DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on March 18, 2026 has been entered.
Response to Amendment
The Amendment filed March 18, 2026 has been entered. Claims 1, 3 – 7 and 9 – 13 are pending in the application with claims 2, 8 and 14 being cancelled. The amendment to claims has overcome the claim objections and 35 USC 112 rejections set forth in the last final office action, dated 10/23/2025.
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.
Claims 1, 3, 4, 7, 9, 10 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Azuma (JP 2008249231 – herein after Azuma) in view of Yamazaki, Isao (US 2013/0121880 – herein after Yamazaki) further in view of Oshiro Ryusuke (WO 2015/141596 – herein after Oshiro).
In reference to claims 1 and 3, Azuma teaches a liquid-feed-type gas compressor (1) including a compressor main body (31a) that compresses a gas while injecting a liquid into a compression chamber [see fig. 2 and ¶22, ¶30 & ¶31: These paragraphs describe how gas is supplied to the compressor (31a) via a gas side connecting pipe (12) AND oil is returned from the gas/oil separator (32a) to the compressor (31a) through an oil return pipe (323a) & an oil return branch pipe (324a)], a gas-liquid separator (32a) that separates the liquid from a compressed gas discharged from the compressor main body and stores the liquid therein (fig. 2 and ¶21), and a liquid feed system (12, 323a & 324a) that feeds the liquid stored in the gas- liquid separator to the compressor main body (see fig. 2 and ¶22, ¶30 & ¶31), wherein the liquid-feed-type gas compressor comprises:
a sampling line (324a) whose inlet side is connected to a predetermined height position of the gas-liquid separator (fig. 2 and ¶32) and that allows fluid from the predetermined height position of the gas-liquid separator to flow by pressure difference between the inlet side and an outlet side (fig. 2 and ¶34 & ¶50: While not explicitly stated, the examiner takes official notice that it would be inherent for there to be a pressure difference between the inlet side and the outlet side of the sampling line in order for the fluid to flow from the inlet to the outlet);
a controller (implicit feature); and
an informing device that informs a determination result of the controller [¶34 & ¶50: While “an informing device” is not explicitly described/identified, it is inherent that the informing device is present to perform all of the describe steps. For instance, ¶34 describes how the system of Azuma is able to determine if oil or gas is flowing through the oil return branch pipe (324a) by monitoring the readings from a temperature sensor (TS0) and comparing the detected temperature to some threshold value. ¶50 describes how the system determines if an oil recovery operation from the outdoor units (3a & 3b) are necessary based on the determination as to whether gas or oil is flowing through the oil return branch pipe. This would necessitate some form of “informing device” that provided the result from the analysis of the temperature reading from the temperature sensor (which the controller uses to determine whether gas or liquid is flowing through the oil return branch pipe)],
wherein the predetermined height position is a height at which the liquid flows into the sampling line (324a) when a liquid level is above the predetermined height position, and the gas flows into the sampling line (324a) when the liquid level is below the predetermined height position (see ¶34: “This temperature sensor TS0 is configured to detect the temperature of the oil passing through the oil return branch pipe 324a. However, if the oil level in the oil separator 32a drops below a predetermined oil level, refrigerant gas will flow into the oil return branch pipe 324a. In this case, the temperature sensor TS0 will measure a lower temperature of the refrigerant gas than when oil is flowing”), as in claim 1.
Azuma remains silent on: a detector that detects a pressure of the fluid that flows in the sampling line; and the controller configured to determine whether the pressure detected by the detector gets out of a set range defined by an upper set value and a lower set value by determining whether the pressure exceeds the upper set value in some cases or falls below the lower set value in some cases; determine that the fluid is liquid when the pressure stays within the set range; and determine that the fluid is gas when the pressure gets out of the set range, as in claim 1.
