Office Action Predictor
Last updated: April 15, 2026
Application No. 18/018,691

Hybrid Drive and Fuel Vaporizer for UAV and Other Mobile Environments

Final Rejection §103
Filed
Jan 30, 2023
Examiner
KIM, JAMES JAY
Art Unit
3747
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Liquidpiston, INC.
OA Round
2 (Final)
70%
Grant Probability
Favorable
3-4
OA Rounds
2y 5m
To Grant
98%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
467 granted / 665 resolved
At TC average
Strong +27% interview lift
Without
With
+27.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
28 currently pending
Career history
693
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
54.8%
+14.8% vs TC avg
§102
22.8%
-17.2% vs TC avg
§112
20.2%
-19.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 665 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 . 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. Claims 21-23, and 29 are rejected under 35 U.S.C. 103 as being unpatentable over Severinsky (US 6,209,672) in view of Pennazza et al (US 12,140,073 hereinafter “Pennazza”). In regards to claim 21: Severinsky teaches a hybrid drive comprising: a load shaft (16); an electric motor (25) coupled to the load shaft (16); a clutch (51) that is coupled to the load shaft (16); a motor/generator (21), disengageably coupled to the load shaft (16) through the clutch (51); an internal combustion engine (40) having an engine output shaft (41), the engine output shaft (41) coupled to the load shaft (16) and the electric motor (25) through the clutch (51), so that the load shaft is driven by a source selected from the group consisting of the electric motor, the internal combustion engine in combination with the motor/generator, and the internal combustion engine in combination with the motor/generator and the electric motor (Figures 8a – 8d show the load shaft driven by the engine, the electric motor, and the generator and combinations thereof); and a power supply (22), coupled to the electric motor and the motor/generator, wherein the load shaft (16), and the clutch (51), and the engine output shaft (41) are co-axially aligned (Shown in Figure 3 of Severinsky). Severinsky does not specify the clutch to be a one-way overrunning clutch, but does recite the usage of overrunning clutches to allow rotation of the road wheels without also rotating the motors (Col 7, Lines 54-58). Pennaza teaches a one-way overrunning clutch (Col 4, Lines 5-18). It would have been obvious to one of ordinary skill in the art at the time of filing of the application to specify the clutch of Severinsky to be a one-way overrunning clutch as taught by Pennaza in order to transmit torque from an electric machine in a single direction (Col 7, Lines 54-58). In regards to claim 22: Severinsky teaches the internal combustion engine both drives the load shaft and causes the motor/generator to recharge the power supply (Col 19, Lines 22-25 of Severinsky). In regards to claim 23: Severinsky teaches the internal combustion engine (40) is started by energy from the power supply delivered to the motor/generator (21) (Col 19, Lines 21-25 and Col 20, Lines 55-57). In regards to claim 29: Severinsky teaches the power supply includes an electronic control unit configured to switch the motor/generator’s mode of operation to a mode of operation selected from the group consisting of motor operation, generator operation, and combinations thereof (Figures 8a shows motor operation). Claims 26-28 are rejected under 35 U.S.C. 103 as being unpatentable over Severinsky in view of Pennaza as applied to claim 21 above, and further in view of Liverieratos et al (US 2018/0194484 hereinafter “Livieratos”). In regards to claim 26: Severinsky does not teach the hybrid drive further comprising a thruster coupled to the load shaft. Livieratos teaches an aircraft having a hybrid drive according to claim 21, further comprising a thruster (212) coupled to a load shaft. It would have been obvious to one of ordinary skill in the art at the time of filing of the application to modify the hybrid drive of Severinsky to have a thruster coupled to the load shaft as taught by Livieratos in order to provide thrust in a desired direction, utilizing the rotation of the shaft to rotate the thruster and providing lift. In regards to claim 27: Severinsky does not teach a method of achieving a quiet mode of operation of a UAV using the hybrid drive of claim 21, the method comprising, in the following order: (1) turning off the internal combustion engine when the quiet mode of operation is required and driving the load shaft solely with the electric motor; and (2) restarting the internal combustion engine when the quiet mode of operation is no longer required, using the motor/generator to restart the internal combustion engine. Livieratos teaches a method of achieving a quiet mode of operation of a UAV using a hybrid drive, the method comprising, in the following order: (1) turning off the internal combustion engine when the quiet mode of operation is required and driving the load shaft solely with the electric motor; and (2) restarting the internal combustion engine when the quiet mode of operation is no longer required, using the motor/generator to restart the internal combustion engine (Paragraphs [0069] - [0071]). It would have been obvious to one of ordinary skill in the art at the time of filing of the application to have the hybrid drive of Severinsky to have the method recited above as taught by Livieratos in order to operate a UAV with a reduced noise signature, and to use the utilize the engine when the requirements for noise levels are not required (Paragraphs [0069] - [0071] of Livieratos). In regards to claim 28: Severinsky does not teach a method of achieving a dash speed operation of an UAV using the hybrid drive of claim 21, the method including driving the load shaft with a combination of the motor/generator, the electric motor, and the internal combustion engine. Livieratos teaches a method of achieving a dash speed operation of an UAV using a hybrid drive, the method including driving the load shaft with a combination of the motor/generator, the electric motor, and the internal combustion engine (Paragraph [0069] recites the operation of the UAV using both the motor/generator and engine). It would have been obvious to one of ordinary skill in the art at the time of filing of the application to have the hybrid drive of Severinsky to have the method recited above as taught by Livieratos in order to operate the UAV at an optimal speed selected by a system designer (Paragraphs [0069] – [0070] of Liveriatos). Allowable Subject Matter Claims 1, 3, 4, 8, 9, 11, 13, 20, 30 and 31 are allowed. The following is an examiner’s statement of reasons for allowance: The prior art does not teach nor render obvious a fuel vaporizer having a fuel inlet, an air inlet, an air/fuel outlet, and a heater that rapidly vaporizes the fuel, wherein the air inlet is disposed downstream of the fuel inlet at a location wherein the fuel has been rapidly vaporized by the heater so that air flows from the air inlet in a direction tangential to flow of the vaporized fuel as recited in independent claims 1 and 30, and wherein claims 3, 4, 8, 9, 11, 13, and 20 depend from claim 1, and wherein claim 31 depends on claim 30. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Claims 24 and 25 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Wherein claim 24 introduces the fuel vaporizer recited in allowable independent claim 1 as stated above, into independent claim 21, and wherein claim 25 depends upon claim 24. Response to Arguments Applicant’s arguments with respect to claim 21 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAMES JAY KIM whose telephone number is (571)270-7610. The examiner can normally be reached M-F 9-5 EST. 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, Logan Kraft can be reached at (571) 270-5065. 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. /JAMES J KIM/Examiner, Art Unit 3747 /HUNG Q NGUYEN/Primary Examiner, Art Unit 3747
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Prosecution Timeline

