US1376337A - Aerofoil - Google Patents

Description

M. F. HUXLEY.

AERGFOIL.

APPLICATION HLEI AuG.8, 1919.

PatentedfApr. 26, 1921.

5 SHEETS-SHEET l.

M. F. HUXLEY.

AEROFOIL.

AFPLICAUON FILED AUG.8, 1919. 1,376,837.

Patented Apr. 26, 1921.

5 SHEETS-SHED' 3.

Fig 5.

M. F. HUXLEY.4

AEROFOIL. APPLICAUON FILED AUG.8, 19I9- 1,376,337.

Patented Apr. 26,1921.

5 SHEETS-SHEET 4.

Ziff

Patented Apr. 26, 1921.

5 SHEETS-SHEET 5.

fnv en for 7.175 Aff-y.

M. F. HUXLEY.

AEROFOIL.

APPLICAUON FILED AUG.8', 1919.

PATENT OFFICE.

MAURICE FRANCIS HUXLEY, OF HENDON, LONDON, ENGLAND.

AEROFOIL.

Speccation of Letters Patent.

Patented Apr. 26, 1921.

Application led August 8, 1919. Serial No. 316,090.

To all w iwf/n. t may concern Be it known that I, MAURICE FRANCIS HUXLEY, a subject of the King of Great Britain, residing at Hendon, London, England, have invented certain new and useful Improvements in Aerofoils,.of which the following is a specification.

This invention relates to improvements in aerofoils used on aeroplanes, and other air-I craft, and also to sections of aerofoil shape such as hydrovanes and the like. I

In the case of an aeroplane it is usual to have aerofoils of a definite section, that is.

the shape of each aerofoil cannot be altered, except as regards the rear portion or trailing edge which is provided with hinged flaps or ailerons for the purpose of balancing and in some cases to act as an air brake.

The lifting property and efficiency of an aerofoil depend on the general curvature of the aerofoil, particularly on the angles of entry and trail and the position of the maximum ordinate. While these angles should be small for high speed, they should be large for low speed. The performance of present day aeroplanes is handicapped by the limitations due to a fixed wing section. The speed range and lifting power of a machine can be enhanced if the shape of the aerofoil is capable of variation.

The object of the invention is to render this variation possible, in a simple and effective manner, and preferably s o thatthe con-- struction of the aerofoil will be rendered economical and without undue increase in weight.

With this object in view the invention consists in an aerofoil having an initial section, designed to give a high lift/drift ratio and provided with a hinged nose and a hinged rear flap, forming separate rigid elements, the two being'inter-connectedso that they are both lowered or both raised to vary the angles of entry and trail simultaneously for the purpose of changing the camber of the section so as to increase or decrease the lift co-efcient of the aerofoil, without a corresponding dangerous displacement of the center of pressure likely to render the aerofoil unstable.

Under conditions when a high lift/drift ratio is the important factor the aerofoil is adjusted to the initial section, whereas under other conditions when a high lift coefficient is of primary importance the cam: ber of the aerofoil is altered so that the angles of entry and trail are increased.

By interconnecting the forward and rear flaps so that both move up or both move down simultaneously, the danger of yexcessive stresses being thrown onto the control mechanism under certain conditions, for eX- ample at small or negative angles of incidence, may be avoided, as the pressure on the nose may be partly balanced by the pressure on the rear flap.

In large machines, for stabilizing purposes the leading and trailing flaps may be so arranged that,they may be operated to increase the camber on one side and decrease it on the other side.

I The invention permits of the central portion of the wing between the spars, remaining fixed as is the present practice, so as to maintain the present character of the wing structure. In this way it facilitates manufacture as the component parts of 4the aerofoil can be made separately and standardized, so that renewals are facilitated. Moreover, it permits of the rear flap being further deflected osi-tively either downward or upward and lndependently of camber deflection, by a separate-control corresponding to what is generally known as aileron control. f

A preferable combination is a hinged front portion capable of rotating on the front spar, and a rear 'portion or flap, eX- tending throughout the rear portion of the wing and hinged to the rear spar. It is also preferred to have the front flap hinged in such a manner that when it is in one position the upper and lower surfaces are both continuous and faired. I

In the accompanying drawings Figure l is a cross section, and v Fig. 2 is a plan of part of an aerofoil with fabric removed to show the mechanism for controlling the forward and trailing sections. v y l Fig. 3 is a plan of half of the aerofoil or wing, diagrammatically indicating the vca-V bles for the controllin mechanism.

Fig. 4f is a cross sectlon of a modified form of the apparatus shown in Fig. l.

Fig. 5 is a cross section through two aerofoils of a bi-plane with the invention applied so that trailing sections of the two planes can be controlled independently of the camber control operating the forward and rear sections.

forming in itself a rigid structure, hinged at 13 to the forward main spar 4, and a rear flap or trailing portion 3 extending throughout the whole length of the aerofoil and hinged to the rear spar 5 at 24. The nose f2 is provided with a suitable number of levers or arms 6, for instance two being shown in l Fig. 3 on each wing or aerofoil secured to the upper surface and extending'rearwardly and of a sha e offering a minimum of head resistance. ach lever 6 is connected by links 7 to a spindle or bar 8 which is so guided that it can be reciprocated but cannot rotate. The end 9 of the bar 8 remote from the links is screw-threaded and passes through a nut 10 which (is shaped on its ext'erior to form a pulley. The other end of the bar 8 is guided by a bearing 21. The pulley nut 10 is'held between a pair of brackets 11 so that it can be rotated freely in either direction by means of a cable 12 passlng over guide ulleys 25, to an operating wheel 26 contro led by a hand wheel 27, in a convenient position for the ilot. The brackets 11 also form bearings or the bar 8. Rotation of the hand-wheel27 and theref ore of the pulley-nut 10 results in reciprocat1on of' each screw-threaded bar 8, 9, and consequently of movement of the `nose 2 about its hinges 13. The pulley-nuts 10 for the bars 8, 9and levers 6 on both wings, are

worked bythe same control, the cable 12 passing from one wing aroundthe wheel 26 over the pulleys 25 to the `other wing. Only one wing is shown in Fig. 3, but the cable 12 and guide ulle s 25 are indicated, the apparatus on t e other wing being identical to that shown.

