WIRE-WOUND INDUCTOR USING MAGNETIC CORES WITH THREE AIR GAPS

Application No. 18/296,639

• Filed: Apr 06, 2023
• Priority: Jan 19, 2023 — TW 112102622
• Examiner: WHITTINGTON, KENNETH
• Art Unit: 3992
• Tech Center: 3900
• Assignee: Acme Electronics Corporation
• OA Round: 2 (Non-Final)

Office Action

FINAL OFFICE ACTION
This final Office action addresses U.S. Application Serial No. 18/296,639, entitled WIRE-WOUND INDUCTOR USING MAGNETIC CORES WITH THREE AIR GAPS.
Claims 1-7 are pending.
Claims 1-7 are rejected.

I. STATUS OF CLAIMS
Applicant filed an amendment on April 27, 2026 (hereinafter the “Apr 2026 Amendment”) in response to the non-final Office action mailed January 28, 2026. In the Apr 2026 Amendment, claims 8-10 were cancelled, claim 1 was amended, and claims 2-7 were unchanged. Therefore, claims 1-7 are pending and examined in this application.

II. PRIORITY
Examiner recognizes the Applicant’s claim of foreign priority to Taiwan Patent Application No. TW112102622, filed January 19, 2023.

III. CLAIM INTERPRETATION
After careful review of the original specification, the prosecution history, and unless expressly noted otherwise by the Examiner, the Examiner is unable to locate any lexicographic definitions (either express or implied) with the required clarity, deliberateness, and precision with regard to pending and examined claims. Because the Examiner is unable to locate any lexicographic definitions with the required clarity, deliberateness, and precision, the Examiner concludes that Applicant is not his own lexicographer for the pending and examined claims. See MPEP §2111.01(IV).
The Examiner further finds that because the pending and examined claims herein recite neither “step for” nor “means for” nor any substitute therefore, the examined claims fail Prong (A) as set forth in MPEP §2181(I). Because all examined claims fail Prong (A) as set forth in MPEP §2181(I), the Examiner concludes that all examined claims do not invoke 35 U.S.C. §112(f). See also Ex parte Miyazaki, 89 USPQ2d 1207, 1215-16 (B.P.A.I. 2008)(precedential)(where the Board did not invoke 35 U.S.C. § 112(f) because “means for” was not recited and because applicant still possessed an opportunity to amend the claims).
Because of the Examiner’s findings above that Applicant is not his own lexicographer and the pending and examined claims do not invoke 35 U.S.C. §112(f) the pending and examined claims will be given the broadest reasonable interpretation consistent with the specification since patentee has an opportunity to amend claims. See MPEP §2111, MPEP §2111.01 and In re Yamamoto et al., 222 USPQ 934 (Fed. Cir. 1984). Under a broadest reasonable interpretation, words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. See MPEP §2111.01(I). It is further noted it is improper to import claim limitations from the specification, i.e., a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment. See MPEP §2111.01(II).

IV. CLAIM REJECTIONS – 35 U.S.C. §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.

IV.A. Obviousness Rejection Applying Yamaguchi and Liang
Claims 1-3 and 4-7 are rejected under 35 U.S.C. §103 as being unpatentable over U.S. Patent Application Publication No. 2018/0233281 to Takayuki Yamaguchi et al. (hereinafter “Yamaguchi”) in view of Japanese Publication No. JP2018074146 to Liang Zhiyong et al. (hereinafter “Liang”).
Regarding claim 1, Yamaguchi teaches:
1. A wire-wound inductor using magnetic cores with three air gaps, comprising:

See Yamaguchi FIGS. 3A, 3B and 4, reprinted below:

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Yamaguchi FIG. 3A/3B Yamaguchi FIG. 4
a magnetic housing, two magnetic posts independently provided at central portions of two opposing inner sides of the magnetic housing respectively and adhesively bonded to the magnetic housing,

