DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of Group I and Species I in the reply filed on 3/29/26 is acknowledged.
Throughout Applicant’s disclosure, Applicant refers to the embodiment of Species I as having a rigid wing that Applicant shows as being moved while maintaining the same shape (figs. 1A−1D). By contrast, Species II and Species III are described as being spread, such that the area of the wing is larger when spread. See, for example, page 4 line 27 to page 5 line 11. Consequently, claim 3, which deals exclusively with spreading the wing and moving the wing to a non-spread state, is not grouped with Applicant’s elected Species I.
Claim 3 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 3/29/26.
Drawings
The drawings are objected to under 37 CFR 1.84. Drawing standards are set forth in 37 CFR 1.84 and explained in greater detail in MPEP §608.02. Drawings must be black and white line drawings (see 37 CFR 1.84(a)(1) and MPEP §608.02(VII)(A)) except in very limited circumstances that do not apply to the present application. The lines must be “solid black lines” (§1.84(a)(1)). Furthermore, “[a]ll drawings must be made by a process which will give them satisfactory reproduction characteristics. Every line, number, and letter must be durable, clean, black…, sufficiently dense and dark, and uniformly thick and well-defined. The weight of all lines and letters must be heavy enough to permit adequate reproduction. This requirement applies to all lines…” (§1.84(l)).
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Interpretation
See above under “Election/Restrictions” for Examiner’s interpretation of “spreading” and “non-spread.”
Certain relative limitations in the claims are being interpreted as broadly understood by one of ordinary skill in the art, rather than being rejected under 35 USC 112(b) as indefinite relative terminology (see MPEP 2173.05(b)(I) “Terms of Degree”).
In light of Applicant’s disclosure, one of ordinary skill in the art would interpret “a low-drag configuration” and “a lift creation configuration” as being essentially synonymous to “a retracted [or collapsed, or folded] configuration” and “a deployed [or extended, or unfolded] configuration” in essentially all known designs where a folded wing is deployed to generate lift. This is because essentially all such designs have lift-induced drag when in a deployed (i.e. in “lift creation”) configuration, as well as increased profile (parasitic) drag when unfolded (since the primary design goal of folding wings in flight is almost always to reduce drag), and the primary goal of unfolding the wing is to generate more lift. Thus, while these limitations are not being considered indefinite, they are not interpreted as adding any appreciable patentable weight beyond being the labels used to identify the folded or unfolded states of the wings.
Similarly, “slowing flight to a speed close to a stall speed of said multirotor aircraft” is understood broadly by one of ordinary skill in the art, since vertical take-off and landing (VTOL) aircraft which rely on aerodynamic lift in forward flight and lift rotors in vertical flight are widely understood as transitioning by slowing down (reducing aerodynamic lift) while increasing upward thrust from vertical flight lift sources. Despite this, the exact stall speed of aircraft is highly dependent on a number of factors. For example, a “free wing” like in claim 4 has essentially no “stall speed” since the free wing weathervanes (i.e. tracks) with the incoming airflow and essentially maintains a negligible angle of attack (angle between chord and airflow) and thus does not encounter the flow separation that causes wing stall (a free wing will drop like a rock if you stop forward flight and remove aerodynamic lift, but technically it does not stall). In terms of interpreting the limitation, one of ordinary skill in the art would generally understand all VTOL aircraft transitioning from aerodynamic lift in forward flight to another form of lift (such as lift rotors) in hover as slowing to a speed close to a stall speed, since hovering (i.e. the final state after transition) is one of negligible forward speed.
Put differently, if a prior art reference began spinning its lift rotors while travelling at or near its forward cruise speed, Examiner would not consider such a teaching to read on “slowing flight to a speed close to a stall speed” (Examiner notes that such references, if they do exist in the art, would be exceedingly rare). However, in order to avoid rejecting the claim under 35 USC 112(b) as indefinite relative terminology, Examiner is interpreting the limitation as reading upon the entire class of VTOL aircraft which rely on forward thrust and aerodynamic lift in forward flight, and then slow forward airspeed to reduce aerodynamic lift while increasing lift from another lift-producing means (such as lift rotors), before finally reaching hover/vertical flight where all lift is provided by these other lift-producing means.
