DETAILED ACTION
Claims 1-15 of U.S. Patent Application No. 19/001,395, filed on 24 December, 2024, were presented for examination, and are currently pending in the application.
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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 24 December, 2024, was filed before the mailing date of this Office Action. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Specification
The abstract of the disclosure is objected to because of minor grammatical errors. In line 1, “plurality sets” should be changed to “plurality of sets” and in line 3, “structures” should be changed to “structure” (singular). A corrected abstract of the disclosure is required and must be presented on a separate sheet, apart from any other text. See MPEP § 608.01(b).
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
Claim Objections
Claims 1-15 are objected to because of the following informalities:
In claim 1, lines 2-3 should be amended as follows (or along these lines):
“a silicon steel main body that has a plurality of sets of magnetic poles, an axis and an outer edge, each set of magnetic poles has a double-layer V-shaped magnet slot structure;”
In claim 8, the limitation “disposed close to where between” should be amended to language that either places the magnetic barrier structures close to the outer edge and the pair of outer magnet slots or (which the Examiner believes is the Applicant’s intention) more simply “disposed between” them.
In claim 11, lines 2-3 should be amended as follows (or along these lines):
“a silicon steel main body that has a plurality of sets of magnetic poles, an axis and an outer edge, each set of magnetic poles has a double-layer V-shaped magnet slot structure;”
In claim 11, lines 5-6 should be amended as follows (or along these lines):
“V-shaped magnet slot group near the axis that has a pair of inner magnet slots and an outer V-shaped magnet slot group near the outer edge that has a pair of outer magnet slots:”
Claims 2-7 and 12-15 are objected to for depending from objected-to claims 1 and 11.
Appropriate correction is required.
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 1-15 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.
Lines 10-12 of claim 1 recite the limitation “close to the axis” twice, once with reference to the inner magnetic bridge and once with reference to the outer magnetic bridge. There is no reference for the word “close” – it could mean “closer to the axis than…. something else is” or “closer to the axis than… to something else…” For examination on the merits, the Examiner will interpret these limitations as “closer to the axis than the outer edge is”.
Lines 7-9 of claim 11 recite the limitation “close to the axis” twice, once with reference to the inner magnetic bridge and once with reference to the outer magnetic bridge. There is no reference for the word “close” – it could mean “closer to the axis than…. something else is” or “closer to the axis than… to something else…” For examination on the merits, the Examiner will interpret these limitations as “closer to the axis than the outer edge is”.
Claims 2-10 and 12-15 are rejected from depending from rejected claims 1 and 11, respectively.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-7 and 10-15 are rejected under 35 U.S.C. 103 as being unpatentable over Isoda (US 2026/0018949 A1) in view of Asano (JP 2013236418 A, provided herein with machine translation), further in view of Takemoto (US 2010/0148612 A1), further in view of Chen (CN 216929839 U, provided herein with machine translation).
With respect to claim 1, Isoda teaches a rotor structure [rotor 5] comprising:
a steel main body [first rotor core 10] (see ¶ 0027 which recites “first rotor core 10 and a second rotor core 20, both of which are made of electromagnetic steel plate…”) that has a plurality of sets of magnetic poles (see the annotated excerpt of fig. 1 wherein the Examiner has labeled poles 2-4, while pole 1 is the one that has the labels 11 and 50 leading to it – see ¶ 0028), an axis (center of shaft 4) and an outer edge (the surface adjacent to and facing the stator 2), each set of magnetic poles has a double-layer V-shaped magnet slot structure (the combination of holes 11 circled by the Examiner below);
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wherein the double-layer V-shaped magnet slot structure includes an inner V-shaped magnet slot group (labeled individually in the annotated excerpt of fig. 2 attached below and comprising two magnet insertion holes 11) near the axis and an outer V-shaped magnet slot group (also labeled in fig. 2 excerpt) near the outer edge;
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the inner V-shaped magnet slot group has a first included angle [A1] between a pair of inner magnet slots, the outer V-shaped magnet slot group has a second included angle [A2] (A1 and A2 were drawn by the Examiner in the blown-up snapshot from fig. 2 below) between a pair of outer magnet slots, the first included angle [A1] is smaller than the second included angle [A2];
