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, see pages 5-6, filed 03/19/2026, with respect to the 35 USC 112(a) Rejection of claim 20 has been fully considered and are persuasive. The 35 USC 112(a) Rejection of claim 20 has been withdrawn.
Applicant’s arguments, see pages 6-11, filed 03/19/2026, with respect to the 35 USC 103 Rejections of claim 1 and all claims depending from it have been fully considered but are not persuasive.
Firstly, regarding the tooth width range/alleged non-overlap argument, Applicant’s reliance on In re Patel is misplaced. While Applicant argues that the prior art (e.g. Matsuura) discloses tooth widths (1.6mm and 1.75mm) outside the claimed range of 1.0-1.5 mm, the rejection is not based solely on Matsuura. As set forth in the Office Action below, Gu teaches a stator core having a tooth width in the range of 1.2 mm to 1.65 mm, which overlaps with the claimed range of 1.0 mm to 1.5 mm. Specifically, the overlap occurs in the range of 1.2 mm to 1.5 mm. It is well established that overlapping ranges establish a prima facie case of obviousness (see In re Peterson, In re Aller). Accordingly, Applicant’s argument regarding lack of overlap is not applicable to the rejection as maintained.
Secondly, regarding the alleged criticality and unexpected results argument, Applicant’s assertion of criticality and unexpected results is not persuasive. The data presented in Table 2 does not demonstrate that the claimed range is critical. While Applicant shows that efficiency improvements a 1.0 mm (13.8%) and 1.5 mm (12.6%) are higher than at 2.0 mm (9.9%), the data reflects only a gradual change in performance, rather than a sharp or unexpected discontinuity at the claimed boundaries.
A difference of a few percentage points does not, by itself, establish unexpected results, particularly where the trend is consistent with known principles (i.e., smaller tooth widths can reduce magnetic path length and influence efficiency). Such results would have been predictable to a person of ordinary skill in the art.
Additionally, Applicant has not provided evidence that the alleged improvement is commensurate in scope with the claimed range. The data appears limited to select points (1.0 mm, 1.5 ,,, and 2 mm) and does not establish that the entire claimed range of 1.0-1.5 mm exhibits a unique or unexpected property relative to the prior art range (e.g., 1.2-1.65 mm).Notably, the overlapping region (1.2-1.5 mm) is not shown to produce results that are unexpectedly superior to values just outside the claimed range (i.e., near 1.6 mm). Absent such evidence, the alleged criticality is not established.
Lastly, the improvement is presented relative to a different material (1.0% Si steel) rather than isolating tooth width as the sole variable. Therefore, it is unclear whether the observed differences are attributed to tooth width or to other claimed features (e.g., magnetic material properties). As such, the evidence is insufficient to demonstrate that the claimed tooth width range alone yields unexpected results.
Thirdly, regarding the motivation to combine/analogous art argument, Applicant’s argument that Takada is non-analogous art is not persuasive. Although Takada is directed to magnetic materials used in stationary apparatuses (e.g., transformers), it nevertheless relates to soft magnetic materials and their magnetic properties, which are directly relevant to the performance of motor cores such as that of Endo.
A person having ordinary skill in the art would have reasonably consulted references relating to magnetic materials, regardless of the specific end use device, because the underlying electromagnetic principles are the same. The optimization of properties such as iron loss and magnetic flux density is common in both transformers and electric motors. Additionally, the combination does not require bodily incorporation of Takada into Endo, but rather the application of its teachings regarding magnetic material properties to improve motor performance. Such use is consistent with established obviousness principles.
Applicant has not provided sufficient evidence of criticality or unexpected results to overcome the prima facie case. For the reasons above, the 35 USC 103 Rejections of claim 1 and all depending claims will be maintained.
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.
Claims 1, 3, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Endo (US 20170179789 A1) in view of Wu (CN 104328379 A, Takada (US 5993568 A) and Gu (DE 102017002561 A1).
