DETAILED ACTION
Claims 1-13 of U.S. Patent Application No. 18/684,456, filed on 16 February, 2024, were presented for examination. In a preliminary amendment also filed 16 February, 2026, claims 1-13 were canceled and new claims 14-25 were added. Claims 14-25 are currently pending in the application, with claims 14-16 and 22-25 withdrawn from consideration.
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 .
Election/Restrictions
Claims 14-16 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group I, there being no allowable generic or linking claim. Claims 22-25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group III, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 27 May, 2026.
As the application is approaching the allowance stage, Applicant is requested to cancel claims 14-16 and 22-25 in the ensuing response.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 16 February, 2024, and 27 May, 2026, were filed before the mailing date of this Office Action. The submissions are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
It is noted that the NPL citation “PCT International Search Report and Written Opinion of International Searching Authority” could not be considered because the Written Opinion document of the International Search Report is in German, and the Examiner is not fluent in the German language.
Drawings
The drawings are objected to because the pockets “10” (mentioned in ¶ 0072, 0086, and 0090) are not labeled (the reference numeral “10” should appear in at least one of figs. 4 and 5).
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification
The abstract of the disclosure is objected to because it does not correspond to the subject matter of elected Group II (method including stacking the core, inserting magnets, mixing the thixotropic potting compound, feeding the thixotropic potting compound, monitoring, etc). The abstract currently summarizes unelected Group I.
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). Applicant is welcome to any approach they choose, but the abstract should suffice to allow the public to have an idea of what is claimed upon reading the front page of the granted patent.
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 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 17-21 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.
Regarding claim 17, the phrase "in particular" in line 1 renders the claim indefinite because it is unclear whether the limitation following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Regarding claim 17, the phrase "in particular" in line 3 renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
In this case, the contingent limitations following “in particular” are referred to and/or serve as antecedent basis for the axial cut-outs (and consequently pockets, retaining elements, flux barriers) recited later in the claim. So, if the claim were read using the broadest reasonable interpretation, the limitations of lines 4-5 would be left out of consideration, and therefore claims 17-18 would have multiple instances of insufficient antecedent basis, and the claim could not be compared to the prior art and/or a potentially infringing device. The Examiner has interpreted the claim in the narrower sense, such that for examination on the merits, he considers the claim to include the cut-outs, pockets, retaining elements, and flux barriers (although the claim would still be allowable without the inclusion of “pockets, retaining elements and flux barriers” so perhaps those could be deleted during amendment altogether).
Regarding claim 17, the phrase "in particular" in line 14 renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d). The Examiner recommends Applicant simply remove “in particular up to 30oC” from the claim, since the broader range (up to 60oC) was used for examination on the merits, and the claim has been indicated as conditionally allowable anyway.
Regarding claim 17, the phrase "in particular" in line 15 renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d). The Examiner recommends Applicant simply remove “in particular up 4.5 to 5 bar” from the claim, since the broader range (up to 10 bar) was used for examination on the merits, and the claim has been indicated as conditionally allowable anyway.
Claim 17 recites the limitation "the filling" in line 20. There is insufficient antecedent basis for this limitation in the claim. A reader cannot determine whether it referrs to the “feeding” of line 13, or the limitations “gaps are filled” and “cut-outs are fully filled” in line 18.
Regarding claim 18, lines 1-2 recite the limitation “in an auxiliary device”. The Examiner found support for the auxiliary device in the specification and he believes the auxiliary device is a shaft on which, and not in which, the rotor is located, and he further suspects that this is probably a typo or mistranslation – that the word “in” should be changed to “on”. This was the interpretation used during examination on the merits.
Regarding claim 18, the phrase "in particular" in line 2 renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim 19 recites the limitation “balancing the rotor on the at least distribution disc”. Based on a review of the specification, the Examiner believes that this is also a typo or mistranslation, and that the issue can be remedied by changing the limitation to “balancing the rotor with the at least distribution disc”. This was the interpretation used during examination on the merits.
Regarding claim 21, the phrase "in particular" in line 2 renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim 20 is rejected for depending from rejected claim 17.
Allowable Subject Matter
Claims 17-21 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, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims, and if claim 17 were amended to include all the limitations of claim 14 in place of the limitation “potting compound as set forth in claim 14” in line 11.
