DETAILED ACTION
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on October 28, 2025 has been entered.
Response to Arguments
Applicant's arguments filed October 28, 2025 have been fully considered. The drawing objection of September 3, 2025 has been withdrawn based on the amendments to the drawings. The 35 U.S.C 112(a) and 35 U.S.C 112(b) rejections have been withdrawn based on the amendments to the claims.
The previous 35 U.S.C 102 and 103 rejections are withdrawn based on the amendments. New grounds of rejections are presented below.
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 (i.e., changing from AIA to pre-AIA ) 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim 1-3, 5-7, and 9-18 are rejected under 35 U.S.C. 103 as being unpatentable over McGuire (U.S Patent 4,135,856) hereinafter McGuire in view of Mouille et al. (U.S Patent 4,012,169) hereinafter Mouille.
Regarding claim 1, McGuire further discloses:
A hub {Figures 1 and 2, (12)} comprising:
A yoke {Figures 1 and 2 (22)}
an inboard elastomeric bearing attached to the yoke at an inboard-yoke attachment point {Figures 1 and 2, (40) is attached to the yoke by (52)/(54)}
an outboard elastomeric bearing attached to the yoke {Figures 1 and 2, (42) is attached to the yoke by (70)/(72)}
wherein the outboard elastomeric bearing is in an outboard direction from the inboard elastomeric bearing {Figures 1 and 2, (42) is outboard of (40)}
at least two rotor blades {Figure 1 (16) along with (32)/(34), (58), and (64) may be considered part of the blade; Column 1 lines 5-12};
a motor mechanically connected to the at least two rotor blades to rotate the at least two blades {MPEP 2112, this is implicit to a helicopter; Column 1 lines 5-12},
wherein the motor is attached to a frame {MPEP 2112, this is implicit to helicopters; Column 1 lines 5-12}; and
a hub configured to transmit loads from the at least two rotor blades to the frame {Figure 2, hub (12) transmits loads from the blades to the frame},
wherein: the blade attaching feature is coupled to the inboard elastomeric bearing at an inboard-blade attaching feature attachment point {Figures 1 and 2, (40) is attached to blade attaching feature (32)/(34)},
the blade attaching feature is coupled to an outboard elastomeric bearing {Figures 1 and 2, (42) is coupled to blade attaching feature (32)/(34) via (64)}, and
the inboard-yoke attachment point is in an outboard direction from the inboard- blade attachment point {Figures 1 and 2 (52)/(54) are outboard from (46)}.
McGuire does not teach:
wherein the one rotor blade of the at least two rotor blade is itself coupled to the inboard elastomeric bearing at an inboard-blade attachment, and
wherein the one rotor blade of the at least two rotor blade is itself coupled to the outboard elastomeric bearing
Mouille pertains to rotorcraft. Mouille teaches:
wherein the blade attaching feature is part of the blade itself {Figure 3 (2a)/(2b) are part of the blade itself; Column 3 lines 20-33}
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used a blade attachment feature (32)/(34) of McGuire that is itself part of the blade as taught by Mouille. One of ordinary skill in the art would be motivated to do so as this can result in a lightweight and strong blade {Mouille Column 4 lines 60-66}.
The combination of McGuire of Mouille therefore teaches:
wherein the one rotor blade of the at least two rotor blade is coupled to the inboard elastomeric bearing at an inboard-blade attachment {(32)/(34) of McGuire is modified to be the blade based on the teachings of Mouille (2a)/(2b). (32)/(34) of McGuire is coupled to the inboard elastomeric bearing at (46)}, and
wherein the one rotor blade of the at least two rotor blade is coupled to the outboard elastomeric bearing {(32)/(34) of McGuire is modified to be the blade based on the teachings of Mouille (2a)/(2b). (32)/(34) of McGuire is coupled to the outboard elastomeric bearing via (64)}
Regarding claim 2, McGuire further discloses:
wherein the hub is configured to operate in two configurations that are substantially perpendicular to each other {Figures 1 and 2, the hub assembly in the instant application (100) is all that is claimed based on the preamble in claims 1 / 2. The elements that allow for the hub to rotate into the perpendicular configurations is therefore not required. The only thing that is required to meet the claim is that the hub assembly could operate in the claimed two configurations. The examiner finds that this is true. Additionally, no specific structures are claimed that allow for the two configurations. This is therefore a functional limitation that the examiner presumes is inherent as the claimed structure is substantially identical to that of the claim, see MPEP 2112.01 I }.
