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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 06/11/2026 has been entered.
Response to Arguments
Applicant's arguments filed 05/18/2026 have been fully considered but they are not persuasive. The arguments are not found to be convincing. The applicant states that Foskey only shows fibers oriented at discrete angles and does not describe the fibers being curved relative to the tangential direction. However, the applicant does not address the specifics of the rejection already presented on these limitations that describe Figures 2B and 4 showing reductions in spar diameters as the spar extends towards the tip and provides no argument against these assertions. As this requires the surfaces and thereby the fibers forming the surfaces to follow this shape and Figures 2B and 4 show the reduction in diameter not being linear, curved fibers relative to the tangential direction are provided at each of these locations where the diameter is reduced.
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.
Claim(s) 1-4, 6-10 and 12-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Foskey (US 20200047879) in view of Thomas (US 20170306979).
Regarding claim 1, Foskey discloses A blade spar (Figures 2A and 2B, item 201) for a rotor blade for a rotor of an aircraft propeller (Par. 0002), the blade spar comprising:
a laminate structure, the laminate structure comprising a plurality of plies of fibres in a matrix (Par. 0030),
wherein the blade spar has a longitudinal axis defining a longitudinal direction (Figure 2A shows that 201 would have a longitudinal axis going into and out of the page. The axis in Figure 2B would start at the root perpendicular to the cross-section and continue in that direction until the tip), the longitudinal axis extending along a radial direction of the rotor (See discussion above), wherein the blade spar comprises at least a portion that is curved from the longitudinal axis (Figure 2B shows that the spar 201 is curved along the axis and that the surface of the outside becomes smaller which requires the outer surface to curve away from the axis. This curved nature is more clearly shown in Figure 4 and the twist of the spar is described in paragraph 0027),
wherein the plurality of plies comprises a first ply comprising a plurality of first fibres (Par. 0004) wherein an alignment of the first fibres varies along the longitudinal direction to align the first fibres to the curved blade spar (Figure 4 shows a complex shape of the spar where the outer surface of the spar reduces in diameter as the spar extends towards the tip. Thereby, the fibers that are laid up to create the profile change angle to go inwards towards the longitudinal axis and thereby off-axis as the shape changes. The specific angle and layup process can be found in Paragraphs 0035-0041. Because these fibers angle away from or towards the longitudinal axis and do not stay angled with the longitudinal axis, the alignment of the fibers varies in response to the curved blade spar shape),
wherein the blade spar is curved towards the tangential direction, wherein the tangential direction is normal to the longitudinal direction and in the plane of rotation of the rotor, wherein the first fibres are curved towards the tangential direction (As described above, the outer surface of the spar reduces in diameter as the spar extends towards the tip and thereby the shape curves towards the tangential direction. Foskey Figures 2B and 4 further show the spar not being perfectly straight relative to the tangential direction. As the diameter decreases, the fibres must curve tangentially in order to follow the shape of the outer surface of the spar. As this requires the surfaces and thereby the fibers forming the surfaces to follow this shape and Figures 2B and 4 show the reduction in diameter not being linear, curved fibers relative to the tangential direction are provided at each of these locations where the diameter is reduced).
However, Foskey does not explicitly disclose that the alignment of the first fibres varies relative to the longitudinal direction. Foskey and Thomas are analogous prior art because both use automated tape layup composite methods to form composite articles.
Thomas teaches using steered fiber orientations (Par. 0004) during formation that allows the fibers to follow the contour of the blade and twist (Figures 4A-4C) so as to promote optimized centrifugal or aerodynamic loads on the blade (Par. 0095) and change the twist of the blade. Foskey already describes a twist in the blade and the spar and uses automated fiber layout for construction so it would be possible to use the steered fiber layout as described in Thomas in Foskey. As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the steered fiber layout twisting at least partially around the longitudinal axis because it allows for the fibers to follow the contour of the spar and promotes optimized centrifugal or aerodynamic loads on the blade (Par. 0095). These fibres being steered to create the twist would create a variable fibre angle relative to the longitudinal direction.
Regarding claim 2, Foskey in view of Thomas teaches that the blade spar comprises a root, wherein at the root the first fibres are substantially aligned to the longitudinal axis (Foskey Figure 2B item 202 shows the root of the spar. The limitations “substantially aligned” means that the fibers do not have to be exactly aligned with the longitudinal axis. As Figure 2B shows the root extending generally longitudinally the fibers oriented at 0 degrees described in paragraph 0037 would extend substantially along the longitudinal axis).
Regarding claim 3, Foskey in view of Thomas teaches that the blade spar comprises a tip, where at the tip the first fibres are not aligned to the longitudinal axis (Foskey Figure 2B shows that the spar 202 is still reducing in diameter all the way until the tip meaning that the first fibers are directed inward towards the longitudinal axis at that point and are not aligned with the axis).
Regarding claim 4, Foskey in view of Thomas teaches that the blade spar tapers towards the tip, wherein a portion of the first fibres do not extend to the tip (Foskey Paragraph 0044 describes that some of the stacks and fibers can be applied to specific areas to create the shape meaning that some of the fibers do not extend to the tip), wherein a chord length and/or a thickness reduces to cause the blade spar to taper towards the tip (Figure 2B item 201 shows the spar reducing in chord length and thickness along the length).
Regarding claim 6, Foskey in view of Thomas teaches that the blade spar is curved towards an axial direction, wherein the axial direction is parallel to the rotation axis of the rotor, wherein the first fibres are curved towards the axial direction. Foskey Figures 2B and 4 show that the spar reduces in diameter along each plane tangential to the longitudinal direction, meaning that the spar surface is curved in the axial direction.
Regarding claim 7, Foskey in view of Thomas teaches the fibers of the spar twisting with the profile of the spar (See rejection of claim 1 above).
Regarding claim 8, Foskey in view of Thomas teaches that the first fibres are formed from a carbon tape (Foskey Par. 0028).
Regarding claim 9, Foskey in view of Thomas teaches a plurality of first plies (Foskey Paragraph 0037 describes the unidirectional tape being a first layer).
Regarding claim 10, Foskey in view of Thomas teaches that the first fibres are placed with an automated fibre placement process to form the first ply. This is a product by process limitation so the only limitations given weight are what is imparted onto the structure by the automated fibre placement process. There is no clear structure provided by such a process that would not be provided by a manual layup. However, Foskey discloses the use of automated fiber placement (Par. 0029).
Regarding claim 12, Foskey in view of Thomas teaches that the fibres of the second ply are manually or automatically placed. This is a product by process limitation so the only limitations given weight are what is imparted onto the structure by the automated fibre placement process or the manual process. However, Foskey discloses the use of manual or automated fiber placement (Foskey Par. 0029).
Regarding claim 13, Foskey in view of Thomas teaches a rotor blade for a rotor of an aircraft comprising the blade spar according to claim 1 (Foskey Paragraph 0002 and Figure 2B).
Regarding claim 14, Foskey in view of Thomas teaches that the rotor blade is an aircraft propeller blade (Foskey Paragraph 0002).
Regarding claim 15, Foskey in view of Thomas teaches A method of manufacturing a blade spar of claim 1, the method comprising using an automated fibre placement process to align the first fibres (Foskey Paragraph 0029 describes the spar being formed with automated fiber placement).
Conclusion
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/THEODORE C RIBADENEYRA/ Examiner, Art Unit 3745
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