/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 .
Claim Interpretation
It is noted that the applicant introduces the term ‘spanwise profile’ in claims 1, 26 and 29 . This term is not defined in the specification of the application. The most applicable dictionary definition of the term profile is: “a vertical cross section of a structure”. And so, this is being interpreted to mean a spanwise cross section.
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.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 5-9, 11-16, 20, 24-26, and 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sikavi (WO 2020146399 A1) as modified by Williams (US 10336440 B2), Heller (EP 2998218 A1), and Chen (CN 206050054 U).
Regarding claim 1, Sikavi discloses a wing for an aircraft, the wing comprising:
a main wing including a main wing tip (Sikavi, figure 1a, item 104, wing with wing tip); and
a winglet system attached to the main wing tip, the winglet system including (Sikavi, figure 1b, item 150, winglet attached to wing tip):
an upper winglet having an upper winglet tip outboard of the main wing tip (Sikavi, figure 1b, item 152, upper winglet outboard of wing); and
a lowest winglet having a lowest winglet tip outboard of the main wing tip, the upper winglet tip of the upper winglet being disposed higher than the lowest winglet tip of the lowest winglet relative to the main wing tip (Sikavi, figure 1b, item 154, lowest winglet outboard of wing and below upper winglet);
wherein:
the upper and lowest winglets overlap one another along the chord of the main wing tip (Sikavi, figure 4a, items 108, 154, 160, and 164, top view plot of upper and lowest winglets shows winglets overlapping at their root with respect to the wing tip);
the upper and lowest winglets each extend from the main wing tip via a blended portion providing a transition between the main wing tip and the respective upper winglet and lower winglet (Sikavi, figure 1b, items 152, 154, and 156, winglets extending from wing tip via a blended portion); and
a spanwise profile of the lowest winglet extending along a leading edge of the lowest winglet has a midpoint, a slope of the spanwise profile at a point outboard of the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint, (Sikavi, figure 2a, item 154 and 184, slope is more upwards near the tip than at any other point including the midpoint of the lowest winglet; thus, there is point outboard the midpoint which satisfies this condition), except:
the upper and lowest winglet both extends upwardly relative to the main wing tip;
wherein the spanwise profile of the lowest winglet has a slope of the spanwise profile at all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint such that the lowest winglet is curved upwards at points outboard of the midpoint;
the leading edge of the lowest winglet is staggered along a chordwise direction of the main wing tip with respect to a leading edge of the upper winglet.
Williams teaches a winglet with a spanwise profile which has a slope of the spanwise profile at all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint (Williams, figure 1 and abstract, curvature is defined such that midpoint located in zone 2 has a slope less than the slop in zones 3 and 4, where all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint are located), such that the winglet is curved upwards at points outboard of the midpoint (Williams, figure 1 and abstract, winglet curves upwards at any point outboard the midpoint).
Sikavi and Williams are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Sikavi with the curved winglet of Williams in order to mitigate shock formation and smooth stress distribution (Williams, ¶13).
Heller teaches a winglet with an upper and lowest winglet wherein the upper and lowest winglets overlap one another along a chord of a main wing tip (Heller, figure 9, items 7, 21, and 27, ¶17, upper and lowest winglets which overlap each other along main wing tip chord) and
wherein the leading edge of the lowest winglet is staggered along a chordwise direction of the main wing tip with respect to a leading edge of the upper winglet (Heller, figures 6 and 9, items 23 and 29, ¶43, leading edge of lowest winglet is staggered in front of the leading edge of the upper winglet).
Sikavi as modified by Williams and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the relative positioning of the upper and lowest winglets of Sikavi as modified by Williams with the overlapping stagger between the upper and lowest winglet leading edges of Heller with a reasonable expectation of success in order to produce a constant downwash distribution (Heller, ¶18).
Chen teaches a winglet wherein the upper and lower winglets both extend upwardly relative to the main wing tip (Chen, figure 9, items 2 and 3, winglets where one winglet is above the other and the lower winglet extends upwards relative to the main wing).
