Prosecution Insights
Last updated: April 19, 2026
Application No. 18/541,190

MOTOR STRUCTURE AND SPLIT CORE STACKING METHOD

Non-Final OA §102§103
Filed
Dec 15, 2023
Examiner
VAZIRI, MASOUD
Art Unit
2834
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Hyundai Mobis Co., Ltd.
OA Round
1 (Non-Final)
70%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
80%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
94 granted / 135 resolved
+1.6% vs TC avg
Moderate +10% lift
Without
With
+10.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
27 currently pending
Career history
162
Total Applications
across all art units

Statute-Specific Performance

§101
2.1%
-37.9% vs TC avg
§103
55.3%
+15.3% vs TC avg
§102
26.2%
-13.8% vs TC avg
§112
14.9%
-25.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 135 resolved cases

Office Action

§102 §103
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 . Claims 1-20 are pending of which claims 12-20 are withdrawn. Election/Restrictions Applicant's election Group I (claims 1-11) in the reply filed on 12/31/2025 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)). Claim Objections Claim 1 objected to because of the following informalities: “a arc-shaped yoke portion” should be replaced by “an arc-shaped yoke portion.” Appropriate correction is required. 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 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. Claims 1, 2 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Yamada, Y. (US 20200313473 A1). PNG media_image1.png 462 639 media_image1.png Greyscale Regarding claim 1, Yamada discloses a motor structure comprising: a cylinder-shaped motor housing (para [0024]: “The first stator 2 includes a plurality of split cores (21, 22, . . . , 26) disposed in an annular shape facing radially the rotor 1,”) having a hollow (1, fig. 1); a stator core accommodated inside the motor housing and including a plurality of stacked split cores (see abstract: “The first and the second stator are formed of a plurality of split cores being split along a plurality of split surfaces.”, and para [0025]: “The split cores are preferably manufactured by stacking a plurality of electromagnetic steel plates. Here, when the plurality of split cores has the same shape, each split core can be manufactured by stacking electromagnetic steel plates having a single shape.”) including: a first layer (first layer, annotated fig. 1) including first split cores; and a second layer (first layer, annotated fig. 1) including second split cores, the second layer is stacked on the first layer (see fig. 1), wherein PNG media_image2.png 263 390 media_image2.png Greyscale a boundary between the first split cores and a boundary between the second split cores do not match (see abstract: “A position of each of the split surfaces of the second stator is displaced from a position of the corresponding one of the split surfaces of the first stator in the circumferential direction by an angle α (α=(2π/N)/2+n×(2π/N), where N is a least common multiple of the number of magnetic poles of the rotor and the number of split cores, and n is an integer).”; see also fig. 10), and each of the first and second split cores have an arc-shape and include (see figs. 1,2 and 7-11): [[a]] an arc-shaped yoke portion (yoke, annotated fig. 1); and a plurality of teeth (teeth, annotated fig. 1) portions protruding from the yoke portion; and a coil wound around the plurality of teeth portions (para [0007]: “a first stator provided with a plurality of teeth for winding a coil on its inner circumferential side”). Regarding claim 2, Yamada discloses the motor structure of claim 1, wherein the first split cores and the second split cores are the same (see abstract, one is rotated with respect to the other one), and when an intersection angle between the first layer and the second layer is θ (see angle α in annotated fig. 1), a number of slots formed by combining the teeth is x, and a number of split cores constituting the first layer or the second layer is y, θ satisfies the following two equations: θ = (360/x)n (basic math- see the angle alpha in fig. 2 that corresponds to rotation by one slot for n=1), θ # (360/y)n (implied because x is not equal to y; see fig. 2; y=2), and n is a natural number (n=1). Regarding claim 5, Yamada discloses the motor structure of claim 1, wherein the first split cores and the second split cores are identical (see figs. 1 and 10). 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. 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. Claim(s) 3-4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada, Y. (US 20200313473 A1) as evidenced by Akita, H. (US 20090134739 A1). PNG media_image3.png 283 382 media_image3.png Greyscale Regarding claim 3, Yamada discloses the motor structure of claim 1, but does not disclose: wherein the plurality of stacked split core further includes: a third layer including third split cores, the third layer is stacked on the second layer; and a fourth layer including fourth split cores, the fourth layer is stacked on the third layer, and when viewed from above, the boundary between the first split cores and a boundary between the third split cores match, and the boundary between the second split cores and a boundary between the fourth split cores match. However, the added extra limitations amount simply to duplicating of parts- in the instant case- adding a copy of layer 1 and 2 on top of layer 2. Such modifications are within the skills of a person having ordinary skills in the art, as evidenced by Akita in fig. 9, and per MPEP 2144.04 (VI)(B) are not considered inventive. It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to modify the motor structure of claim 1 in such a way that: the plurality of stacked