I came across this morphing aerofoil, but don’t understand how it works please?

Can someone explain also what the components are, like that box in the left?enter image description here

I looked into that reference, but it’s a complex patent, and it didn’t explain the components


1 Answer 1


This is a rotorcraft airfoil. Item 206 is the rear wing spar. All the information you need is provided in the actual patent application.

US Patent Application for COMPLIANT STRUCTURE DESIGN FOR VARYING SURFACE CONTOURS Patent Application (Application #20170274976)

Description of the Design Challenges

Designing an adaptive control surface for a rotorcraft poses significant challenges.

Patent History Publication number: 20170274976 Type: Application Filed: Jun 13, 2017 Publication Date: Sep 28, 2017 Applicant: FLEXSYS, INC. (Ann Arbor, MI) Inventors: Joel A. Hetrick (Ann Arbor, MI), Sridhar Kota (Ann Arbor, MI), Gregory F. Ervin (Canton, MI) Application Number: 15/621,117

FIGS. 18(a), 18(b), and 18(c) are simplified schematic representations of a layered structure arrangement 200 that is provided with web-like structures 202 that are, in this specific illustrative embodiment of the invention, bonded to compliant skin 210, which will be described in greater detail in connection with FIGS. 18(b) and 18(c), below. Referring to FIG. 18(a), layered structure arrangement 200 is shown to be provided with a drive bar 204 that applies a linear force against rear wing spar 206 by operation of an actuator 208. The motion of drive bar 204 is transmitted to a compliant skin 210, the motion of the compliant skin being accommodated by a sliding joint 214 that in some embodiments of the invention may be configured as an elastomer panel (not shown).

  • $\begingroup$ Hi Mike, So does that mean the box is a drive bar? I thought the component behind the box was that? $\endgroup$
    – Warrick
    Commented Mar 26, 2023 at 18:19
  • $\begingroup$ Yes, (204) is called the drive bar. It is kind of like a movable wing spar that causes the outer skin to extend. The actuator (208) pushes against the fixed rear wing spar (206) which causes the drive bar (204) to move. The drive bar (204) is attached to the outer skin (210). When (204) moves, so does (210). $\endgroup$ Commented Mar 26, 2023 at 18:46
  • $\begingroup$ @MikeSowsun Patent language is impossible obtuse. I don't understand my own patents, and yet I was the inventor! It's a WAG, but I figure that patent language is comprehensible by less than 1% of the population. For instance, "... a layered structure arrangement 200 that is provided with web-like structures 202..." is grammatically incorrect, and yet that's SOP. The upshot is that it would be nice if you could provide a plain-language description of what the patent is actually saying. $\endgroup$ Commented Mar 28, 2023 at 11:56

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