Sikavi as modified by Williams and Heller and Chen are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Sikavi as modified by Williams and Heller with the configuration of the middle winglet extending upwards relative to the wing of Chen as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing.
Regarding claim 6, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 5, wherein the spanwise profile of the lowest winglet has a lowest winglet inflection (Sikavi, figure 1b, item 154, lowest winglet curves downwards from the main wing tip and curves upwards near the winglet tip which requires an inflection point on the lowest winglet).
Regarding claim 7, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 6, wherein: the lowest winglet inflection is disposed between an inboard portion of the spanwise profile of the lowest winglet proximate to the main wing tip and an outboard portion of the spanwise profile; and the inboard portion of the spanwise profile is shorter than the outboard portion of the spanwise profile (Sikavi, figure 1b, lowest winglet curves downwards from the main wing tip and curves upwards near the winglet tip which requires an inflection point on the lowest winglet, the inflection point is disposed at a point on the lowest winglet, the lowest winglet can be considered to have portions that are closer to the wing tip than other portions of the lowest winglet ).
Regarding claim 8, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 7, wherein at least a majority of the outboard portion of the spanwise profile is concave relative to a space between the upper and lowest winglets viewed along the chord of the main wing tip (Sikavi, figure 1b, item 154, lowest winglet has an upwardly curved end section and is hence concave with respect to the space between the winglets).
Regarding claim 9, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 7, wherein at least a majority of the outboard portion of the spanwise profile is curved when viewed along the chord of the main wing tip. (Sikavi, figure 1b, item 154, lowest winglet has a curved end section).
Regarding claim 10, Sikavi as modified by Williams and Heller teaches the wing as defined in claim 1, wherein the lowest winglet tip is oriented upwardly (Chen, figure 9, item 3, winglet is orientated upwards; note that the lowest winglet is modified here).
Sikavi as modified by Williams, Heller, and Chen (as previously applied) and Chen are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Sikavi as modified by Williams, Heller, and Chen with the middle winglet extending upwards relative to the wing of Chen as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing.
Regarding claim 11, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein a junction angle between the upper and lowest winglets viewed along the chord of the main wing tip is between 60 degrees and 90 degrees.
Heller teaches a winglet wherein a junction angle between the upper and lowest winglets viewed along the chord of the main wing tip is between 60 degrees and 90 degrees (Heller, claim 9, junction angle is between 45 and 100 degrees and preferably between 50 and 80 degrees).
Sikavi as modified by Williams, Heller, and Chen and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the junction angle of Sikavi as modified by Williams and Heller with the junction angle between 50 and 80 degrees of Heller in order to reduce induced drag (Heller, paragraph 26).
Regarding claim 12, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein a junction angle between the upper and lowest winglets viewed along the chord of the main wing tip is greater than 45 degrees and up to 150 degrees.
Heller teaches a winglet wherein a junction angle between the upper and lowest winglets viewed along the chord of the main wing tip is greater than 45 degrees and up to 150 degrees (Heller, claim 9, junction angle is between 45 and 100 degrees and preferably between 50 and 80 degrees).
Sikavi as modified by Williams, Heller, and Chen and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the junction angle of Sikavi as modified by Williams, Heller, and Chen with the junction angle between 50 and 80 degrees of Heller in order to reduce induced drag (Heller, paragraph 26).
Regarding claim 13, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein a root chord length of the lowest winglet is between 55% and 80% of a length of the chord of the main wing tip (Heller, claim 6 and figure 3 item 19, lowest wing tip device is between 20% and 80% of the winglet chord, which spans the entire wing tip chord).
Heller teaches a winglet wherein a root chord length of the lowest winglet is between 55% and 80% of a length of the chord of the main wing tip (Heller, claim 6 and figure 3 item 19, lowest wing tip device is between 20% and 80% of the winglet chord, which spans the entire wing tip chord).
Sikavi as modified by Williams, Heller, and Chen and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the root chord length of Sikavi as modified by Williams, Heller, and Chen with the root chord length between 55% and 80% of the wing tip chord of Heller in order to reduce induced drag (Heller, paragraph 26) and improve lift distribution.