See Yamaguchi FIGS. 3A, 3B and 4 above, magnetic housing comprising independent core portions 15A-15D. Further see Yamaguchi ¶0064 which states “the respective members are practically adhered to each other with an adhesive, when necessary, in a state of being positioned to each other. Moreover, as described later, a relative position between the respective members is fixed by filling an insulating adhesive between the respective members.” Nevertheless, to the extent not explicitly taught, Liang in ¶0042 teaches that insulating gaps members between can be formed of an adhesive. It would have been obvious to use either an adhesive to bond the post cores of Yamaguchi to the housing using adhesives between the insulating member or simply use insulating adhesive members as taught by Liang. One having ordinary skill in the art would do so to maintain the components together without “any further need to bond the post cores together. See Liang id.
an isolation unit provided in the magnetic housing and enclosing the magnetic posts, and

See FIGS. 3A, 3B and 4 above, isolation unit 40A.
a coil provided on the isolation unit,
See FIGS. 3A, 3B and 4 above, coil 20.
wherein a non-magnetic insulating member is provided between one of the two opposing inner sides of the magnetic housing and a corresponding said magnetic post to form a first air gap, another non-magnetic insulating member is provided between the other of the two opposing inner sides of the magnetic housing and a corresponding said magnetic post to form a second air gap, and a third air gap defined by an air space is formed between the two magnetic posts, and the third air gap is free of any non-magnetic insulating member.

See FIGS. 3A, 3B and 4 above, insulating members 16A-16C provided between magnetic housing and posts 15A-15D forming three air gaps.
However, Yamaguchi does not teach the third air gap free of an insulating member. Nevertheless, Liang teaches a similar core structure for an inductor (See Liang FIG. 6, reprinted below) having a similar core structure comprising post cores 42a

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Liang FIG. 6
and 42b connected to housing members 54a with three air gaps with insulating members 44a, 44b and 44c provided between the cores. Furthermore, Liang teaches at ¶0044 that “an air gap may be provided instead of the gap member.” It would thus have been obvious to make one or more of the air gaps of Yamaguchi to be either a gap member or an air gap as taught by Liang. One having ordinary skill in the art would do so because such using an air-air gap instead of a gap member for the third air gap (and/or and the other gaps) in Yamaguchi is explicitly taught in Liang. Furthermore, Examiners find such a modification is predictable since using an air-air gap and an insulating gap member are equivalent alternatives for providing insulation between the gapped post cores. See MPEP §2143(C).
Regarding claim 2, Yamaguchi and Liang teach the inductor of claim 1 and further wherein:
2. The wire-wound inductor of claim 1, wherein the two opposing inner sides of the magnetic housing are flat surfaces.

Note combination of Yamaguchi and Liang proposed above for claim 1. Further see Yamaguchi FIGS. 3A, 3B and 4 above, note inner surfaces of the magnetic housing surfaces 15A and 15D have flat surfaces where they abut the insulating members 16A and 16C.
Regarding claim 3, Yamaguchi and Liang teach the inductor of claim 1 and further wherein:
3. The wire-wound inductor of claim 1, wherein the magnetic housing and the magnetic posts form an assembly of a PM configuration, a PQ configuration, or an RM configuration.

Note combination of Yamaguchi and Liang proposed above for claim 1. Further see FIGS. 3A, 3B and 4 above, and FIG. 2, reprinted below, note streamline pot-core shape.

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Yamaguchi FIG. 2
Regarding claim 5, Yamaguchi and Liang teach the inductor of claim 1 and further wherein:
5. The wire-wound inductor of claim 1, wherein magnetic posts are made of a manganese-zinc ferrite, a nickel-zinc ferrite, a magnesium-zinc ferrite, an iron-silicon alloy, an iron-nickel alloy, an iron-silicon-aluminum alloy, a nickel-iron-molybdenum alloy, an amorphous alloy, or a nanocrystalline alloy.

Note combination of Yamaguchi and Liang proposed above for claim 1. Further see Yamaguchi ¶0071 wherein the material for the core 15A-15D are made from “pure iron or an iron alloy containing at least one kind of additive element selected from elements of Ni, Cu, Cr, Mo, Mn, C, Si, Al, P, B, N and Co.”
Regarding claim 6, Yamaguchi and Liang teach the inductor of claim 1 and further wherein:
6. The wire-wound inductor of claim 1, wherein the non-magnetic insulating members are made of an insulating material selected from the group consisting of an FR-4 material and a polyester film.

