Prosecution Insights
Last updated: April 19, 2026
Application No. 18/593,424

HIGH-POWER CORE SYSTEM

Non-Final OA §103
Filed
Mar 01, 2024
Examiner
ANDREWS, MICHAEL
Art Unit
2834
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Mainspring Energy Inc.
OA Round
1 (Non-Final)
64%
Grant Probability
Moderate
1-2
OA Rounds
3y 0m
To Grant
89%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
778 granted / 1218 resolved
-4.1% vs TC avg
Strong +25% interview lift
Without
With
+24.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
43 currently pending
Career history
1261
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
49.8%
+9.8% vs TC avg
§102
27.1%
-12.9% vs TC avg
§112
20.5%
-19.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1218 resolved cases

Office Action

§103
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This Office Action is responsive to the Applicant's communication filed 15 January 2026. In view of this communication, claims 1-3, 5, 7-8, 11, 13, 15-20, 29, 32, 35, and 69-78 are now pending in the application. Election/Restriction Claim(s) 35 and 69-78 is/are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Further, claim(s) 16-20 is/are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 15 January 2026. Priority Receipt is acknowledged of papers submitted under 35 U.S.C. 119(a)-(d) or (f), 365(a) or (b), or 386(a), which papers have been placed of record in the file. Information Disclosure Statement The information disclosure statement(s) submitted on 21 March 2025 was/were filed before mailing of the first action on the merits. Accordingly, the information disclosure statement(s) is/are being considered by the examiner. Disclosure The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed. The following title is suggested: Linear Generator with Multiple Inboard and Outboard Linear Electric Machines. The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification. 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 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. 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, 29, and 32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Svrcek et al. (US 2020/0195093 A1), hereinafter referred to as “Svrcek”, in view of Robertson (US 3,170,406), hereinafter referred to as “Robertson”. Regarding claim 1, Svrcek discloses a linear generator [200] (fig. 2; ¶ 0089) comprising: a plurality of linear electromagnetic machines (LEMs) [252,256] coaxially arranged in sequence along a longitudinal axis (fig. 2; ¶ 0094), wherein: PNG media_image1.png 784 358 media_image1.png Greyscale each LEM [252,256] comprises: a respective translator [220,210], and a respective stator [228,218] (fig. 2; ¶ 0089-0090); the plurality of LEMs [252,256] comprises a pair of outboard LEMs [252,256], each on a respective opposing end of the sequence (fig. 2; ¶ 0094); a pair of gas springs [297-299], each respectively arranged outboard of the pair of outboard LEMs [252,256] in contact with the respective translators [220,210] of the outboard LEMs [252,256] (fig. 2; ¶ 0091); and a reaction section [297] arranged between adjacent LEMs [252,256] of the plurality of LEMs [252,256], wherein the reaction section [297] is in contact with respective translators [220,210] of the respective adjacent LEMs [252,256] (fig. 2; ¶ 0091-0092). Svrcek does not disclose a plurality of the reaction sections [297] (i.e. only two translators and a single reaction section are disclosed). Robertson discloses a linear engine comprising a plurality of inboard translators [36] and a plurality of outboard translators [37], a pair of gas springs [23], and a plurality of reaction sections [rs] arranged between adjacent translators [36,37] (fig. 4; col. 4, lines 25-39), wherein each of the plurality of reaction sections [rs] is in contact with a respective translator [36,37] (fig. 4; col. 4, lines 40-51; col. 5, lines 12-27). PNG media_image2.png 232 633 media_image2.png Greyscale It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the LEMs of Svrcek having both inboard and outboard translators with a plurality of reaction sections between each translator as taught by Robertson, in order to balance the momentum of the translators thereby eliminating vibration of the device (col. 5, lines 12-27 of Robertson). Regarding claim 2, Svrcek, in view of Robertson, discloses the linear generator [200] of claim 1, as stated above, wherein each translator [220,210] comprises a respective piston [221,211] (fig. 2; ¶ 0091); and each of the plurality of reaction sections [297] is in contact with a respective piston [221,211] of the translators [220,210] (fig. 2; ¶ 0091). Regarding claim 3, Svrcek, in view of Robertson, discloses the linear generator [200] of claim 1, as stated above. Svrcek does not disclose that the plurality of LEMs [252,256] comprises at least four LEMs [252,256]. However, the combination with Robertson discloses duplicating the translators and reaction sections of the LEMs. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use multiple stators as well, for the purpose of increasing power output of the linear generator, since it has been held that the mere duplication of the essential working parts of a device involves only routine skill in the art. St. Regis Paper Co. v. Bemis Co., 193 PSQ 8. Regarding claim 29, Svrcek, in view of Robertson, discloses the linear generator [200] of claim 1, as stated above, wherein each gas spring [299,298] of the pair of gas springs [297-299] comprises: a gas spring housing volume [299,298] defined at least in part by an end-cap [224,214] of the respective translator [220,210] of the respective outboard LEM [252,256] of the pair of outboard LEMs [252,256] (fig. 2; ¶ 0091); and at least one port [241,231] within the gas spring housing volume [299,298] that communicates pressure from the gas spring [299,298] to at least one gas bearings [226-227,216-217] along which respective translators [220,210] of the plurality of LEMs [252,256] translate (fig. 2; ¶ 0091-0093). Regarding claim 32, Svrcek, in view of Robertson, discloses the linear generator [200] of claim 1, as stated above, wherein at least one gas spring [299,298] of the pair of gas springs [297-299] comprises a reaction section [297] (fig. 2; ¶ 0091-0092). Allowable Subject Matter Claim(s) 5, 7-8, 11, 13, and 15 is/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. The following is a statement of reasons for the indication of allowable subject matter: Regarding claim 5, and all claims dependent thereon, the prior art does not disclose, inter alia, the linear generator of claim 1, wherein: the plurality of LEMs consists of four LEMs; and an inboard pair of LEMs of the plurality of LEMs are sized to generate more power than the outboard pair LEMs. While the prior art discloses outboard linear electromagnetic machines and renders obvious providing additional reaction sections and their associated linear electromagnetic machines, e.g. the grounds of rejection above, it does not disclose any variation in the sizes or outputs of the inboard and outboard linear electromagnetic machines. Thus, the limitations recited above, and best shown in figure 11 of the application, are neither anticipated nor rendered obvious by the prior art. 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.” Citation of Relevant Prior Art The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure. Prior art: Gadda et al. (US 2016/0208686 A1) discloses a linear electrical generator comprising a plurality of translators, a plurality of stators, gas springs on outboard ends of the translators, and a reaction section between the translators. Roelle et al. (US 2012/0204836 A1) discloses a linear free piston combustion engine comprising four pistons with a plurality of reaction sections therebetween. Kaneko et al. (US 2005/0109295 A1) discloses a linear electrical generator comprising a plurality of translators, a plurality of stators, springs on outboard ends of the translators, and a reaction section between the translators. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael Andrews whose telephone number is (571)270-7554. The examiner can normally be reached on Monday-Thursday, 8:30am-3:00pm. 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, Oluseye Iwarere can be reached at 571-270-5112. 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 the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Michael Andrews/ Primary Examiner, Art Unit 2834
Read full office action

Prosecution Timeline

Mar 01, 2024
Application Filed
Feb 12, 2026
Non-Final Rejection — §103
Mar 11, 2026
Interview Requested
Mar 19, 2026
Applicant Interview (Telephonic)
Mar 19, 2026
Examiner Interview Summary

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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
64%
Grant Probability
89%
With Interview (+24.7%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 1218 resolved cases by this examiner. Grant probability derived from career allow rate.

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