DETAILED ACTION
Claims 1-13 of U.S. Patent Application No. 18/391,012, filed on 20 December, 2023, were presented for examination. In a preliminary amendment also filed 20 December, 2023, new claims 14-20 were added. In the response filed 24 December, 2025, claims 2-4, 6-9, and 14-20 were canceled and new claim 21 was added. Claims 1, 5, 10-13, and 21 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 .
Response to Arguments
Applicant's arguments filed 24 December, 2025, have been fully considered but they are not persuasive.
Applicant's arguments filed 24 December, 2025, with respect to rejections of claims 1-4, 6-12, 14-15, and 17 under 35 U.S.C. 102(a)(1) as anticipated by Hacklberger, claims 5 and 16 under 35 U.S.C. 103 as unpatentable over Hacklberger in view of Hossain, and claim 13 under 35 U.S.C. 103 as unpatentable over Hacklberger in view of Graves, have been fully considered but they are not persuasive.
In page 9 of the response, Applicant lists the limitations of claim 1, as amended, which includes, nearly verbatim, all limitations of original claims 1-4 and 6-10, inclusive. It is noted that all of these claims were indicated in the prior Office action as anticipated by Hacklberger.
At the bottom of page 9 Applicant alleges that the “coolant cap”, introduced in line 13 of claim 1 as currently amended, performs three distinct functions simultaneously: 1) constitute the axial end of the housing, 2) carry the rotor bearing, and 3) physically contain the coolant inlet, collecting area, and forwarding channel. The Examiner has already established, hereinbelow and in the prior Office action, that Hacklberger teaches these features, but as this is not the claim language, the Examiner will move on to deal with the allegation, at the top of page 10, that Hacklberger fails to disclose such a cap, and that it teaches 1) the bearing [13] supported by a bearing shield [11] (it is noted by the Examiner that the original rejection of claim 4 had bearing shield [11] as part of the “coolant cap” that is the crux of Applicant’s argument), 2) the coolant inlet/outlet [928/29] are located in a separate cover element [27] (it is noted by the Examiner that the original rejection of claim 4 had the cover element [27] as part of the “coolant cap” too), and 3) the cover element [27] is a separate part bolted onto the bearing shield [11].
The Examiner does not dispute this. The coolant cap, in the broadest reasonable interpretation of previous claims 5 and 10 and currently amended claim 1 that the Examiner is using, consists of the bearing shield [11] and cover element [27] bolted together. The bearing shield [11] and cover element [27] are bolted together and the combination yields a single coolant cap which constitutes the axial end of the housing, carries the bearing, and physically contains the coolant inlet, collecting area, and forwarding channel (see rejection of claim 1 below for details).
Applicant then alleges that the Office action asserts that the combination of the bearing shield [11] and the cover element [27] corresponds to the claimed coolant cap. The Examiner agrees, since this is what was laid out in the preceding paragraph.
Applicant then states, in line 8 of page 10, “however, the claimed coolant cap is singular”.
The Examiner counters – “the coolant cap of Hacklberger is singular” – once 11 and 27 are bolted together, they form a singular coolant cap, just like the plates of a vehicle differential, once bolted together, form a single differential, and just like a gasket seated in a bottle-cap combines with the bottle-cap to form a single cap.
And although this argument seems sufficient, by the Examiner, to explain why Hacklberger’s coolant cap is “singular” in a broadest reasonable interpretation, the Examiner must point out that claim 1 does not use real claim language or any limitation to establish why and how the claimed coolant cap should be interpreted as integral, unitary, or other near-synonyms of “singular” that are usually used in claims to establish that something is not composed of multiple parts. In other words, regardless of the basis of the argument and the rationales on both sides thereof, Applicant is arguing here something that is not actually in claim 1, a claim which at no point makes an attempt to limit the cooling cap to being of unitary construction in a way that precludes anticipation by Hacklberger.
