Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3836099 A
Publication typeGrant
Publication dateSep 17, 1974
Filing dateSep 28, 1973
Priority dateSep 28, 1973
Publication numberUS 3836099 A, US 3836099A, US-A-3836099, US3836099 A, US3836099A
InventorsBrennan W, Kriechbaum G, O Neill E
Original AssigneeUs Navy
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Airfoil camber change system
US 3836099 A
Abstract
An airfoil camber change system for changing the camber of the leading or trailing edges of airfoils. The system includes a flexible continuous upper surface, a lower surface comprising a plurality of slidable overlapping segments and one or more actuation mechanisms. The actuation mechanism includes a plurality of bell cranks and links that are operatively connected to the upper and lower airfoil surfaces. A primary actuator is provided to drive the actuation mechanisms. When the system is driven the actuation mechanism changes the camber profile and maintains proper separation and support of the upper and lower surfaces. The profile is changed by bending the upper constant length surface and shortening the lower surface by increasing the overlap of the slidable overlapping segments.
Images(1)
Previous page
Next page
Description  (OCR text may contain errors)

United States Patent [1 1 ONeill et al.

[451 Sept. 17, 1974 AIRFOIL CAMBER CHANGE SYSTEM [75] Inventors: Edward T. ONeill, Renton; William M. Brennan, Edmonds, both of Wash; Gerhard K. Kriechbaum, Hagnau, Bodensee, Germany [73] Assignee: The United States of America as represented by the Secretary of the Navy, Washington, DC.

[22] Filed: Sept. 28, 1973 [21] Appl. No.: 401,746

Primary Examiner-Trygve M Blix Assistant ExaminerJesus D. Sotelo Attorney, Agent, or Firm-R. SJSciascia; Charles D. B. Curry [57] ABSTRACT An airfoil camber change system for changing the camber of the leading or trailing edges of airfoils. The system includes a flexible continuous upper surface, a lower surface comprising a plurality of slidable overlapping segments and one or more actuation mechanisms. The actuation mechanism includes a plurality of bell cranks and links that are operatively connected to the upper and lower airfoil surfaces. A primary actuator is provided to drive the actuation mechanisms. When the system is driven the actuation mechanism changes the camber profile and maintains proper separation and support of the upper and lower surfaces. The profile is changed by bending the upper constant length surface and shortening the lower surface by increasing the overlap of the slidable overlapping segments.

6 Claims, 3 Drawing Figures PAIENIEB SEPI mm FlG 2A AIRFOIL CAMBER CHANGE SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airfoil camber change mechanism and more particularly to an airfoil camber change mechanism that is rapid acting and provides a continuous smooth airfoil and a high degree of airfoil support.

2. Description of the Prior Art Most prior airfoil camber change systems have employed relatively slow moving members that have not been subjected to high air ram forces. These relatively low speed systems have not provided the rapid time response required by high performance aircraft. In addition, these prior systems do not provide sufficient airfoil support to prevent deflection of the skin or airfoil panels. Some prior systems have employed rapid acting flaps. However, these systems have used single hinged flaps that presented abrupt changes in airfoil curvatures. The present invention overcomes these disadvantages by providing an airfoil camber change system that is rapid acting, has a smooth airfoil, has high strength and is particularly useful in high performance aircraft.

SUMMARY OF THE INVENTION Briefly, the present invention comprises an airfoil camber change system for changing the camber of the leading or trailing edges of airfoils. The system includes a flexible continuous upper surface, a lower surface comprising a plurality of slidable overlapping segments and one or more actuation mechanisms. The actuation mechanism includes a plurality of bell cranks and links that are operatively connected to the upper and lower airfoil surfaces. A primary actuator is provided to drive the actuation mechanisms. When thesystem is driven the actuation mechanism changes the camber profile and maintains proper separation and support of the upper and lower surfaces. The profile is changed by bending the upper constant length surface and shortening the lower surface by increasing the overlap of the slidable overlapping segments.

