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 Amendment
The new grounds of rejection set forth below are necessitated by applicant’s amendment filed on August 11, 2025. In particular, claims 5 and 6 which are newly presented. This combination of limitations was not present at the time of the previous office action. Thus, the following action is properly made final.
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 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kumazawa (US 2021/0062883) in view of Yoshizawa et al (US 2022/0177993).
Regarding claims 1-2 and 4-5, Kumazawa teaches a friction pair consisting of a disk brake pad and a disk rotor ([0002]). The disk brake pad is a friction material which contains no copper ([0042]) and contains a binder ([01222]), a fiber base ([0147]) and friction modifier ([0127]). Kumazawa teaches that the composition comprises from 4 to 15 % of a carbonaceous lubricant such as graphite and coke ([0064]) and zirconia (zirconium oxide) is present in the amount from 1 to 25 % by mass ([0113]) which has the recited Mos hardness. The zirconia has an average particle diameter of 0.1 to 15 microns (0112]). Kumazawa teaches that the friction material has a thermal conductivity of greater than 1.1 W/mK ([0199]). Kumazawa teaches that the lubricant may be an artificial graphite, a natural graphite and/or petroleum coke ([0075]).
However, Kumazawa fails to teach that the disk rotor is a stainless-steel disk rotor.
Yoshizawa teaches a disc rotor for use in a disk brake which is stainless steel (Abstract).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have the disc rotor of Kumazawa be stainless steel as taught by Kumazawa. One would have been motivated to do so in order to receive the expected benefit of having a corrosion resistance disk rotor (Yoshizawa, [0004]).
Claim(s) 3 and 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kumazawa (US 2021/0062883) in view of Yoshizawa et al (US 2022/0177993), Yaguchi et al (US 2016/0356332) and Grivei et al (US 2013/0260150).
The discussion regarding Kumazawa and Yoshizawa in paragraph 4 above is incorporated here by reference.
Regarding claim 3, Kumazawa teaches that the Kumazawa teaches that the lubricant may be an artificial graphite, a natural graphite and/or petroleum coke ([0075]).
However, it fails to teach the presence of a graphite sheet pulverized powder and the resilient graphite carbon.
Yaguchi teaches a friction material which incorporates resilient graphite carbon particles ([0023]).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use the resilient graphite particles of Yaguchi as a graphite component of Kumazawa. One would have been motivated to do so in order to receive the expected benefit of preventing chipping in the friction material (Yaguchi, [0028]).
Grivei teaches a friction material for brake pads ([0084]) which incorporates a graphite sheet ([0056]) pulverized powder ([0080]).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use the graphite sheet pulverized powder of Grivei as a graphite component of Kumazawa. One would have been motivated to do so in order to receive the expected benefit of having a graphite with improved feed ability in processing and homogenous distribution in the composition (Grivei, Abstract).
Regarding claim 6, Kumazawa teaches that the composition comprises zirconia (zirconium oxide) is present in the amount from 1 to 25 % by mass ([0113]) which has the recited Mos hardness. The zirconia has an average particle diameter of 0.1 to 15 microns (0112]).
Response to Arguments
The 23 USC 112 rejections set forth in paragraph 3 of the office action mailed on May 30, 2025 have been withdrawn in light of applicant’s amendment filed on August 11, 2025.
Applicant's arguments filed August 11, 2025 have been fully considered but they are not persuasive for the reasons set forth below:
Applicant’s argument: A friction material composition optimized for high conductivity cast iron such as the one disclosed in Kumazawa would not be expected to perform reliably when paired with a stainless-steel rotor and would likely lead to excessive thermal fade, reduced wear resistance, and braking instability.
Examiner’s response: There appears to be no teaching away in either reference from using the friction brake pad of Kumazawa with a stainless-steel rotor of Yoshizawa. In fact, when referencing the back metal for use with the friction material, Kumazawa indicates either iron or stainless steel in paragraph [0155], so both these metals are frequently used in the friction material art. While applicant argues that this combination would result in non-performance, without data to support this, it is mere conjecture and is not persuasive.
Applicant’s argument: Kumazawa tolerates up to 0.5 wt. % copper, in contrast, the present invention requires a copper content of 0%.
Examiner’s response: Kumazawa also states that there can be no copper in the formulation. Please refer to paragraph [0042].