Note combination of Yamaguchi and Liang proposed above for claim 1. Yamaguchi further discloses the non-magnetic insulating members to form the first and second air gaps, but not the material therefore. Nevertheless, Liang in FIG. 6 above teaches a gapped core 40A having three air gaps with insulating members 44a-44c in the air gaps. Furthermore, Liang teaches the insulating members are made from synthetic resins, i.e., polyester, and as discussed above, adhesive. It would have been obvious at the time the invention was made to make the insulating members of Yamaguchi out of polyester as taught by Liang. One having ordinary skill in the art would do so because making such insulating member out of polyester is well known in the art as explicitly taught by Liang as provided above.
Regarding claim 7, Yamaguchi and Liang teach the inductor of claim 1 and further wherein:
7. The wire-wound inductor of claim 1, wherein the first air gap and the second air gap are defined by a same distance.

Note combination of Yamaguchi and Liang proposed above for claim 1. Further see FIGS. 3A, 3B and 4 above, note spacings for the gaps at non-magnetic layers 16A-16C.

IV.B. Obviousness Rejection Applying Yamaguchi, Liang and Sullivan
Claim 4 is rejected under 35 U.S.C. §103 as being unpatentable over Yamaguchi and Liang as applied to claim 1 above, and further in view of U.S. Patent Application Publication No. 2022/0208429 to Charles Sullivan et al. (hereinafter “Sullivan”). Regarding this claim, Yamaguchi teaches the features of claim 1 as evidenced above and Yamaguchi at ¶0071 wherein the material for the core members 15A-15D is made from “pure iron or an iron alloy...” However, Yamaguchi does not explicitly disclose the ferrite alloys required in claim 4. Nevertheless, Sullivan teaches magnetic core structures for inductors wherein “[t]he magnetic core materials may include, but are not limited to, one or more of iron, various steel alloys, cobalt, ferrites including manganese-zinc (MnZn) and/or nickel-zinc (NiZn) ferrites, nano-granular materials such as Co—Zr—O, and powdered core materials made of powders of ferromagnetic materials mixed with organic or inorganic binders.” See Sullivan ¶0063. It would have been obvious at the time the invention was filed to using the zinc alloys for the core members 15A-15D of Yamaguchi as taught by Sullivan. One having ordinary skill in the art would do so because as such materials, including ferrites including manganese-zinc (MnZn) and/or nickel-zinc (NiZn) ferrites are well known for use in magnetic pot type core structures as taught by Sullivan. Thus, this combination teaches the magnetic housing is made of a ferrite selected from the group consisting of a manganese-zinc ferrite, a nickel-zinc ferrite, and a magnesium-zinc ferrite, and the magnetic posts are made of a ferrite or a magnetic alloy (which would include those listed).

IV.C. Obviousness Rejection Applying Huang and Liang
Claims 1-3 and 4-7 are rejected under 35 U.S.C. §103 as being unpatentable over Taiwan Patent Publication No. TWM494994 to Jia-Ping Huang et al. (hereinafter “Huang”) in view of Liang.
Regarding claim 1, Huang teaches:
1. A wire-wound inductor using magnetic cores with three air gaps, comprising:

See Huang FIGS. 2 and 4, reprinted below:

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Huang FIG. 2 Huang FIG. 4
a magnetic housing, two magnetic posts independently provided at central portions of two opposing inner sides of the magnetic housing respectively and adhesively bonded to the magnetic housing,

See Huang FIGS. 2 and 4 above, magnetic housing comprising core portions 2 and 3. However, Huang does not explicitly teach adhesive bonding. Nevertheless, Liang in ¶0042 teaches that insulating gaps members between can be formed of an adhesive material. It would have been obvious to use either an adhesive to bond the post cores of Yamaguchi to the housing using adhesives between the insulating member or simply use insulating adhesive members as taught by Liang. One having ordinary skill in the art would do so to maintain the components together without “any further need to bond the post cores together. See Liang id.
an isolation unit provided in the magnetic housing and enclosing the magnetic posts, and

