DETAILED ACTION
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 29 October 2025 has been considered by the examiner.
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 8, 10-11, 18, 20-22 & 26 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Gluckstern et al. (US 4,538,130).
Regarding claim 8, Gluckstern teaches a magnet comprising a plurality of permanent magnet units,1 each of the plurality of permanent magnet units comprising:
a main pole piece (segment) 12a including permanent magnet sheets (blocks 14a/16a/18a/20a comprising plates 110) with a substantially same first thickness (Fig.3A), the permanent magnet sheets of the main pole piece 12a being stacked in a first stacking direction which is in a direction of the first thickness (i.e., direction generally parallel to y-axis; Fig.1)…; and
an auxiliary pole piece (segment) 12b including permanent magnet sheets (blocks 14b/16b/18b/20b comprising plates 110) with a substantially same second thickness, the permanent magnet sheets of the auxiliary pole piece 12b being stacked in a second stacking direction which is in a direction of the second thickness (i.e., direction angled related to y-axis; Fig.1), wherein the second stacking direction of the permanent magnet sheets 110 of the auxiliary pole piece 12b crosses a second magnetization direction of the permanent magnet sheets 110 of the auxiliary pole piece 12b (note directions of respective second stacking and easy-axis of magnetization of auxiliary pole piece 12b; Fig.1).
wherein the auxiliary pole piece 12b is positioned adjacent to the main pole piece 12a with the second stacking direction and the second magnetization direction of the permanent magnet sheets 110 of the auxiliary pole piece 12b differing from the first stacking direction and a first magnetization direction of the permanent magnet sheets 110 of the main pole piece 12a (i.e., note respective stacking directions and easy-axes of magnetization; Fig.1), with a magnetic flux being focused at the main pole piece 12a (Fig.1),
wherein each of the permanent magnet units includes the main pole piece 12a and the auxiliary pole piece 12b joined together, and each of the plurality of the permanent magnet units having the same cross-sectional shape including the main pole piece and the auxiliary pole piece joined together are arranged in a predetermined direction (note same cross-sectional shape of all the segments 12a-12p; Fig.1).
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Regarding the feature of “the first stacking direction of the permanent magnet sheets of the main pole piece crosses the first magnetization direction of the permanent magnet sheets of the main pole piece”, while the example in Figs.3A-3C shows the sheets 110 stacked in a “down” direction corresponding to a preselected, easy-axis of magnetization direction 120 of block 100 (c.7:62-64), the pre-selected easy-axis of magnetization of the block may be in other directions since Gluckstern teaches the fabrication method includes “providing a rectangular-shaped magnet block with an easy-axis of magnetization parallel to a first surface thereof ...” (c.4:40-43). Thus, for instance, a “first surface” may be taken as the reference such that the easy-axis of magnetization 120 of the block 100 is perpendicular to the stacking direction of sheets 110 (instead of “down” as shown in Fig.3), in which case “the first stacking direction of the permanent magnet sheets [110] of the main pole piece [12a] crosses the first magnetization direction of the permanent magnet sheets of the main pole piece.” Although not explicitly described, Gluckstern implicitly encompasses the claimed feature.
Regarding claim 10, the first thickness is the same as the second thickness (since all blocks are made from “standard size” plates of material; c.7:59; Fig.3A).
Regarding claim 11, at least one of the main pole piece 12a and the auxiliary pole piece 12b is further divided in a direction orthogonal to the respective first thickness or to the respective second thickness (corresponding to blocks 14a/16a/18a/20a and 14b/16b/18b/20b; Fig.2).
