Prosecution Insights
Last updated: April 19, 2026
Application No. 18/793,538

SPLIT VALVES FOR REGULATING FLUID FLOW IN CLOSED LOOP SYSTEMS

Non-Final OA §103§112
Filed
Aug 02, 2024
Examiner
MCCALISTER, WILLIAM M
Art Unit
3753
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
General Electric Company
OA Round
1 (Non-Final)
69%
Grant Probability
Favorable
1-2
OA Rounds
2y 10m
To Grant
88%
With Interview

Examiner Intelligence

Grants 69% — above average
69%
Career Allow Rate
699 granted / 1015 resolved
-1.1% vs TC avg
Strong +19% interview lift
Without
With
+19.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
33 currently pending
Career history
1048
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
38.6%
-1.4% vs TC avg
§102
29.8%
-10.2% vs TC avg
§112
26.2%
-13.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1015 resolved cases

Office Action

§103 §112
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 with traverse of species D of Figure 5 in the reply filed on 11/14/25 is acknowledged. The traversal is on the ground(s) that there are allegedly inventive concepts common to both Species A and Species B, and that there are allegedly inventive concepts common to species C, D and E, and that therefore no substantial search burden exists. This is not found persuasive at least because the elements of search burden are set forth in the restriction requirement. Also, Applicant’s argument that there is common inventive subject matter is an issue relevant under Unity of Invention practice for an International Application or a National Stage application filed under 35 USC 371. However this application was filed under 35 USC 111(a), and therefore different elements are required of the restriction requirement. (See the restriction requirement which explicitly establishes these required elements.) What is more, the specifically-argued feature (that both split valves 200 and 300 of FIG 2 and FIG 3 include “a split valve with bellows and cascading pressure chambers for regulating fluid flowing through a thermal transport bus”), is hybrid language newly appearing in Applicant’s arguments of 11/14/25, which language is not actually present in the claims. The requirement is still deemed proper and is therefore made FINAL. Claims 1-17 will be treated on the merits. 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 1-11 and 17 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. In claim 1, the phrase “the first piston to include a piston shaft, a first head, and a second head” (examiner’s underline) is unclear. Particularly it cannot be determined if the shaft and two heads are positively required of the claim. To the contrary, is this merely a limitation directed to Applicant’s intention to include, and does the claim therefore only require a capability of the first piston to be fitted with a shaft and two heads? (If the piston shaft, first head and second head are meant to be positively required of the claim, it is suggest that the conventional transitional phrase “comprising” or “including” be used, rather than “to include”, in order to avoid confusion.) Where applicant acts as his or her own lexicographer to specifically define a term of a claim contrary to its ordinary meaning, the written description must clearly redefine the claim term and set forth the uncommon definition so as to put one reasonably skilled in the art on notice that the applicant intended to so redefine that claim term. Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999). The terms “determines a position” and “determining a position” in claims 7 and 11 are used by the claims to mean “determining a commanded position”, while the accepted meaning is “calculating an actuation position”. The term is indefinite because the specification does not clearly redefine the term. Regarding claims 10 and 17, it cannot be determined what is “based on a difference between a pressure measurement and a target pressure” – is it the pressure error or the positional threshold? 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1-3 and 6 as understood is/are rejected under 35 U.S.C. 103 as being unpatentable over Applicant’s Admitted Prior Art (hereinafter “AAPA”, see Applicant’s Figure 1 and the accompanying description), in view of either Otteman (US 5,007,328) or Ishigaki (US 5,848,608). Regarding claim 1, Applicant admits as prior art a split valve to regulate a first flowrate and a second flowrate of a fluid within a closed loop system, the split valve comprising: an electrohydraulic servo valve (102) coupled to a first piston (108, 110, 112) via a first hydraulic flowline (104) and a second hydraulic flowline (106), the first piston to include a piston shaft (108), a first head (110), and a second head (112), the first hydraulic flowline to output a first pressure of a hydraulic fluid, the second hydraulic flowline to output a second pressure of the hydraulic fluid (e.g., Applicant’s para. 0024: “EHSV 102 which actuates the piston via pressure outputs from … 104 and … 106”); a seal (114) fixed to at least one of the first head or the second head, the seal to hermetically seal the fluid from the hydraulic fluid (due to its location therebetween, see FIG 1); and a control system (*inherent, which inherent control system must be present in order to perform the function quoted below from para. 0024) connected to the electrohydraulic servo valve, the control system to adjust the first flowrate and the second flowrate of the fluid through a first fluid chamber (115) (see para. 0024: “For example, if the flowrate through the first outlet flowline 118 is too high, then a sensor in the fluid system sends a signal to the EHSV 102 to increase pressure output of the first hydraulic flowline, thereby decreasing a pressure output of the second hydraulic flow line. This change in pressure outputs causes the piston to move in a direction that restricts flow of the fluid through the