STATEMENT OF THE OBJECTS OF THE INVENTION An object of the present invention is to provide an airfoil camber change system that provides rapid camber changes.

Another object of the present invention is to provide an airfoil camber change system that provides a smooth airfoil.

Still another object of the present invention is to provide an airfoil camber change system that rigidly supports the airfoil surfaces.

Still another object of the present invention is to provide an airfoil camber change system that may be subject to high air ram forces such as encountered on high performance aircraft.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view of an aircraft employing the airfoil camber change system of the present invention;

FIG. 2A is a side elevation of the airfoil camber change system of FIG. 1 when in the undeflected position; and

FIG. 2B is a side elevation of the airfoil camber 0 change system of FIGS. 1 and 2A when'in the deflected position.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 is schematically illustrated an aircraft having a body 11, tail section 13 and wings 15. The airfoil camber change system 17 is shown on the leading edge of the wing 15. However, it is to be understood that the airfoil camber change system of the present invention may be also used to change the camber of the trailing edge of the wing. Moreover, the basic system is not limited to aircraft but may be used where contour change is desired. The airfoil camber change system 17 includes a plurality of similar spaced apart actuation mechanisms 19, an upper flexible continuous airfoil surface 21, a plurality of overlapping segments 23, 25, 27 forming the lower airfoil surface. Actuation of the system 17 is initiated by primary actuator 29 driving push-pull rod 31 which actuates bell cranks 33 which moves actuation links 35 in a push-pull manner. It is to be understood that many different types of primary actuation may be employed.

In FIGS. 2A and 2B, taken at section 2-2 of FIG. 1, is illustrated the side elevation of the airfoil camber change system 17 including upper surface 21, a plurality of overlapping segments 23, 25 and 27 forming the lower surface and actuation mechanism 19. The actuation mechanism 19 includes a plurality of bell cranks 37, 39 and 41. Bell crank 37 is rotatably mounted on lug 43 and one leg of the bell crank is rotatably mounted on actuator link 35 and the other leg is rotatably attached to one end of link 45. The other end of link 45 is rotatably mounted on lug 47 that is rigidly attached to the first slidable overlapping segment 27. Bell crank 39 is rotatably mounted on lug 47 and one leg of the bell crank is rotatably mounted on the end of actuator link 35 and to one end of actuator extension link 49. The other leg of bell crank 39 is rotatably mounted on one end of link 51 which has its other end rotatably mounted on lug 53 which is rigidly attached to the second slidable overlapping segment 25. Bell crank 41 is rotatably mounted on lug 53 and one leg of the bell crank is rotatably mounted'on the other end of extension link 49. The other end of bell crank 41 is rotatably mounted on one end of link 55 which has its other end rotatably mounted on lug 57 which is rigidly attached to the third overlapping segment 23. The last overlapping segment 23 is attached to the leading edge 59. A plurality of spacer links 61, 63, 65, 67, 69 and 71 are provided to support the upper and lower airfoil surfaces and to maintain the desired airfoil thickness. One end of spacer link 61 is rotatably mounted on lug 43 and the other end is rotatably mounted on lug 73 which is rigidly attached to upper surface 21. One end of link 63 is rotatably mounted on lug 47 and the other end is rotatably mounted on lug 73. One end of link 65 is rotatably mounted on lug 47 and the other end is rotatably mounted on lug 75 which is rigidly attached to upper surface 21. One end of link 67 is rotatably mounted on lug 75 and the other end is rotatably mounted on lug 53. One end of link 69 is rotatably mounted on lug 53 and the other is rotatably mounted on lug 77 which is rigidly attached to upper surface 21. One end of link 71 is rotatably mounted on lug 77 and the other end is rotatably mounted on lug 57. It should be noted that the spacer links and the airfoil surface form triangular truss segments which have high strength characteristic. For example, spacer links 63 and 65 along with segment 79, of upper airfoil surface 21, form this desired triangular truss configuration. It

should be also noted that the spacer links lengths become progressively shorter to conform with the airfoil configuration both in the undeflected position shown in FIG. 2A and in the deflected position shown in FIG. 2B.