Regarding claim 18, Gluckstern teaches a method of manufacturing a magnet, comprising:
constructing a main pole piece 12a by “cutting out” [sic] a stacked body (block) 100 including a stack of permanent magnet sheets 110 from a predetermined direction (i.e., block 100 cut into elements; c.4:36-57; c.7:52-c.8:16; Figs.3A-3C), the stack of permanent magnet sheets 110 of the main pole piece being stacked in a first stacking direction which is in a direction of thickness of a sheet in the stack of permanent magnet sheets of the main pole piece (Fig.3A)…;
constructing an auxiliary pole piece 12b by “cutting out” [sic] a stacked body 100 including a stack of permanent magnet sheets 110, the stack of permanent magnet sheets of the auxiliary pole piece 12b being stacked in a second stacking direction which is in a direction of thickness of a sheet in the stack of permanent magnet sheets of the auxiliary pole piece (c.3:36-57; c.7:52-c.8:16; Figs.3A-3C), wherein the second stacking direction of the permanent magnet sheets 110 of the auxiliary pole piece 12b crosses the second magnetization direction of the permanent magnet sheets of the auxiliary pole piece (note directions of respective second stacking and easy-axis of magnetization of auxiliary pole piece 12b; Fig.1);
positioning the auxiliary pole piece 12b adjacent to the main pole piece 12a with the first stacking direction and a first magnetization-direction of the permanent magnet sheets 110 of the auxiliary pole piece 12b differing from the second stacking direction and a second magnetization direction of the permanent magnet sheets 110 of the main pole piece 12a, with a magnetic flux being focused at the main pole piece (Fig.1), and
arranging a plurality of permanent magnet units in a predetermined direction, each of the plurality of the permanent magnet units including the main pole piece 12a and the auxiliary pole piece 12b joined together, and each of the plurality of the permanent magnet units having the same cross-sectional shape including the main pole piece and the auxiliary pole piece joined together (note same cross-sectional shape of all the segments 12a-12p; Fig.1).
Regarding the feature “wherein the first stacking direction of the permanent magnet sheets of the main pole piece crosses the first magnetization direction of the permanent magnet sheets of the main pole piece”, Gluckstern teaches the fabrication method includes “providing a rectangular-shaped magnet block with an easy-axis of magnetization parallel to a first surface thereof ...” (c.4:40-43). Thus, for instance, a “first surface” may be taken as the reference such that the easy-axis of magnetization 120 of the block 100 is perpendicular to the stacking direction of sheets 110 (instead of “down” as shown in Fig.3), in which case “the first stacking direction of the permanent magnet sheets [110] of the main pole piece [12a] crosses the first magnetization direction of the permanent magnet sheets [110] of the main pole piece [12a]”. Although not explicitly described, Gluckstern implicitly encompasses the claimed feature.
Regarding claim 20, the second stacking direction of the permanent magnet sheets 110 of the auxiliary pole piece 12b is “diagonal” (in the sense of being angled with respect to) the first stacking direction of the permanent magnet sheets 110 of the main pole piece 12a and is also “diagonal” to a direction perpendicular to the first stacking direction of the permanent magnet sheets 110 of the main pole piece 12a (Fig.1).
Regarding claim 21, as best understood, a quantity of sheets in at least one of the permanent magnet sheets 110 of the main pole piece 12a and the permanent magnet sheets of the auxiliary pole piece 12b is greater than or equal to a quantity of “divisions perpendicular to” [sic] the respective first stacking direction or to the respective second stacking direction (e.g., a block 100 comprises eight plates 110; c.7:62-63, which is more than the divisions in the direction perpendicular to the respective stacking directions; Fig.1).
Regarding claim 22, at least one the permanent magnet sheets 110 of the main pole piece 12a and the permanent magnet sheets 110 of the auxiliary pole piece 12b are “divided” [sic] in a direction different from the respective first stacking direction or from the respective second stacking direction (e.g., note directions of divisions formed by various cuts in block 100; Figs.3A-3C).
Regarding claim 26, the magnetization direction of the permanent magnet sheet that constitutes the main pole and the magnetization direction of the permanent magnet sheet that constitutes an interpole forms an acute angle (Fig.1).
Claims 8, 10, 13, 19, 22, 26 & 28-29 are rejected under 35 U.S.C. 103 as being unpatentable over Smith et al. (US 8,400,038) in view of Rong (US 11,894,719).
