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 1-13 are pending.
Response to Arguments
Applicant’s arguments, see pages 5-8, filed 03/26/202, with respect to the rejection(s) of claim(s) 1 and 7 under 35 USC 102(a)(1) have been fully considered and are persuasive. Specifically, Examiner agrees that the added new limitations to claims 1 and 7 are not disclosed by Rasmussen. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Boubaker et al., US 20220140684 A1 (same as GB 2582941 A). This prior art was provided by Applicant on 07/05/2023.
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, 5, 7-10 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Boubaker et al. (US 20220140684 A1) in view of Semmer, S., (EP 2662950 A1).
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Regarding claim 1, Boubaker discloses a stator (stator, annotated fig. 2) of an electric machine (200, fig. 2) comprising
an annular stator (stator, annotated fig. 2) having a longitudinal centre axis (“[0060] As before, the stator 208 comprises a magnetic stator core 210, and plurality of longitudinal slots 212 that extend through the stator core 210 in the direction of the longitudinal axis.”),
the stator including axial stator slots (slots, annotated fig. 2); and
stator teeth (inner and outer teeth, annotated fig. 2) formed between adjacent stator slots,
each stator slot receiving a conductor of a stator winding (conductor, annotated fig. 2),
the stator having stator sectors (sector, annotated fig. 2),
each stator sector including an outermost stator tooth (outer teeth, annotated fig. 2) at each angular outer edge of the stator sector and intermediate stator teeth (inner teeth, annotated fig. 2) between the two outermost stator teeth,
a width of the two outermost stator teeth in each stator sector being equal (see, annotated fig. 2),
adjacent stator slots within each stator sector being distanced by a first slot pitch (first pitch, annotated fig. 2) and adjacent stator slots belonging to different stator sectors being distanced by a second slot pitch (second pitch, annotated fig. 2), wherein
the first slot pitch is smaller than the second slot pitch (see annotated fig. 2), the slot pitches being defined by angles between radii from the stator center to stator centerlines see annotated fig. 2),
each stator slot having a substantially uniform slot width through a radial height of the stator slot (see rectangular slots in fig. 2), and each stator tooth having a substantially trapezoidal cross-section (rectangular slots results in trapezoidal teeth, see figs. 2, 3 and 6).
Boubaker does not disclose the stator being formed of stator sectors.
Semmer teaches a stator for an electrical machine “comprising a plurality of interconnected stator segments (2) forming a generally annular structure, each stator segment (2) including - a yoke (3) extending over a section of the annular structure; - a plurality of teeth (4) projecting radial outwards from the yoke (3) so as to define a plurality of gaps (5) intermediately arranged between the teeth (4), each gap (5) containing conductive windings (6) that are retained therein by a means of fixture”, (see the abstract).
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As for the reason, Semmer states: “As it is difficult and expensive to manufacture large components as one piece, it is common to assemble structural members like rotors from smaller components. The smaller components are easy to manufacture and to assemble.”
For ease of manufacturing and assembly, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to split the stator into a plurality of sectors, for example, along the lines denoting boundaries of various phases. This would result in having a stator that is formed of stator sectors.
Regarding claim 2, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in claim 1, wherein the width of each of the two outermost stator teeth in each stator sector is over 50% of the width of the intermediate stator teeth (implied- the width of the inner and outer are about equal).
Regarding claim 3, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in claim 1, wherein the width of each of the two outermost stator teeth in each stator sector is at least 75% of the width of the intermediate stator teeth (implied- the width of the inner and outer are about equal).
Regarding claim 5, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in any of claim 1, wherein the width of each of the two outermost stator teeth in each stator sector is equal to the width of the intermediate stator teeth (see annotated fig. 2).