first outlet flowline 118 and enables flow of the fluid through the second outlet flow line 120.”), the first piston to be located in the first fluid chamber (see FIG 1). AAPA does not disclose seal to be a bellows as claimed. However each of Otteman (col. 3 lines 3-7) and Ishigaki (col. 7 lines 38-45) independently teaches that it was known in the art before the effective filing date that a bellows can be interchanged with such a seal. It therefore would have been obvious to one of skill in the art at the time of invention to use bellows in place of the AAPA seal(s), for example to decrease friction and resistance to sliding of the AAPA piston. Regarding claim 2, AAPA discloses wherein the first fluid chamber includes at least an inlet flowline (116), a first outlet flowline (118), and a second outlet flowline (120). Regarding claim 3, AAPA discloses wherein the control system determines a first effective area of the first outlet flowline and a second effective area of the second outlet flowline (the control system causes the piston to move up and down, blocking or allowing flow into the outlet flowlines, as described at para. 0024; note that this claim shows the term “determines” means “to influence” or “to control”). Regarding claim 6, AAPA discloses wherein the first piston is driven by a first pressure output from the first hydraulic flowline (104) and a second pressure output from the second hydraulic flowline (106), and the obvious modification set forth in the analysis of claim 1 above results in the bellows being fixed to the first head of the first piston and the first fluid chamber. The magnetic LVDT shaft fixed to the piston as claimed is not disclosed or taught in the cited prior art, however it was well-known to use a ferromagnetic LVDT shaft fixed to such a piston for the purpose of measuring linear displacement (official notice), and it would have been obvious to use such a ferromagnetic LVDT shaft to similarly measure the position of the AAPA piston. Claim(s) 1-3, 6-9 and 11-16 (1-3, 6-9 and 11 as understood; *where 1-3 and 6 are rejected in the alternative, should it be determined that AAPA does not inherently disclose a control system), is/are rejected under 35 U.S.C. 103 as being unpatentable over AAPA in view of either Otteman or Ishigaki, and further in view of Sopha (US 4,061,155). Regarding claims 1 and 7-9, AAPA in view of Otteman or Ishigaki render obvious the invention as claimed, with exception to: wherein the control system determines a position of the first piston based on a pressure or temperature measurement, actuating the first piston based on commanded position, actual position, or a positional error of the first piston between the commanded position and actual position (and with arguable exception to the inherent control system, as required of claim 1). Sopha teaches that it was known to determine (i.e., to effect, or influence; via controller 17) a position of a similar valve spool based on pressure measurements (14, 15, 16; “transducers operative for sensing the position of the valve member and the pressures at the inflow and consumer ports and generating corresponding electrical feedback signals”), and to actuate the piston via a similar EHSV 12 based on commanded position (from 50, which is influenced by command 51), actual position (from 27), or positional error of the first piston between the commanded position and actual position (as compared at 53; see col. 5 lines 54-56) using a controller (17). To provide closed-loop control of AAPA’s system, it would have been obvious to use a controller which determines position based on pressure measurement, and which actuates the first piston using the EHSV based on a commanded position, actual position, or positional error between the commanded and actuation position of the first piston, as similarly taught by Sopha. Regarding claims 2-3 and 6, see the corresponding analyses set forth above. Regarding claims 11-16, the claimed method would necessarily be performed during the normal and usual operation of the device set forth under this obviousness analysis. (The steps of claim 11 correspond to apparatus claims 1, 7 and 8; the step of claim 12 corresponds to apparatus claim 1; the step of claim 13 corresponds to apparatus claim 2; the step of claim 14 corresponds to apparatus claim 3; the step of claim 15 corresponds to apparatus claim 8; and the step of claim 16 corresponds to apparatus claim 9.) Allowable Subject Matter Claims 4, 5, 10 and 17 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action without changing the scope, and to include all of the limitations of the base claim and any intervening claims. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 11,098,811 discloses a two-way valve which uses a bellows to similarly seal between a process fluid and an actuating fluid. Any inquiry concerning this communication or earlier communications from the examiner should be directed to WILLIAM M MCCALISTER whose telephone number is (571)270-1869. The examiner can normally be reached M-F from 7am to 6pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, CRAIG SCHNEIDER, can be reached at telephone number 571-272-3607, or Kenneth Rinehart can be reached at 571-272-4881. 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 Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). 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) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form. /WILLIAM M MCCALISTER/Primary Examiner, Art Unit 3753 2/18/26
Read full office action

Prosecution Timeline

Aug 02, 2024
Application Filed
Feb 18, 2026
Non-Final Rejection — §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
69%
Grant Probability
88%
With Interview (+19.1%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 1015 resolved cases by this examiner. Grant probability derived from career allow rate.

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