US2422035A - Actuating mechanism for aerodynamic surfaces - Google Patents

Description

ACTUATING MECHANISM FOR AERODYNAMIC SURFACES Filed Aug. 21, 1943 2 Sheets-Sheet 1 INVENTOR JOHN NOYES JR.

BY I

ATTORNEY June 10, 1947. J NOYES, JR 2,422,035

ACTUATING MECHANISM FOR AERODYNAMIG SURFACES I Filed Aug. 21, 1943 2 Sheets-Sheet 2 a: gg llimim INVENTOR. aox-m NOYES JR A TTORNE Y Patented June 10, 1947 ACTUATING MECHANISM FOR, AEBQ- DYNAMIC SURFACES.

John Noyes, Jr., University City, Mo., assignor to. The Gurtiss-Wright Corporation, a cornmration of Delaware Application August 21, 1943, Serial No. 499,746

Claims. 1.

This invention relates to improvements in airplane control systems and more particularly to an improved and novel arrangement of an actuating mechanism for aerodynamic surfaces.

In certain arrangements or configurations of main supporting surfaces for airplane, and especially in those cases in which the main surface is generally characterized as having a high degree of sweep back angle, it is necessary to provide some means for arrangement for maintaining the longitudinal stability characteristics of the airplane when it is found necessary to utilize high lift devices such as flaps. Moreover, it is particularly important in such an arrangement that longitudinal stability or adverse pitching moments be closely controlled during landing or take-off operations of the airplane, since at that time any adverse disturbance of the direction of the airplane becomes a critical factor and may impair the safe operation thereof. Therefore,

the present invention constitutes what is believed to be an important improvement in the arrangement of. control surfaces in an airplane of the above type and especially when high lift devices or flaps are in. use, for the pitching moment produced thereby is automatically compensated by the concurrent upward deflection of the usual lateral control surfaces such as ailerons.

Accordingly, an important object of the present invention is to provide an interconnection between the usual lateral control system and any suitable high lift device for the purpose of trimming the airplane in its longitudinal attitude.

Another object is to provide an operating system for carrying out the above stated purposes and. in which the lateral control system is free for normal operation in the usual manner.

Further objects of the present invention reside in the provision of means for automatically moving the high lift device or flaps into a deflected or down position and at the same time, moving the lateral control surface, for example ailerons, into. an upward deflected position to counteract and. substantially cancell out pitching moments produced by the. flap devices.

Other objects and advantages to be attained herein. will: be pointed out and described in the following specification covering a preferred embodiment of the present invention when considered in view of the accompanying drawings in which:

1 is a general schematic view of the principalparts and elements of the present invention arranged: on a supporting" surface or wing;

Fig. 2 is a partial sectional elevation particu- 2 larly illustrating the driving mechanism and its operative connection with a flap device of split typ Fig. 3 is a further sectional detail of the aileron mechanism and its relation with respect to the wing surface,

Fig. 4 is a plan view of the diiferential mechanism showing further details thereof, and

5 is a front elevational view of the differential mechanism of Fig. 4.

Referring now in particular to Fig. l, the general arrangement of the several parts and elements of the present invention is clearly indicated, and as thereshown, includes a high lift device or flap I0 arranged to be pivotally deflected by a motor and gear unit H. A lateral control surface or aileron I2, is positioned along the trail-ing edge ofthe wing or main supporting surface l3, and a differential lever mechanism I4 is conveniently arranged with respect to the aileron and with respect to the motor and gear unit II, in order that a suitable interconnecting means as a chain or combination chain and cable l5 may be disposed therebetween for operation of a secondary control device later described. The

differential mechanism I4 also includes means for the connection of primary control cables I6, which cables are suitably mounted to ride on pulley units I1 and are rigged with the usual pilots control column (not shown), hence the aileron can be utilized for importing lateral control to the airplane.