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{the Examiner used fig. 2 to measure that A1 is approximately 102o and A2 is approximately 112o – Isoda’s written description does not mention that fig. 2 is drawn to scale, such that the exact difference could be exactly deduced from the drawings, and Isoda does not quantify/describe the included angles or the difference between them, but other lines of evidence for the difference being existent are at hand, as the Examiner has laid out below:
a) every other drawing in Isoda shows the same difference in angles;
b) the difference measured by the Examiner is 10o which substantially eliminates any chance that it is inadvertent, and
c) most references the Examiner has collected with a double V-shaped pole arrangement (many are included in the attached PTO Form 892) have the difference visible to a greater or lesser extent, including Chen, used later in this rejection [and providing evidence that if Isoda is not showing the difference on purpose, one of ordinary skill in the art would find it obvious in light of Chen or one of the other references explicitly teaching this to believe that Isoda’s teachings include the difference], which actually recites in ¶0067 that “θ2 is equal to or smaller than the first magnetic pole angle θ1…”
CHEN
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CHEN}
wherein the inner V-shaped magnet slot group has an inner magnetic bridge (labeled by the Examiner in the annotated fig. 2 excerpt below) close to the axis along a radial direction {the reference does not label or discuss the magnetic bridges, however the area between the slots is solid (steel) and by extending between two open, non-solid areas is by definition a bridge}, and the outer V-shaped magnet slot group has an outer magnetic bridge (also labeled by the Examiner in the fig. 2 excerpt) close to the axis along the radial direction, a width of the inner magnetic bridge is greater than a width of the outer magnetic bridge (although not described in the reference as drawn to scale, fig. 2 definitely shows this, which is very common in the art – see for example fig. 5 of Chen, both above and below);
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wherein any pair of the pair of inner magnet slots and the pair of outer magnet slots has two long edges (also labeled by the Examiner for all four slots in this slot group), and the one of the two long edges that is relatively far away from the corresponding inner magnetic bridge or the corresponding outer magnetic bridge has a blocking point [guide portion 13] (see ¶0033 which recites “on the long side of the magnet insertion hole 11, each guide portion 13 is formed to protrude into the interior of the magnet insertion hole 11…”).
Isoda does not teach wherein the inner V-shaped magnet slot group or the outer V-shaped magnet slot group has a pair of radial magnetic bridges extending from the pair of inner magnet slots or the pair of outer magnet slots respectively, and the pair of radial magnetic bridges are farther from the axis than the inner magnetic bridge or the outer magnetic bridge.
Asano discloses a rotor structure comprising a main body [rotor core 11] having a plurality of sets of magnetic poles [pairs of gaps 12a, 12b, 12c], an axis [O] and an outer edge, each set of magnetic poles has a V-shaped magnet slot structure including an outer V-shaped magnet slot group near the outer edge, wherein any pair of the pair of outer magnet slots has two long edges.
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Asano teaches wherein the outer V-shaped magnetic slot group has a pair of radial magnetic bridges [bridge parts 15] extending from the pair of outer magnet slots [12a/12b], and the pair of radial magnetic bridges [15] are farther from the axis [O] than the outer bridge (in this Asano’s case the bridge is the apex of the V-shape where there would in other rotors be a space between the magnets – Asano’s device does not have the magnetic bridge of the type of Isoda but the bridge/bridgeless options are simply alternatives to each other, well known in the art).
Asano’s disclosure is a discussion of improving on various rotors of this type, and other types, which rotors all have radial magnetic bridges on both sides of the slot group. Asano takes for granted that the reader knows what the radial magnetic bridges are for, why they are there, and what advantages they provide – however, during its discussion of how to reduce stress on them, and on a rotor containing them, Asano never gets around to saying why a person of ordinary skill in the art would incorporate them in a rotor.
Takemoto discloses a rotor nearly identical to Asano’s, but Takemoto’s rotor only has one radial magnetic bridge [14] per pole.
