US1961996A - Airplane construction - Google Patents

Description

June 5, 1934. 9 s. 1'. WILLIAMS 1,961,996

' AIRPLANE CONSTRUCTION Filed March 2, 1932 5 Sheets-Sheet 1 INVENTOR ,seldenfm'lliamfi BY I (W W ATTORN EY;

u 5, 1934- s. T. WILLIAMS 1,961,996

AIRPLANE CONSTRUCTION Filed March 2, 1932 5 Sheets-Shet 2 INVENTOR Slden Z'M'llz'ams BY M M 7 K44 ATTORN EYS June 5, 1934. s. 'r. WILLIAMS AIRPLANE CONSTRUCTION 5 Sheets-Sheet 3 Filed llarch 2. 1932 INVENTOR S a I w 0 A M a uY B June 1934- s. T. WILLIAMS 6 ,996

AIRPLANE CONSTRUCTION Filed larch 2,1932

5- Sheets-$heet 4 INVENTOR Seldm Z'mm'm;

ATTORNEY! 7 June 5, 1934. s. T. WILLIAMS 1,961,996

AIRPLANE CONSTRUCTION Filed March 2. 1932* 5 SheetswSheet 5 \INVENTOR 58mm 11mm BY r ATTORNEYS Patented June 5, 1934 orries CONSTRUCTION Seldcn '1. Williams, Bellerose, Y. Application March 2, 1932, Serial No. 596,211

11 Claims. (Cl. 244-19) This invention relates to airplane and airfoil constructions, particularly of the class having wing structures designed for auto-rotation.

The objects of this invention include the pro- 6 vision of wing structures and arrangements thereof of the above indicated class adaptable for use in aircraft to provide improved efllciency, flexibility of control and lifting power with a high degree of safety and stability without sacriiice of speed.

Various further and more specific objects, features and advantages will clearly appear fromthe detailed description given below, taken in connectlon with the accompanying drawings'which form a part of this specification and illustrate, merely by way of example, certain embodiments of the invention.

The invention consists in such novel features, arrangements and combinations of parts as may be shown and described in connection with the structures herein disclosed, by way of example only, and as illustrative of preferred embodiments. v

- In the 'drawings' Figs. 1, 2 and 3 are plan, front and side views respectively of an airplane constructed according to my invention in one of its embodiments;

Fig. 4 is a plan view partly in section and partly broken away, showing one of the rotating wing structures of such an airplane;

Fig. 5 is a side view partly in section of the wing structure, showing Fig. 4; Fig. 6 is an enlarged sectional view taken substantially along the line ,6-6 of Fig. 4, and showing in further detail, features of the wing structure of Figs. 4 and 5;

Fig. 7 is a vertical sectional view taken substantially along the line 7-.-7 of Fig. 6, showing further details;

Figs. 8 and 9 are views similar to Figs. 4 and 5 respectively, but showing an alternative embodiment of my invention; Fig. 10 is a plan view partly broken away of still another wing structure embodying my inventicn;

Figs. 11 and'12 are sectional views taken substantially along the line 11-11 of Fig. 10, showing the movable parts in two different operative positions; a

Figs. 13 and 14 are sectional views respectively illustrating in further detail various parts of a structure such as of Fig. 10; and

Figs. 15, 16 and 17 are plan, front and side views respectively of an airplane including an alternative embodiment of my invention as\applied to a- "pusher type airplane with a sweep back wing structure.

The airplane shown in Figs. 1, 2 and 3 may be provided with a fuselage 20, propeller 21, horizontal stabilizers as at 22, elevators as at 23, a

rudder 24, a vertical mi 25 and landing gear 26, all of these parts being of conventional or well-known forms. The particular construction shown in these figures may also be provided with a pair of. comparatively small'lower wing panels as at 27 and 28 provided with ailerons of conventional type as indicated at 29. These lower wing panels'not only serve as auxiliary wings in horizontal flight but also provide a convenient means for carrying the ailerons for lateral control of the plane and to provide a structural support for the rotating wings, hereinafter described.

As is indicated at 30 and 31, I have provided a pair of upper wing structures in the form of circular auto-rotatable disc-like airfoils, each of which has hinged at spaced points to the periphery thereof a plurality of supplemental wind driven airfoils as at 32 extending in a generally radial direction in respect to the disc-like members. As indicated in Figs. 2 and 3, these rotats0 able airfoils may for example be supported upon the lower wing structure as by a suitable tripod structure which may comprise a vertically extending pylon 33, cooperating with forwardly and rearwardly extending bracing struts as at 34 and s1, 35. However, it will be understood that other forms of supporting means might be provided for the rotating wing elements and attached for example directly to the fuselage. If desired, the tripod structure may be strengthened as by the use of lift wires indicated at 36 and 37. The lower wing panels may be braced and retained as by the use of struts 38 and landing wires 39.