Referring now to Fig. 2, a preferred arrangement for mounting the flap Ill and for connecting the flap with the operating motor and gear unit 1 I is shown to advantage. The interconnection between the flap and operating motor includes a horn ill, a connecting member or arm l9, and a crank arm 20 operatively carried in the motor-gear unit I I. In this arrangement the operating motor and gear box may be suitably bolted or otherwise secured by the provision of flange ears 2l= to a vertical member of the'wing structura-suoh as a spar or beam; indicated at 22. The crank arm or operating member 20 is mounted on a shaft Hand is adapted to be turned through a'predetermined angle so the flap l0 will be moved through approximately 45 between its closed or up position and its down position. The dotted line position of the arm 2!), connecting rod l9, and horn l8, clearly indicate the amount of angular deflection and motion necessary for this purpose. While it is not important to the present invention to show the exact or a particular arrangement of the gearingto be contained in the unit II, it is contemplated that any suitable system of reduction gears may be employed between the driving motor such as the one indicated at 24 Fig. 1, and the shaft 23 for operating arm 20. The particular novelty claimed for this operating unit II is exemplified in the further arrangement and addition of a driving shaft '25 and sprocket gear 26, fixedly secured to the shaft. This latter driving shaft 25 is arranged substantially normal to the flap operating shaft 23 in order that the driving chain or chain and cable combination may extend spanwise of the wing for convenient engagement with a secondary control or an actuator and sprocket 2'! which will be described in more detail in connection with the differential lever device shown to particular advantage in Figs. 4 and 5. The motor is essentially of high speed type and therefore requires a considerable gear reduction for each of the operating shafts 23 and 25. A requirement of this gear reduction is that the flap Ill be deflected downwardly through an angle of approximately 45 and that concurrently with this flap motion, the chain drive means 5 operate actuator 21 to produce approximately a upward deflection of the aileron surface |2. It is, of course, understood that the amount of deflection of the fiap l0 and the counter-deflection of the aileron l2 will be governed by certain design features peculiar to each installation and that for the present invention, the above indicated degrees of movement for both the flap and the aileron apply to best advantage in an arrangement shown in Fig. 1. Though not shown, any suitable type of double acting limit switch, responsive to the movement of flap l0, may be inserted in the electric system for motor 24. This limit switch should act to stop the motor upon the flap reaching the limits of its travel, both up and down.

Referring now to Fig. 3, there is indicated one suitable arrangement for hingedly mounting the aileron member l2 on a pivot shaft 30, which extends longitudinally thereof and is suitably mounted in fixed bearing members (not shown) carried by an adjacent structural part of the wing I3. A suitable horn 3| is attached to the inner margin of the aileron l2 and the same is provided with a boss or ear 32 for the attachment of a push-pull rod 33, the latter member being connected with the differential lever mechanism l4. There is also shown in Fig. 3 the position of actuator 21 relative to the aileron and its securement to the structural member or spar 22.

A more detailed showing of the differential mechanism l4 will be found in Figs. 4 and 5. As there shown, the differential mechanism includes a pair of substantially vertically spaced supporting arms 34 each of which is pivotally mounted at one end in a suitable bracket element 35 while the opposite end of each of these arms 34 is secured in spaced adjacence so that the operating arm 36 of the actuator member 21 may be pivotally positioned therebetween. A bell crank member or element 31 is arranged between the supporting arms 34 and is also pivotally mounted on a shaft 38, the latter shaft serving as the common pivot for each of the arms 34 with respect to the bracket 35. Thebell crank member or element 3'! is formed to provide a pair of control cable arms 39 and 40 and an operating arm 4|. The arrangement and relation of the several arms on the bell crank 31 is such that cable arms 39 and 40 project oppositely therefrom whileoperating arm 4| is angularly arranged at substantially a position from each of the cable arms. The bell crank 31 is further arranged so that the cable arms 39 and 40 respectively are positioned at the lower and upper extremities thereof, while the operating arm 4| is disposed intermediately thereof. Moreover the bell crank member 31 may be conveniently formed as an integral member, however, it is equally possible to construct the same of separate parts which are assembled in a fixed manner. A second bell crank or transfer member 42 is pivotally mounted in the space between supporting arms 34 and is arranged at a suitable position intermediate the ends of these supporting arms, for pivotal movement about pivot elements 43. The transfer member 42 is provided with a single operating arm 44, the outer end of which is provided with a pair of suitable pivotal connections for a connecting link 45 and the push-pull rod 33. Link 45 forms the interconnection between bell crank arm 4| and transfer member 42 as clearly indicated in Fig. 4. A suitable cable member [6 extends from the cable arms 39 and 40 respectively to the pilots control column (not shown) located in the cockpit or other position in the fuselage.

Considering first the normal operation of this differential lever mechanism I4, it will be understood that the pilot may move the control column in a side to side manner, and that tension thereby will be exerted in either one or the other of the cables I 6 in the usual manner. If we assume, for the purpose of this description, that a pull is exerted on cable i6 connected to the cable arm 39, the bell crank 3'! will be moved in a clockwise direction as viewed from Fig. 4. Angular displacement of cable arm 39 will cause operating arm 4| to move in accordance therewith and, in turn, link 45 will exert a clockwise rotational force on the intermediately disposed transfer member or secondary bell crank 42. The motion of the latter bell crank 42 will be transmitted to push-pull rod 33 through its connection with the arm 44 as before described. The backward or rearward movement of push-pull rod 33 will effect an upwardly directed movement or deflection of aileron surface I2, and the degree of deflection will be determined by the extent of clockwise rotation of bell crank 37. It will be observed that the differential lever mechanism utilizes the principle of a pantograph in that pivot points 38, 43, and the pivotal connections at each end of link 45 form the corners of a parallelogram lever system. In this pantograph arrangement, the supporting arms 34 are relatively fixed with respect to the remainder of the system and therefore displacement of the arm 4| will result in substantially the same displacement of the arm 44 provided the two arms 4| and 44 are of equal lengths.