However, Yamazaki teaches an apparatus, wherein a detector (pressure sensor 26 shown in fig. 2) is coupled to a sampling line or flow conduit (24). The detector (26) detects the liquid or gas phase of the fluid flowing in the sampling line (24) by monitoring the pressure of the fluid in the sampling line and generating an equivalent pressure/oscillation signal. Figure 3 (in view of disclosure in ¶37) shows four different kind of pressure signals for four kinds of fluids having different viscosity flowing in the conduit/line (24). Two of those pressure signals are (1) a signal (labelled “air-sucking”) corresponding to when air flows and (2) a signal (labelled “Normal 1” or “Normal 2”) corresponding to when liquid flows in the line/conduit (24). The “normal” sinusoidal signal is between an upper predetermined/set value (at crest of the wave) and a lower predetermined/set value (at through of the wave). When the fluid is air in the conduit, “air-sucking” pressure signal is generated and this signal exceeds the upper set value and the lower set value of “normal 1/2” pressure signal.
Azuma teaches a use of temperature sensor (TS0) to determine whether the fluid in the sampling line is gas or liquid (see disclosure in ¶34 & ¶50). Yamazaki teaches a use of pressure sensor (26) to determine whether the fluid in the sampling line is gas or liquid. Because both Azuma and Yamazaki are directed towards “determining the phase of the fluid flowing in a sampling line”, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to substitute one method (i.e. of Azuma) for the other (i.e. of Yamazaki) to achieve the predictable result of analyzing the fluid flowing in the conduit for determination of the liquid level in the tank/vessel. KSR Int’l v. Teleflex Inc., 127 S. Ct. 1727, 1740-41, 82 USPQ2d 1385, 1396 (2007).
Thus, Azuma, as modified, teaches the liquid-feed-type gas compressor comprising: a detector (of Yamazaki) that detects a pressure of the fluid that flows in the sampling line (of Azuma), a controller (of Azuma) that is configured to determine whether the pressure detected by the detector gets out of a set range defined by an upper set value (value at “crest” of the normal pressure signal) and a lower set value (value at “trough” of the normal pressure signal) by determining whether the pressure exceeds the upper set value in some cases or falls below the lower set value in some cases; determine that the fluid is liquid when the pressure stays within the set range (i.e. when the detector of Yamazaki shows “normal 1 or normal 2" pressure signal as shown in fig. 3 of Yamazaki); and determine that the fluid is gas when the pressure gets out of the set range (i.e. when the detector of Yamazaki shows “air-sucking” pressure signal as shown in fig. 3 of Yamazaki).
Azuma, as modified by Yamazaki, fails to teach the liquid-feed-type gas compressor: “a control pressure sensor that detects a pressure of compressed gas, and when the pressure detected by the control pressure sensor becomes equal to an unloading start pressure the controller is configured to control a suction throttle valve to a closed state, and is configured to switch to a no-load operation of the compressor main body”, as in claim 1; and “the liquid-feed-type gas compressor includes at least one of the suction throttle valve that closes an intake side of the compressor main body and a relief valve that releases the gas on a discharge side of the compressor main body in order to carry out switching of the compressor main body from a load operation to the no-load operation”, as in claim 3.
However, Oshiro teaches a liquid-feed-type gas compressor (fig. 1) for compressing air, where the system comprises: a compressor main body (1); a gas-liquid separator (4); a controller (29); a control pressure sensor (13) that detects a pressure of compressed gas (see fig. 1), and when the pressure detected by the control pressure sensor becomes equal to an unloading start pressure the controller is configured to control a suction throttle valve (3) to a closed state, and is configured to switch to a no-load operation of the compressor main body (see page 2, last 8 lines; page 3, lines 1-5), as in claim 1; and the liquid-feed-type gas compressor (fig. 1) includes at least one of the suction throttle valve (3) that closes an intake side of the compressor main body (1; fig. 1) and a relief valve (16) that releases the gas on a discharge side of the compressor main body (1) in order to carry out switching of the compressor main body from a load operation to the no-load operation (see page 12, last 9 lines and page 13, lines 1-8), as in claim 3.
Modifying the compressor assembly of Azuma to include a suction throttle valve and a pressure sensor would provide the benefit of including a means for regulating how much gas is sucked into the compressor, providing greater control over the operation of the system. Adding a relief valve to Azuma would help to prevent the system from becoming damaged due to over-pressurization. PLEASE NOTE, that while features of an apparatus may be recited either structurally or functionally, claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed. Cir. 1997). A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987) (MPEP 2114). In the instant case, the proposed modification of Azuma in view of Oshiro discloses all the structural limitations of the claimed invention, including a gas compressor with a suction throttle valve, a pressure sensor & a relief valve, and thus, is structurally capable of “carry out switching of the compressor main body from load operation to no-load operation”.