Regarding claim 14, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein a root chord length of the upper winglet is between 55% and 80% of a length of the chord of the main wing tip (Heller, claim 6 and figure 3 item 19, upper wing tip device is between 20% and 80% of the winglet chord, which spans the entire wing tip chord).
Heller teaches a winglet wherein a root chord length of the upper winglet is between 55% and 80% of a length of the chord of the main wing tip (Heller, claim 6 and figure 3 item 19, upper wing tip device is between 20% and 80% of the winglet chord, which spans the entire wing tip chord).
Sikavi as modified by Williams, Heller, and Chen and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the upper winglet root chord length of Sikavi as modified by Williams, Heller, and Chen with the rear winglet root chord length of Heller in order to reduce induced drag (Heller, paragraph 26).
Regarding claim 15, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, wherein an amount of overlap of root chords of the upper and lowest winglets is between 10% and 60% of a length of the chord of the main wing tip (Heller, claim 9 and figure 3 item 19, overlap between 5% and 30% of the wingtip devices, which span the entire wing tip chord).
Regarding claim 16, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein the leading edge of the lowest winglet is disposed forward of a leading edge of the upper winglet relative to the chord of the main wing tip.
Heller teaches a winglet wherein the leading edge of the lowest winglet is disposed forward of a leading edge of the upper winglet relative to the chord of the main wing tip (Heller, figure 6, items 21 and 27, front blade is below the rear blade).
Sikavi as modified by Williams, Heller, and Chen and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the overlap between the upper and lowest winglets of Sikavi as modified by Williams, Heller, and Chen with the forward and aft winglets located downwards and upwards respectively of Heller in order to allow for natural meshing of pressure distributions (Heller, paragraph 28).
Regarding claim 17, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, wherein a leading edge of the upper winglet is disposed forward of the leading edge of the lowest winglet relative to the chord of the main wing tip (Chen, figure 8, items 2 and 3, upper winglet is disposed as forward most winglet).
Sikavi as modified by Williams, Heller, and Chen (as previously applied) and Chen are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the winglet configuration of Sikavi as modified by Williams, Heller, and Chen with the upper winglet extending in front of the lower winglets of Chen as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing
Regarding claim 18, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 17, wherein an overlap between the upper and lowest winglets extends from a junction of the upper and lowest winglets to the lowest winglet tip (Chen, figure 6, items 2, 3, and 4, overlap between winglets extends to the lower winglet tip; note lowest winglet is modified with the teaching of Chen).
Sikavi as modified by Williams, Heller, and Chen (as previously applied) and Chen are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the winglet configuration of Sikavi as modified by Williams, Heller, and Chen with the winglets overlapping from the junction at the root to a lower winglet tip of Chen in order to as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing
Regarding claim 20, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, wherein a spanwise profile of the upper winglet has a first upper winglet inflection (Sikavi, paragraph 61, upper winglet curves upwards from the wing and curves towards down at the tip thereby creating an inflection point).
Regarding claim 24, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, wherein the upper winglet tip is disposed outboard of the lowest winglet tip (Sikavi, figure 2a, item, 176 and 184, lowest winglet tip extends only to 115 inches whereas the upper winglet tip extends to 135 inches).
Regarding claim 25, Sikavi as modified by Williams, Heller, and Chen teaches an aircraft comprising the wing as defined in claim 1 (Sikavi, figure 1a, item 100 and 104, aircraft for attaching winglet to the tip of wings).
