Prosecution Insights
Last updated: April 19, 2026
Application No. 18/527,614

LIQUID LEVEL SENSING SYSTEM AND METHOD FOR MEASURING LIQUID LEVEL

Non-Final OA §102§103§112
Filed
Dec 04, 2023
Examiner
FITZGERALD, JOHN P
Art Unit
2855
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Simmonds Precision Products Inc.
OA Round
1 (Non-Final)
75%
Grant Probability
Favorable
1-2
OA Rounds
2y 11m
To Grant
78%
With Interview

Examiner Intelligence

Grants 75% — above average
75%
Career Allow Rate
630 granted / 839 resolved
+7.1% vs TC avg
Minimal +3% lift
Without
With
+2.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
27 currently pending
Career history
866
Total Applications
across all art units

Statute-Specific Performance

§101
3.9%
-36.1% vs TC avg
§103
38.8%
-1.2% vs TC avg
§102
19.2%
-20.8% vs TC avg
§112
30.3%
-9.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 839 resolved cases

Office Action

§102 §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 with traverse of Group I invention, and Fig. 2a of Species I; greater than zero degrees and less than 180 degrees of Species II and Figs. 1a and 1b of Species III in the reply filed on 09 January 2026 is acknowledged. The traversal is solely directed to the species election of Species II, and is on the ground(s) that the restriction requirement required a selection between an embodiment that is not disclosed, being a probe angle of zero degrees and an embodiment that is disclosed, being a probe position angle greater than zero and less than 180 degrees. This is found persuasive, and, as such, the species election requirement regarding Species II is withdrawn. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement regarding between Groups I and II, or Species I and III, the election of Group I, Fig. 2 and Figs. 1a and 1b has been treated as an election without traverse (MPEP § 818.01(a)). Claims 9, 10, 13 and 15-20 are withdrawn from consideration as being directed to non-elected Group II invention and Species I of Figs. 2b or 2c, and non-elected Species III of Figs. 4a and 4b. The requirement is still deemed proper and is therefore made FINAL. Claim Rejections - 35 USC § 112 Claims 3 and 14 is 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. Claim 3 recites the limitation “the openings in….outer walls” in lines 1-2. There is insufficient antecedent basis for an opening in the outer wall in the claim Claim 14 recites the limitation "the liquid-hydrogen tank" in lines 1-2. There is insufficient antecedent basis for this limitation in the claim. Claim Rejections - 35 USC § 102 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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 1 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by U.S. 3,448,616 to Wostl et al. Wostl et al. disclose a liquid level sensing system (see Fig. 1 and entire reference) including a sensing probe including an axial guided wave (AGW) transducer (18, 20, 22), wherein the AGW transducer includes a sensing element (18) and a rod (10) operatively associated with the AGW transducer, wherein the AGW transducer is operatively connected with a first end of the rod; and inherently including a liquid tank in which a second end of the rod extends through an opening in an inner wall of the liquid tank into the liquid tank, wherein the first end of the rod and the AGW transducer are outside of the inner wall (as recited in instant independent claim 1). Claim(s) 1 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by U.S. 2007/0169549 to Kwun et al. Kwun et al. disclose a liquid level sensing system (see Fig. 2 and entire reference) including a sensing probe including an axial guided wave (AGW) transducer (16), wherein the AGW transducer includes a sensing element (4) and a rod (18) operatively associated with the AGW transducer, wherein the AGW transducer is operatively connected with a first end of the rod; and including a liquid tank (12) in which a second end of the rod extends through an opening in an inner wall of the liquid tank into the liquid tank, wherein the first end of the rod and the AGW transducer are outside of the inner wall (as recited in instant independent claim 1). Claim(s) 1 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by U.S. 2002/0023489 to Reimelt et al. Reimelt et al. disclose a liquid level sensing system (see Fig. 1 and entire reference) including a sensing probe including an axial guided wave (AGW) transducer (1, 2, 4), wherein the AGW transducer includes a sensing element (20) and a rod (5) operatively associated with the AGW transducer, wherein the AGW transducer is operatively connected with a first end of the rod; and including a liquid tank (6) in which a second end of the rod extends through an opening in an inner wall of the liquid tank into the liquid tank, wherein the first end of the rod and the