DETAILED ACTION
Election/Restrictions
Applicant's election with traverse of Species of Fig. 17B in the reply filed on 7/27/26 is acknowledged. The traversal is on the ground(s) that the claims are drawn to this Species. This is found persuasive. Claims 31−60 are pending and will be examined.
The requirement is made FINAL.
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.
Claims 54−56 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or joint inventor regards as the invention.
Claim 54 recites that “the blade channel is formed within at least one of the plurality of propeller blades,” however claim 45 recites that “each of the plurality of propeller blades comprising a blade channel inside the propeller blade.” Claim 54 therefore appears to suggest that only one blade could have a blade channel, which is inconsistent with claim 45.
Claims 54−56 recite the limitation “the blade channel.” There is insufficient antecedent basis for this limitation in the claims.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 40 and 54 are rejected under 35 U.S.C. 112(d) because they do not specify a further limitation upon the claims from which they depend.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 31, 34−36, 40−41, 43−45, 48−50, 54−55, 57−58, and 60 are rejected under 35 USC §102(a)(1) as being anticipated by US Pre-Grant Publication No. 2023/0074603 to Manning.
Regarding claim 45, Manning teaches an aircraft 10, comprising: a propeller assembly 14 for an aircraft, comprising: a propeller, comprising:
a hub 16;
a plurality of propeller blades 18, each of the plurality of propeller blades comprising a blade channel (coolant channel 30) inside the propeller blade and configured to circulate fluid (para. [0037]);
a motor assembly 20 configured to rotate the propeller about a rotation axis (para. [0034]); and
an oil flow path (see dashed arrows and fluid lines depicted in fig. 3 and solid arrow in fig. 2) configured to circulate oil through the motor assembly and through each blade channel of the plurality of propeller blades to thermally couple the motor assembly to the plurality of propeller blades (para. [0037]), wherein the plurality of propeller blades comprises a primary heat exchanger of the motor assembly (para. [0037]; where one of ordinary skill in the art would interpret the arrangement as a primary heat exchanger since no other heat exchangers are disclosed, and a single liquid cooling system is generally all that is required in the art to adequately remove sufficient heat).
Regarding claim 48, Manning teaches that each of the plurality of propeller blades further comprises a thermal conductor (para. [0035]; where one of ordinary skill in the art would interpret aluminum as being a thermal conductor due to its good thermal conductivity as a metal) configured to conduct heat from the blade channel to a portion of the propeller blade that is radially outward from the blade channel (fig. 2).
Regarding claims 49−50, Manning teaches that the blade channel extends radially outward through at least one of the plurality of propeller blades by not more than 70 or 50% of a blade radius measured from the rotation axis (where para. [0036] discloses that the coolant extends one third of the span from root to tip, one of ordinary skill in the art would interpret Manning as teaching not more than 50% of a radius measured from the rotation axis, where the distance from root to rotation axis being far less than necessary to remain under 50%).
Regarding claim 54, as best understood, Manning teaches that the blade channel is formed within at least one of the plurality of propeller blades (paras. [0035]−[0036]).
Regarding claim 55, Manning teaches that the blade channel is bonded to a hollow interior of at least one of the plurality of propeller blades (where the bonding step is considered product-by-process, see MPEP § 2113, and one of ordinary skill in the art would understand from the disclosure that the blades are hollow, as is conventional in the art).
Regarding claims 57−58, Manning teaches that at least one blade channel includes an inward blade channel segment 30a and an outward blade channel segment 30b;
wherein the propeller further comprises:
an oil channel inlet configured to circulate oil to the inward blade channel segment (fig. 3); and
an oil channel outlet configured to receive oil from the outward blade channel segment (fig. 3).
Regarding claim 60, Manning teaches that the plurality of propeller blades includes two, three, four, or five propeller blades (fig. 1).
Regarding claims 31, 34−36, 40−41, and 43−44, the claims are rejected under Manning as discussed above for corresponding claims 45, 48−50, 54−55, and 57−58.