The secondary controller or actuator device 21 which is directly subject to operational control by the motor gear unit through the chain drive I5 is suitably mounted in a supporting bracket 46. This actuator device 21 includes a sprocket wheel or gear 41 mounted for rotation on a bearing carried by bracket 46 and operatively related with an internally positioned screw jack 48 and integrally formed operating arm 36. The operation of member 27 is such that upon its rotation by movement of the chain drive [5, the screw jack and operating arm will be threaded inwardly or outwardly without relative rotation as dictated by the direction of rotation of the drive shaft 25, Fig. 2. Since operating arm 36 of this secondary controller 21 is directly and pivotally connected with the free end of the supporting arms 34 of the differential lever mechanism l4, it will be seen that angular displacement of the supporting levers 34 about pivot shaft 38 will result. Hence the actuator member 21 will serve angularly and bodily to displace the differential lever system through any desired degree of displacement. Assuming that the control cables [6 are at that time fixed so as to immobilize the pantograph system and especially the transfer member 42, it will be evident that bodily displacement of the differential lever mechanism M will result in an angular displacement of the aileron surface l2 through interconnection of the push-pull rod 33. Hence a secondary control over the position of the aileron is established without interference with the primary or pilots control through cables I6.

The foregoing description covers a preferred arrangement of operating parts and elements for carrying out the stated objects, and is believed to exemplify a very simple yet efficient and trouble-free arrangement of operating mechanisms for the rapid and positive angular adjustment between the flap l and the aileron l2. As before stated, it is of material importance especially in an airplane configuration in which the main supporting surface is characterized by a high degree of sweep-back angle, that the longitudinal stability thereof be positively and adequately provided for at such times as it becomes necessary to utilize high lift devices such as flaps or the like, An important advantage which is attained in the present invention is evidenced in the arrangement of the differential lever device M, which permits at all times the normal and free operation of the aileron l2 for attaining lateral control of the airplane and at the same time, for permitting a certain and advantageous amount of angular deflection to be imposed thereon for the purpose of trimming the airplane in its longitudinal attitude. Hence the aileron member I2 serves in its usual capacity as a lateral control member and also as a trimming device when employed in combination with high lift devices or flaps.

It is apparent that the above described embodiment of the present invention discloses an efficient and simple structure and one which will attain each and every one of the objects herein set forth; but it is to be understood, however, that certain modifications, alterations, and other minor changes may be made in the several parts and elements hereof without departing from the spirit and intended scope of the invention as defined by the claims hereinafter appended.

What is claimed is:

1. In a control mechanism for operating a device or agency, a first crank lever, a second crank lever, a link pivoted to and interconnecting said first and second crank levers, a push-pull rod connected to said second crank lever and to the device or agency to be operated, means for angularly adjusting said first crank lever to effect a longitudinal change of position of the said push-pull rod to operate the device or agency, relatively fixed means for supporting the said first and second crank levers in a pivotal manner, and means for moving the fixed supporting means to superpose a longitudinal change of position of said push-pull rod irrespective of the change of position of said push-pull rod by said adjusting means.

2. In a control system for the simultaneous actuation of different aerodynamic surfaces, a gear unit having a first and second operating shaft, a crank on the first shaft, means operatively connecting the crank with an aerodynamic surface, a rotary element on the second operating shaft, a differential mechanism associated with a different aerodynamic surface for effecting independent operation thereof, a rotary controller unit operatively related with a differential mechanism and adapted to be driven by the rotary element on the second shaft, and power means for said gear unit whereby the crank will be moved to effect a displacement of the associated aerodynamic surface and the rotary controller unit will be operated to effect displacement of the differential mechanism and consequently a displacement of the associated different aerodynamic surface.

3. In an airplane control system, an aileron surface, flap means, a differential mechanism mounted for swinging movement and including a crank system carried thereby, means connecting said crank system with the aileron surface, means for actuating said crank system to move said aileron, a power unit operatively associated with said flap means for moving the same, and means connecting said power unit with said differential mechanism whereby said differential mechanism may be moved simultaneously with movement of said flap means to effect concurrent movement of said aileron irrespective of the action of said means for actuating said crank system.

4. In an airplane, an aileron, a flap, a differential mechanism mounted for swinging movement and including a crank system operatively carried thereby, a push-pull rod connecting said crank system with said aileron, means actuating said crank system to move said aileron, means for moving said flap, and means operated by said flap moving means for swinging said differential mechanism in a manner to effect a' longitudinal change of position of said push-pull rod and hence movement of said aileron.

5. In an airplane, an aileron, a flap, a differential mechanism mounted for swinging movement and including a crank system operatively carried thereby, a push-pull rod connecting said crank system with said aileron, cable means for actuating said crank system, a motor operated unit for moving said flap, and means operatively interconnecting the motor operated unit and said differential mechanism whereby operation of said motor unit to effect movement of said flap will be accompanied by a simultaneous swinging movement of said differential mechanism and hence movement of said aileron.

JOHN NOYES, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,992,157 Hall Feb. 19, 1935 2,172,289 Munk Sept. 5, 1939

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