The operation of the airfoil camber change system of the present invention is as follows. When actuator link 35 is moved to the left, to a predetermined stop position, the actuation mechanism 19 retains the airfoil in the undeflected position shown in FIG. 2A. It should be particularly noted that due to air pressure on the lower overlapping segments, that the lower legs of the bell cranks and the lower links 45, 51 and 55 are in tension and therefore the pivot connection between these links and the bell crank legs will not buckle during normal operation.

When the actuator link 35 is moved to the right, to a predetermined stop position, then all three bell cranks 37, 39 and 41 rotate clockwise. This reduces the distance between lower lugs 43, 47, 53 and 57 and results in greater overlapping of slidable overlapping segments 23, 25 and 27. It should be noted that overlapping segments 23, 2S and 27 are flexible and therfore maintain a tight seal and provide a smooth lower airfoil surface. To minimize the discontinuity of the lower surface and to increase flexibility, the trailing edge of movable segments 23, 25 and 27 are made thinner than the leading edges. The legs of the bell cranks 37, 39 and 41 are made progressively shorter to achieve the desired airfoil camber. It should be particularly noted that by changing the lengths of the bell cranks and the links that virtually any camber profile can be achieved. Also, any number of overlapping segments and a corresponding increase or decrease in number of bell cranks and links may be employed. It is to be understood that each of the above described links, lugs and bell cranks may in actual practice comprise pairs of links, lugs and bell cranks. This may be done to provide added strength and more rigid support.

a. an upper airfoil surface made of continuous flexible material;

b. a lower airfoil surface comprising a plurality of overlapping segments;

c. at least one actuation mechanism for simultaneously changing the camber of saidupper and lower surfaces; j

d. said actuation mechanism including a plurality of elongated spacer means each having one end rotatably mounted on said upper surface and having the other end respectively rotatably mounted on a plurality of first pivot members respectively connected to said plurality of overlapping segments of said lower surface;

e. a plurality of bell cranks respectively rotatably mounted on said plurality of first pivot members;

f. first means operatively interconnecting adjacent bell cranks and adjacent segments;

g. second means for actuating said bell cranks to slide said overlapping segments with respect to each other; whereby h. during actuation of said second means the camber change of said upper surface is about the same as said lower surface.

2. The system of claim 1 wherein:

a. one leg of each of said plurality of bell cranks being operatively connected to said second means;

b. said first means comprises a plurality of links; and

c. the other leg of said bell cranks being respectively operatively connected to said plurality of links.

3. The system of claim 2 wherein:

a. said second means comprises a plurality of links respectively connecting said one legs of adjacent bell cranks.

4. The system of claim 1 wherein:

a. said upper surface includes a plurality of spaced apart second pivot members; Y

b. said one ends of first and second adjacent elongated spacer means being rotatably mounted on one of said second pivot members;

c. said one ends of third and fourth adjacent elongated spacer means being rotatably mounted on another of said second pivot members; whereby d. said plurality of elongated spacer means form a plurality of triangular support structures.

5. The system of claim 1 wherein:

a. said plurality of bell cranks are sequentially of decreasing size.