Claims 31, 42, 45, 56, and 59 are rejected under 35 USC §102(a)(1) as being anticipated by German Patent Doc. DE-102017106774-B4 to Schneider et al. (“Schneider”).
Regarding claim 45, Schneider teaches an aircraft (helicopter 2), comprising: a propeller assembly for an aircraft, comprising: a propeller, comprising:
a hub (rotor head 3);
a plurality of propeller blades 2, each of the plurality of propeller blades comprising a blade channel (fluid line 7) inside the propeller blade and configured to circulate fluid (para. [0040]);
a motor assembly configured to rotate the propeller about a rotation axis (where Schneider discloses a gearbox 6, and one of ordinary skill in the art would understand that such a gearbox requires an input of motive force, where the source of motive force together with the gearbox constitutes the motor assembly); and
an oil flow path configured to circulate oil through the motor assembly and through each blade channel of the plurality of propeller blades to thermally couple the motor assembly to the plurality of propeller blades, wherein the plurality of propeller blades comprises a primary heat exchanger of the motor assembly (paras. [0040]−[0041]).
Regarding claim 56, Schneider teaches that the blade channel runs along an entire length of at least one of the plurality of propeller blades (para. [0040]; figs. 1−2).
Regarding claim 59 Schneider teaches that the aircraft is a vertical takeoff and landing aircraft (e.g. a helicopter).
Regarding claims 31 and 42, the claims are rejected under Schneider as discussed above for corresponding claims 45 and 56.
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.
Claims 32−33, 37, 39, 46−47, 51, and 53 are rejected under 35 USC §103 as being unpatentable over Manning.
Regarding claims 32−33, 39, 46−47, and 53, Manning fails to teach that, during operation of the propeller assembly, at least 30, 50, or 70% of heat generated by the motor assembly is transferred to an external environment by thermal conduction through the plurality of propeller blades. It would have been obvious to one of ordinary skill in the art at the time of filing to configure the oil cooler such that at least 70% of the heat is transferred through the environment, since oil coolers are well known means for cooling engines and are generally capable of achieving such cooling rates, particularly where the oil cooler is the only active cooling system, with negligible heat being lost directly from engine parts to a similarly hot surrounding environment.
Regarding claims 37 and 51, Manning fails to teach that the blade channel extends radially outward through at least one of the plurality of propeller blades by not more than 30% of a blade radius measured from the rotation axis. It would have been obvious to one of ordinary skill in the art at the time of filing to modify Manning to have such a radial extent of the blade channel as a matter of routine design choice, depending on the heat loss requirements as well as the desired location for the concentration of de-icing on the propeller (where distal portions of the propeller experience greater speed and centripetal force, and therefore shed ice more easily than the inner 30% of the blade radius measured from the rotation axis).
Claims 38 and 52 are rejected under 35 USC §103 as being unpatentable over Manning in view of US Patent No. 2,779,423 to Cushman.
Regarding claims 38 and 52, Manning teaches that the propeller has a spinner (fig. 1), but fails to teach that the propeller further comprises a spinner, the spinner having a spinner channel configured to circulate fluid, and the oil flow path is further configured to circulate oil through the spinner channel to thermally couple the motor assembly to the spinner.
Cushman teaches a propeller spinner 54 having an oil cooler 41, the spinner having a spinner channel (inlet 40, outlet 42, intertube passages as described in col. 2 lines 41−55) configured to circulate fluid, and the oil flow path is further configured to circulate oil through the spinner channel (col. 2 lines 41−55). It would have been obvious to one of ordinary skill in the art at the time of filing to provide the spinner of Manning with such an oil cooler in order to thermally couple the motor assembly to the spinner, in order to allow for even greater cooling of the engine compared to oil coolers in propeller blades alone, thereby ensuring more efficient operation of the engine.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael B Kreiner whose telephone number is (571)270-5379. The examiner can normally be reached Monday-Friday 9:00-5:00.
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, Joshua Michener can be reached at (571) 272-1467. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/M.B.K./Examiner, Art Unit 3642 /JOSHUA J MICHENER/Supervisory Patent Examiner, Art Unit 3642