Applicant’s argument: Kumazawa does not teach or suggest this exclusion of metallic fibers. Paragraph [0146] expressly contemplates the use of metal fibers.
Examiner’s response: While paragraph [0146] does list metal fibers, it does not mandate the inclusion of them. It is noted that many other types of fibers are acceptable such as inorganic fibers, organic fibers and or carbon-based fibers and only one type of fiber is required ([0140). Therefore, while metal fibers are taught, they are not necessitated in the material.
Applicant’s argument: Claim 1 recites a narrow thermal conductivity range of 1.2-3.0 W/mK. Kumazawa only discloses materials having thermal conductivity greater than 1.2 W/mK without specifying an upper limit or functional target range. Even if some of the Examples in Kumazawa happen to fall within or near the claimed range, they do so without design intent or predictable outcome.
Examiner’s response: Kumazawa teaches the recited thermal conductivity range. As such, it meets the limitation of the claimed invention. The fact that applicant may have used a different method or design to reach this property does not carry much patentable weight.
Applicant’s argument: Yoshizawa does not mention brake pads, friction materials, or friction performance. Nor does it suggest pairing its stainless-steel rotor with any specific brake pad.
Examiner’s response: Yoshizawa teaches that the stainless-steel rotor is used in conjunction with brake pads in general and is an excellent alternative to cast iron rotors (please refer to background art) in certain applications.
Applicant’s argument: There is no articulated rationale or motivation for a person of ordinary skill in the art at the time of the invention to combine the teachings of Kumazawa and Yoshizawa. The examiner’s rationale appears to be based on hindsight reasoning.
Examiner’s response: The motivation to combine the references is clearly recited in the rejection above and is in order to receive the expected benefit of having a corrosion resistance disk rotor (Yoshizawa, [0004]).
Applicant’s argument: There is no reasonable expectation of success with the combination of Kumazawa and Yoshizawa. Stainless steel is very different from cast iron and this difference directly impact pad wear, friction stability and fade resistance. Combining the two would be speculative and unpredictable.
Examiner’s response: There appears to be no teaching away in either reference from using the friction brake pad of Kumazawa with a stainless-steel rotor of Yoshizawa. In fact, when referencing the back metal for use with the friction material, Kumazawa indicates either iron or stainless steel in paragraph [0155], so both these metals are familiar in the friction material art. While applicant argues that this combination would result in non-performance, without data to support this, it is mere conjecture and is not persuasive.
Applicant’s argument: Nowhere does Kumazawa suggest that the type or morphology of carbonaceous lubricant itself may be tailored to control thermal conductivity or frictional behavior. There is no teaching or motivation in Kumazawa to employ specialized carbon forms such as resilient graphite carbon or graphite sheet pulverized powder to achieve the thermal performance required in the claimed invention.
Examiner’s response: The independent claim does not recite any type or morphology of the carbonaceous lubricant and therefore, is not within the scope of the claimed invention. The specialized carbon forms such as resilient graphite carbon and/or carbon sheet are taught by Yaguchi and Grivei respectively. Kumazawa teaches the recited thermal conductivity, and as such, reads on the claimed invention limitation.
Applicant’s argument: None of Kumazawa, Yoshizawa, Yaguchi or Grivei teaches or suggests the used of the claimed components for the purpose of achieving a controlled thermal conductivity range or addressing the unique thermal challenges posed by stainless steel rotors.
Examiner’s response: In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant’s argument: Yaguchi’s use of resilient graphite carbon is directed to improving chipping resistance not thermal regulation. Grivei is focused on enhancing feedablility during manufacturing and homogenous dispersion of the carbon components and not improving thermal conductivity or braking stability.
Examiner’s response: The Yaguchi reference and the Grivei reference are used to teach in the resilient graphite carbon particles and the graphite sheet pulverized powder. There are clear motivations and reasons to combine listed in the above rejections. The thermal conductivity is taught by the primary reference, Kumazawa. Braking stability is not within the scope of the claimed invention as it is not recited in the limitations of the claims.
Conclusion
THIS ACTION IS MADE FINAL. 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 DORIS L LEE whose telephone number is (571)270-3872. The examiner can normally be reached M-F 8 am - 5 pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Arrie Lanee Reuther can be reached at 571-270-7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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DORIS L. LEE
Primary Examiner
Art Unit 1764
/DORIS L LEE/Primary Examiner, Art Unit 1764