Therefore, the examiner holds that it would have been obvious to a person having ordinary skill in the art at the effective filing date of the claimed invention to modify the gas compressor assembly of Azuma to further include a suction throttle valve, a pressure sensor & a relief valve, as taught by Oshiro, to provide the benefit of allowing for greater control over the operation of the compressor as well as protecting the system from over pressurization.
In reference to claim 4, Azuma teaches the liquid-feed-type gas compressor, wherein the outlet side of the sampling line (324a) is connected to the liquid feed system [see fig. 2: The outlet side of the sampling line (324a) is fluidically connected to the gas side connecting pipe (12), which directs the gas & oil back to the suction side of the compressor, AND is fluidically connected to the outlet of the oil return pipe (323a)].
In reference to claim 7, this claim is reciting the same limitations that were previously presented in Claim 1 EXCEPT that Claim 7 specifies that the detector detects pressure of the fluid that flows on a system on a downstream side connected to the outlet side of the sampling line on the liquid feed system (as opposed to Claim 1 which recites that the detector detects pressure of the fluid “that flows in the sampling line”). Therefore, with respect to all of the limitations in Claim 7 that were previously recited in Claim 1, they are rejected under the same prior art as those used in the rejection to Claim 1.
With respect to the limitation in Claim 7 that WAS NOT previously recited in Claim 1, Azuma also teaches: a detector (TS4 or TS5) that detects temperature of the fluid that flows on a system on a downstream side connected to the outlet side of the sampling line on the liquid feed system [see fig. 2 and ¶37: Azuma teaches how the operating temperatures are monitored in various locations in the system, which includes locations immediately before suction from the compressor (31a), which can also be used to determine (by the suction temperature) whether a sufficient amount of oil is being drawn through the sampling line, similar to the temperature detected by the temperature sensor TS0)].
Because both Azuma and Yamazaki are directed towards “determining the phase of the fluid flowing in a sampling line”, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to also substitute one method (i.e. at TS4 or TS5 of Azuma) for the other (i.e. of Yamazaki) to achieve the predictable result of analyzing the multi-phase fluid flowing in the conduit for determination of whether the multi-phase fluid is the gas/liquid or whether amount of oil returned is sufficient. KSR Int’l v. Teleflex Inc., 127 S. Ct. 1727, 1740-41, 82 USPQ2d 1385, 1396 (2007).
In reference to claim 9, this claim is reciting the same limitations that were previously presented in claim 3. Therefore, claim 9 is rejected under the same prior art as those used in the rejection of claim 3.
In reference to claim 10, this claim is reciting the same limitations that were previously presented in claim 4. Therefore, claim 10 is rejected under the same prior art as those used in the rejection of claim 4.
In reference to claim 13, this claim is reciting the same limitations that were previously presented in claim 1 (it is noted that claim 13 states that the detector is able to detect the pressure of the fluid that is flowing “in the sampling line”. As noted above claim 1 is directed to an embodiment where the detector is detecting the pressure/temperature of the fluid that is flowing “in the sampling line”). Therefore, claim 13 is rejected under the same prior art as those used in the rejection of claim 1 [please note the claimed frequency characteristic being present in view of figs. 3 and 4 of Yamazaki: frequency of the pulsation (pressure signal) is higher when gas/air is present and frequency of the pulsation (pressure signal) is lower when liquid is present].
Claims 5 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Azuma in view of Yamazaki further in view of Oshiro, Park et al (US 2016/0231008 – herein after Park) and Wang (US 2015/0026142 – herein after Wang).
Regarding Claim 5,
Azuma, as modified, teaches the invention substantially as claimed but does not teach: wherein the compressor main body, the gas-liquid separator, and the liquid feed system configure a compressor unit disposed on a same base, and the informing device includes a display that is mounted on the compressor unit and displays information based on the determination result of the controller.
However, Park teaches (see fig. 3 and ¶58) how it was known that a compressor (20) & gas-liquid separator (70) can be installed on an upper surface of a common base (110).
