DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This Office Action is responsive to the Applicant's communication filed 22 December 2025. In view of this communication, claims 1-16 are now pending in the application, with claim 16 being withdrawn from consideration.
Election/Restriction
Claim(s) 16 is/are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 22 December 2025.
Priority
Receipt is acknowledged of papers submitted under 35 U.S.C. 119(a)-(d) or (f), 365(a) or (b), or 386(a), which papers have been placed of record in the file.
Disclosure
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.
The following title is suggested:
Stator Assembly with Potting Body Form Fit to Housing Receptacle Portion
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification.
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 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.
Claim(s) 1-9 and 11-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lieu et al. (US 2001/0045782 A1), hereinafter referred to as “Lieu”, in view of Kreidler et al. (US 2016/0069349 A1), hereinafter referred to as “Kreidler”.
Regarding claim 1, Lieu discloses a stator assembly [41] for a spindle motor [40] having a rotation axis (fig. 4-12; ¶ 0064), comprising:
a stator receptacle portion [42r] of a motor housing [42r] of the spindle motor [40], wherein the stator receptacle portion [42rp] defines a disk-shaped contact face [42cf] for receiving the stator [41] (fig. 4, 10-11; ¶ 0067; the stator is attached to a recess within the base plate, 42),
a stator [41], which is disposed on the disk-shaped contact face [42cf] (fig. 4), and
a potting body [56] (fig. 4; ¶ 0064-0067),
wherein the stator [41] is potted in the stator receptacle portion [42rp] (¶ 0067),
PNG
media_image1.png
444
1157
media_image1.png
Greyscale
the potting body [56] is connected to the stator receptacle portion [42rp] in a form- fitting manner in such a way that the stator [41] in the stator receptacle portion [42rp] is secured by the potting body [56] at least in the axial direction (fig. 4; ¶ 0064, 0067; the thermoplastic material extends through the holes in the base plate, fixing the stator thereto due to the larger area of the holes on the opposite side).
Lieu does not disclose the spindle motor being an axial flux motor.
Kreidler discloses a spindle motor [14] arranged as an axial flux motor with a stator [30] arranged axially adjacent to a rotor [32] within a housing [56] (fig. 1-3; ¶ 0033).
PNG
media_image2.png
548
899
media_image2.png
Greyscale
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to form the motor of Lieu as an axial flux motor as taught by Kreidler, in order to reduce axial thickness, weight and complexity, and the associated costs thereof (¶ 0003 of Kreidler).
Regarding claim 2, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 1, as stated above, wherein the potting body [56] is connected to the stator receptacle portion [42rp] in a form-fitting manner by way of one groove [55] or a plurality of grooves [55] (fig. 4, 10-11; ¶ 0064, 0067, 0079).
Regarding claim 3, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 2, as stated above, wherein the one groove [55] or the plurality of grooves [55] is/are recessed into the stator receptacle portion [42rp] in at least one of radial direction and axial direction (fig. 4; the grooves extend axially, and the chamfered portion on the lower surface is also recessed in the radial direction).
Regarding claim 4, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 2, as stated above, wherein the one groove [55] or the plurality of grooves [55] is/are recessed into the stator receptacle portion [42rp] and configured in such a manner that the one groove [55] or the plurality of grooves [55] defines/define an undercut for the potting body [56] to engage with in the axial direction (fig. 4; ¶ 0064; “the holes are enlarged on the side of the baseplate opposite to the stator assembly 41, and the thermoplastic material is thus locked to the baseplate”).
Regarding claim 5, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 2, as stated above, wherein the potting body [56] engages in the one groove [55] or the plurality of grooves [55] (fig. 4; ¶ 0064; “the holes are enlarged on the side of the baseplate opposite to the stator assembly 41, and the thermoplastic material is thus locked to the baseplate”).
Regarding claim 6, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 2, as stated above, wherein the one groove [55] or the plurality of grooves [55] extends/extend in a substantially ring-shaped manner in the circumferential direction (fig. 10; ¶ 0067).
Regarding claim 7, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 2, as stated above, wherein the stator receptacle portion [42rp] comprises an axial end wall [42cf] which defines the disk-shaped contact face [42cf] (fig. 4, 11).
Regarding claim 8, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 7, as stated above, wherein at least one groove [55] is recessed into the axial end wall [42cf] in the axial direction (fig. 4; the grooves extend axially).
