Prosecution Insights
Last updated: April 19, 2026
Application No. 17/918,779

TRANSFORMER AND MANUFACTURING METHOD

Final Rejection §103
Filed
Oct 13, 2022
Examiner
LIAN, MANG TIN BIK
Art Unit
2837
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Hitachi Energy Ltd.
OA Round
2 (Final)
70%
Grant Probability
Favorable
3-4
OA Rounds
2y 10m
To Grant
97%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
921 granted / 1312 resolved
+2.2% vs TC avg
Strong +26% interview lift
Without
With
+26.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
82 currently pending
Career history
1394
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
53.4%
+13.4% vs TC avg
§102
23.5%
-16.5% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1312 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 . Response to Arguments Applicant’s arguments with respect to claims 1-20 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. Drawings The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the “joining the bottom and sides of the fluid-tight insert by oil-tight weld seams” as recited in claim 17 must be shown or the feature(s) canceled from the claim(s). No new matter should be entered. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. 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 1-4, 6-14, 16 and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Bodla et al. (U.S. Pub. No. 2019/0350111 A1) in view of Jones (U.S. PG. Pub. No. 2012/0193138 A1). With respect to claim 1, Bodla et al., hereinafter referred to as “Bodla,” teaches a transformer 100 (FIG. 1), comprising: a tank 102 having tank walls 106 comprise composite panels 106-112, and wherein the tank has a fluid-tight insert 114 configured to prevent an insulation fluid from contacting the composite panels, wherein the composite panels abut on an outer surface of the fluid-tight insert (paras. [0048], [0049] and [0051]). Bodla does not expressly teach the tank walls comprise composite panels having a layered structure comprising first and second skin layers, with a core positioned between the first and second skin layers. Jones teaches a transformer (FIGs. 1A-2), wherein the tank walls 108 comprise composite panels 120 having a layered structure comprising first and second skin layers 224a and 224b, and with a core 244 positioned between the first and second skin layers (paras. [0017] and [0019]). It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to have the skin layers and the core therebetween as taught by Jones to the transformer of Bodla to improve cooling while simultaneously minimizing weight increase (para. [0003]). With respect to claim 2, Bodla in view of Jones teaches the transformer of claim 1, wherein the fluid-tight insert is oil-tight (Bodla, para. [0051]). With respect to claim 3, Bodla in view of Jones teaches the transformer of claim 1, wherein a bottom (floor) and plural sides 106-112 of the fluid-tight insert are integrally formed or joined to each other by welding (Bodla, para. [0051]). With respect to claim 4, Bodla in view of Jones teaches the transformer of claim 1, wherein the fluid-tight insert is made of metal (para. [0051]). With respect to claim 6, Bodla in view of Jones teaches the transformer of claim 1, wherein an inner surface of the fluid- tight insert is composed of planar faces (Bodla, para. [0049]). With respect to claim 7, Bodla in view of Jones teaches the transformer of claim 6, wherein the inner surface of the fluid- tight insert is free from stiffener structures (Bodla, para. [0051]). With respect to claim 8, Bodla in view of Jones teaches the transformer of claim 1, wherein the composite panels have a higher bending stiffness than the fluid-tight insert (Bodla, para. [0051]). With respect to claim 9, Bodla in view of Jones teaches the transformer of claim 1, wherein the tank walls include a bottom wall (floor) and several side walls 106-112, wherein the bottom wall and each of the several side walls respectively comprises at least one of said composite panels (Bodla, para. [0051]). With respect to claim 10, Bodla in view of Jones teaches the transformer of claim 9, wherein the bottom wall comprises several composite panels and/or each of the several side walls comprises several of said composite panels (Bodla, para. [0051]). With respect to claim 11, Bodla in view of Jones teaches the transformer of claim 1, wherein the transformer comprises bushings (not expressly shown, this type of transformers would have bushings) and wherein the composite panels contain or are made of non-magnetic materials adjacent the bushings (Bodla, para. [0051]). With respect to claim 12, Bodla in view of Jones teaches the transformer of claim 1, wherein the composite panels include a filler in cells of the core (Jones, para. [0019]). With respect to claim 13, Bodla teaches a method of producing a transformer tank 102 (FIG. 1), comprising: forming a fluid-tight insert 114; and affixing composite panels 106-112, on the fluid-tight insert in such a way that the composite panels abut on an outer surface of the fluid-tight insert, wherein the fluid-tight insert is configured to prevent an insulation fluid from contacting the composite panels (paras. [0048], [0049] and [0051]). Bodla does not expressly teach composite panels having a layered structure including first and second skin layers and a core placed between the first and second skin layers. Jones teaches a method of producing a transformer tank 100 (FIGs. 1A-2), comprising: affixing composite panels 120 having a layered structure (structure of layers 224a and 224b) including first and second skin layers 224a and 224b and a core 244 placed between the first and second skin layers (paras. [0017] and [0019]). It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to have the skin layers and the core therebetween as taught by Jones to the method of Bodla to improve cooling while simultaneously minimizing weight increase (para. [0003]). With respect to claim 14, Bodla in view of Jones teaches the method of claim 13, wherein the fluid-tight insert is an integral component having a bottom (floor) and sides 106-112, wherein the method further comprising forming the bottom and sides by bending or by vacuum forming (Bodla, para. [0051]). With respect to claim 16, Bodla in view of Jones teaches the method of claim 13, wherein the core comprises a honeycomb core (Jones, para. [0019]). With respect to claim 18, Bodla in view of Jones teaches the method of claim 13, wherein forming the fluid-tight insert comprises forming the fluid-tight insert from at least one of metal and polymer (Bodla, para. [0051]). With respect to claim 19, Bodla in view of Jones teaches the transformer of claim 1, wherein a bottom (floor) and a plurality of sides 106-112 of the fluid-tight insert are formed by bending or vacuum forming (Bodla, para. [0051]). With respect to claim 20, Bodla in view of Jones teaches the transformer of claim 1, wherein the core comprises a honeycomb core (Jones, para. [0019]). Claims 5 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Bodla in view of Jones, as applied to claim 1 above, and further in view of Yang (U.S. PG. Pub. No. 2011/0043312 A1). With respect to claim 5, Bodla in view of Jones teaches the transformer of claim 1. Bodla in view of Jones does not expressly teach the fluid-tight insert is made of polymer. Yang teaches a transformer 10 (Fig. 1), wherein the fluid-tight insert 12 is made of polymer (Yan, para. [0045]). It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to have the polymer insert as taught by Yang to the transformer of Bodla in view of Jones to reduce weight. With respect to claim 15, Bodla in view of Jones teaches the method of claim 13. Bodla in view of Jones does not expressly teach affixing the composite panels on the fluid-tight insert comprises affixing the composite panels by means of an adhesive. Yang teaches a method of producing a transformer tank 10 (Fig. 1), wherein affixing the composite panels 133 and or (walls 13a, annotated Fig. 1, e.g., “steel” and “insulating plate, para. P0040] and or “(FRP)” para. [0042]) on the fluid-tight insert 12 comprises affixing the composite panels by means of an adhesive (Yang, para. [0053]). It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to have the adhesion as taught by Yang to the method of Bodla in view of Jones to improve mechanical bonding between the insert and the panels. Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Bodla in view of Jones, as applied to claim 13 above, and further in view of Boe et al. (U.S. PG. Pub. No. 2015/0077205 A1). With respect to claim 17, Bodla in view of Jones teaches the method of claim 14. Bodla in view of Jones does not expressly teach joining the bottom and sides of the fluid-tight insert by oil-tight weld seams. Boe et al., hereinafter referred to as “Boe,” teaches a method of producing a transformer tank 15 (FIG. 1) comprising joining the bottom (“bottom plate”) and sides (“side walls”) of the fluid-tight insert by oil-tight weld seams (para. [0058]). It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to have the weld seams as taught by Boe to the method of producing a transformer tank of Bodla in view of Jones to sufficiently protect against foreign objects, such as ingress of sea water. 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 MANGTIN LIAN whose telephone number is (571)270-5729. The examiner can normally be reached Monday-Friday 0800-1700. 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, Shawki S. Ismail can be reached at 571-272-3985. 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. /MANG TIN BIK LIAN/ Primary Examiner, Art Unit 2837
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Prosecution Timeline

Oct 13, 2022
Application Filed
Sep 22, 2025
Non-Final Rejection — §103
Oct 16, 2025
Interview Requested
Nov 17, 2025
Examiner Interview Summary
Nov 17, 2025
Applicant Interview (Telephonic)
Dec 23, 2025
Response Filed
Feb 23, 2026
Final Rejection — §103
Mar 19, 2026
Interview Requested
Apr 15, 2026
Examiner Interview Summary
Apr 15, 2026
Applicant Interview (Telephonic)

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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
97%
With Interview (+26.4%)
2y 10m
Median Time to Grant
Moderate
PTA Risk
Based on 1312 resolved cases by this examiner. Grant probability derived from career allow rate.

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