Regarding claim 8, Smith teaches a magnet comprising a plurality of permanent magnet units 2, each of the plurality of permanent magnet units comprising:
a main pole piece including (center) permanent magnet sheets 421a/422a with a substantially same first thickness, the permanent magnet sheets of the main pole piece being stacked in a first stacking direction which is in a direction of the first thickness (i.e., horizontal direction, Fig.6B), wherein the first stacking direction of the permanent magnet sheets 421a/422a of the main pole piece crosses the first magnetization direction of the permanent magnet sheets 421a/422a of the main pole piece (i.e., magnet segments 421a and 422a have angles of polarization slightly less than and slightly greater than the nominal angle of polarization; Fig.6B),
an auxiliary pole piece including permanent magnet sheets 421b/421c/421d/421e with a substantially same second thickness, the permanent magnet sheets of the auxiliary pole piece being stacked in a second stacking direction which is in a direction of the second thickness (i.e., horizontal direction, Fig.6B), wherein the second stacking direction of the permanent magnet sheets of the auxiliary pole piece 421b/421c/421d/421e crosses the second magnetization direction of the permanent magnet sheets 421b/421c/421d/421e of the auxiliary pole piece (i.e., each successive magnet segment 422b, 422c, 422d, 422e has an angle of polarization greater than the magnet segment immediately preceding it, while each successive magnet segment 421b, 421c, 421d, 421e has an angle of polarization less than the magnet segment immediately preceding it; c.8:30-52; Fig.6B),
wherein the auxiliary pole piece 421b/421c/421d/421e is positioned adjacent to the main pole piece 421a/422a with…the second magnetization direction of the permanent magnet sheets of the auxiliary pole piece 421b/421c/421d/421e differing from…the first magnetization direction of the permanent magnet sheets of the main pole piece 421a/422a (i.e., note arrows denoting respective flux axes of auxiliary poles piece 421b/421c/421d/421e and main pole piece 421a/422a; Fig.6B) with a magnetic flux being focused at the main pole piece 421a/422a, and
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wherein each of the permanent magnet units includes the main pole piece 421a/422a and the auxiliary pole piece 421b/421c/421d/421e joined together, and each of the plurality of the permanent magnet units having the same cross-sectional shape including the main pole piece and the auxiliary pole piece joined together are arranged in a predetermined direction (note same cross-sectional shape of multiple units in, e.g., Figs.16, 20a & 23).
Smith differs only in that the first and second stacking directions are the same, i.e., “the second stacking direction…of the permanent magnet sheets of the auxiliary pole piece [421b/421c/421d/421e]” does not “differ[r] from the first stacking direction…of the permanent magnet sheets of the main pole piece [421a/422a].”
But, Rong teaches a permanent magnet 78 of a rotor including a main pole (central) piece 120 and auxiliary pole pieces (sides) 108, 110 comprising respective magnet sheets (corner pieces) 140/158 and 174/190 stacked in direction of the magnetization (easy-axis) direction 210 of the main pole piece 120 but with magnetization (easy) axes oblique with respect thereto (c.5:12-17; Fig.5). By using multiple pieces of magnetic material, some of which have different magnetization/easy-axis directions, the magnet increases resistance to demagnetization (c.5:4-6) and reduces eddy-current loss (c.6:36-37).
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Thus, it would have been obvious before the effective filing date to modify Smith’s auxiliary pole and provide an auxiliary pole with a stacking direction as taught by Rong since this would have increased resistance to demagnetization and reduces eddy-current loss. Further, in the combination, the second stacking direction of the permanent magnet sheets of the auxiliary pole piece of Rong differs from the second stacking direction of the permanent magnet sheets of the main pole piece of Smith.
Regarding claim 10, in Smith the first thickness is the same as the second thickness.
Regarding claim 13, in Smith a rotor includes the magnet (c.18:15-154; Figs.26-27). Similarly, Rong teaches a rotor includes the magnet (abstract).
Regarding claim 19, Smith teaches the magnet segments are bonded together to form the permanent magnet unit (c.23:44-46). Similarly, Rong teaches the main pole piece and the auxiliary pole piece are bonded together (c.4:49-50).
Regarding claim 22, in the combination, the permanent magnet sheets of the auxiliary pole piece of Rong are “divided in a direction different” [sic] from the respective first stacking direction or from the respective second stacking direction of Smith.
Regarding claim 26, the magnetization direction of the permanent magnet sheet that constitutes the main pole and the magnetization direction of the permanent magnet sheet that constitutes an interpole forms an acute angle (Smith, Figs.6B&7B).
Regarding claim 28, every other adjacent permanent magnet unit among the plurality of permanent magnet units has the same magnetization direction of the main pole piece and auxiliary pole piece (i.e., alternate N & S poles in Smith, Fig.35-36).