Applicant then says what the bearing shield and cover element of Hacklberger don’t do what the coolant cap of the instant application does but again, the Examiner’s counter-argument isn’t about what each component does but what the combined structure does, since he has established that Hacklberger comprises a coolant cap that meets the relevant limitations of the claims.
Applicant then alleges that there is no motivation to merge the bearing shield and cover element into a single monolithic part, but again, the Examiner must point out that the claim does not have a limitation requiring this (monolithic could probably serve as another synonym for integral or unity, if it can be found in the specification). The motivation for combining will have to wait until the requisite limitation has been inserted in the claim for the Office to address it.
Applicant continues to allege deficiencies in Hacklberger that are outside the realm of the actual limitations of claim 1 as currently amended, and the Examiner’s counter remains the same – they do not materially make up for the broad interpretation of claim 1, as currently amended, that has Hacklberger anticipating it.
With respect to formal matters, Applicant asserts that the Substitute Drawing Sheets filed 12/24/2025, the amendments to the title and specification, and the amendments to the claims (and cancelation of objected-to claims), overcome the objection to Fig. 2, the specification objections, the claim objections, and the rejections under 35 U.S.C. 112. The Examiner concurs, these objections and rejections have been withdrawn.
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 1 and 10-12 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Hacklberger (US 2021/0376685 A1).
With respect to claim 1, Hacklberger teaches an electric machine [1] with
a housing [combined housing 3, bearing shield 11, mounting surface 11C, and cover 27] (see ¶ 0019 and 0030),
a rotor [combined rotor 7 and rotor shaft 10] with a rotor cooling channel [combined central recess 10a and annular space 10b, both part of rotor cooling portion 15a] (see ¶ 0021), and
a stator [stator 4 including core 5 and cooling jacket 30] with stator cooling channels [31, part of stator cooling portion 15b] (see ¶ 0031),
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the housing having a distribution system [15 including rotor cooling portion 15a and stator cooling portion 15b, as well as channel portion 32b] for guiding a coolant flow from the rotor cooling channel [10a/10b] to the stator cooling channels [31] (the last segment of ¶ 0031 recites “the further fluid channel portion 32b, on the other hand, forms a connection channel to the fluid cooling jacket 30 of the stator 4. The fluid cooling device 15 can accordingly have a cooling portion 15a for cooling the rotor 7 and a cooling portion 15b for cooling the stator 4. The cooling fluid flows successively through the cooling portions 15a, 15b, and a fluid connection provided therebetween is formed as a stationary, tubeless connection channel 32b” – it is noted that there is no figure showing the channel portion 32 in context with the other elements other than fig. 4 – however, fig. 3 in conjunction with ¶ 0030 describe a cover element 27 that houses the fluid channels 32a/32b and show how it relates to the axial ends of the stator and rotor);
wherein a collecting area [outlet 29] (see joint annotated excerpts of figs. 2, 3, and 4 below) for collecting the coolant flow exiting from the rotor cooling channel [10a/10b] is provided, the housing [3/11/11C/27] further having a forwarding channel [32b] (see fig. 4 excerpt above and also the citation from ¶ 0031) for guiding the coolant flow from the collecting area [29] to the stator cooling channels [31] (¶ 0031 recites “two fluid channel portions 32a, b in fluid communication with the fluid inlet channel 28 and the fluid outlet channel 29 of the cover element 27…” – the end of ¶ 0031 describes how channel portion 32b communicates with stator cooling portion 15b which has the channels 31 – also, the arrows in fig. 1 establish that the flow outside the tube 16, or in spaces 10a/10b, is passing left-to-right, such that in fig. 2 it must end at outlet 29);
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wherein a coolant inlet [combined fluid inlet channel 28, cooling tube 16, and axial projection 11e] for guiding coolant flow into the rotor [7/10] is provided (see fig. 2 excerpt above, wherein it is at the end of the inside of tube 16, while the arrows from fig. 1 show the flow passing from right-to-left inside the tube – ¶ 0031 recites “two fluid channel portions 32a,b in fluid communication with the fluid inlet channel 28 and the fluid outlet channel 29”);