6. The system of claim 1 wherein:

a. each of said plurality of first pivot members are connected to the leading edge of the overlapping segment to which it is connected.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1567531 *Mar 24, 1923Dec 29, 1925Piero MagniVariable fluido-dynamic wings such as for aeroplanes
US1880019 *Apr 3, 1922Sep 27, 1932Harper Carl BrownAirplane
US2022806 *Dec 9, 1933Dec 3, 1935Grant Charles HAirfoil
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3941334 *Mar 31, 1975Mar 2, 1976The Boeing CompanyVariable camber airfoil
US3994451 *Mar 28, 1974Nov 30, 1976The Boeing CompanyVariable camber airfoil
US3994452 *Aug 22, 1975Nov 30, 1976The Boeing CompanyVariable camber airfoil
US4040579 *Aug 25, 1975Aug 9, 1977The United States Of America As Represented By The Secretary Of The NavyVariable camber leading edge airfoil system
US4053124 *Jul 26, 1976Oct 11, 1977The Boeing CompanyVariable camber airfoil
US4113210 *Mar 28, 1977Sep 12, 1978The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern IrelandFlexible aerofoils
US4171787 *Jul 21, 1977Oct 23, 1979Zapel Edwin JVariable camber leading edge for airfoil
US4200253 *Apr 3, 1978Apr 29, 1980British AerospaceAircraft wing drooping leading edge device
US4252287 *May 31, 1979Feb 24, 1981Dornier GmbhTransverse force-connected body with variable profiling, particularly an airplane wing
US4553722 *Dec 30, 1982Nov 19, 1985The Boeing CompanyVariable-camber airfoil
US4873278 *Nov 14, 1986Oct 10, 1989General Electric CompanyInhibition of irradiation yellowing in polysulfone compositions
US6123297 *May 20, 1997Sep 26, 2000Saab AktiebolagSegmented flap with variable camber for aircraft wing
US6796534 *Sep 10, 2002Sep 28, 2004The Boeing CompanyMethod and apparatus for controlling airflow with a leading edge device having a flexible flow surface
US6978971Jun 15, 2004Dec 27, 2005The Boeing CompanyMethods and apparatuses for controlling airflow proximate to engine/airfoil systems
US7059563Jun 3, 2003Jun 13, 2006The Boeing CompanySystems, apparatuses, and methods for moving aircraft control surfaces
US7216831Nov 12, 2004May 15, 2007The Boeing CompanyShape changing structure
US7243881Jun 3, 2004Jul 17, 2007The Boeing CompanyMulti-function trailing edge devices and associated methods
US7264206Sep 30, 2004Sep 4, 2007The Boeing CompanyLeading edge flap apparatuses and associated methods
US7270305Jun 15, 2004Sep 18, 2007The Boeing CompanyAircraft leading edge apparatuses and corresponding methods
US7300021May 20, 2005Nov 27, 2007The Boeing CompanyAerospace vehicle fairing systems and associated methods
US7309043Apr 27, 2005Dec 18, 2007The Boeing CompanyActuation device positioning systems and associated methods, including aircraft spoiler droop systems
US7322547Jan 31, 2005Jan 29, 2008The Boeing CompanyAerospace vehicle leading edge slat devices and corresponding methods
US7338018Feb 4, 2005Mar 4, 2008The Boeing CompanySystems and methods for controlling aircraft flaps and spoilers
US7340883Nov 12, 2004Mar 11, 2008The Boeing CompanyMorphing structure
US7357358Feb 27, 2004Apr 15, 2008The Boeing CompanyAircraft leading edge device systems and corresponding sizing methods
US7367530Jun 21, 2005May 6, 2008The Boeing CompanyAerospace vehicle yaw generating systems and associated methods
US7424350Feb 2, 2004Sep 9, 2008The Boeing CompanyVehicle control systems and corresponding sizing methods
US7475854Nov 21, 2005Jan 13, 2009The Boeing CompanyAircraft trailing edge devices, including devices with non-parallel motion paths, and associated methods
US7494094Sep 8, 2004Feb 24, 2009The Boeing CompanyAircraft wing systems for providing differential motion to deployable lift devices
US7500641Aug 10, 2005Mar 10, 2009The Boeing CompanyAerospace vehicle flow body systems and associated methods