Having all of the components mounted onto a common base would provide the benefit of helping to prevent the various liquid-feed-type gas compressor parts/components from moving relative to each other, thereby ensuring proper connections.
Therefore, the examiner holds that it would have been obvious to a person having ordinary skill in the art at the effective filing date of the claimed invention to modify the gas compressor assembly of Azuma to have the compressor, gas-liquid separator & necessary piping disposed on a same base, as taught by Park, to provide the benefit of preventing the movement of the various components relative to each other.
Wang teaches how it is known that the display and analytics applications may be integrated into the compressor (see ¶39).
Having the Azuma’s controller (and a display) integrated into their compressor unit would provide the benefit of having the controller & display localized in a common location for easier observation & monitoring.
Therefore, the examiner holds that it would have been obvious to a person having ordinary skill in the art at the effective filing date of the claimed invention to modify the gas compressor assembly of Azuma to have the controller & a display mounted on the compressor body, as taught by Wang, to provide the benefit of creating a central location for a user to monitor the compressors operation.
Regarding Claim 11,
This claim is reciting the same limitations that were previously presented in claim 5. Therefore, claim 11 is rejected under the same prior art as those used in the rejection of claim 5.
Claims 6 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Azuma in view of Yamazaki further in view of Oshiro, Park et al (US 2016/0231008 – herein after Park) and Denis et al (US 2015/0273611 – herein after Denis).
Regarding Claim 6,
Azuma, as modified, teaches the invention substantially as claimed but does not teach: wherein the compressor main body, the gas-liquid separator, and the liquid feed system configure a compressor unit disposed on a same base, and the informing device includes a communication terminal that is separated from the compressor unit and displays information based on the determination result of the controller, the determination result being received through a communication channel.
However, Park teaches (see fig. 3 and ¶58) how it was known that a compressor (20) & gas-liquid separator (70) can be installed on an upper surface of a common base (110).
Having all of the components mounted onto a common base would provide the benefit of helping to prevent the various liquid-feed-type gas compressor parts/components from moving relative to each other, thereby ensuring proper connections.
Therefore, the examiner holds that it would have been obvious to a person having ordinary skill in the art at the effective filing date of the claimed invention to modify the gas compressor assembly of Azuma to have the compressor, gas-liquid separator & necessary piping disposed on a same base, as taught by Park, to provide the benefit of preventing the movement of the various components relative to each other.
Denis teaches how it is known to have a compressor (68), where the current operating status of the compressor communicates with a wireless remote control device (30; see ¶44). This teaching (once incorporated into the compressor assembly of Azuma) would result in an informing device includes a communication terminal that is separated from the compressor unit and displays information based on the determination result of the controller, the determination result being received through a communication channel.
Having the Azuma’s controller communicate with a wireless remote control device would provide the benefit of allowing a user to monitor the operation of the compressor remotely.
Therefore, the examiner holds that it would have been obvious to a person having ordinary skill in the art at the effective filing date of the claimed invention to modify the gas compressor assembly of Azuma to have the controller communicate with a wireless remote control device, as taught by Denis, to provide the benefit of allowing a user to remotely monitor the operational status of the compressor.
Regarding Claim 12,
This claim is reciting the same limitations that were previously presented in claim 6. Therefore, claim 12 is rejected under the same prior art as those used in the rejection of claim 6.
Response to Arguments
The following arguments filed March 18, 2026 have been fully considered:
Arguments with respect to rejection over Azuma, Mifune and Matsuzaka: These arguments are moot since the rejection of the claims in this office action no longer relies upon references of Mifune and Matsuzaka.
With respect to Yamazaki: No arguments are presented with respect to Yamazaki, specifically with respect to the amended feature related to the pressure detector.
With respect to Matsuzaka: These arguments are moot since this reference is no longer relied upon in the rejection of the claims in this office action. The rejection now relies upon newly found prior art of Oshiro to teach the amended feature related to the no-load operation of the compressor main body.
Conclusion
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/CHIRAG JARIWALA/Examiner, Art Unit 3746
/ESSAMA OMGBA/Supervisory Patent Examiner, Art Unit 3746
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