Regarding claim 3, the combination of McGuire and Mouille further teaches:
wherein the hub comprises a pitch horn configured to couple one of the at least two rotor blades at an attachment to the inboard elastomeric bearing {McGuire Figures 1 and 2, hub (12) has a pitch horn (38) that is attached to the rotor blade that is coupled to the inboard elastomeric bearing}
wherein the one blade comprises a first flange and a second flange {McGuire Figure 2, (32)/(34) respectively have a first flange by (46) on the top and a second flange by (46) on the bottom; (32)/(34) of McGuire is modified to be the blade based on the teachings of Mouille (2a)/(2b)}, and
wherein the inboard elastomeric bearing is between the first flange and the second flange {McGuire Figure 2, the inboard elastomeric bearing (40) is between the two flanges described above}
Regarding claim 5, the combination of McGuire and Mouille further teaches:
wherein the hub is configured to transmit a substantially inplane force from the inboard elastomeric bearing and the outboard elastomeric bearing to the one blade {McGuire Figure 2 (40) and (42) both transmit centrifugal loads which is an inplane force from the blade(s); Column 9 line 31- Column 10 line 2}.
Regarding claim 6, the combination of McGuire and Mouille further teaches:
wherein the inboard elastomeric bearing is configured to bear the centrifugal force of one of the at least two rotor blades in compression {McGuire Figure 2 (40) bears centrifugal loads in compression; Column 9 lines 31-43}.
Regarding claim 7, the combination of McGuire and Mouille further teaches:
wherein the outboard elastomeric bearing is configured to bear a centrifugal force of one of the at least two rotor blades if the inboard elastomeric bearing fails to bear the centrifugal force of the one blade {McGuire Figure 2 (40) and (42) both transmit centrifugal force from the blade(s). If the inboard elastomeric bearing were to fail, the outboard elastomeric bearing would necessarily bear centrifugal forces; Column 9 line 31- Column 10 line 2}.
Regarding claim 9, the combination of McGuire and Mouille further teaches:
wherein the inboard elastomeric bearing and the outboard elastomeric bearing are each configured to allow for a change in pitch of one of the at least two rotor blades {McGuire Figures 1 and 2, (40) and (42) both allow for the change in pitch of the blades; Column 11 lines 42-51}.
Regarding claim 10, McGuire further discloses:
wherein the frame or the hub comprises a sensor configured to sense a failure mode of one or more of the inboard elastomeric bearing and the outboard elastomeric bearing {The frame is not a part of the claimed hub assembly. The hub assembly transmit loads to the frame as claimed in claim 1. If the frame comprises the claimed sensor it is not required by the claim because the claim is to “a hub”. The hub only needs to be compatible with a frame that has the claimed sensor. The examiner finds this is true for the hub of McGuire}.
Regarding claim 11, McGuire discloses:
A hub assembly {Figures 1 and 2, (12)}, the hub assembly comprising:
a yoke {Figures 1 and 2, (23)/(24)};
at least one inboard elastomeric bearing attached to the yoke at an inboard-yoke attachment point {Figures 1 and 2, (40) is attached to the yoke by (52)/(54)}
at least one outboard elastomeric bearing attached to the yoke {Figures 1 and 2, (42) is attached to yoke (24) via the opening (29) and (32). The outboard elastomeric bearing may be considered to include (58)/(64) as its bearing housing }; and
wherein the outboard elastomeric bearing is in an outboard direction from the inboard elastomeric bearing {Figures 1 and 2, (42) is outboard of (40)}
at least two rotor blades configured to generate thrust {Figure 1 (16) along with (32)/(34), (58), and (64) may be considered part of the blade if not considered part of the elastomeric bearings; Column 1 lines 5-12},
wherein: the blade attaching feature is coupled to the inboard elastomeric bearing at an inboard-blade attaching feature attachment point {Figures 1 and 2, (40) is attached to blade attaching feature (32)/(34)},
the blade attaching feature is coupled to an outboard elastomeric bearing {Figures 1 and 2, (42) is coupled to blade attaching feature (32)/(34) via (64)}, and
the inboard-yoke attachment point is in an outboard direction from the inboard- blade attachment point {Figures 1 and 2 (52)/(54) are outboard from (46)}.