Regarding claim 29, the permanent magnet units are arranged consecutively in the circumferential direction of the motor, and the cross-sectional shape of the magnet units in a direction perpendicular to the axial direction of the motor is the same for adjacent permanent magnet units among the plurality of permanent magnet units (e.g., plural poles of Smith, Figs.33-36).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Smith, further in view of Rong and Pan (US 5,184,395).
Regarding claim 18, Smith teaches a method of manufacturing a magnet, comprising:
constructing a main pole piece…, the stack of permanent magnet sheets of the main pole piece 421a/422a being stacked in a first stacking direction which is in a direction of thickness of a sheet in the stack of permanent magnet sheets of the main pole piece, wherein the first stacking direction of the permanent magnet sheets of the main pole piece 421a/422a crosses the first magnetization direction of the permanent magnet sheets of the main pole piece (i.e., magnet segments 421a and 422a have angles of polarization slightly less than and slightly greater than the nominal angle of polarization; Fig.6B)
constructing an auxiliary pole piece…, the stack of permanent magnet sheets of the auxiliary pole piece 421b/421c/ 421d/421e being stacked in a second stacking direction which is in a direction of thickness of a sheet in the stack of permanent magnet sheets of the auxiliary pole piece; the second stacking direction of the permanent magnet sheets of the auxiliary pole piece 421b/421c/421d/421e crosses the second magnetization direction of the permanent magnet sheets of the auxiliary pole piece (i.e., each successive magnet segment 422b, 422c, 422d, 422e has an angle of polarization greater than the magnet segment immediately preceding it, while each successive magnet segment 421b, 421c, 421d, 421e has an angle of polarization less than the magnet segment immediately preceding it; c.8:30-52), and
positioning the auxiliary pole piece adjacent to the main pole piece with the second stacking direction and a second magnetization-direction of the permanent magnet sheets of the auxiliary pole piece 421b/421c/ 421d/421e differing from the…first magnetization direction of the permanent magnet sheets of the main pole piece 421a/422a (i.e., note arrows denoting respective flux axes of auxiliary poles piece 421b/421c/421d/421e and main pole piece 421a/422a; Fig.6B) with a magnetic flux being focused at the main pole piece (Fig.6B), and
arranging a plurality of permanent magnet units in a predetermined direction, each of the permanent magnet units including the main pole piece and the auxiliary pole piece joined together, and each of the plurality of the permanent magnet units having the same cross- sectional shape including the main pole piece 421a/422a and the auxiliary pole piece 421b/421c/421d/421e joined together (note same cross-sectional shape of multiple units in, e.g., Figs.16, 20a & 23).
Smith does not teach “the first stacking direction…of the permanent magnet sheets of the auxiliary pole piece differ[s] from the second stacking direction…of the first permanent magnet sheets of the main pole piece.” Also, Smith does not teach constructing the main and auxiliary pole pieces “by cutting out a stacked body including a stack of permanent magnet sheets from a predetermined direction.”
But, regarding the first difference, Rong teaches a permanent magnet 78 of a rotor including a main pole (central) piece 120 and auxiliary pole pieces (sides) 108, 110 comprising respective magnet sheets (corner pieces) 140/158 and 174/190 stacked in direction of the magnetization (easy-axis) direction 210 of the main pole piece 120 but with magnetization (easy) axes oblique with respect thereto (c.5:12-17; Fig.5). By using multiple pieces of magnetic material, some of which have different magnetization/easy-axis directions, the magnet increases resistance to demagnetization (c.5:4-6) and reduces eddy-current loss (c.6:36-37).
Thus, it would have been obvious before the effective filing date to modify Smith’s auxiliary pole and provide and auxiliary pole with a stacking direction as taught by Rong since this would have increased resistance to demagnetization and reduces eddy-current loss. Further, in the combination, the second stacking direction of the permanent magnet sheets of the auxiliary pole piece of Rong differs from the first stacking direction of the permanent magnet sheets of the main pole piece of Smith.