Claim 1
Endo discloses the following limitation(s):
A motor core (11) formed by stacking a plurality of sheet-shaped magnetic materials (electromagnetic steel plates of a rotor and/ stator core; para. 0015) with a tooth width (D) of 0.5 mm or more (approximately 2.2mm for the rotor core, para. 0036) and 12 or more of slots (14) arranged between the teeth (13),
Endo is silent however to the following limitation(s)
The motor core is formed by stacking a plurality of sheet-shaped soft magnetic materials
wherein the soft magnetic material has an iron loss of 220 W/kg or less when excited at a maximum magnetic flux density of 1.0 T and a frequency of 3000 Hz,
and [the soft magnetic material has] and has a magnetic flux density of 1.60 T or more in a magnetic field of 5000 A/m
a tooth width of 1.0 mm or more and 1.5 mm or less
As for limitations I and II, Wu teaches a method of forming a sheet with a soft magnetic material of Silicon Gradient Steel with a 3.5wt% concentration of Steel and a 6.5wt% concentration of Si to produce a product called a JNHF Core (see conclusion for supplemental prior art regarding JNHF core). According to Wu, this method is not limited to manufacturing this product, and the method can be used for manufacturing various electronic applications involving cores used for transformers, motors, and inductors (Wu, para. 0002-0003). This material aligns with that of the “Silicon-gradient steel” listed in row 12 of Table 1 on page 0030 of Applicant’s Specifications (reproduced below).
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Accordingly, Wu’s Silicon gradient Steel will exhibit the same material properties and characteristics under the same conditions and on that basis it will exhibit an iron loss of 220 W/kg or less when excited at a maximum magnetic flux density of 1.0 T and a frequency of 3000 Hz. 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 modified Endo’s motor core to be formed by stacking a plurality of sheet-shaped soft magnetic materials, wherein the soft magnetic material has an iron loss of 220 W/kg or less when excited at 1.0 T and 3000 Hz. Such a modification would be advantageous as the Si content of 6.5wt% compared to the general Si content of 4.5wt% on electrical steel will increase the resistivity of the electrical steel by reducing eddy current loss (Wu, para. 0002).
As fir limitation III, Takada teaches a method of forming a sheet with a soft magnetic material of Silicon Gradient Steel with an average Si concentration of 3.5% wt or more at a magnetic flux density of 2.0T or more as illustrated in Takada’s Fig. 4 (see para. 55).
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This material aligns with that of the “Silicon-gradient steel” listed in rows 5 and or 11 of Table 1 on page 0030 of Applicant’s Specifications (reproduced below).
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Accordingly, Takada’s Silicon gradient Steel will exhibit the same material properties and characteristics under the same conditions and on that basis it will exhibit an iron loss of 220 W/kg or less when excited at a maximum magnetic flux density of 1.0 T or more and a frequency of 3000 Hz. 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 modified Endo’s motor core to be formed by stacking a plurality of sheet-shaped soft magnetic materials, wherein the soft magnetic material has an iron loss of 220 W/kg or less when excited at 1.0 T or more and 3000 Hz. Such a modification when employed similar to Takada’s teaching would be advantageous significantly decreases residual magnetic flux density without increasing iron loss in the concentration gradient of the sheet (para. 3).
With regard to limitation IV, Gu teaches a tooth width (TW) that is preferably designed to be between 1.2 mm and 1.65mm (see para. 0056).
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Stator tooth width is a result-effective variable that influences magnetic flux density, saturation characteristics, and iron loss in electric machines. It would have been obvious to a person having ordinary skill in the art to modify the tooth width of the motor core of Endo to fall within the range taught by Gu in order to achieve predictable electromagnetic performance.
Furthermore, the claimed range (1.0-1.5mm) overlaps with the range disclosed in Gu (1,2-1.65mm). It is well established that obviousness in the absence of evidence of criticality or unexpected results. The fact that Gu is directed to a different application (e.g., hard disk drive) does not distract from its applicability, as both references relate to electric motors employing laminated stator cores, and he optimization of tooth width is a common design consideration across such devices.