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Takemoto teaches in ¶ 0074 that “since the gaps 14 function as magnetic resistance, an iron core portion 16, which is magnetically divided from the magnetic pole portions 10 in the circumferential direction, is formed between the circumferentially adjacent magnetic pole portions 10…” Following this, in ¶ 0129 Takemoto teaches the gaps formed to open in the circumferential surface of the rotor reduce the influence of the magnetic repulsive force between the iron core portion and the teeth (of the stator), and the result is that torque is increased in the motor.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to make the rotor structure of Isoda, while incorporating magnetic radial bridges, as taught by Asano, in order to reduce the influence of the magnetic repulsive force between the core and the teeth thereby increasing motor torque (motivation taken from Takemoto ¶ 0129).
Neither Isoda nor Asano nor Takemoto explicitly teaches:
wherein the steel main body is a silicon steel main body, and
wherein the silicon steel main body has a rivet point, and a connection line between a geometric center of the rivet point and the axis passes through the inner magnetic bridge and the outer magnetic bridge.
Chen discloses yet another motor rotor core comprising (double) V-shaped magnetic slot structures with inner and outer magnetic bridges, and is deemed analogous art.
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With respect to (a) above, Chen teaches wherein the steel main body [rotor lamination 20] is a silicon steel main body (¶ 0063 of the provided translation recites “the plurality of rotor laminations 20 are made of silicon steel sheets…”).
It would have been obvious to a person of ordinary skill in the art to make the rotor structure of Isoda in view of Asano, further in view of Takemoto, while using silicon steel for the steel main body of Isoda, as taught by Chen, in order to increase electrical resistivity, thereby mitigating energy loss and overheating, as is well known in the art (the Examiner notes that most of the references in PTO Form 892 are probably using silicon steel, they just don’t mention it by name, obviously using the publication opportunity to discuss more important matters such as inventive concepts).
With respect to (b) above, Chen further teaches wherein the silicon steel main body [20] has a rivet point [26], and a connection line (the Examiner has drawn and labeled the line) between a geometric center of the rivet point [26] and the axis passes through the inner magnetic bridge [24c] and the outer magnetic bridge [22c].
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It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to make the device of Isoda in view of Asano, further in view of Takemoto, further in view of Chen, and provide a rivet point, as taught by Chen, such that it could be engaged by a rivet to secure the rotor to other rotor bodies (Chen ¶ 0063), thereby increasing the structural strength of the overall rotor structure (Chen ¶ 0066), as is commonly done in the art.
To summarize, Isoda provides the general structure of the relevant type rotor structure with V-shaped magnet slot groups and magnetic bridges, and Chen supplements the items that are not explicitly taught by Isoda but which are surely part of Isoda (silicon steel, how the rotor core plates are secured together, the angle of the inner slot group being smaller than the angle of the outer slot group, etc.), such that these commonalities should be seen together as being the state of the art.
Isoda goes one step further in providing the blocking points, which are also well-known in the art (see discussion of references cited but not used in the Conclusion section below). Therefore, all of the clauses/features of claim 1 are known, and known to be used together in various ways, including in the way claimed in claim 1.
Asano and Takemoto best teach the radial magnetic bridges. The Examiner has included more prior art references in PTO Form 892 that teach them, and selected a few for inclusion in the Conclusion section below. This feature is also known but could not be located in a reference that also explicitly (in a way that would suffice as evidence to make a rejection) teaches the blocking points.
The Examiner believes that Takemoto has provided a modular explanation of the advantages of the radial magnetic bridges, and Asano and Takemoto show them in V-shaped-pole rotors, in the same place where the instant application shows them. The Examiner believes the motivation in Takemoto supports a prima facie case that a person of ordinary skill in the art would modify a blocking-point-containing rotor like Isoda to include the radial magnetic bridges like those taught in Asano and Takemoto. Both Isoda and US 2024/0372423 A1 (see Conclusion section below) teach the advantages of blocking points on top of teaching the blocking points themselves, such that there is also a prima facie case to allege it would be obvious to modify one of the references in PTO Form 892 that already has the radial magnetic bridges with that feature.