Regarding claim 7, Boubaker, as modified by Semmer in claim 1 and discussed regarding claim 1, discloses an electric machine comprising
an annular stator having a longitudinal centre axis,
the stator including axial stator slots and stator teeth formed between adjacent stator slots,
each stator slot receiving a conductor of a stator winding,
the stator being formed of stator sectors,
each stator sector including an outermost stator tooth at each angular outer edge of the stator sector and intermediate stator teeth between the two outermost stator teeth,
a width of the two outermost stator teeth in each stator sector being equal,
adjacent stator slots within each stator sector being distanced by a first slot pitch and adjacent stator slots belonging to different stator sectors being distanced by a second slot pitch, and
a rotor (rotor, annotated fig. 2), wherein
the first slot pitch is smaller than the second slot pitch and a rotor, the slot pitches being defined by angles between radii from the stator center to stator centerlines, each stator slot having a substantially uniform slot width through a radial height of the stator slot, and each stator tooth having a substantially trapezoidal cross-section.
Regarding claim 8, Boubaker as modified by Semmer in claim 1 and discussed regarding claim 7 discloses the electric machine as claimed in claim 7, wherein the stator of the electric machine is quasi-skewed in relation to the rotor of the electric machine due to the asymmetry of the teeth in the stator of the electric machine (see the matches and mismatches between the rotor magnets and stator poles in annotated fig. 2; see also fig. 3).
Regarding claim 9, Boubaker as modified by Semmer in claim 1 and discussed regarding claim 7 discloses the electric machine as claimed in claim 7, wherein the rotor is provided with permanent magnets (magnets, annotated fig. 2).
Regarding claim 10, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in claim 2, wherein the width of each of the two outermost stator teeth in each stator sector is at least 75% of the width of the intermediate stator teeth (implied- the width of the inner and outer are about equal).
Regarding claim 12, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in claim 2, wherein the width of each of the two outermost stator teeth in each stator sector is equal to the width of the intermediate stator teeth (see annotated fig. 2).
Claim(s) 4, 6, 11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Boubaker in view of Semmer and further in view of Wang et al. (CN 111245118 A).
Regarding claims 4 and 6, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in claim 1, but does not disclose: wherein the width of each of the two outermost stator teeth in each stator sector is smaller or greater than the width of the intermediate stator teeth.
First, within manufacturing tolerances, it’s known to a person having ordinary skills in the art that it’s possible that the width of each of the two outermost stator teeth in each stator sector to be slightly smaller or greater than the width of the intermediate stator teeth. Applicant has not shown any significant improvement for infinitesimal increase or decrease in the size of the outer teeth with respect to the inner teeth.
Second, referring to annotated fig. 5c, below, Wang teaches a sectorized stator for an electric machine for minimizing cogging torque by varying the width of at least one outer tooth of a sector with respect the others (see the narrow and wide teeth in annotated fig. 5c; see the abstract too). In the instant case, the two outer teeth are required to be equal and modifying the width of both outer teeth could further lower the cogging torque.
Furthermore, Wang also teaches the cogging torque is at least a function of a number of variables including the number of teeth and the ratio of the wider tooth to the narrower tooth of the outer teeth to the width of inner teeth (see the equation in para [0079]). This effectively means that in each sector at least one tooth should be wider or narrower the other teeth to improve the performance of the electric motor. Optimizing a result effective variable is within the skills of a person having ordinary skills in the art.
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For minimizing the cogging torque, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention that: the width of each of the two outermost stator teeth in each stator sector is smaller or greater than the width of the intermediate stator teeth.
Regarding claims 11 and 13, Boubaker as modified by Semmer in claim 1 discloses the stator as claimed in claim 2, but does not disclose wherein the width of each of the two outermost stator teeth in each stator sector is smaller or greater than the width of the intermediate stator teeth.
As just discussed regarding claims 4 and 6, for minimizing the cogging torque, it would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention that: the width of each of the two outermost stator teeth in each stator sector is smaller or greater than the width of the intermediate stator teeth.
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.
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/MASOUD VAZIRI/Examiner, Art Unit 2834
/OLUSEYE IWARERE/Supervisory Patent Examiner, Art Unit 2834
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