DETAILED ACTION
Response to Arguments
Applicant's arguments filed 07/22/2026 have been fully considered but they are not persuasive. The applicant argues that the prior art does not teach electromagnetic steel having an expansion coefficient within the claimed range. This argument is moot in view of new grounds of rejection.
Upon further consideration of the arguments and prior art, it became apparent that the units used by the applicant to describe the linear expansion coefficient are different from multiple prior art references, and units normally used in the art such as SI units 1/K, or 1/°C, or ppm. This makes the claim vague and indefinite because um/°C does not properly describe a linear expansion coefficient. It appears that the applicant may have intended to use ppm units, however, this is also not clear because the examiner could not find any portion of the disclosure that explains how the units used by the applicant correlate to ppm units, or units normally used in the art.
Furthermore, the applicant focuses on the prior art lacking electromagnetic steel expansion coefficient, however, the prior art already discloses electromagnetic steel material. This material inherently has a liner expansion coefficient. The disclosure of the claimed invention does not describe any significant difference, in terms of the material composition between the electromagnetic steel that is claimed, and conventional electromagnetic steel of the prior art. All that is mentioned is that silicon is included, which is standard for electromagnetic steel. Thus, electromagnetic steel of the prior art already includes the linear expansion coefficient that is the same as that of the claimed device, because electromagnetic steel material is also the same.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-2 and 4-9 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
In re claim 1, the units used for linear expansion coefficient appear to be improper because they are different than conventional units of 1/K, or 1/°C, or ppm. The examiner could not find an explanation of the claimed units or support in the disclosure to equate the claimed units to standard/conventional units.
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.
Claim(s) 1-2 and 4-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kitada (US 2014/0327329) in view of Nagano et al. (US 2020/0116761).
In re claim 1, Kitada, in figures 1-9, discloses a rotor core comprising: a stacked core (110) constituted by stacking a plurality of electromagnetic steel sheets (112) containing silicon (silicon is not explicitly mentioned, however, it is well known in the art that electromagnetic steel contains silicon), the stacked core including a magnet housing portion provided so as to extend in a stacking direction of the electromagnetic steel sheets; a permanent magnet (120) disposed in the magnet housing portion of the stacked core; and a thermosetting resin material (130) filled in the magnet housing portion between the stacked core and the permanent magnet to fix the permanent magnet in the magnet housing portion, the resin material contains silica as an inorganic filler (this is disclosed throughout the specification; paragraphs 68-70 disclose the amounts of silica that is within the claimed weight range). Kitada teaches the expansion coefficient of resin material extending down to 10 ppm/°C (paragraphs 157-160) but does not explicitly teach the expansion coefficient of steel. Nagano however, teaches a core that uses silicon steel having linear expansion coefficient (see paragraph 55) that appears to be within the range intended to be claimed by the applicant. Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used steel having an expansion coefficient with the claimed values as disclosed by Nagano in the device of Kitada, to allow for improved retention of the magnets within the steel sheets.
In re claim 2, Kitada in view of Nagano discloses that the coefficient of linear expansion of the resin material is smaller than the coefficient of linear expansion of the electromagnetic steel sheets.
In re claim 4, Kitada in view of Nagano discloses that the coefficient of linear expansion of the resin material is equal to or less than the coefficient of linear expansion of the electromagnetic steel sheets, and more than a coefficient of linear expansion of the permanent magnet (the permanent magnet of Kitada is made from the same material as the magnet of the invention (see paragraph 34) thereby inherently meeting this limitation).
In re claim 5, Kitada in view of Nagano discloses that the coefficient of linear expansion of the permanent magnet is in the claimed range (this is inherent because Kitada magnet is made from the same material as the magnet of the invention).
In re claim 6, Kitada in view of Nagano discloses the coefficient of linear expansion of the resin material is a value that is closer to the coefficient of linear expansion of the electromagnetic steel sheets than a middle value between the coefficient of linear expansion of the electromagnetic steel sheets and the coefficient of linear expansion of the permanent magnet (this is inherently present since the materials of the prior art are the same as the materials of the invention).
In re claim 7, Kitada in view of Nagano discloses that the magnet housing portion is a space formed by overlapping hole portions provided in the electromagnetic steel sheets in an axial direction, a periphery of the space being closed (as best seen in figures 3-6).
In re claims 8-9, Kitada in view of Nagano discloses a process of manufacturing. In accordance to MPEP 2113, the method of forming the device is not germane to the issue of patentability of the device itself. Therefore, the process of melting the resin to the claimed temperatures and then curing, has not been given patentable weight. Please note that even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product, i.e resin, does not depend on its method of production, i.e. heating and curing at first and second temperatures. In re Thorpe, 227 USPQ 964, 966 (Federal Circuit 1985).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Alexander Talpalatski whose telephone number is (571)270-3908. The examiner can normally be reached 10 AM - 6 PM PT.
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 Ismail can be reached at 5712723985. 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.
/Alexander Talpalatski/Primary Examiner, Art Unit 2837
Prosecution Insights