With respect to claim 17, and all claims depending therefrom, the prior art of record fails to teach or reasonably suggest, inter alia, a method of producing a rotor, in particular of a permanently excited dynamo-electric machine, the method comprising:
stacking a laminated core of the rotor, in particular punch stacking with essentially axial cut-outs for accommodating permanent magnets, with the cut-outs having pockets, retaining elements and flux barriers;
inserting the permanent magnets into the pockets;
additional axial stacking of the laminated core by at least one distribution disc on an end face of the laminated core, with the distribution disc including at least one feed and at least one annular channel in communication with the at least one feed,
mixing a thixotropic potting compound in situ in a static or dynamic mixing tube;
said thixotropic potting compound comprising a base resin material formed as a two-component reactive resin containing a predefinable amount of a thermally conductive additive and/or an additive affecting a gelling of the potting compound, wherein Aerosil fumed silica is present in a range between 0.1-0.5% by volume;
feeding the thixotropic potting compound at an infeed temperature of up to 60oC, at a flow rate of up to 10 mm per second and at a predefinable pressure of up to 10, via the at least one feed of the distribution disc and via the at least one annular channel into a space not taken up by the permanent magnets in the cut-outs, until at least all axial gaps are filled or until the cut-outs are fully filled with the thixotropic potting compound; and
monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
The following reasons for allowance make reference to the references that have been summarized below, in the Conclusion section.
Buettner teaches the basic framework of the method, such as a) stacking the core and then b) additionally axially stacking a distribution disc on the end face of the core, the distribution disc having an annular channel in communication with a feed, subsequently c) feeding potting compound into the cut-outs of the rotor are filled, around the magnets, via the annular channel.
Buettner does not teach the potting compound being the thixotropic potting compound of claim 14. Buettner further does not teach monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
Darby teaches the thixotropic potting compound of claim 14.
The Examiner finds insufficient motivation in the references themselves to suggest it would have been obvious to a person of ordinary skill to modify Buettner’s method to use Darby’s thixotropic compound. Even if there was sufficient motivation, neither reference teaches monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
The prior art search turned up four references (including one from an IDS) that teach a thixotropic potting compound used to fill the area around the magnets inside the pockets of a rotor. They are Kasahara, Osaka, Hori, and Sato (again, see below). Each of these references fails to teach feeding the thixotropic potting compound into the space of the pockets/magnets, and therefore cannot teach lines 13-19 of claim 17 (which includes feeding at a temperature, rate, and pressure through an annular channel in a distribution disc).
These references potentially affect the patentability of claim 17 in two ways:
a) It could be alleged that they (one or more of them) would have motivated a person of ordinary skill in the art who was practicing the method of Buettner to use the thixotropic potting compound of Buettner. A potential rejection would be Buettner in view of [Kasahara, Osaka, Hori, or Sato], further in view of Darby. The Examiner cannot find sufficient motivation for structuring such a rejection that is not hindsight-reasoning or indicative of more-than-ordinary skill in the art. And even if such rejection were made, none of the references teaches monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
b) It could be alleged that Kasahara, Osaka, Hori, or Sato would (as a base reference) be obvious for modification via Buettner on the potting-feeding/insertion end, and also obvious for modification via Darby on the thixotropic-compound end – in other words, hypothetically, Kasahara teaches a method while omitting injection molding via a distribution disc (with an annular channel) and the recipe for thixotropic compound of claim 14, and it would be obvious to modify the former (method) with Buettner’s method and the latter (potting recipe) with Darby’s recipe. Again, the Examiner cannot find sufficient motivation for structuring such a rejection that is not hindsight-reasoning or indicative of more-than-ordinary skill in the art. And even if such rejection were made, none of the references teaches monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
Since the step of monitoring of the filling of the rotor by detecting a dynamic versus static pressure of the potting compound corresponds to the varying viscosity of the potting compound while it is filling the cut-outs, and this would only be useful for doing so while using a thixotropic potting compound, the Examiner believes that the omission of this step in the art of record completely precludes any attempt at rejection under 35 U.S.C. 103.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Buettner (DE 102008027758 A1, provided herein with machine translation) teaches a method for producing a rotor [1] of a dynamo-electric machine, the method comprising:
stacking a laminated core [11] of the rotor with cut-outs [2] for accommodating permanent magnets (see ¶ 0031-0037 and joint annotated excerpt of figs. 1-2 attached below);
additional axial stacking of the laminated core by at least one distribution disc [end disk 6] on an end face of the laminated core [11], with the distribution disc including at least one feed [F/12] and at lest one annular channel [7] in communication with the at least one feed;
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feeding potting compound at an infeed temperature at a predefinable pressure (see ¶ 0035-0036) via the at least one feed [F/12] of the distribution disc [6] and via the at least one annular channel [7] into a space not taken up by the permanent magnets in the cutouts – it can be understood that the feeding is done until at least all axial gaps are filled or until the cut-outs are fully filled.
Buettner does not teach (claim 14) wherein the potting compound is a thixotropic potting compound comprising a base resin material formed as a two-component reactive resin containing a predefinable amount of a thermally conductive additive and/or an additive affecting a gelling of the potting compound, wherein Aerosil fumed silica is present in a range between 0.1-0.5% by volume.