See Huang FIGS. 2 and 4 above, isolation unit 11.
a coil provided on the isolation unit,
See Huang FIGS. 2 and 4 above, coil 12.
wherein a non-magnetic insulating member is provided between one of the two opposing inner sides of the magnetic housing and a corresponding said magnetic post to form a first air gap, another non-magnetic insulating member is provided between the other of the two opposing inner sides of the magnetic housing and a corresponding said magnetic post to form a second air gap, and a third air gap defined by an air space is formed between the two magnetic posts, and the third air gap is free of any non-magnetic insulating member.

See Huang FIGS. 2 and 4 above, insulating members 4 provided between magnetic housing and posts 2 and 3 forming three air gaps. However, Huang does not teach the third air gap free of an insulating member. Nevertheless, Liang teaches a similar core structure for an inductor (See Liang FIG. 6, reprinted above) having a similar core structure comprising post cores 42a and 42b connected to housing members 54a with three air gaps with insulating members 44a, 44b and 44c provided between the cores. Furthermore, Liang teaches at ¶0044 that “an air gap may be provided instead of the gap member.” It would thus have been obvious to make one or more of the air gaps of Huang to be either a gap member or an air gap as taught by Liang. One having ordinary skill in the art would do so because such using an air-air gap instead of a gap member for the third air gap (and/or and the other gaps) in Huang is explicitly taught in Liang. Furthermore, Examiners find such a modification is predictable since using an air-air gap and an insulating gap member are equivalent alternatives for providing insulation between the gapped post cores. See MPEP §2143(C).
Regarding claim 2, Huang and Liang teach the inductor of claim 1 and further wherein:
2. The wire-wound inductor of claim 1, wherein the two opposing inner sides of the magnetic housing are flat surfaces.

Note combination of Huang and Liang as proposed above for claim 1. Thus, see Huang FIGS. 2 and 4 above, note inner surfaces of the magnetic housing surfaces 2 have flat surfaces where they abut the insulating members 4.
Regarding claim 3, Huang and Liang teach the inductor of claim 1 and further wherein:
3. The wire-wound inductor of claim 1, wherein the magnetic housing and the magnetic posts form an assembly of a PM configuration, a PQ configuration, or an RM configuration.

Note combination of Huang and Liang as proposed above for claim 1. Further see Huang FIGS. 2 and 4 above, note core shape.
Regarding claim 7, Huang and Liang teach the inductor of claim 1 and further wherein:
7. The wire-wound inductor of claim 1, wherein the first air gap and the second air gap are defined by a same distance.

Note combination of Huang and Liang as proposed above for claim 1. Further see Huang FIGS. 2 and 4 above, note spacings for the gaps at non-magnetic layers 4.

V. EXAMINER’S RESPONSES TO APPLICANT’S ARGUMENTS
Examiner has fully considered the Applicant’s arguments provided in the Apr 2026 Amendment. However, Examiner find them generally moot in view of the new grounds of rejection provided in this Office action.

VI. CONCLUSION
Claims 1-7 are pending.
Claims 1-7 are rejected.
Applicant's substantial amendments to the claims in the Apr 2026 Amendment necessitated the new/amended grounds 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 C.F.R. §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 C.F.R. §1.17(a)) pursuant to 37 C.F.R. §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 KENNETH WHITTINGTON whose telephone number is [phone]. The examiner can normally be reached 8:30am - 5:00pm, Monday - Friday.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Andrew Fischer can be reached at [phone]. The fax phone number for the organization where this application or proceeding is assigned is [phone].
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/KENNETH WHITTINGTON/Primary Examiner, Art Unit 3992

Prosecution Timeline

• Apr 06, 2023: Application Filed
• Jan 28, 2026: Non-Final Rejection mailed — §103
• Apr 27, 2026: Response Filed
• May 06, 2026: Final Rejection mailed — §103 (current)