US7506842Oct 5, 2004Mar 24, 2009The Boeing CompanyAircraft control surface drive system and associated methods
US7546727Nov 12, 2004Jun 16, 2009The Boeing CompanyReduced noise jet engine
US7578484Jun 14, 2006Aug 25, 2009The Boeing CompanyLink mechanisms for gapped rigid krueger flaps, and associated systems and methods
US7607617Dec 22, 2005Oct 27, 2009Airbus Deutschland GmbhWing unit, in particular spar box, for forming aerodynamically active surfaces of an aircraft, in particular airfoils, horizontal tail units or rudder units of a plane
US7611099Sep 7, 2005Nov 3, 2009The Boeing CompanySeal assemblies for use with drooped spoilers and other control surfaces on aircraft
US7644575Feb 5, 2008Jan 12, 2010The Boeing CompanyMorphing structure
US7708231Nov 21, 2005May 4, 2010The Boeing CompanyAircraft trailing edge devices, including devices having forwardly positioned hinge lines, and associated methods
US7721999Jun 5, 2007May 25, 2010The Boeing CompanyAerospace vehicle fairing systems and associated methods
US7726610Jan 12, 2009Jun 1, 2010The Boeing CompanySystems and methods for providing differential motion to wing high lift device
US7744040Nov 4, 2008Jun 29, 2010The Boeing CompanyAircraft trailing edge devices, including devices with non-parallel motion paths, and associated methods
US7766282Dec 11, 2007Aug 3, 2010The Boeing CompanyTrailing edge device catchers and associated systems and methods
US7828250Jul 17, 2007Nov 9, 2010The Boeing CompanyLeading edge flap apparatuses and associated methods
US7891611Dec 28, 2007Feb 22, 2011The Boeing CompanySystems and methods for controlling aircraft flaps and spoilers
US7909292Sep 16, 2009Mar 22, 2011Airbus Deutschland GmbhWing unit, in particular spar box, for forming aerodynamically active surfaces of an aircraft, in particular airfoils, horizontal tail units or rudder units of a plane
US7913955Mar 23, 2009Mar 29, 2011The Boeing CompanyAircraft control surface drive system and associated methods
US7954769Dec 10, 2007Jun 7, 2011The Boeing CompanyDeployable aerodynamic devices with reduced actuator loads, and related systems and methods
US8038103Jul 2, 2009Oct 18, 2011The Boeing CompanyAircraft trailing edge devices, including devices having forwardly positioned hinge lines, and associated methods
US8186143Sep 28, 2009May 29, 2012The Boeing CompanyMorphing structure and method
US8226048Dec 9, 2008Jul 24, 2012The Boeing CompanyLink mechanisms, including Stephenson II link mechanisms for multi-position flaps and associated systems and methods
US8382045Jul 21, 2009Feb 26, 2013The Boeing CompanyShape-changing control surface
US8397485Feb 24, 2012Mar 19, 2013The Boeing CompanyMorphing structure and method
US8567726Oct 3, 2011Oct 29, 2013The Boeing CompanyAircraft trailing edge devices, including devices having forwardly positioned hinge lines, and associated methods
USRE44313Oct 22, 1997Jun 25, 2013The Boeing CompanyAirplane with unswept slotted cruise wing airfoil
DE2713902A1 *Mar 29, 1977Oct 6, 1977Secr Defence BritTragfluegel
EP1398269A1 *Sep 9, 2003Mar 17, 2004The Boeing CompanyMethod and apparatus for controlling airflow with a leading edge device having a flexible flow surface
EP1674389A1 *Dec 20, 2005Jun 28, 2006Airbus Deutschland GmbH (HRB 43527)Structure, in particular spar box, for forming aerodynamically active surfaces of air vehicles
EP2727825A1 *Oct 30, 2012May 7, 2014C.I.R.A. (Centro Italiano Ricerche Aerospaziali) - S.C.P.A.Device for modifying the airfoil geometry
WO1997044238A1 *May 20, 1997Nov 27, 1997Patrick BerrySegmented flap with variable camber for aircraft wing
WO2003082671A1 *Mar 28, 2003Oct 9, 2003Linsley-Hood RichardAerofoil with variable camber
Classifications
U.S. Classification244/214, 244/215
International ClassificationB64C3/00, B64C3/48
Cooperative ClassificationB64C3/48
European ClassificationB64C3/48