With respect to claim 2/1, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 1, but none of the references explicitly teaches wherein the width of the inner magnetic bridge is 1.5 an air gap width between the rotor structure and a stator structure. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the inner magnetic bridge width and the air gap width. Increasing the inner magnetic bridge width augments mechanical strength of the rotor but reduces the magnetic circuit, such that it is kept as small as possible without mechanical failure. Increasing air gap width reduces torque and efficiency of the motor, such that it is kept as small as possible without the rotor being allowed to touch the stator. A practitioner of ordinary skill in the art would set out to make both as small as possible and during the course of optimizing the two values, could find that 1.5 is an optimum ratio during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor that does not contact the stator teeth, respectively.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 3/11, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 1, but none of the references explicitly teaches wherein the width of the outer magnetic bridge is equal to an air gap width between the rotor structure and a stator structure. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the outer magnetic bridge width and the air gap width. Increasing the outer magnetic bridge width augments mechanical strength of the rotor but reduces the magnetic circuit, such that it is kept as small as possible without mechanical failure. Increasing air gap width reduces torque and efficiency of the motor, such that it is kept as small as possible without being allowed to touch the stator. A practitioner of ordinary skill in the art would set out to make both as small as possible and during the course of optimizing the two values, could find that a 1-to-1 ratio is an optimum ratio during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor that does not contact the stator teeth, respectively.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 4/1, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 1, but none of the references explicitly teaches wherein the pair of radial magnetic bridges have a width greater than an air gap width between the rotor structure and a stator structure. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the radial magnetic bridges’ widths and the air gap width. Increasing the radial magnetic bridges’ widths increases resistance between the poles but reduces mechanical strength of the rotor core, such that they are (see Takemoto citation above) kept significantly large but obviously they are restricted by the space available and the tendency of the rotor to fly apart due to the weight of the magnets if the radial magnetic bridges are made too big – in fact Asano’s entire discussion is about increasing their strength. Increasing air gap width reduces torque and efficiency of the motor, such that it is kept as small as possible without being allowed to touch the stator. A practitioner of ordinary skill in the art would set out to make the radial magnetic bridges large but find her/himself constrained by Asano’s considerations, while making the air gap as small as possible, and during the course of optimizing the two values, could find that having the radial magnetic bridge width greater than the air gap width is an optimum condition during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor that does not contact the stator teeth, respectively.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 5/4/1, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 4, Asano further teaches the silicon steel main body comprising a plurality of silicon steel sheets stacked along an axial direction [C] (see first 2 lines of ¶ 0007 of Chen translation).
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However, none of the references explicitly teaches wherein the width of the pair of radial magnetic bridges is smaller than a thickness of a single one of the silicon steel sheets. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the radial magnetic bridges’ widths and the steel sheet thickness. Increasing the radial magnetic bridges’ widths increases resistance between the poles but reduces mechanical strength of the rotor core, such that they are (see Takemoto citation above) kept significantly large but obviously they are restricted by the space available and the tendency of the rotor to fly apart due to the weight of the magnets if they are made too big – in fact Asano’s entire discussion is about increasing their strength. Increasing silicon steel sheet thickness reduces electrical resistance, leading to overheating, such that it is typically kept small/thin – however making the thickness too small leads to higher manufacturing cost. A practitioner of ordinary skill in the art would set out to make the radial magnetic bridges larger but find her/himself constrained by Asano’s considerations, while making the silicon steel sheets small but not to the point where manufacturing costs rise, and during the course of optimizing the two values, could find that having the radial magnetic bridge width greater than the silicon steel sheet thickness is an optimum condition during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor whose core does not conduct too much electricity that could lead to overheating.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 6/1, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 1, Isoda further teaches a plurality of magnets [permanent magnets 50] disposed in the pair of inner magnet slots and the pair of outer magnet slots, each of the magnets [50] having a width W [W], and the blocking point has a height h [H] (width and height labeled in the fig. 4 excerpt attached below).
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Isoda does not explicitly teach wherein W/10<h<W/5. It does not describe such a ratio, and although fig. 4 appears to satisfy the range (h seems to be about equal to W/5), Isoda does not claim that its drawings are to-scale.
