Prosecution Insights
Last updated: April 19, 2026
Application No. 18/726,522

Compressor with reduced start-up torque

Non-Final OA §103
Filed
Jul 03, 2024
Examiner
JARIWALA, CHIRAG
Art Unit
3746
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Cavendish Hydrogen A/S
OA Round
1 (Non-Final)
61%
Grant Probability
Moderate
1-2
OA Rounds
3y 1m
To Grant
89%
With Interview

Examiner Intelligence

Grants 61% of resolved cases
61%
Career Allow Rate
245 granted / 399 resolved
-8.6% vs TC avg
Strong +27% interview lift
Without
With
+27.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
69 currently pending
Career history
468
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
45.5%
+5.5% vs TC avg
§102
21.8%
-18.2% vs TC avg
§112
29.0%
-11.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 399 resolved cases

Office Action

§103
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 Group I (claims 1, 6, 8, 10 – 13, 15, 17 – 19) in the reply filed on January 21, 2026 is acknowledged. Claim Objections Claim 6 is objected to because of the following informality: Claim 6, lines 1-2: “wherein said compressor system” should read --wherein said Appropriate correction is required. 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. 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. Claims 1, 6, 8, 10 – 12, 15, 17 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Takano et al. (US 2015/0153005 – herein after Takano) in view of Borup et al. (US 2023/0265969 – herein after Borup). In reference to claim 1, Takano teaches a compressor system (10, see fig. 1) comprising: a high-pressure gas compressor (14) having a compressor inlet (see fig. A below) and a compressor outlet (see fig. A below), wherein an inlet volume (this volume is defined by conduit portion labeled “C” in fig. A below) is defined between a compressor inlet valve (20) and said compressor inlet (see fig. A below), wherein said compressor outlet is fluidly connected to a receiving vessel (dispenser 16 or gas tank 2), a motor (see ¶43: “The crankshaft 37 is provided in the crankcase 33, and is driven by a motor not shown to rotate”) configured to drive a crankshaft (37+38) of said compressor, a controller (47, see fig. 1 and ¶47) configured to control operation of said compressor, said compressor inlet valve and said motor, during a plurality of successive operation cycles, wherein during a shut-down part of an operation cycle, said compressor inlet valve (20) is configured for being closed before said crankshaft stop rotation [see ¶74: an action of closing the inlet valve (referred as second opening/closing valve 20) on the suction side before the crankshaft stops rotation (during deceleration phase) {crankshaft is rotating due to inertia; note the phrasing "compressor 14 takes times to stop" in ¶74}], and wherein during a start-up part of a subsequent operation cycle, said compressor inlet valve is configured for being opened after at least one completed compression stroke [see ¶61-¶64: opening the inlet valve (20) only after the motor has started and built up to a predetermined rotational speed (referred as "first rotational speed"). This rotational threshold control is a stronger requirement than simply "at least one completed compression stroke" and fully anticipates the limitation "at least one completed compression stroke”]. PNG media_image1.png 628 1272 media_image1.png Greyscale Fig. A: Edited fig. 1 of Takano to show claim interpretation. Takano does not teach the system, wherein the high-pressure gas compressor is a diaphragm gas compressor. However, Borup teaches a hydrogen refueling station (see fig. 5 and ¶220) comprising a compressor (38), wherein the compressor can be a “piston-metal diaphragm compressor” (see ¶201). It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to substitute a piston compressor in the compressor system of Takano for a piston-metal diaphragm compressor as taught by Borup in order to obtain the predictable result compressing the hydrogen. KSR Int’l v. Teleflex Inc., 127 S. Ct. 1727, 1740-41, 82 USPQ2d 1385, 1396 (2007). Furthermore, this modification would be motivated by the known benefits of diaphragm compressors in high-pressure hydrogen systems, such as providing a hermetic seal to prevent gas contamination and leakage. In reference to claim 6, Takano teaches the system, wherein said system (10) is part of a hydrogen refueling station (see ¶34: “A gas filling apparatus 10 according to this embodiment is intended to supply hydrogen gas to a fuel cell vehicle 4, which is an example of a tank-equipped apparatus in which a gas tank 2 is mounted, and is provided in a hydrogen station as a hydrogen gas fueling station, for example.”). In reference to claim 8, Takano, as modified, teaches the system, wherein said high-pressure diaphragm gas compressor comprises a metal diaphragm (as taught by Borup). In reference to claim 10, Takano teaches the system, wherein said controller (47) is further configured