Regarding claim 26 (as best understood), Sikavi discloses a winglet system for a wing of an aircraft, the winglet system comprising:
an attachment end for attachment to a main wing of the aircraft, the attachment end defining an airfoil section having a chord (Sikavi, figure 1b, item 104, wing has a wing tip with an airfoil cross section where the winglet are attached);
an upper winglet (Sikavi, figure 1b, item 152); and
a lowest winglet (Sikavi, figure 1b, item 154), wherein, when the attachment end is attached to the main wing of the aircraft:
the upper and lowest winglets each extend from the main wing tip via a blended portion providing a transition between the main wing tip and the respective upper winglet and lower winglet (Sikavi, figure 1b, items 152, 154, and 156, winglets extending from wing tip via a blended portion);
the upper winglet has an upper winglet tip outboard of the attachment end (Sikavi, figure 1b, item 152, upper winglet tip is outboard of the wing tip attachment section);
the lowest winglet has a lowest winglet tip outboard of the attachment end (Sikavi, figure 1b, item 154, lowest winglet tip is outboard of the wing tip attachment section);
the upper winglet tip of the upper winglet is disposed higher than the lowest winglet tip of the lowest winglet relative to the attachment end (Sikavi, figure 1b, items 152 and 154, lowest winglet below upper winglet);
the upper and lowest winglets overlap one another along the chord of the attachment end (Sikavi, figure 4a, items 108, 154, 160, and 164, top view plot of upper and lowest winglets shows winglets overlapping at their root with respect to the wing tip);
a spanwise profile of the lowest winglet extending along a leading edge of the lowest winglet has a midpoint, a slope of the spanwise profile at a point outboard of the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint (Sikavi, figure 2a, item 154 and 184, slope is more upwards near the tip than at any other point including the midpoint of the lowest winglet; thus, there is point outboard the midpoint which satisfies this condition),
a spanwise profile of the upper winglet and a spanwise profile of the lowest winglet has a substantially constant curvature (Sikavi, figure 4a, items 152 and 154, upper and lowest winglet profiles have substantially constant curvatures), except:
the upper and lowest winglet both extends upwardly relative to the main wing tip;
wherein the spanwise profile of the lowest winglet has a slope of the spanwise profile at all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint such that the lowest winglet is curved upwards at points outboard of the midpoint; and
the leading edge of the lowest winglet is staggered along a chordwise direction of the main wing tip with respect to a leading edge of the upper winglet.
Williams teaches a winglet with a spanwise profile which has a slope of the spanwise profile at all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint (Williams, figure 1 and abstract, curvature is defined such that midpoint located in zone 2 has a slope less than the slop in zones 3 and 4, where all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint are located), such that the winglet is curved upwards at points outboard of the midpoint (Williams, figure 1 and abstract, winglet curves upwards at any point outboard the midpoint).
Sikavi and Williams are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Sikavi with the curved winglet of Williams in order to mitigate shock formation and smooth stress distribution (Williams, ¶13).
Heller teaches a winglet with an upper and lowest winglet wherein the upper and lowest winglets overlap one another along a chord of a main wing tip (Heller, figure 9, items 7, 21, and 27, ¶17, upper and lowest winglets which overlap each other along main wing tip chord) and
wherein the leading edge of the lowest winglet is staggered along a chordwise direction of the main wing tip with respect to a leading edge of the upper winglet (Heller, figures 6 and 9, items 23 and 29, ¶43, leading edge of lowest winglet is staggered in front of the leading edge of the upper winglet).
Sikavi as modified by Williams and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the relative positioning of the upper and lowest winglets of Sikavi as modified by Williams with the overlapping stagger between the upper and lowest winglet leading edges of Heller with a reasonable expectation of success in order to produce a constant downwash distribution (Heller, ¶18).
Chen teaches a winglet wherein the upper and lower winglets both extend upwardly relative to the main wing tip (Chen, figure 9, items 2 and 3, winglets where one winglet is above the other and the lower winglet extends upwards relative to the main wing).
Sikavi as modified by Williams and Heller and Chen are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Sikavi as modified by Williams and Heller with the configuration of the middle winglet extending upwards relative to the wing of Chen as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing.
Regarding claim 28, Sikavi as modified by Williams and Heller teaches the winglet system as defined in claim 26, wherein the upper winglet extends upwardly relative to the attachment end (Sikavi, figure 1b, item 152, upper winglet extends upwards from the main wing tip) and the lowest winglet extends downwardly relative to the attachment end (Sikavi, figure 1b, item 154, lowest winglet extends downwards from the main wing tip).