Significantly, Buettner does not teach monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
It is also noted that Buettner teaches letting the finished product cool to room temperature after curing, so it can be assumed that the temperature of feeding is greater than 60o.
Darby (US 6,280,846 B1) teaches the thixotropic potting compound of claim 14, which is invoked in line 11 of claim 17 – specifically Darby teaches a thixotropic compound (the “composition” recited in col. 2, lines 47-65) for fixing a permanent magnet in a rotor of a permanently excited synchronous machine (it is a composition “for moulding” and thus could be used for potting anything), the thixotropic potting compound comprising a base resin material [combined unsaturated polyester resin (item “a”) and co-polymerisable monomer (item “b”)] formed as a two-component reactive resin [the base resin consisting of items “a” and “b”] containing a predefinable amount of a thermally conductive additive and/or an additive affecting a gelling of the potting compound [thixotropic agent (item “c”)], wherein fumed silica is present in a range between 0.1-0.5% by volume” {col. 4, lines 17-24 recite, inter alia, “optimum performance…. is achieved by simultaneous incorporation of minor amounts of fumed silica, for example 0.1% to 2.5%...” (the term “Aerosil” has been disregarded since it is a trade name and should be removed from the claims in the next amendment)}.
Kasahara (WO 2013013128 A2, provided herein) provides a method for producing a rotor of a dynamo-electric machine. Although the stacking of the laminated core is not described, it would be an obvious step and although only pockets [140] are shown, retaining elements and flux barriers are common in the art.
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Kasahara teaches inserting the permanent magnets [110] into the pockets [140].
Kasahara further teaches {vis-à-vis claim 14} a multi-component potting compound [10] which contains a base resin [curable thermally expanding epoxy resin] formed as a two-component reactive resin reactive resin containing a predefinable amount of a thermally conductive additive and/or an additive affecting a gelling of the potting compound {see the second paragraph of page 3 which recite, inter alia, “(a) a curable epoxy resing, (b) a latent hardening agent, (c) thermally expanding capsules, and (d) solvent…”}. Kasahara specifically recites that the agent is “a thixotropic agent such as fumed silica, and a heat conductive filler such as boron nitride, and the like…” (page 11, lines 16-17).
Thus, Kasahara inherently teaches mixing the thixotropic potting compound. Doing so in a tube would have been obvious to a person of ordinary skill.
However, Kasahara does not teach the method steps of feeding the thixotropic potting compound (into the rotor) at an infeed temperature, via a feed in a distribution disc, into the space not taken up by the permanent magnets, because Kasara prefabricates magnet-potting laminated plies before inserting them into the rotor pockets. Thus, Kasahara cannot teach monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
Osaka (US 223/0183414 A1) teaches a curable composition comprising fumed silica (¶ 0134 – so it is thixotropic), and which is described in the abstract ¶ 0010-0012 as being similar to, but not completely like, claim 14. Further, ¶ 0026 recites that the composition could be used “for fixing a magnet inserted into a hole provided in a rotor core…”
Osaka’s composition is mixed (blended).
Like Kasahara, Osaka does not teach the method steps of feeding the thixotropic potting compound (into the rotor) at an infeed temperature, via a feed in a distribution disc, into the space not taken up by the permanent magnets. Thus, Osaka cannot teach monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
Hori (JP 2003176459 A, provided herein with machine translation) is one more of the handful of references that teaches a thixotropic potting compound in conjunction with inserting magnets into rotor pockets (see the end of ¶ 0011 as well as elsewhere in the translation) wherein the potting compound having thixotropic agents, viscosity modifiers, plasticizers (¶ 0030).
Hori makes a single reference to injection molding the magnets in the rotor but this is only done during a discussion of the background, and the discussion is accompanied by a list of drawbacks in the state of the art. Consequently Hori does not teach the method steps of feeding the thixotropic potting compound (into the rotor) at an infeed temperature, via a feed in a distribution disc, into the space not taken up by the permanent magnets. Thus, Hori cannot teach monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
Sato (JP 2019140848 A, provided by Applicant in an IDS) is the last example (of 4) known by the Examiner of a rotor having a thixotropic potting compound used for securing the magnets in the pockets.
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Like Kasahara, Sato does not teach the method steps of feeding the thixotropic potting compound (into the rotor) at an infeed temperature, via a feed in a distribution disc, into the space not taken up by the permanent magnets, because Sato prefabricates magnet-potting laminated plies before inserting them into the rotor pockets (the reference recites “in assembling the rotor 3, after the magnet 34 to which the adhesive 60 has been applied in advance is stacked…”). Thus, Sato cannot teach monitoring the filling of the rotor by detecting a dynamic versus static pressure of the potting compound.
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
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