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 1−2, 4−6, and 20 are rejected under 35 USC §102(a)(1) as being anticipated by US Patent No. 9,132,915 to Zhu.
Regarding claim 1, Zhu teaches a method of controlling a multirotor aircraft having a body (fuselage 22), at least three motors (four VTOL fans 100 and two rotatable fans 102 in fig. 7) and at least one foldable wing (canard wings 116 and main wings 130), and a control unit (computer 42) configured to control said at least three motors and said at least one foldable wing (fig. 9, see in particular folding wing servos 120, 136, 138; see also cols. 10−12 for details of controlling the at least three motors);
wherein said at least one foldable wing is foldable about a folding axis (vertical axis at wing base for canard wings 116, longitudinal axis for inboard 134 and outboard 132 portions of wings 130), wherein said at least one foldable wing is controllable with said control unit to transition between a low-drag configuration and a lift creation configuration (col. 6 lines 43−52) during all flight stages (i.e. the wing positions are controlled throughout the entire flight); the method comprising:
a) during a transition to horizontal flight from vertical flight:
the control unit instructs said at least one foldable wing to unfold by rotating about said folding axis, wherein during unfolding said at least one foldable wing remains in said low-drag configuration (i.e. prior to horizontal flight the wings are in a low-drag configuration since they product no aerodynamic lift and have no lift-induced drag); and
once unfolded, said at least one foldable wing is locked into said lift creation configuration relative to said body (i.e. as seen in fig. 8, where wings are controlled to remain in place via servos 120, 136, 138); or
b) during transition from horizontal flight to one of hovering or vertical flight:
the control unit instructs said at least one foldable wing to transition from said lift creation configuration to said low-drag configuration by unlocking and/or collapsing said at least one foldable wing, thereby destroying lift and/or drag (i.e. by slowing forward flight, the control unit is instructing to transition from lift creation due to faster forward airspeed to low drag configuration where slower airspeed lowers lift-induced drag); and
subsequently folding said at least one foldable wing by rotating about said folding axis (i.e. such as folding wing section 132 as seen in vertical flight configuration of fig. 7).
Regarding claim 2, Zhu teaches that said at least one foldable wing is lockable with respect to said folding axis so at as to selectively enable or prevent rotation of said at least one foldable wing about said folding axis (where the position of the wings is continuously controlled by servos, one of ordinary skill in the art would understand the wings as being locked in respective positions by the corresponding servo).
Regarding claim 4, Zhu teaches that said at least one foldable wing is a spreadable wing 130 that may be collapsed to assume said low-drag configuration (i.e. when 132 is folded in as in fig. 7); and may be spread (as in fig. 8) to assume said lift creation configuration.
Regarding claim 5, Zhu teaches that during said transition from horizontal flight to one of hovering or vertical flight as recited in step (b), said method further comprises:
slowing flight to a speed close to a stall speed of said multirotor aircraft (col. 9 line 59 to col. 10 line 7);
initiating at least one vertical motor to carry the weight of the aircraft instead of said at least one foldable wing (as in fig. 7, with VTOL fans 100 providing lift, where the lack of forward thrust results in no lift being aerodynamically produced by the foldable wings).
Regarding claim 6, Zhu teaches that said at least one foldable wing is folded about said folding axis in a direction selected from at least one of:
rearward about said folding axis, therein positioning said at least one
upward about said folding axis (for inboard 134 and outboard 132 wing sections).
Regarding claim 20, Zhu teaches a system as described above for claims 1−2 and 4−6.
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.
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/M.B.K./Examiner, Art Unit 3642 /JOSHUA J MICHENER/Supervisory Patent Examiner, Art Unit 3642
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