However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the blocking point height and the magnet width. The magnet width is set by the slot width, while the blocking point height needs to be just tall enough to disallow the magnet from getting wedged between it and the opposite wall, which would lead to the magnet wearing down the blocking point after millions of rotations and then slipping past. A practitioner of ordinary skill in the art would set out to make the blocking point as small as possible but making it too small would make it potentially unreliable at perpetually immobilizing the magnet. The optimized value is a result effective variable, which is the ratio that balances this tradeoff and there is enough evidence from fig. 4 of Isoda to predict that the routine experimentation performed to balance the tradeoff would be just as likely to result in a ratio under 1/5 as a ratio over 1/5, while a person of ordinary skill in the art would also predict that making it less than 1/10 risks the magnet wearing against the blocking point and/or wedging past it.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 7, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 1, Chen further teaches wherein the rivet point [26] has a rectangular shape or a circular shape.
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With respect to claim 10/1, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 1, but none of the references explicitly teaches wherein the ratio of the width of the inner magnetic bridge to the width of the outer magnetic bridge ranges from 1.2 to 1.6. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the inner magnetic bridge width and the outer magnetic bridge width. Increasing the inner magnetic bridge width and/or the outer magnetic bridge width augments mechanical strength of the rotor but reduces the magnetic circuit. A practitioner of ordinary skill in the art would set out to make both as small as possible and during the course of optimizing the two values, could find that 1.2-1.6 is an optimum ratio during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail while maintaining the magnetic circuit for both V-shaped magnet slot structures.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 11, Isoda teaches a rotor structure [rotor 5] comprising:
a steel main body [first rotor core 10] (see ¶ 0027 which recites “first rotor core 10 and a second rotor core 20, both of which are made of electromagnetic steel plate…”) that has a plurality of sets of magnetic poles (see the annotated excerpt of fig. 1 wherein the Examiner has labeled poles 2-4, while pole 1 is the one that has the labels 11 and 50 leading to it – see ¶ 0028), an axis (center of shaft 4) and an outer edge (the surface adjacent to and facing the stator 2), each set of magnetic poles has a double-layer V-shaped magnet slot structure (the combination of holes 11 circled by the Examiner);
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wherein the double-layer V-shaped magnet slot structure includes an inner V-shaped magnet slot group (labeled individually in the annotated excerpt of fig. 2 attached below and comprising two magnet insertion holes 11) near the axis that has a pair of inner magnet slots [11] and an outer V-shaped magnet slot group (also labeled in fig. 2 excerpt) near the outer edge that has a pair of outer magnet slots [11];
wherein the inner V-shaped magnet slot group has an inner magnetic bridge (labeled by the Examiner in the fig. 2 excerpt) close to the axis along a radial direction {the reference does not label or discuss the magnetic bridges, however the area between the slots is solid (steel) and by extending between two open, non-solid areas is by definition a bridge}, and the outer V-shaped magnet slot group has an outer magnetic bridge (also labeled by the Examiner in the fig. 2 excerpt) close to the axis along the radial direction, a width of the inner magnetic bridge is greater than a width of the outer magnetic bridge (although not described in the reference as drawn to scale, fig. 2 definitely shows this, which is very common in the art);
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wherein any pair of the pair of inner magnet slots and the pair of outer magnet slots has two long edges (also labeled by the Examiner for all four slots in this slot group), and the one of the two long edges that is relatively far away from the corresponding inner magnetic bridge or the corresponding outer magnetic bridge has a blocking point [guide portion 13] (see ¶0033 which recites “on the long side of the magnet insertion hole 11, each guide portion 13 is formed to protrude into the interior of the magnet insertion hole 11…”).
Isoda does not teach wherein the inner V-shaped magnet slot group or the outer V-shaped magnet slot group has a pair of radial magnetic bridges extending from the pair of inner magnet slots or the pair of outer magnet slots respectively, and the pair of radial magnetic bridges are farther from the axis than the inner magnetic bridge or the outer magnetic bridge.
Asano discloses a rotor structure comprising a main body [rotor core 11] having a plurality of sets of magnetic poles [pairs of gaps 12a, 12b, 12c], an axis [O] and an outer edge, each set of magnetic poles has a V-shaped magnet slot structure including an outer V-shaped magnet slot group near the outer edge, wherein any pair of the pair of outer magnet slots has two long edges.