Claim 3/1
Endo as modified by Wu, Takada and Gu teaches the following limitation(s):
The motor core according to claim 1 , wherein the soft magnetic material is an electrical steel sheet (Takada, Abstract), and the electrical steel sheet has a Si concentration distribution in a thickness direction (Si content distribution along thickness direction; Takada, para. 3-4).
Claim 19/1
The motor core according to claim 1, wherein the soft magnetic material is an electrical steel sheet, and the electrical steel sheet has an average Si concentration of 2.0 mass% to 3.5 mass% (3.5% as taught by Takada, para. 55).
Claims 4-6, 9, 12, 15, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Endo modified by Takada and Gu in view of Horst (US 20090195109 A1).
Claim 4/1
Endo as modified by Wu, Takada and Gu teaches the motor of claim 1, but is silent to the following limitation(s):
and a rotor in which 14 or more magnets are arranged in a circumferential direction.
Horst conversely teaches a motor (10) comprising a rotor (32) in which 14 or more magnets (fourteen magnets illustrated in Fig. 4) are arranged in a circumferential direction.
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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 modified Endo’s motor core as modified by Takada and Gu so that a rotor in which 14 or more magnets are arranged in a circumferential direction. Such a modification would be advantageous as high torque will be produced due to the external rotor motor configuration of Horst’s motor, compared to internal rotor motor configurations.
Claim 5/1
Endo as modified by Wu, Takada and Gu teaches the following limitation(s):
A motor (100) having a sealed outer rotor structure (rotor 11 sealed by motor casing 2),
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Endo as modified by Wu, Takada and Gu does not teach the following:
wherein a rotor is arranged outside the motor core according to claim 1.
Horst conversely teaches a motor (10) comprising a rotor (32), wherein the rotor (32) is arranged outside a motor core (50; Horst, Fig. 3 above). 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 modified Endo’s motor core as modified by Takada and Gu so that a rotor is arranged outside the motor core according to claim 1. Such a modification would be advantageous as high torque will be produced due to the external rotor motor configuration of Horst’s motor, compared to internal rotor motor configurations.
Claim 20/5/1
Endo as modified by Wu, Takada and Gu teaches: The motor according to claim 5, but is silent to: wherein the sealed outer rotor structure is configured to be operable without a cooling air introduction structure.
Endo’s motor comprises an air blower (100). Despite comprising of this cooling air structure, it does not take away from Endo’s teaching of the limitations identified in claims 1 or 5. The rotor lamination structure of Endo may be applied to Wu, Takada, and Gu. A person of ordinary skill in the art of the claimed invention would have ascertained that that the motor of claim 5 would not need to comprise a cooling structure in order to operate. Its inclusion would have contributed to increasing the efficiency of the motor however the rotor needs not to be comprised within this structure in order to operate efficiently.
Claim 6/4/1
Endo as modified by Wu, Takada and Gu teaches the following limitation(s):
The motor according to claim 4, wherein the rotor (32; Horst) is arranged outside the motor core (11; Endo), and the motor has a sealed outer rotor structure (rotor 11 sealed by motor casing 2; Endo, Fig. 1).
Claim 9/3/1
Endo as modified by Wu, Takada and Gu teaches the motor of claim 3, but is silent to the following limitation(s):
and a rotor in which 14 or more magnets are arranged in a circumferential direction.
Horst conversely teaches a motor (10) comprising a rotor (32) in which 14 or more magnets (fourteen magnets illustrated in Fig. 4 in claim 4 above) are arranged in a circumferential direction. 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 modified Endo’s motor core as modified by Takada and Gu so that a rotor in which 14 or more magnets are arranged in a circumferential direction. Such a modification would be advantageous as high torque will be produced due to the external rotor motor configuration of Horst’s motor, compared to internal rotor motor configurations.