McGuire does not teach:
wherein the one rotor blade of the at least two rotor blade is itself coupled to the inboard elastomeric bearing at an inboard-blade attachment, and
wherein the one rotor blade of the at least two rotor blade is itself coupled to the outboard elastomeric bearing
Mouille pertains to rotorcraft. Mouille teaches:
wherein the blade attaching feature is part of the blade itself {Figure 3 (2a)/(2b) are part of the blade itself; Column 3 lines 20-33}
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used a blade attachment feature (32)/(34) of McGuire that is itself part of the blade as taught by Mouille. One of ordinary skill in the art would be motivated to do so as this can result in a lightweight and strong blade {Mouille Column 4 lines 60-66}.
The combination of McGuire of Mouille therefore teaches:
wherein the one rotor blade of the at least two rotor blade is coupled to the inboard elastomeric bearing at an inboard-blade attachment {(32)/(34) of McGuire is modified to be the blade based on the teachings of Mouille (2a)/(2b). (32)/(34) of McGuire is coupled to the inboard elastomeric bearing at (46)}, and
wherein the one rotor blade of the at least two rotor blade is coupled to the outboard elastomeric bearing {(32)/(34) of McGuire is modified to be the blade based on the teachings of Mouille (2a)/(2b). (32)/(34) of McGuire is coupled to the outboard elastomeric bearing via (64)}
Regarding claim 12, the combination of McGuire and Mouille further teaches:
wherein one of the at least two rotor blades comprises a first flange and a second flange {McGuire Figure 2, (32)/(34) respectively have a first flange by (46) on the top and a second flange by (46) on the bottom; (32)/(34) of McGuire is modified to be the blade based on the teachings of Mouille (2a)/(2b)}, and
wherein the inboard elastomeric bearing is between the first flange and the second flange {Figure 2 (40) is between (32) and (34) at the location flange location where (46) is}.
Regarding claim 13, McGuire further discloses:
further comprising a pitch horn configured to couple to one of the at least two rotor blades at the inboard elastomeric bearing {McGuire Figures 1 and 2, hub (12) has a pitch horn (38) that is attached to the rotor blade that is coupled to the inboard elastomeric bearing}.
Regarding claim 14, McGuire further discloses:
wherein the yoke is configured to transmit a substantially in-plane load to one of the at least two rotor blades through the inboard elastomeric bearing and the outboard elastomeric bearing {Figure 2, the yoke (23)/(24) transmit centrifugal loads which are in-plane loads to the rotor blades through the inboard and outboard elastomeric bearings (40)/(42); Column 9 line 31- Column 10 line 2}.
Regarding claim 15, McGuire further discloses:
wherein one of the at least two rotor blades is configured to operate to generate vertical lift for a vertical take-off configuration of an aircraft {Figures 1 and 2, a hub assembly is all that is claimed based on the preamble in claims 11 / 15. The airframe and elements that allow for the hub to rotate are not claimed. The only thing that is required to meet the claim is that the hub could operate as claimed. The examiner finds that this is true in a helicopter the rotor generates lift for vertical take-off; Column 1 lines 5-28}, and
wherein the one blade is configured to generate substantially horizontal thrust for a horizontal flight configuration of an aircraft {Figures 1 and 2, helicopters are able to accelerate forward through the air which means thrust is generated in additional to lift; Column 1 lines 5-28. It is noted that the claim does not require that the force produced by the rotor is purely or substantially in a horizontal direction. Additionally, a hub assembly is all that is claimed based on the preamble in claims 11 / 15. The airframe and elements that allow for the hub to rotate are not claimed}.
Regarding claim 16, McGuire further discloses:
wherein the inboard elastomeric bearing is configured to bear a centrifugal force of one of the at least two rotor blades {Figure 2 (40) bears centrifugal loads in compression; Column 9 lines 31-43}.
Regarding claim 17, McGuire further discloses:
wherein the outboard elastomeric bearing is configured to bear a centrifugal force of one of the at least two rotor blades if the inboard elastomeric bearing fails to bear the centrifugal force of the one blade {Figure 2 (40) and (42) both transmit centrifugal force from the blade(s). If the inboard elastomeric bearing were to fail, the outboard elastomeric bearing would necessarily bear centrifugal forces; Column 9 line 31- Column 10 line 2}.
Regarding claim 18, McGuire further discloses:
wherein each of the outboard elastomeric bearing and the inboard elastomeric bearing comprises an elastomer layer and a metal layer {Figure 2 (40) and (42), comprise elastomer and metal layers; Column 7 line 48 – Column 8 line 11}.
Claim 2 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over McGuire in view of Mouille as applied to claims 1 and 11 above, and in further view of Kizhakkepat et al. (U.S Pre-Grant Publication 20190016455) hereinafter Kizhakkepat.