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Asano teaches wherein the outer V-shaped magnetic slot group has a pair of radial magnetic bridges [bridge parts 15] extending from the pair of outer magnet slots [12a/12b], and the pair of radial magnetic bridges [15] are farther from the axis [O] than the outer bridge (in this Asano’s case the bridge is the apex of the V-shape where there would be a space between the magnets – Asano’s device does not have the magnetic bridge of the type of Isoda but the bridge/bridgeless options are simply alternatives to each other, well known in the art).
Asano’s disclosure is a discussion of improving on various rotors of this type, and other types, which rotors all have radial magnetic bridges on both sides of the slot group. Asano takes for granted that the reader knows what the radial magnetic bridges are for, why they are there, and what advantages they provide – however, during its discussion of how to reduce stress on them, and on a rotor containing them, Asano never gets around to saying why a person of ordinary skill in the art would incorporate them in a rotor.
Takemoto discloses a rotor nearly identical to Asano’s, but Takemoto’s rotor only has one radial magnetic bridge [14] per pole.
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Takemoto teaches in ¶ 0074 that “since the gaps 14 function as magnetic resistance, an iron core portion 16, which is magnetically divided from the magnetic pole portions 10 in the circumferential direction, is formed between the circumferentially adjacent magnetic pole portions 10…” Following this, in ¶ 0129 Takemoto teaches the gaps formed to open in the circumferential surface of the rotor reduces the influence of the magnetic repulsive force between the iron core portion and the teeth (of the stator), and the result is that torque is increased in the motor.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to make the rotor structure of Isoda, while incorporating magnetic radial bridges, as taught by Asano, in order to reduce the influence of the magnetic repulsive force between the core and the teeth thereby increasing motor torque (motivation taken from Takemoto ¶ 0129).
Neither Isoda nor Asano nor Takemoto explicitly teaches wherein the steel main body is a silicon steel main body.
Chen discloses yet another motor rotor core comprising (double) V-shaped magnetic slot structures with inner and outer magnetic bridges, and is deemed analogous art.
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Chen teaches wherein the steel main body [rotor lamination 20] is a silicon steel main body (¶ 0063 of the provided translation recites “the plurality of rotor laminations 20 are made of silicon steel sheets…”).
It would have been obvious to a person of ordinary skill in the art to make the rotor structure of Isoda in view of Asano, further in view of Takemoto, while using silicon steel for the steel main body of Isoda, as taught by Chen, in order to increase electrical resistivity, which keeps electricity from passing through the rotor, thereby mitigating energy loss and overheating, as is well known in the art (the Examiner notes that most of the references in PTO Form 892 are probably using silicon steel, they just don’t mention it by name, using the publication opportunity to discuss more important matters such as inventive concepts).
To summarize, Isoda provides the general structure of the relevant type rotor structure with V-shaped magnet slot groups and magnetic bridges, and Chen supplements the items that are not explicitly taught by Isoda but which are surely part of Isoda (i.e. silicon steel).
Isoda goes one step further in providing the blocking points, which are also known in the art (see discussion of references cited but not used in the Conclusion section below). Therefore, all of the clauses/features of claim 1 are known, and known to be used together in various ways, including in the way claimed in claim 1.
Asano and Takemoto best teach the radial magnetic bridges. The Examiner has included more prior art references in PTO Form 892 that teach them. This feature is also known but could not be located in a reference that also explicitly (in a way that would suffice as evidence to make a rejection) teaches the blocking points.
The Examiner believes that Takemoto has provided a modular explanation of the advantages of the radial magnetic bridges, and Asano and Takemoto show them in V-shaped-pole rotors, in the same place where the instant application shows them. The Examiner believes the motivation in Takemoto supports a prima facie case that a person of ordinary skill in the art would modify a rotor like Isoda and/or Chen to include the radial magnetic bridges like those taught in Asano and Takemoto. Both Isoda and US 2024/0372423 A1 (see Conclusion section below) teach the advantages of blocking points on top of teaching the blocking points themselves, such that there is also a prima facie case to allege it would be obvious to modify one of the references in PTO Form 892 that already has the radial magnetic bridges with that feature.