Jan 30, 2023
Application Filed
Feb 27, 2025
Non-Final Rejection — §103
Jul 07, 2025
Response Filed
Oct 14, 2025
Examiner Interview (Telephonic)
Oct 31, 2025
Final Rejection — §103
Apr 06, 2026
Response after Non-Final Action

Precedent Cases

Applications granted by this same examiner with similar technology

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2y 5m to grant Granted Mar 24, 2026
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Patent 12565870
VALVE ARRIVAL TIME DETECTION IN FUEL SYSTEM HAVING DUAL SOLENOID OPERATED VALVES
2y 5m to grant Granted Mar 03, 2026
Patent 12560129
TRANSPORT VEHICLE WITH HEAT ENGINE AND METHOD FOR CHARACTERIZING ACOUSTIC EMISSIONS OF SAID VEHICLE
2y 5m to grant Granted Feb 24, 2026
Patent 12546246
VALVE BODY, FLOW PATH SWITCHING VALVE, AND HEAT MEDIUM SYSTEM FOR AUTOMOBILE
2y 5m to grant Granted Feb 10, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
70%
Grant Probability
98%
With Interview (+27.3%)
2y 5m
Median Time to Grant
Moderate
PTA Risk
Based on 665 resolved cases by this examiner. Grant probability derived from career allow rate.

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