Regarding the second difference, Pan teaches a method of manufacturing a field generators (MF), including a method of cutting and arranging tiles of magnetic material to obtain designated shapes for assembly into magnet forming elements (EFM). The method comprises constructing a main pole piece by cutting out a stacked body including a stack of permanent magnet sheets from a predetermined direction (i.e., in step 7, assembled tiles are cut into sections with, e.g., rectangular shapes; c.3:60-66; claim 1, Figs.1&2g). Pan’s method provide a process for producing magnetic field generators using conventional magnetic tiles, thereby overcoming the obstacles and drawbacks of the presently used technologies such as errors and dissymmetries introduced in the magnetic system resulting in field non-uniformities (c.1:31-54).
Thus, it would have been obvious before the effective filing date to cut out a stacked body of the main and auxiliary pole pieces of Smith and Rong since Pan teaches this method would have provided a process for producing magnetic field generators using conventional magnetic tiles, thereby overcoming obstacles and drawbacks such as errors and dissymmetries introduced in the magnetic system resulting in field non-uniformities.
Allowable Subject Matter
Claim 12 is allowed.
The prior art of record does not appear to teach the claimed magnet including, inter alia, “the permanent magnet unit…includes, in a portion of a core being a thrust generation element, a T-shaped magnet holder including a wall-shaped part extending in a direction orthogonal to the thrust generation direction between the permanent magnet units, and an enlarged part extending from an end of the wall-shaped part in a direction overlaying a corner portion on an end side of each of the permanent magnet units, and wherein the outer peripheral surface of the permanent magnet unit is exposed between adjacent magnet holders.”
Claims 24-25 & 27 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The prior art does not further teach:
“the stacked direction and magnetization direction of each permanent magnet sheet are perpendicular to each other in each of the main pole piece and auxiliary pole piece” (claim 24); or
“wherein the magnetization direction of each permanent magnet sheet is aligned in each of the main pole piece and auxiliary pole piece” (claim 25); or
“the magnetization directions of the main poles and an interpole of adjacent magnet units are opposite to each other” (claim 27).
Response to Arguments
Applicant’s arguments filed 31 December 2025 have been considered but are not wholly persuasive.
Regarding Gluckstern as applied to claim 8, Applicant argues each of the plurality of permanent magnet units does not have the same cross-sectional shape (Response, p.10). This is not persuasive since, as seen in Fig.1 for example, each of the plurality of permanent magnet units comprises a segment block forming the main pole piece (e.g., segment block 12a) joined to a segment block forming an auxiliary pole piece (e.g., segment block 12b). As evident from Fig.1, both have the same cross-sectional shape, as do all the other blocks.
Regarding Smith and Rong as applied to claim 8, it was argued Rong does not teach various features (1)-(3) (Response, p.11). This is not persuasive. As noted in the rejection, Smith teaches all these features except for “the second stacking direction…of the second permanent magnet sheets of the auxiliary pole piece differ[s] from the first stacking direction…of the first permanent magnet sheets of the main pole piece.” Rong meanwhile a permanent magnet 78 of a rotor including a main pole (central) piece 120 and auxiliary pole pieces (sides) 108, 110 comprising respective magnet sheets (corner pieces) 140/158 and 174/190 stacked in direction of the magnetization (easy-axis) direction 210 of the main pole piece 120 but with magnetization (easy) axes oblique with respect thereto (c.5:12-17; Fig.5). By using multiple pieces of magnetic material, some of which have different magnetization/easy-axis directions, the magnet increases resistance to demagnetization (c.5:4-6) and reduces eddy-current loss (c.6:36-37). Thus, with respect to Smith’s auxiliary pole and its stacking direction, it would have been obvious before the effective filing date to provide an auxiliary pole with a stacking direction as taught by Rong since this would have increased resistance to demagnetization and reduces eddy-current loss. In the combination, the second stacking direction of the permanent magnet sheets of the auxiliary pole piece 140/158 or 174/190 of Rong differs from the second stacking direction of the permanent magnet sheets of the main pole piece 421a/422a of Smith.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BURTON S MULLINS whose telephone number is (571)272-2029. The examiner can normally be reached 9-5. 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.
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/BURTON S MULLINS/Primary Examiner, Art Unit 2834
1 In the Fig.1 embodiment, there are four units, including main pole pieces/segments 12a, 12e 12i and 12m, each with auxiliary pole pieces on either side.
2 For example, plural magnet assemblies 20 on a rotor; c.7:45-47; c.13:15-27; Figs.16, 20a & 23.