Claim(s) 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sikavi (WO 2020146399 A1) as modified by Williams (US 10336440 B2) and Heller (EP 2998218 A1) as applied to claim 1 above, and further in view of Gratzer (US 5102068 A).
Regarding claim 19, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein a spanwise profile of the upper winglet extending along a leading edge of the upper winglet is tangent-discontinuous with a leading edge of the main wing when viewed along the chord of the main wing tip (Gratzer, figure 1b, items 1 and 2, upper part of winglet joins with the wing tip in a tangent discontinuous manner).
Gratzer teaches a winglet wherein a spanwise profile of the upper winglet extending along a leading edge of the upper winglet is tangent-discontinuous with a leading edge of the main wing when viewed along the chord of the main wing tip (Gratzer, figure 1b, items 1 and 2, upper part of winglet joins with the wing tip in a tangent discontinuous manner).
Sikavi as modified by Williams, Heller, and Chen and Gratzer are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the upper winglet of Sikavi as modified by Williams, Heller, and Chen with the tangent discontinuous attachment of the upper part of the winglet of Gratzer as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing
Claim(s) 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sikavi (WO 2020146399 A1) as modified by Williams (US 10336440 B2), Heller (EP 2998218 A1), and Chen (CN 206050054 U) as applied to claim 20 above, and further in view of Kirk (US 20110024573 A1).
Regarding claim 21, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 20, except:
wherein the spanwise profile of the upper winglet has a second upper winglet inflection (Kirk, figure 4, items 21, 22, 23, 24, and 27, curvature at 21 creates an inflection point and the change in curvature at 23 creates a second inflection point).
Sikavi as modified by Williams, Heller, and Chen and Kirk are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the upper winglet of Sikavi as modified by Williams, Heller, and Chen with the winglet having two points of inflection of Kirk as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing
Claim(s) 22 and 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sikavi (WO 2020146399 A1) as modified by Williams (US 10336440 B2), Heller (EP 2998218 A1), and Chen (CN 206050054 U) as applied to claim 1 above, and further in view of Freedman (CA 2800627 A1).
Regarding claim 22, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein the lowest winglet is aft-swept relative to the chord of the main wing tip (Heller, claim 5 and figure 13, upper and lowest winglets have a greater sweep than the wing).
Freedman teaches a winglet system including an upper and lowest winglet wherein the lowest winglet is aft-swept relative to the chord of the main wing tip (Freedman, figure 5, item 214)
Sikavi as modified by Williams, Heller, and Chen and Freedman are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the upper winglet of Sikavi as modified by Williams, Heller, and Chen with the lowest winglet being having a greater sweep than the wing of Freedman in order to reduce wave drag from transonic flows.
Regarding claim 23, Sikavi as modified by Williams, Heller, and Chen teaches the wing as defined in claim 1, except:
wherein the upper winglet is aft-swept relative to the chord of the main wing tip.
Freedman teaches a winglet system including an upper and lowest winglet wherein the upper winglet is aft-swept relative to the chord of the main wing tip (Freedman, figure 4, item 114)
Sikavi as modified by Williams, Heller, and Chen and Freedman are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the upper winglet of Sikavi as modified by Williams, Heller, and Chen with the lowest winglet being having a greater sweep than the wing of Freedman in order to reduce wave drag from transonic flows.
Claim(s) 29 (as best understood) and 32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hawley (US 20090072079 A1) in view of Sikavi (WO 2020146399 A1), Williams (US 10336440 B2), Heller (EP 2998218 A1) and Chen (CN 206050054 U).