wherein the coolant inlet [28/16/11e], the collecting area [29] and the forwarding channel [32b] (32b, as explained above and shown in fig. 4, is on first mounting surface 11c) are formed in a coolant cap [combined first bearing shield 11 which contains all elements 11a, 11b, 11c, 11d, and cover element 27] (in the new annotated excerpts of figs. 1 and 4 below, the Examiner has labeled an area of 11 and 27 that generally constitutes the “coolant cap” as claimed) which constitutes an axial end (the right end in fig. 1) of the housing [3/11/11C/27];
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wherein the coolant cap (labeled in the fig. 1 excerpt above and also in the new annotated excerpt of fig. 2 attached below) carries a bearing [first bearing 13] for a shaft [10] of the rotor [7] (see ¶ 0019);
wherein the rotor cooling channel [10a/10b] is provided within a rotor shaft [10] (referring again to the annotated fig. 2 excerpt above – also, see ¶ 0021 and fig. 1);
wherein one axial end (the left axial end – see ¶ 0026 and new annotated excerpt of fig. 1 attached below) of the rotor cooling channel [10a/10b] is closed [by closure 24];
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the coolant inlet [28/16/11e] is formed by a projection [11e, or 16 together with 11e] which extends into the rotor coolant channel [10a/10b] (see new annotated fig. 2 excerpt below and ¶ 0029 – keeping in mind that the coolant channels clearly run all the way to element 29); and
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wherein the coolant cap (roughly labeled area of elements 11 and 27 in fig. 2, new annotated excerpt attached below) comprises a central cavity (labeled in the excerpt, but also visible in fig. 1, generally the space radially inward of the windings of the stator and axially within the right-most extreme of end wall element 11c) in which an open axial end (the right end, and that shown entering from the left in fig. 2) of the rotor shaft [10] is arranged, the cavity receiving a coolant guiding element [base body 11d, shaded gray by the Examiner in the excerpt] having the projection [11e] and forming the collecting area [29] (see ¶ 0029).
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With respect to claim 10/1, Hacklberger teaches the machine of claim 1, and further teaches wherein the central cavity receives a coolant guiding element [base body 11d, shaded gray by the Examiner in the excerpt] having the projection [11e] (see ¶ 0029).
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With respect to claim 11/1, Hacklberger teaches the machine of claim 1, and further teaches wherein the rotor cooling channel [10a/10, part of rotor cooling portion 15a], the collecting area [29], the forwarding channel [32b] and the stator cooling channels [31, part of stator cooling portion 15b] are connected (see new annotated joint excerpt of figs. 1 and 4 attached below) in series so as to receive the entire coolant flow (the last segment of ¶ 0031 recites “the further fluid channel portion 32b, on the other hand, forms a connection channel to the fluid cooling jacket 30 of the stator 4. The fluid cooling device 15 can accordingly have a cooling portion 15a for cooling the rotor 7 and a cooling portion 15b for cooling the stator 4. The cooling fluid flows successively through the cooling portions 15a, 15b, and a fluid connection provided therebetween is formed as a stationary, tubeless connection channel 32b” – it is noted that there is no figure showing the channel portion 32 in context with the other elements other than fig. 4 – however, fig. 3 in conjunction with ¶ 0030 describe a cover element 27 that houses the fluid channels 32a/32b and show how it relates to the axial ends of the stator and rotor – it has been established already above how collecting area is the inlet for 32b).
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With respect to claim 12/1, Hacklberger teaches the machine of claim 1, and further teaches wherein the stator [4] is formed from stator windings [6] and a carrier element [stator core 5] (see ¶ 0019), cooling channels [31] extending in an axial direction along the outer surface of the carrier element [5] (axial direction and extent drawn and labeled by the Examiner in the new fig. 1 excerpt attached below – see also ¶ 0031).
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Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Hacklberger in view of Hossain (US 2014/0077635 A1).
