high risk of a low oil level occurrence. However, Yang teaches wherein the controller (electric control system, paragraph 0012) is configured to control the oil pumping device (drive device is an oil pump, paragraph 0009) and the at least one valve (driving device 3 between the each of return oil port connected with two compressor with function of opening and closing the second control valve 107, paragraph 0012) to deliver more oil to a compressor that has a high risk of a low oil level occurrence (high oil level compressor is continuously flowing into the oil balance pipe 2 to replenish the lubricant 1, which is repeated in the process, high oil level compressor 1 is continuously reduced, low oil level compressor 1 is continuously increased until the level difference between 1 of two compressors in parallel is balanced, paragraph 0008) or to control the oil pumping device and the at least one valve block the transfer of oil from a compressor that has a high risk of a low oil level occurrence. Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the combined teachings to include wherein the controller is configured to control the oil pumping device and the at least one valve to deliver more oil to a compressor that has a high risk of a low oil level occurrence or to control the oil pumping device and the at least one valve block the transfer of oil from a compressor that has a high risk of a low oil level occurrence in view of the teachings of Yang in order to yield the predictable result of maintaining the compressors between the oil level height substantially equivalent. Further, it is understood, claim 9 includes an intended use recitation, for example “…configured to...”. 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. Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Saunders as modified by Song, Siegert and Lu, as applied to claim 1 above, and in further view of Sekiya et al (US 8109116 B2, hereinafter Sekiya). Regarding claim 10, the combined teachings teach the invention as described above but fail to teach wherein the at least one oil pump includes a volumetric oil pump configured to measure and output an amount of pumped oil. However, Sekiya teaches wherein the at least one oil pump includes a volumetric oil pump configured to measure and output an amount of pumped oil (the centrifugal pump 76 is described as the pump for feeding the lubricating oil 9 into the bearing and the sliding portion, but any type of pump such as a volume-type pump may equally be used, col 10 lines 15-21). Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the combined teachings to include wherein the at least one oil pump includes a volumetric oil pump configured to measure and output an amount of pumped oil in view of the teachings of Sekiya in order to yield the predictable result of maintaining minimum required oil level. Further, it is understood, claim 10 includes an intended use recitation, for example “…configured to...”. 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. Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Saunders as modified by Song, Siegert and Lu, as applied to claim 1 above, and in further view of Fraser et al (CN 110325803 A, hereinafter Fraser). Regarding claim 12, the combined teachings teach the invention as described above but fail to teach wherein the at least one oil pump includes a bidirectional oil pump. However, Fraser teaches wherein the at least one oil pump includes a bidirectional oil pump (a bidirectional pump, the two-way pump can move the oil moves to the first compressor 182 from second compressor 184 to second compressor 184 or in a second direction along the first direction from the first compressor 182, paragraph 0020). Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the combined teachings to include wherein the at least one oil pump includes a bidirectional oil pump in view of the teachings of Fraser in order to yield the predictable result of moving oil in multiple ways. Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Saunders as modified by Song, Siegert and Lu, as applied to claim 1 above, and in further view of Yamamoto et al (CN 1764809 A). Regarding claim 15, the combined teachings teach the invention as described above but fail to teach wherein the at least one valve includes a two-way valve located in an oil equalization branch of the common oil equalization line, which is fluidly connected to a respective compressor, and configured to control an oil flow between the oil pumping device and the respective compressor fluidly connected to said oil equalization branch. However, Yamamoto teaches wherein the at least one valve (two-way valve 21e, figure 1) includes a two-way valve (two-way valve 21e) located in an oil equalization branch (balance pipe 31) of the common oil equalization line (oil equalizing pipe 61), which is fluidly connected to a respective compressor (via oil groove 60, figure 1), and configured to control an oil flow between the oil pumping device and the respective compressor fluidly connected to said oil equalization branch (each oil equalizing pipe 61 on the opening-closing valve V2 and the opening and closing valve V3, and the other is through the two-way valve 21e, 21e is connected with balance pipe 31, paragraph 0013). Therefore, it would have been obvious to a person skilled in the art before the effective filing date of the invention to modify the system in the combined teachings to include wherein the at least one valve includes a two-way valve located in an oil equalization branch of the common oil equalization line, which is fluidly connected to a respective compressor, and configured to control an oil flow between the oil pumping device and the respective compressor fluidly connected to said oil equalization branch in view of the teachings of Yamamoto in order to yield the predictable result of preventing oil amount imbalance. Further, it is understood, claim 15 includes an intended use recitation, for example “…configured to...”. 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. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to DARIO DELEON whose telephone number is (571)272-8687. The examiner can normally be reached Monday-Friday 9:00am-5:00pm. 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. /DARIO ANTONIO DELEON/Examiner, Art Unit 3763 /JERRY-DARYL FLETCHER/Supervisory Patent Examiner, Art Unit 3763
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Prosecution Timeline

Jun 28, 2024
Application Filed
May 06, 2026
Non-Final Rejection mailed — §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

1-2
Expected OA Rounds
63%
Grant Probability
97%
With Interview (+33.4%)
2y 8m (~9m remaining)
Median Time to Grant
Low
PTA Risk
Based on 191 resolved cases by this examiner. Grant probability derived from career allowance rate.

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