Claim 12/3/1
Endo as modified by Wu, Takada and Gu teaches the following limitation(s):
A motor (100) having a sealed outer rotor structure (rotor 11 sealed by motor casing 2; Endo, Fig. 1), Endo as modified by Wu, Takada and Gu does not teach the following:
wherein a rotor is arranged outside the motor core according to claim 3.
Horst conversely teaches a motor (10) comprising a rotor (32), wherein the rotor (32) is arranged outside a motor core (50; Horst, Fig. 3 above). 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 modified Endo’s motor core as modified by Takada and Gu so that a rotor is arranged outside the motor core according to claim 1. Such a modification would be advantageous as high torque will be produced due to the external rotor motor configuration of Horst’s motor, compared to internal rotor motor configurations.
Claim 15/9/3/1
Endo as modified by Wu, Takada and Gu teaches the following limitation(s):
A motor (100) having a sealed outer rotor structure (rotor 11 sealed by motor casing 2; Endo, Fig. 1), Endo as modified by Wu, Takada and Gu does not teach the following:
wherein a rotor is arranged outside the motor core according to claim 9.
Horst conversely teaches a motor (10) comprising a rotor (32), wherein the rotor (32) is arranged outside a motor core (50; Horst, Fig. 3 above). 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 modified Endo’s motor core as modified by Takada and Gu so that a rotor is arranged outside the motor core according to claim 1. Such a modification would be advantageous as high torque will be produced due to the external rotor motor configuration of Horst’s motor, compared to internal rotor motor configurations.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Endo as modified by Wu, Takada and Gu in view of Oda (WO2019117089) .
Claim 18/3/1
Endo as modified by Wu, Takada and Gu teaches the motor core according to claim 3, but is silent to: wherein the Si concentration distribution has a difference ΔSi between a Si concentration in a mid-thickness and a Si concentration in a surface layer of 1.5 mass% to 3.5 mass%.
It is a known concept however to optimize the Si concentration distribution between an Si concentration in a mid-thickness and an Si concentration in a surface layer to have a difference between 1.5 mass% to 3.5 mass%. Oda for example teaches an electrical steel sheet optimized to comprise of a mid-thickness part with a Si concentration of 3.4 % or more while having, on its both surfaces, surface layers with a Si concentration of 5 mass% to 8 mass% (para. 4). Thus, on its lower end range, the Oda’s Si concentration distribution has a difference of at least 1.6 mass%.
It would have therefore been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to have modified Endo’s motor core as modified by Takada and Gu such that the Si concentration distribution has a difference between 1.5 mass% to 3.5 mass%.
Optimizing the Si difference to controlled parameters such as this enables would enable a sheet to achieve both high-frequency iron loss reduction and high magnetic flux density (para. 4).
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.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Misao Namikawa (JFE_Steel_Corporation, see 892) teaches a method of manufacturing a magnetic gradient high Si Steel Sheet JNHF Core with an Si concentration of 6.5wt% with the Si profile below,
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JFE Corporation (JFE_10JNEX900, see 892) teaches a manufacturing method comprising forming JNEX Super Core’s. One core, called the JNEX Core is formed of a 6.5% silicon steel sheet with uniform silicon content throughout the sheet. This core is ideal for low core loss and low noise (zero magnetostriction) needs in the high-frequency range. JFE Corporation also disclosed a second JNEX Super Core called a JNHF Core comprised of a silicon steel sheet with 6.5% silicon content only in the surface layer. This core exhibits even lower core loss than JNEX CORE for the high-frequency in excess of 5kHz.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AHMED F SECK whose telephone number is (571)272-4638. The examiner can normally be reached Monday - Friday 7:30 am - 4:30 pm.
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/AHMED F SECK/ Examiner, Art Unit 2834
/CHRISTOPHER M KOEHLER/ Supervisory Patent Examiner, Art Unit 2834
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