split core further includes: a third layer including third split cores, the third layer is stacked on the second layer; and a fourth layer including fourth split cores, the fourth layer is stacked on the third layer, and when viewed from above, the boundary between the first split cores and a boundary between the third split cores match, and the boundary between the second split cores and a boundary between the fourth split cores match. Regarding claim 4, Yamada discloses the motor structure of claim 1, but does not disclose: wherein the first layer and the second layer are repeatedly stacked. As discussed regarding claim 4, repeatedly stacking the layers amount to duplicating of parts and is within the skills of a person having ordinary skills in the art. Increasing layers result in longer stator core and a longer electric machine can generate a larger torque. To have a motor structure with a larger torque, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to modify the motor structure of claim 1 in such a way that: the first layer and the second layer are repeatedly stacked. Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada, Y. (US 20200313473 A1) in view of Takizawa, et al. (US 20190140500 A1). PNG media_image4.png 301 589 media_image4.png Greyscale Regarding claim 6, Yamada discloses the motor structure of claim 1, but does not disclose wherein the first split cores and the second split cores have different lengths. Takizawa teaches a first and second split cores in, see figs. 6 and 7, wherein the two split cores have different lengths. Takizawa states that using split cores results in increasing motor torque without increasing the axial length of the motor (see para [0005]: “being capable of increasing a main magnetic flux contributing to torque without increase in axial length of the entirety of the motor.”) It is also noted that by combining split cores of different lengths, the mechanical strength of the stator core is increased. For increasing torque of the motor and mechanical strength of the stator, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to modify the motor structure of claim 1 in such a way that: the first split cores and the second split cores have different lengths. Claim(s) 7-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada, Y. (US 20200313473 A1) in view of Yokoyama, H. (CN 110492626 A). Regarding claims 7 and 8, Yamada discloses the motor structure of claim 1, but does not disclose further comprising a flow path portion at the boundary between the split cores among the plurality of stacked split cores, wherein the flow path portion penetrates from one end of the yoke portion to the other end of the yoke portion in a radial direction of the yoke portion. Yokoyama teaches creating a flow path (see path in annotated fig. 3, below) in the yoke of a stator core wherein the flow path portion penetrates from one end of the yoke portion to the other end of the yoke portion in a radial direction of the yoke portion, and wherein the flow path is used for cooling the stator (“225 cooling medium supply part by gap”). PNG media_image5.png 284 486 media_image5.png Greyscale For cooling the motor structure, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to modify the motor structure of claim 1 in such a way that the structure further comprising a flow path portion at the boundary between the split cores among the plurality of stacked split cores, wherein the flow path portion penetrates from one end of the yoke portion to the other end of the yoke portion in a radial direction of the yoke portion. Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yamada, Y. (US 20200313473 A1) in view of Yokoyama, H. (CN 110492626 A), and further in view of Sugiura, et al. (WO 2023248466 A1). Regarding claim 11, Yamada as modified by Yokoyama in claim 7 discloses the motor structure of claim 7, but does wherein the yoke portion has a through hole penetrating the yoke portion in the axial direction of the plurality of stacked split cores. PNG media_image6.png 410 571 media_image6.png Greyscale Sugiura teaches a similar motor structure that includes a plurality of stacked split cores (9, fig. 2) wherein for cooling the stator, the yoke has a through hole penetrating the yoke portion (hole, annotated fig. 2) in the axial direction of the plurality of stacked split cores (“A recess 17 is formed on the outer periphery of the yoke 11. The recess 17 forms a coolant flow path with the shell 30.”). For further cooling of the motor structure via axial cooling channels, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to further modify the motor structure of claim 7 in such a way that the yoke portion has a through hole penetrating the yoke portion in the axial direction of the plurality of stacked split cores. Allowable Subject Matter Claims 9-10 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. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to MASOUD VAZIRI whose telephone number is (571)272-2340. The examiner can normally be reached M-F, 8am-5pm 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, the examiner’s supervisor, SEYE IWARERE can be reached on (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 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. /MASOUD VAZIRI/Examiner, Art Unit 2834 /OLUSEYE IWARERE/Supervisory Patent Examiner, Art Unit 2834
Read full office action

Prosecution Timeline

Dec 15, 2023
Application Filed
Jan 15, 2026
Non-Final Rejection — §102, §103 (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
70%
Grant Probability
80%
With Interview (+10.3%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 135 resolved cases by this examiner. Grant probability derived from career allow rate.

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