Regarding claim 2, the combination of McGuire and Mouille teaches the hub of claim 1, but does not explicitly teach:
wherein the hub is configured to operate in two configurations that are substantially perpendicular to each other.
Kizhakkepat pertains tiltrotor hub and bearing configurations. Kizhakkepat teaches:
wherein the hub is configured to operate in two configurations that are substantially perpendicular to each other {Figure 1A and 1B, rotor (24A/B) rotates pylon (22A/B); [0028]}.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the rotor of McGuire in the context of a tilt-rotor aircraft as taught by Kizhakkepat. One of ordinary skill in the art would be motivated to do so as tiltrotor aircraft are able to have the advantage of having a helicopter flight mode and an airplane flight mode which allows vertical take-off and landing as well as improved efficiency {Kizhakkepat [0002]-[0003]}.
Regarding claim 15, the combination of McGuire and Mouille teaches the hub of claim 11, but does not explicitly teach:
wherein one of the at least two rotor blades is configured to operate to generate vertical lift for a vertical take-off configuration of an aircraft, and
wherein the one blade is configured to generate substantially horizontal thrust for a horizontal flight configuration of an aircraft.
Kizhakkepat pertains tiltrotor hub and bearing configurations. Kizhakkepat teaches:
wherein one of the at least two rotor blades is configured to operate to generate vertical lift for a vertical take-off configuration of an aircraft {Figure 1B, the rotors (24A/B) generate vertical lift for vertical take-off of the aircraft; [0003]}, and
wherein the one blade is configured to generate substantially horizontal thrust for a horizontal flight configuration of an aircraft {Figure 1A, the rotors (24A/B) provide horizontal thrust; [0003]}.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the rotor of McGuire in the context of a tilt-rotor aircraft as taught by Kizhakkepat. One of ordinary skill in the art would be motivated to do so as tiltrotor aircraft are able to have the advantage of having a helicopter flight mode and an airplane flight mode which allows vertical take-off and landing as well as improved efficiency {Kizhakkepat [0002]-[0003]}.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over McGuire in view of Mouille as applied to claim 3 above, and in further view of Choi et al. (U.S Pre-Grant Publication 20190002085) hereinafter Choi.
Regarding claim 4, the combination of McGuire and Mouille teaches the hub of claim 3, but is silent regarding details of a pitch controller and therefore does not explicitly disclose:
wherein the hub comprises a link configured to couple the pitch horn to a pitch controller.
Choi pertains to rotor systems including hubs of aircraft. Choi teaches:
wherein the hub comprises a link configured to couple the pitch horn to a pitch controller {Figure 3B (238) is a link that couples the pitch horn (218B) to a pitch controller (240); [0037]}.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the a link to connect the pitch horn to a pitch controller as taught by Choi for the rotor of McGuire. One of ordinary skill in the art would be motivated to do so as this allows for the pitch to be controlled by a system such as a swash plate which is well known {Choi [0037}}.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over McGuire in view of Mouille as applied to claims 1 and 11 above, and in further view of Paulson et al. (U.S Pre-Grant Publication 20190185151) hereinafter Paulson.
Regarding claim 21, the combination of McGuire and Mouille teaches the hub of claim 3, but does not teach:
wherein the pitch horn has at least two prongs such that:
a first prong of the at least two prongs is attached to the one blade at a top surface of the one blade being on the first flange and
a second prong of the at least two prongs is attached to the one blade at a bottom surface of the one blade being on the second flange.
Paulson pertains to rotor craft. Paulson teaches:
wherein the pitch horn has at least two prongs {Figure 2a (225) has an upper and lower “arm” for each blade; [0025]} such that:
a first prong of the at least two prongs is attached to the one blade at a top surface {Figure 2a, the first upper prong of (225) is connected to the top surface of (235) which may be considered part of the blade} and
a second prong of the at least two prongs is attached to the one blade at a bottom surface {Figure 2a, the second lower prong of (225) is connected to the bottom surface of (235) which may be considered part of the blade}.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have a pitch link as taught by Paulson for the pitch link of the combination of McGuire and Mouille. One of ordinary skill in the art would be motivated to do so this is a simple substitution of one pitch link design for another, see MPEP 2143 I B {Paulson [0025]}. Both designs are known to cause pitch rotations to the blade; therefore, when the pitch link design of McGuire is substituted for the pitch link of Paulson the result is substantially identical and predictable.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL K. REITZ whose telephone number is (571)272-1387. The examiner can normally be reached M-F 7:30 a.m. -5:30 p.m.
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/MICHAEL K. REITZ/Examiner, Art Unit 3745