With respect to claim 12/11, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 11, but none of the references explicitly teaches wherein the width of the inner magnetic bridge is 1.5 an air gap width between the rotor structure and a stator structure. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the inner magnetic bridge width and the air gap width. Increasing the inner magnetic bridge width augments mechanical strength of the rotor but reduces the magnetic circuit, such that it is kept as small as possible without mechanical failure. Increasing air gap width reduces torque and efficiency of the motor, such that it is kept as small as possible without being allowed to touch the stator. A practitioner of ordinary skill in the art would set out to make both as small as possible and during the course of optimizing the two values, could find that 1.5 is an optimum ratio during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor that does not contact the stator teeth, respectively.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 13/11, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 11, but none of the references explicitly teaches wherein the width of the outer magnetic bridge is equal to an air gap width between the rotor structure and a stator structure. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the outer magnetic bridge width and the air gap width. Increasing the outer magnetic bridge width augments mechanical strength of the rotor but reduces the magnetic circuit, such that it is kept as small as possible without mechanical failure. Increasing air gap width reduces torque and efficiency of the motor, such that it is kept as small as possible without being allowed to touch the stator. A practitioner of ordinary skill in the art would set out to make both as small as possible and during the course of optimizing the two values, could find that a 1-to-1 ratio is an optimum ratio during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor that does not contact the stator teeth, respectively.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 14/11, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 11, but none of the references explicitly teaches wherein the pair of radial magnetic bridges have a width greater than an air gap width between the rotor structure and a stator structure. However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the radial magnetic bridges’ widths and the air gap width. Increasing the radial magnetic bridges’ widths increases resistance between the poles but reduces mechanical strength of the rotor core, such that it (see Takemoto citation above) kept significantly large but obviously it is restricted by the space available and the tendency of the rotor to fly apart due to the weight of the magnets if they are made too big – in fact Asano’s entire discussion is about increasing their strength. Increasing air gap width reduces torque and efficiency of the motor, such that it is kept as small as possible without being allowed to touch the stator. A practitioner of ordinary skill in the art would set out to make the radial magnetic bridges larger but find her/himself constrained by Asano’s considerations, while making the air gap as small as possible, and during the course of optimizing the two values, could find that having the radial magnetic bridge width greater than the air gap width is an optimum condition during routine experimentation alone. The result effective variables are the most effective widths for both features, and they will be optimized for a rotor that does not mechanically fail and a rotor that does not contact the stator teeth, respectively.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
With respect to claim 15/11, Isoda in view of Asano, further in view of Takemoto, further in view of Chen, teaches the rotor structure of claim 11, Isoda further teaches a plurality of magnets [permanent magnets 50] disposed in the pair of inner magnet slots and the pair of outer magnet slots, each of the magnets [50] having a width W [W], and the blocking point has a height h [H] (width and height labeled in the fig. 4 excerpt attached below).
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Isoda does not explicitly teach wherein W/10<h<W/5. It does not describe such a ratio, and although fig. 4 appears to satisfy the range (h seems to be about equal to W/5), Isoda does not claim that its drawings are to-scale.
However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to attempt to find the optimum ratio between the blocking point height and the magnet width. The magnet width is set by the slot width, while the blocking point height needs to be just tall enough to disallow the magnet from getting wedged between it and the opposite wall, which would lead to the magnet wearing down the blocking point after millions of rotations and then slipping past. A practitioner of ordinary skill in the art would set out to make the blocking point as small as possible but making it too small would make it potentially unreliable at perpetually immobilizing the magnet. The optimized value is a result effective variable, which is the ratio that balances this tradeoff and there is enough evidence from fig. 4 of Isoda to predict that the routine experimentation performed to balance the tradeoff would be just as likely to result in a ratio under 1/5 as a ratio over 1/5, while a person of ordinary skill in the art would also predict that making it less than 1/10 risks the magnet wearing at the blocking point and/or wedging past it.