Each screw-threaded bar 8, 9, also'carries a short stub shaft 14-for another pulley 15 over which "a cable 16 passes and is connected to an arm or lever 17 fixed to the lower or upper surface of the rear flap 3 similarly to. that adopted with ordinary ailerons. The end of the stub shaft 14 passes a slot 43 in a'plate 25' through so as to prevent t e bar 8 from turning.

The cables 16 Vtake the place .of the usual'aileron cable and may be similarly controlled,there being a suitable number of levers 17 and. cables 16 for instance two on each win as shown in Fig. 3. Consequently,- while tie rear ap 3 may be controlled independently as an aileron, it can be moved simultaneously with the nose owing to the reciprocation of the screw-threaded bars 8, 9, carrying the ulleys 15 over which the cables16 pass. he 70 cables 16 from each wing are led over suit-y ableguide pulleys 28 to a control lever 29 of usual form.

When the wings are arranged sothat lateral stabilizing is effected by an increase of camber on one side of the machine, and a decrease on the other, the pulley 15 may be dispensed with and the screwed end of the bar 8, 9, directly connected to the lever 17 by a member such as a tube 30capable of 80 taking tension and compression as indicated in Fig. 4. i The mechanism may be set or arranged in the aerofoil and therefore offers no head resistance. The nose and rear flaps may be divided instead of each extending along the;` whole len th of an aerofoil, andthe portions" on one si e maybe arranged to positively operate those on the other side for stabilizing purposes. Such a modification is illustrated in Figs. 5 and 6 in which similar reference numerals indicate corresponding parts in the other figures. A lcross-tie cable 20 on the upper aerofoil is led over guide pulleys 18 to levers 17 which are arranged on 95 the upper sides of the aileron or movable trailing portions 3 so that the operate-in reverse angles of deflection. Fhe ailerons of the uppei` and lower aerofoils are connected as usual by cables or cross-ties 19 so 100 that they lwork in unison. The cable 16 of the lower aerofoil is connected tothe usual control lever. This arrangement enables the ailerons to be controlled independently of the nose 2, as in ordinary practice, or in 10i conjunction with the nose 2 for variation ofcamber. The central portion or portions of rear flaps 3 in Fig. 6 may be provided with camber mechanism of the kind above re= ferred to and illustrated by Fig. 4, wherein the pulley 15 is dispensed w1th and the screwed end of the bar y8, 9, is connected to the lever 17 by a tube or like member 30. In the form shown in Figs. 7, 8, and 9, a 4 single screw-threadedbar9 1s arranged near 11| the'center of the aerofoil for operating all the levers 6, 17. The screw-threaded bar 9 is fitted with a nut in the form of a pulley v10 adapted t0 be rotated by a cable 31- b means of suitable control lever or han .-120

wheel near the pilot. Y f When the pulley 10 is rotated the screw-" threaded bar 9 is reciprocated and oscillates a lever 32 pivoted atY 33, and to which lever the bar 9 is pivotally connected at 34. The 12 cables 35,' 36, connected to tn e lever' 32,' either cross over each other` and pass around de pulleys 42 and are attached to the uvlers 6 and 17, as shown at the left hand side of Fig. 9, or they pass direct from the 130 lever 32, and are connected to levers 37 pivoted at 38 and having arms 39 to which the levers 6 are connected by link rods 40, the levers 6 being linked to the levers 17 by tubes or rods 30.

Fig. 9 shows two outer wings consisting of a fixed portion l, a hinged nose 2 and hinged rear flap 3 and a central fixed plane 41.

I claim,

l. An aerofoil having an initial section designed for the purpose of giving a high lift/drift ratio and provided with a hinged nose and a hinged rear flap, forming separate rigid elements, controlling means for moving said nose and flap upwardly and downwardly together, for the Dui-pose of varying the angles of entry and trail simultaneously, and additional controlling means for further delecting said rear flap upwardly and downwardly for the purpose of lateral control, `substantially as hereinbefore set forth.

2.' An aerofoil having an initial section designed for the purpose of giving a high lift/drift ratio, and provided with a hinged nose and a hinged rear flap, forming separate rigid elements, levers rigidly attached to said nose and rear flap, mechanism connected to said levers, adapted to move said levers simultaneously, said mechanism including a reciprocatory bar, links connecting one end of said bar to one of said levers on said nose, a pulley on said bar, a cable passing around said pulley and connected to one of said levers on said rear flap, and means for reciprocating said bar, substantially as and for the purpose hereinbefore set forth.

3. An aerofoil having an initial section designed for the purpose of giving a high lift/drift ratio, and provided with a hinged nose and a hinged rear flap, means for lowering and raising said rear ap independently of the nose for stabilizing purposes, and means for lowering and raising said nose, said nose lowering and raising means being adapted to operate said rear flap lowering and raising means, for the purpose of insuring simultaneous operation of the nose and rear flap, for the purpose of changing the camber of the section, substantially as and for thepurpose hereinbefore set forth.

In testimony whereof I have signed my name to this specication in the presence of two subscribing witnesses.

MAURICE. FRANCIS HUXLE Y.

Witnesses Y B. CLARK, F. SQUIRE.

Images