to control a compressor outlet valve (18, see fig. 1 and ¶57) located in said fluid connection between said compressor outlet (see fig. A above) and said receiving vessel (16/2). In reference to claim 11, Takano teaches the system, wherein said controller (47) is further configured to control a recycling valve (45b, see fig. 1 and ¶50) located in a fluid connection between said compressor inlet and said controller outlet. In reference to claim 12, Takano teaches the system, wherein during normal operation, said controller (47) is configured (see ¶61) to close said compressor outlet valve (18) and opening said recycling valve (45b). In reference to claim 15, Takano teaches the system, wherein said controller (47) is further configured to open said compressor inlet valve (20) when said crankshaft reaches a rotation threshold [see ¶61-¶64: opening the inlet valve (20) only after the motor has started and built up to a predetermined rotational speed (referred as "first rotational speed"); this predetermined/first rotational speed constitutes “a rotation threshold”]. In reference to claim 17, Takano teaches the system, wherein during said shut-down part said controller (47) is further configured to close said compressor outlet valve (18) and opening said recycling valve (45b). In reference to claim 19, Takano teaches the system, wherein said recycling valve (45b) is a pressure regulation valve (see ¶81). Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Takano in view of Borup and Zheng et al. (CN 209244834U – herein after Zheng). Takano teaches the system, wherein said controller (47) is further configured for controlling said complete compression stroke as a first compression stroke [controller is capable of having the claimed feature as discussed above in claim 1; see ¶61-¶64]. Takano remains silent on the system, wherein the first compression stroke configured including an initial movement of the crankshaft in a direction of rotation opposite to the direction of rotation of the crankshaft after said first complete compression stroke. However, Zheng teaches a compressor system wherein (see ¶23-¶25 of translation), after starting the compressor, a crankshaft is rotated in a direction of rotation (i.e. reverse direction), opposite to its normal direction of rotation, for balancing the intake and exhaust pressure difference to eliminate startup resistance. It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the system of Takano for configuring it to include an initial movement of the crankshaft in a direction of rotation opposite to normal crankshaft’s rotational direction as taught by Zheng for the purpose of balancing the intake and exhaust pressure difference to eliminate startup resistance, as recognized by Zheng above. Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Takano in view of Borup and Otsuka et al. (US 2022/0154709 – herein after Otsuka). Takano teaches the system, wherein during said shut-down part, said controller (47) is further configured to close said recycling valve (45b) and open said compressor outlet valve (18) [see ¶74, ¶77, ¶78: controller is capable of performing claimed function]. Takano remains silent on the system, further comprising a buffer storage. However, Otsuka teaches a similar system, comprising a compressor (10), wherein compressor’s outlet is fluidly connected to a buffer storage (pressure accumulator 3). It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to provide a buffer storage as taught by Otsuka on the downstream side of the compressor in the system of Takano for the purpose of accumulating the hydrogen gas having the high pressure and supplied from the compressor in the high-pressure state, as recognized by Otsuka (see ¶13), and for equalizing pressure variations caused by the gas compressor. Thus, Takano, as modified, teaches the system, wherein during said shut-down part, said controller (47) is further configured to close said recycling valve (45b) and open said compressor outlet valve (18) thereby fluidly connecting said compressor outlet and a buffer storage (provided using the teaching of Otsuka). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHIRAG JARIWALA whose telephone number is (571)272-0467. The examiner can normally be reached M-F 8 AM-5 PM. 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, ESSAMA OMGBA can be reached at 469-295-9278. 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. /CHIRAG JARIWALA/Examiner, Art Unit 3746 /ESSAMA OMGBA/Supervisory Patent Examiner, Art Unit 3746
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Prosecution Timeline

Jul 03, 2024
Application Filed
Feb 17, 2026
Non-Final Rejection — §103 (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
61%
Grant Probability
89%
With Interview (+27.2%)
3y 1m
Median Time to Grant
Low
PTA Risk
Based on 399 resolved cases by this examiner. Grant probability derived from career allow rate.

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