The applicant should note that it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Furthermore, the applicant should note that it has been held that where the general working conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
Allowable Subject Matter
Claims 8-9 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, and the claim objection to claim 8, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
With respect to claim 8, and claim 9 which depends therefrom, the prior art of record does not teach or reasonably suggest, inter alia, a rotor structure comprising:
a silicon steel main body has a plurality sets of magnetic poles, an axis and an outer edge, each set of magnetic pole has a double-layer V-shaped magnet slot structure;
wherein the double-layer V-shaped magnet slot structure includes an inner V-shaped magnet slot group near the axis and an outer V-shaped magnet slot group near the outer edge, the inner V-shaped magnet slot group has a first included angle between a pair of inner magnet slots, the outer V-shaped magnet slot group has a second included angle between a pair of outer magnet slots, the first included angle is smaller than the second included angle;
wherein the inner V-shaped magnet slot group has an inner magnetic bridge close to the axis along a radial direction, and the outer V-shaped magnet slot group has an outer magnetic bridge close to the axis along the radial direction, a width of the inner magnetic bridge is greater than a width of the outer magnetic bridge;
wherein any pair of the pair of inner magnet slots and the pair of outer magnet slots has two long edges, and the one of the two long edges that is relatively far away from the corresponding inner magnetic bridge or the corresponding outer magnetic bridge has a blocking point;
wherein the silicon steel main body has a rivet point, and a connection line between a geometric center of the rivet point and the axis passes through the inner magnetic bridge and the outer magnetic bridge; and
wherein the inner V-shaped magnet slot group or the outer V-shaped magnet slot group has a pair of radial magnetic bridges extending from the pair of inner magnet slots or the pair of outer magnet slots respectively, and the pair of radial magnetic bridges are farther from the axis than the inner magnetic bridge or the outer magnetic bridge;
wherein the silicon steel main body further includes a plurality of magnetic barrier structures disposed between the outer edge and the pair of outer magnet slots.
The prior art search did not turn up any references that have the claimed radial magnetic bridges disposed outwardly of the magnetic bridges of the V-shaped magnet slot group, wherein the same reference had multiple magnetic barrier structures between the outer edge and the pair of outer magnet slots.
Barrier structures between the outer edge and the pair of outer magnet slots are known in the art, well-enough known that the Examiner will omit citing an example here (although some are in the attached PTO Form 892). As shown above, and below in the conclusion section, radial magnetic bridges are also somewhat well known in the art. However, claim 1 is very narrow, even though the Examiner alleges it would be obvious to one of ordinary skill in art, such that further modifying the structure of Isoda in view of Asano, further in view of Takemoto, further in view of Chen, to incorporate one more structure, albeit a known structure, begins to verge on hindsight reasoning. But more importantly, adding multiple magnetic barrier structures radially outward of the outer magnet slots creates a new flux dynamic with the radial magnetic bridges, such that the Examiner does not believe that the result of doing so would be as predictable as adding them to a rotor without magnetic bridges. Thus, the Examiner believes a prima facie case for further modifying the structure of claim 1 with magnetic barrier structures is weak, and will not make it here.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2023/0208224 A1 teaches all of claim 11 and almost all of claim 1, including the inner V-shaped magnet slot group having a lesser included angle than the outer V-shaped magnet slot group as well as a considerably larger magnetic bridge width – importantly the reference does teach blocking points in the same embodiment with radial magnetic bridges.
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This reference was not used in the rejection because the blocking points are not explicitly described and the radial magnetic bridges are differently located and shaped from those of the instant application, such that the Examiner believed that the long-term prosecution would benefit by using Isoda in view of Asano, instead of this reference, even though doing it this way was more complicated (up front).
Similarly, CN 109660039 A teaches radial magnetic bridges [“auxiliary groove” 7] in combination with what appear to be undescribed blocking points.
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US 2024/0372423 A1 teaches blocking points as well as other features of claim 1.
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US 2016/0028279 A1 teaches blocking points.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANIEL K SCHLAK whose telephone number is (703)756-1685. The examiner can normally be reached Monday - Friday, 9:30 am - 6:00 pm EST.
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/Daniel K Schlak/Examiner, Art Unit 2834
/OLUSEYE IWARERE/Supervisory Patent Examiner, Art Unit 2834
Prosecution Insights