Regarding claim 29, Hawley discloses an aircraft comprising:
a fuselage (Hawley, figure 3, item 104);
one or more engines for propelling the aircraft, the one or more engines mounted to the fuselage (Hawley, figure 3, items 130 and 132); and
a first wing and a second wing disposed on opposite sides of the fuselage (Hawley, figure 3, item 102), the first and second wings each including:
a main wing including a main wing tip (Hawley, figure 3, item 102, each wing has a wing tip); and
a winglet system attached to the main wing tip (Hawley, figure 3, item 102, each wing tip has a winglet attached), the winglet system including:
an upper winglet having an upper winglet tip outboard of the main wing tip (Hawley, figure 3, item 102, winglet is oriented upwards); except:
the winglet also includes a lowest winglet having a lowest winglet tip outboard of the main wing tip;
wherein:
the upper winglet tip of the upper winglet is disposed higher than the lowest winglet tip of the lowest winglet relative to the main wing tip;
the upper and lowest winglets overlap one another along the chord of the main wing tip;
the upper and lowest winglets each extend from the main wing tip via a blended portion providing a transition between the main wing tip and the respective upper winglet and lower winglet;
the upper and lowest winglet both extends upwardly relative to the main wing tip;
a spanwise profile of the lowest winglet extending along a leading edge of the lowest winglet has a midpoint, a slope of the spanwise profile at all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint such that the lowest winglet is curved upwards at points outboard of the midpoint; and
the leading edge of the lowest winglet is staggered along a chordwise direction of the main wing tip with respect to a leading edge of the upper winglet.
Sikavi teaches a winglet design wherein: an upper winglet having an upper winglet tip outboard of the main wing tip (Sikavi, figure 1b, item 152)
the winglet also includes a lowest winglet having a lowest winglet tip outboard of the main wing tip (Sikavi, figure 1b, item 154); wherein:
the upper winglet tip of the upper winglet is disposed higher than the lowest winglet tip of the lowest winglet relative to the main wing tip (Sikavi, figure 1b, items 152 and 154, upper winglet is higher than the lowest winglet);
the upper and lowest winglets are staggered along a chord of the main wing tip (Sikavi, figure 4a, items 108, 154, 160, and 164, top view plot of upper and lowest winglets shows winglets having staggered root with respect to the wing tip);
the upper and lowest winglets overlap one another along the chord of the main wing tip (Sikavi, figure 4a, items 108, 154, 160, and 164, top view plot of upper and lowest winglets shows winglets overlapping at their root with respect to the wing tip);
the upper and lowest winglets each extend from the main wing tip via a blended portion providing a transition between the main wing tip and the respective upper winglet and lower winglet (Sikavi, figure 1b, items 152, 154, and 156, winglets extending from wing tip via a blended portion);
the lowest winglet extends downward from the main wing tip (Sikavi, figure 4a, item 155, lowest winglet extending downwards);
a spanwise profile of the lowest winglet extending along a leading edge of the lowest winglet has a midpoint, a slope of the spanwise profile at a point outboard of the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint (Sikavi, figure 2a, item 154 and 184, slope is more upwards near the tip than at any other point including the midpoint of the lowest winglet; thus, there is point outboard the midpoint which satisfies this condition).
Hawley and Sikavi are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the winglet design of Hawley with the winglet including an upper and lowest winglet of Sikavi in order to reduce drag with a lowest bending moment penalty (Sikavi, ¶4).
Williams teaches a winglet with a spanwise profile which has a slope of the spanwise profile at all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint being inclined more upwardly than a slope of the spanwise profile at the midpoint (Williams, figure 1 and abstract, curvature is defined such that midpoint located in zone 2 has a slope less than the slop in zones 3 and 4, where all points outboard of the midpoint closer to the lowest winglet tip than to the midpoint are located), such that the winglet is curved upwards at points outboard of the midpoint (Williams, figure 1 and abstract, winglet curves upwards at any point outboard the midpoint).
Hawley as modified by Sikavi and Williams are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Hawley as modified by Sikavi with the curved winglet of Williams in order to mitigate shock formation and smooth stress distribution (Williams, ¶13).
Heller teaches a winglet with an upper and lowest winglet wherein the upper and lowest winglets overlap one another along a chord of a main wing tip (Heller, figure 9, items 7, 21, and 27, ¶17, upper and lowest winglets which overlap each other along main wing tip chord) and
wherein the leading edge of the lowest winglet is staggered along a chordwise direction of the main wing tip with respect to a leading edge of the upper winglet (Heller, figures 6 and 9, items 23 and 29, ¶43, leading edge of lowest winglet is staggered in front of the leading edge of the upper winglet).