Regarding claim 9, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 7, as stated above, wherein the stator receptacle portion [42rp] furthermore comprises at least one of a radially inner ring-shaped wall [42iw] and a radially outer ring-shaped wall [42ow] which, conjointly with the axial end wall [42cf], delimit a ring-shaped depression (fig. 4, 10-11).
Regarding claim 11, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 7, as stated above, wherein at least one of the one groove [55] or plurality of grooves [55] extends in the axial direction away from the axial end wall [42cf] (fig. 4; the grooves extend axially).
Lieu, in view of Kreidler does not disclose the grooves extending by at most up to 30% of a maximum axial width of the potting body [56].
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to construct the grooves of Lieu with the relative dimensions claimed, for the purpose of limiting the size of the grooves and thus the axial space occupied by the motor, and since the only difference between the motor of Lieu and the claimed motor is a recitation of relative dimensions of the claimed device. In Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984).
Regarding claim 12, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 1, as stated above. Kreidler discloses the axial flux motor [14] furthermore comprising a cooling device [78] which is disposed so as to be in or axially adjacent to the stator receptacle portion [42rp] (fig. 1-5; ¶ 0041).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the motor of Lieu having a cooling device as taught by Kreidler, in order to dissipate heat generated by the stator windings thereby improving motor efficiency.
Regarding claim 13, Lieu, in view of Kreidler, discloses the stator assembly [41] as claimed in claim 1, as stated above, wherein the potting body [56] comprises a resin material (¶ 0047).
Regarding claim 14, Kreidler discloses an axial flux motor [14] for a fan [10] (fig. 1-2; ¶ 0029, 0035), comprising:
a motor housing [56] (fig. 1-3; ¶ 0038-0039),
a shaft [49] which is rotationally mounted in the motor housing [56] (fig. 1-3; ¶ 0038-0039),
at least one rotor [32] which is disposed so as to be rotationally fixed on the shaft [49] in the motor housing [56] (fig. 1-3; ¶ 0036),
a stator assembly [30], wherein the stator [30] is disposed so as to be axially adjacent to the rotor [32] in the motor housing [56] (fig. 3; ¶ 0033).
Lieu/Kreidler discloses the stator assembly [41] as claimed in claim 1, as stated above.
Regarding claim 15, Kreidler discloses a high-voltage fan [10] (fig. 1-2; ¶ 0029, 0035; the term “high voltage” does not imply any additional structural requirements, though Kreidler does disclose a three-phase motor, multi-phase motors typically operating at higher voltage levels) comprising:
an axial flux motor [14] (fig. 3; ¶ 0033), and
a fan wheel [12] which is mounted so as to be rotationally fixed on the shaft [49] outside the motor housing [56] (fig. 1-3; ¶ 0038-0039).
Lieu/Kreidler discloses the motor [40] as claimed in claim 14, as stated above.
Allowable Subject Matter
Claim(s) 10 is/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 following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 10, and all claims dependent thereon, the prior art does not disclose, inter alia, the stator assembly as claimed in claim 9, wherein the one groove or the plurality of grooves are recessed radially into at least one of the radially inner ring-shaped wall and the radially outer ring-shaped wall.
While the prior art discloses similar grooves in radial walls of stator receptacles, e.g. figure 1 of Iwasaki (cited below), such stator receptacles are not equivalent to those claimed as no axial end wall is present. And, no rationale has been found as to why one of ordinary skill in the art would have been motivated to combine these teachings with the grooves of the claimed stator receptacles. Thus, the prior art neither anticipates nor renders obvious the invention recited in claim 10, and shown in figure 3 of the application.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Citation of Relevant Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure. Prior art:
Koch et al. (US 2025/0030281 A1) discloses a molded stator within a stator receptacle with radial and axial surfaces, one radial surface having a recessed groove into which the mold material is form-fitted.
Iwasaki et al. (US 2015/0372544 A1) discloses an axial air gap motor having a stator within a stator receptacle with only a radial surface, the radial surface having a recessed groove into which the mold material is form-fitted.
Kim et al. (US 2010/0141058 A1) discloses an axial air gap motor for driving a fan assembly.
Kuwert et al. (US 5,986,365) discloses a molded stator within a stator receptacle with radial and axial surfaces, the axial surface having a recessed groove into which the mold material is form-fitted.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael Andrews whose telephone number is (571)270-7554. The examiner can normally be reached on Monday-Thursday, 8:30am-3:00pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Oluseye Iwarere can be reached at 571-270-5112. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Michael Andrews/
Primary Examiner, Art Unit 2834