With respect to claim 5/1, Hacklberger teaches the machine of claim 1, and further teaches wherein the housing [3] is made from metal (first lines of ¶ 0031). However, Hacklberger does not explicitly teach wherein the coolant cap is made from metal. It is noted that the coolant cap is part of the assembly under the umbrella label 11, which is more or less an end cap for the housing. Hacklberger does not provide a preferred material for element 11. Element 11 does constitute an end cap for the machine.
Hossain discloses an electric machine with an inner rotor surrounded by a stator, wherein a housing [8] and at least one end plate [20] contain coolant passages [35 and 38].
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Hossain teaches wherein the end plate [20] is made from cast metal (¶ 0022 recites “End covers 19, 20 are typically cast and machined using aluminum or other metal…”).
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 coolant cap of Hacklberger using metal, as taught by Hossain, in order to economically and accurately form the coolant cap and the passages through it, as aluminum (Hossain’s cast material) is well known to be easy to cast its outer dimensions and then machine out passages and other internal structure therein after the casting. Cast aluminum offers many benefits over other materials including being corrosion resistant during persistent contact to liquids and also being lightweight and nonmagnetic. Hoissan mentions that the materials are “typically” cast and machined using aluminum and this indicates cast aluminum as a preferred metal in these situations, such that one of ordinary skill in the art, while manufacturing Hacklberger’s machine, would have found it obvious to try Hoissan’s metal, since this is typical and also because Hacklberger is already utilizing cast aluminum for the housing.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Hacklberger in view of Graves (US 2019/0006914 A1).
With respect to claim 13/12/1, Hacklberger teaches the machine of claim 12, but omits teaching wherein coolant exiting from the axial ends of stator cooling channels is guided onto axial ends of the stator winding.
Graves discloses an electric machine with an inner rotor [117] spinning on a rotor shaft [119], wherein an outwardly disposed stator [116] is cooled by a stator cooling ring [200] disposed thereabout on the stator outer surface (see ¶ 0032).
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Graves teaches coolant [oil] exiting from the axial ends of stator cooling channels [202 and 203] (see ¶ 0031) is guided [arrows 315 and 317] onto axial ends [306 and 307] of the stator winding (see ¶ 0032).
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 machine of Hacklberger while utilizing the winding cooling scheme of Graves in order to directly cool the winding ends, as is well known in the art.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Hacklberger in view of Graves as applied to claim 13 above, and further in view of Rippel (US 20140042841 A1).
With respect to claim 21/13/12/1, Hacklberger in view of Graves teaches the machine of claim 13, Graves further teaches wherein the coolant that is guided onto the axial ends of the stator winding is collected [in oil reservoir 102 and/or the passage leading thereto] (see ¶ 0030 recites “from stator end-windings 122, the oil ultimately drains back to oil reservoir 102…”).
Rippel discloses an electric machine comprising a housing, a rotor with cooling channels, a stator with cooling channels, the housing having a distribution system for guiding coolant to and from both the stator cooling channels [56] and the rotor cooling channels [42/50], wherein coolant exiting from axial ends of the stator channels [70] is guided onto axial ends of stator windings (see the fig. 1 excerpt attached below wherein the Examiner has labeled winding ends and some arrows that depict the coolant flow onto said winding ends).
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Rippel teaches wherein the coolant that is guided onto the axial ends of the stator winding [30] is collected in a sump [82] at the bottom of the housing (see ¶ 0027 which recites “coolant flow from both the rotor and stator is received by drainage cavity 76. Drainage cavity 76 in turn drains liquid coolant via front drain port 78 and rear drain port 80 into coolant sump 82…”).
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 machine of Hacklberger in view of Graves, while incorporating the sump at the bottom of the housing, as taught by Rippel, in order to collect the coolant using only gravity, thereby obviating a pump, simplifying the machine and reducing manufacturing costs, as is well known in the art.
Double Patenting
The provisional Double Patenting rejection applied to claims 1-20 in the prior Office action has been withdrawn because the identical claims 1-20 of co-pending Application No. 18/545,118 have been canceled and newly added claims 21-31 have no subject overlap at all with the claims of the present application.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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