Sikavi as modified by Williams and Heller are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the relative positioning of the upper and lowest winglets of Sikavi as modified by Williams with the overlapping stagger between the upper and lowest winglet leading edges of Heller with a reasonable expectation of success in order to produce a constant downwash distribution (Heller, ¶18).
Chen teaches a winglet wherein the upper and lower winglets both extend upwardly relative to the main wing tip (Chen, figure 9, items 2 and 3, winglets where one winglet is above the other and the lower winglet extends upwards relative to the main wing).
Hawley as modified by Sikavi, Williams, Heller, and Chen are both considered analogous art as they are both in the same field of winglet design. It would have been obvious before the effective filing date of the application for one of ordinary skill in the art to modify the lowest winglet of Hawley as modified by Sikavi, Williams, Heller, and Chen with the configuration of the middle winglet extending upwards relative to the wing of Chen as a known configuration of prior art elements according to alternative winglet designs to yield a predicable resulting winglet. Such a modified winglet would reduce the induced drag of the wing.
Regarding claim 32, Hawley as modified by Sikavi, Williams, Heller, and Chen teaches the aircraft as defined in claim 29, wherein the aircraft is devoid of any engines for propelling the aircraft mounted to the first and second wings (Hawley, figure 3, items 102, 130, and 132, wings do not have engines mounted on to them).
Response to Arguments
Applicant’s arguments, see page 7 of applicant’s reply, filed 01/13/2026, with respect to rejections under 35 USC 112(b) have been fully considered and are persuasive. These rejections have been withdrawn.
Applicant's arguments filed 01/13/2026 regarding the 35 USC §103 rejections of claims 1, 6-26, 29, and 32 have been fully considered but they are not persuasive.
Applicant argues that:
Chen and Sikavi teach away from modifying the lowest winglet of Sikavi to curve upwards
Applicant points ¶64-¶65 of Sikavi describing the advantages of the configuration
This does not constitute teaching away. Applicant is merely pointing towards a purported advantage of Sikavi, not a showing that the lowest winglet of Sikavi could not be modified as described.
Applicant purports that one of ordinary skill would add the third fin of Chen instead of modifying one of the existing fin of Sikavi
This is not found persuasive because this does not constitute teaching away. Applicant is merely contemplating an alternative combination of elements, but this is not the only possible combination. None of the evidence provided by applicant here shows that the proposed modification of the rejection would be impossible.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure
Enzo (GB 2587429 A) teaches a winglet with upper and lowest parts and where the upper part has a point of inflection
Min (KR 101772223 B1) teaches an aircraft including a winglet that has an upper and lowest surface which has a sweep greater than that of the wing.
Dhandhnia (US 10625847 B2) teaches an aircraft including a split winglet with a forward and an aft surface wherein one of the surfaces is higher than the other.
Eberhardt (US 20090039204 A1) teaches a winglet with two feather like parts.
Detert (US 20090084904 A1) teaches a split winglet with one part of the winglet being above the other part.
Witte (US 20160009379 A1) teaches a bifurcated winglet construction including a junction angle between the upper and lowest surfaces.
Welles (US 4674709 A) teaches a split winglet with an upper part and a lowest part.
Klug (US 4722499 A) teaches a split winglet design for an aircraft.
Gratzer (US 5102068 A) teaches a spiroid winglet.
Garang (WO 2008155566 A1) teaches a winglet design for an aircraft wherein the winglet has an inflection point
Chirstopher (WO 2012007358 A1) teaches a winglet design with an upper part being tangent continuous with the wing along its span and a lowest surface being tangent discontinuous with the wing.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/RYAN ANDREW YANKEY/Examiner, Art Unit 3642 /JOSHUA J MICHENER/Supervisory Patent Examiner, Art Unit 3642