AGW transducer are outside of the inner wall (as recited in instant independent claim 1). Claim(s) 1 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by CN 111306442 B to Li et al. Li et al. disclose a liquid level sensing system (see Fig. 1 and entire reference and English translation) including a sensing probe including an axial guided wave (AGW) transducer (4), wherein the AGW transducer includes a sensing element (41) and a rod (43) operatively associated with the AGW transducer, wherein the AGW transducer is operatively connected with a first end of the rod; and including a liquid tank (1) in which a second end of the rod extends through an opening in an inner wall of the liquid tank into the liquid tank, wherein the first end of the rod and the AGW transducer are outside of the inner wall (as recited in instant independent claim 1). Claim(s) 1 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2018/0100756 to Ichimura et al. Ichimura et al. disclose a liquid level sensing system (see Figs. 1-2 and entire reference) including a sensing probe including an axial guided wave (AGW) transducer (50), wherein the AGW transducer includes a sensing element and a rod (20) operatively associated with the AGW transducer, wherein the AGW transducer is operatively connected with a first end of the rod; and including a liquid tank (70) in which a second end of the rod extends through an opening in an inner wall of the liquid tank into the liquid tank, wherein the first end of the rod and the AGW transducer are outside of the inner wall (as recited in instant independent 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. Claim(s) 2-7, 11, 12 and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN 111306442 B to Li et al. and U.S. 2021/0372570 to Stubenrach. Li et al. disclose a liquid level sensing having all the previously recited elements of instant independent claim 1. Li et al. further disclose the liquid tank holds a cryogenic liquid (LNG), wherein the inner wall of the cryogenic liquid tank is surrounded by an outer wall (2), wherein the second end of the rod extends through an opening/joint assembly (71) in the inner wall (as recited in instant dependent claim 2); wherein the openings (71, 72) in the inner and outer walls of the cryogenic liquid tank are at a top side of the cryogenic liquid tank, wherein the top side of the cryogenic liquid tank is opposite a bottom side of the cryogenic liquid tank, wherein the second end of the rod is spaced apart from the bottom side of the cryogenic liquid tank (as recited in instant dependent claim 3); wherein the outer wall of the cryogenic liquid tank and the inner wall of the liquid-hydrogen tank are separated by a vacuum jacket (see Background of Li et al. regarding C-type double layer vacuum tank) (as recited in instant dependent claim 4); wherein the sensing probe is positioned at an angle (vertical of 90 degrees) with respect to a liquid level plane of the cryogenic liquid tank (as recited in instant dependent claim 5); wherein the angle (vertical of 90 degrees) of the sensing probe with respect to the liquid level plane is greater than zero degrees and less than 180 degrees (as recited in instant dependent claim 6); wherein the sensing element inherently includes at least one transmitter and/or receiver (as recited in instant dependent claim 7); wherein the cryogenic liquid tank includes both liquid natural gas and gaseous natural gas and a liquid natural gas and gaseous natural gas interface exists therebetween, such that the liquid natural gas occupies a bottom portion of the cryogenic liquid tank and the gaseous natural gas occupies a top portion of the tank (as recited in instant dependent claim 11); wherein the at least one transmitter is configured to transmit a pulse along a length of the rod from the first end of the rod to the second end of the rod and back to the first end of the rod, wherein the at least one receiver is configured to receive a reflected pulse (as recited in instant dependent claim 12); and wherein a longitudinal axis of the liquid-hydrogen tank extends parallel to a liquid level surface within the liquid-hydrogen tank (see Fig. 1) (as recited in instant dependent claim 14). Li et al. disclose all the elements regarding a cryogenic-liquid tank, but does not explicitly disclose the cryogenic liquid being hydrogen, thus a lquid-hydrogen tank (as recited in instant dependent claims 2-7, 11, 12 and 14. However, liquid-hydrogen is also a cryogenic fluid, and, as such, the liquid level sensing system would function equally as well in a liquid-hydrogen tank containing liquid hydrogen, and to determine the level/interface of liquid-hydrogen below a gaseous hydrogen within a liquid-hydrogen tank, thus it would have been obvious to one having ordinary skill in the art as of the effective filing date to employ a liquid-hydrogen tank and associated hydrogen liquid stored therein to determine the level of liquid hydrogen within the tank. Such liquid-hydrogen tanks are known, which is evidenced by Stubenrach (see entire reference), which discloses a tank (see Figs. 1-2) for storing cryogenic liquids, including a liquid-hydrogen tank sharing many of the same elements as the cryogenic liquid tank disclosed by Li et al., wherein the tank forms an inner container/tank for receiving the cryogenic hydrogen liquid of a double-walled container/tank, which additionally comprises an outer container (11) and the inner container, i.e. the storage container (1) and wherein a vacuum is formed between the outer tank/container and the inner tank/container (see para 0031). Thus it would have been obvious to one having ordinary skill in the art to employ the Li et al. liquid level sensing system for cryogenic liquids, employing liquid-hydrogen, also a cryogenic fluid, thus rendering the system to employ a liquid-hydrogen tank to contain both liquid hydrogen and gaseous hydrogen and determine the interface/level between the two, or any other cryogenic liquid, as desired, to determine the level therein, meeting all the limitations regarding liquid-hydrogen recited in instant dependent claims 2-7, 11, 12 and 14. Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN 111306442 B to Li et al. and U.S. 2021/0372570 to Stubenrach as applied to claims 1 and 7 above, and further in view of U.S. 2025/0044140 to Jensen et al. Li et al. and Stubenrach disclose a liquid level sensing having all of the elements recited previously. Li et al. and Stubenrach do not explicitly disclose that the at least one transmitter and/or receiver includes one transmitter and a plurality of receivers, as recited in instant dependent claim 8. Jensen et al. discloses a liquid level sensing system (100) (see entire reference) wherein in a particular embodiment, includes a single transmitter and a plurality of receivers (see para 0121). It would have been obvious to one having ordinary skill in the art as of the effective filing date of the instant invention to modify the liquid level sensing system disclosed by Li et al. and Stubenrach, by employing one transmitter and a plurality of receivers, as taught by Jensen et al., thus providing a single-input, multiple-output sensor arrangement, allowing for the plurality of receivers to be respectively operable at different times to obtain a plurality of liquid level measurements (see para 0121), thus meeting the limitations recited in instant dependent claim 8. In addition, it would have been obvious to one of ordinary skill in the art as of the effective filing date to modify the liquid level sensing system disclosed by Li et al. and Stubenrach, to employ one transmitter and plurality of receivers, ensuring the returning wave/signal obtained in the event of one of the plurality of receivers failing or stops functioning, thus allowing continuous measurement of the liquid level without interruption. Furthermore, the instant filed specification fails to disclose that employing one transmitter and a plurality of receivers is employed for any specific engineering design purpose or reasons in regards to the liquid level sensing, or that one transmitter and a plurality of receivers solves a particular design/engineering problem, thus it would be well within the ordinary skill level to employ one transmitter and a plurality of receivers in the liquid level sensing system disclosed by Li et al. and Stubenrach, as a matter of design choice by one of ordinary skill in the art as of the effective filing date, further meeting the limitations recited in instant dependent claim 8. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Applicant is invited to review PTO form 892 accompanying this Office Action listing Prior Art relevant to the instant invention cited by the Examiner. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Primary Examiner John Fitzgerald whose telephone number is (571) 272-2843. The examiner can normally be reached on Monday-Friday from 7:00 AM to 3:30 PM E.S.T. If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor John Breene, can be reached at telephone number (571) 272-4107. 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. The central 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. /JOHN FITZGERALD/Primary Examiner, Art Unit 2855
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Prosecution Timeline

Dec 04, 2023
Application Filed
Jan 21, 2026
Non-Final Rejection — §102, §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
75%
Grant Probability
78%
With Interview (+2.6%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 839 resolved cases by this examiner. Grant probability derived from career allow rate.

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