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 § 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 1-7 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.
At claim 1, line 3, “a condenser” should be changed to “the condenser.” As currently written, “a condenser” is recited at both lines 2 and 3 of the claim, rendering it unclear whether these are intended to be the same or different condensers. Claims 2-7 are also rejected since they depend from claim 1.
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 nonobviousness.
Claim(s) 1-2, 6-9. 13-16, and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bush et al. (US 7891201 B1).
As per claims 1, 8, and 15, Bush et al. disclose a system (and corresponding method and non-transitory computer-readable medium controls) comprising: a flash tank 20 configured to receive two-phase refrigerant from a condenser 40; a first expansion valve 75 disposed between the condenser and an inlet of the flash tank; a pressure sensor 72; and a controller 70 configured to: receive a first pressure measurement from the pressure sensor; determine, based on the first pressure measurement, that a liquid refrigerant level within the flash tank is below a threshold height (col. 9, lines 21-28); and open the first expansion valve to provide additional refrigerant to the flash tank (see col. 9, lines 21-28 re. increasing flow through expansion valve 75 when sensed pressure is above a threshold to increase the corresponding height of liquid refrigerant within the flash tank). While Bush et al. discusses these controls in terms of a pressure threshold instead of a liquid level threshold, this passage also presents these two parameters as being directly (inversely) correlated. Accordingly, It would have been obvious to one of ordinary skill in the art at the effective filing date of the application to alternatively reframe these controls in terms of a liquid refrigerant level threshold since the detected pressure functions as a proxy for this value (and the liquid refrigerant level is a function of the controlled pressure), and further since it is the liquid level in the flash tank that is ultimately being controlled.
As per claim 2, 9, and 16,, Bush et al. further disclose wherein the controller is further configured to: receive a second pressure measurement from the pressure sensor 75 and determine, based on the second pressure measurement, that the liquid refrigerant level within the flash tank is above the threshold height (col. 9, lines 13-21); and close the first expansion valve to prevent additional refrigerant from being supplied to the flash tank (see col. 9, lines 13-21 re. reducing flow through expansion valve 75 when sensed pressure is below a threshold to decrease the corresponding height of liquid refrigerant within the flash tank). Again, While Bush et al. discusses these controls in terms of a pressure threshold instead of a liquid level threshold, this passage also presents these two parameters as being directly (inversely) correlated. Accordingly, It would have been obvious to one of ordinary skill in the art at the effective filing date of the application to alternatively reframe these controls in terms of a liquid refrigerant level threshold since the detected pressure functions as a proxy for this value (and the liquid refrigerant level is a function of the controlled pressure), and further since it is the liquid level in the flash tank that is ultimately being controlled.
As per claims 6, 13, and 20, Bush et al. disclose wherein the flash tank is further configured to separate the two-phase refrigerant into a liquid refrigerant and a gaseous refrigerant (col. 2, lines 34-41; etc.), wherein the liquid refrigerant is provided to an evaporator 50 and the gaseous refrigerant is provided to a compressor 30B (Figs. 1-2; etc.).
As per claims 7 and 14, further comprising a second expansion valve 55 disposed between the flash tank and an evaporator 50 (Figs. 1-2; etc.), wherein the first expansion valve is configured to reduce a first pressure of refrigerant received from the condenser to a second pressure (expands refrigerant traveling from the condenser into the flash tank) , and wherein the second expansion valve is configured to reduce a third pressure of refrigerant received from the flash tank to a fourth pressure (expands refrigerant traveling from the flash tank into the evaporator).
Claim(s) 3-5, 10-12, and 17-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bush et al. (US 7891201 B1) in view of Kuruda et al. (US 2013/0171709 A1).
As per claims 3, 10, and 17, Bush et al. do not teach wherein the pressure sensor is a differential pressure sensor configured to measure a pressure difference between the inlet of the flash tank and a base of the flash tank. Kuruda et al. teach the basic concept that liquid level within a flash tank can be controlled based on a sensed differential pressure (paras. 0047, 0050; etc.). While Kuruda et al. is directed to distillation rather than refrigeration, the basic physics of a flash tank remain the same. It would have been obvious to one of ordinary skill in the art at the effective filing date of the application to alternatively use differential pressure as a proxy the flash tank liquid level within the system of Bush et al. for the same basic purpose of optimizing valve controls to maintain that liquid level a desired height according to the particular needs of the system.
As per claims 4, 11, and 18, Bush et al. in view of Kuruda et al. (as discussed regarding claims 3, 10, and 17) do not teach wherein the pressure sensor is a first absolute pressure sensor disposed at a base of a liquid refrigerant within the flash tank. However, since sensor 17 measures a temperature difference between an upper portion of the tank and the base of the tank (see Figs. 1-3; para. 0047; etc.), one or ordinary skill in the art could have easily conceived of determining such pressure differential by comparing separate pressure values taken at those locations, whereby the lower of these pressure sensors would constitute an absolute pressure sensor disposed at the base. It would thus have been obvious to one or ordinary skill in the art at the effective filing date of the application to utilize an absolute pressure sensor disposed at the base of the flash tank of Bush et al. as part of a generally understood technique for determining liquid level based on detected differential pressure.
As per claims 5, 12, and 19, Bush et al. do not an additional absolute pressure sensor disposed at a different location within the flash tank than the first absolute pressure sensor. As already discussed (see claims 4, 11, and 18), it would thus have been obvious to one or ordinary skill in the art at the effective filing date of the application to utilize a pair of absolute pressure sensors (based on the teachings of Kuruda et al.) of Bush et al. as part of a generally understood technique for determining liquid level based on detected differential pressure, and that such an arrangement would comprise an additional pressure sensor (that is, additional to the absolute pressure sensor disposed at the base of the flash tank) disposed at an upper location of the flash tank (in order to achieve the same generally differential pressure as measured by sensor 17 as shown in Figs 1-2 of Kuruda et al.. Accordingly, such a pressure sensor would have been further obvious to one or ordinary skill in the art at the effective filing date of the application to apply to the system of Bush et al. as part of a generally understood technique for determining liquid level based on detected differential pressure as already discussed regarding claims 4, 11, and 18.
Cited Prior Art
The following references not applied in the rejections above are considered pertinent to Applicant’s disclosed invention.
Prins et al. (US 11959676 B2), Hugh et al. (US 2023/0392840 A1), Furui et al. (US 9803897 B2), Sun et al. (US 2015/0300713 A1), Liu et al. (US 2012/0227427 A1), Kasahara et al. (US 8205464 B2), Huff et al. (US 2011/0162397 A1), Mira et al. (US 2010/0132399 A1 and US 2010/0115975 A1), and Ozaki et al. (US 6044655) teach various related flash tank and corresponding expansion valve controls arrangements.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARC E NORMAN whose telephone number is (571)272-4812. The examiner can normally be reached 8:00-4:30 M-F.
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/MARC E NORMAN/Primary Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763