As indicated in Fig. 2, the wing structures 30 and 31 are preferablyarranged at a slight dihedralangle in respect to each other to assure automatic banking upon turning the airplane and to improve its stability in flight. That is, the spindles as at 40 (see Fig. 9) upon which these elements rotate, are preferably tilted upwardly and inwardly toward the fuselage. Also, as is indicated in further detail in Fig. 9, the rotatable elements are. preferably mounted on call or conventional roller bearings to readily permit the desired auto-rotation of these elements during flight. As is indicated by the arrows in Fig. 1, the rotatable wing structures 30 and 31 are intended to rotate in opposite'directions, the wing 30 for example rotating counterclockwise and the wing 31 clockwise, as viewed in Fig. 1. By

hicle wheels 2 reason of this counter rotation the gyroscopic effects are counterbalanced or compensated, thus rendering the airplane in flight more fully susceptible to control by the pilot.

The rotatable wing structures may take'various forms, which will now be described in further detail. Referring to Fig. 4, a hub member 41 is provided at the center of a wheel-like structure having spokes 42 formed of wire for example, and attached at their outer ends to a rigid rim-member 43. As is indicated in Fig. 5, some of the spokes may be connected to the upper end of the hub and others to the lower end, whereby a series of concentric annular members as at 44 may be mounted thereon to provide over the top and bottom surfaces of the wheel-like structure a support for the covering material 45 following the contours of the desired airfoil shape. The members 44 may be secured to the wire spokes 42 as by welding or by binding with wire, as indicated at 46 in Fig. 9. The covering material 45 may comprise airplane cloth suitably doped in any well-known manner. The spokes 42 at the points where the same are joined to the rim 43 may be threaded or otherwise provided with means permitting tightening of the spokes in a manner similar to the construction of vehaving wire spokes.

The surface contours of the circular airfoil are preferably so constructed as to provide a relatively stable center of pressure for these members, regardless of the angle of incidence that the'same may assume during flight. For this purpose, these elements may be constructed so that the forward half of any vertical section extending parallel to the line of flight, will have contours approximating for example that of the well-known Gtittingen section #429. However, any variation of the center of pressure on these elements may be compensated for by adjustments of the horizontal stabilizer 22 and the elevators 23.

In horizontal flight these circular airfoils will act as standard airfoils and add to the lift of the rotating-wing surfaces. Furthermore, I have found that such revolving airfoils possess lifting advantages in that the low pressure area above the wing and the high pressure area below such wing is substantially increased on advancing through the air at a positive angle of incidence. The-low pressure area above and the high pressure below the wing structure is also augmented during descent. In addition, these circular airfoils cooperate with the wing elements 32 hereinafter described to increase the lifting power thereof under all conditions of flight. That is, the circular airfoils tend to increase the amount of air passing the wing elements 32, thereby increasing their dynamic action.

For purposes of illustration 1 have shown each of the circular airfoils as provided with four autorotating airfoil elements 32, although under some circumstances a greater or lesser number may be found to be desirable. As indicated in Fig. 4 each of these members may be fastened as by a hinge 47 to the rim 43. These airfoils are shown as being of a generally rectangular outline and the section or form thereof may be similar to that of a conventional airplane wing. In fact, each is an individual airplane wing constrained to glide on a circular flight path under the action of the air due to the motion of the airplane through the air. Each of these rectangular wings is attached to the circular wing at such an initial angle of incidence as to maintain auto-rotation with the desired rate of rotation, lift and wing position. The hinges at 4'7 permit these airfoils to hinge upwardly or downwardly and if desired, a universal joint type of hinge may also be employed tov permit fore and aft movement. Constructions of such type will be described hereinafter. Rotation of these rectangular airfoils on their own axes is, however, not permitted or else is restricted within predetermined limits, as will be hereinafter explained. With the horizontal hinge structure as shownin Figs. 4 to '7, however, only the flapping motion is permitted.

Referring to Figs. 6 and '7, the hinge structure 4'7 and connected parts will now be described in further detail. In the particular example here shown, the rim 43 is partially embraced by a hinge'pintle carrying member 48 secured as by a dowel 49 and radial spokes 42 to the rim 43. The hinge pintle 50 is embraced by a cylindrical member 51 which has welded or otherwise secured thereto a U-shaped member 52, the arms of which may be riveted or otherwise secured to a pair of channel members 53 and 54 which comprise a rigid central support for the wind driven airfoil or wing .elements 32. As shown in Fig. 4, wing ribs as at 55 may be mounted on the members 53 and 54 for carrying the wing covering material. The inner edges of the wing element may be strengthened and streamlined by a rigid member 56 secured to the hinge member 52. The member 56 may be formed with edges cut at an angle as shown at 5'7 and 58 at points below and above the hinge member 48. These angles are such as to limit respectively the extent of the downward and upward movement of thawing element. When the airplane is at rest, for example on the ground, the wing elements 32 will be supported against dropping to a vertical position by reason of the engagement of the angular surface 57 with the hinge member 48. The wing elements will therefore be held against dropping to a position where it might be dimcult for the plane to properly start in flight. Also, if the plane in flight should encounter some extremely abnormal condition, the wing elements 32 will be held against flapping to a vertical position by reason of the engagement of the angular surface 58 with the hinge element 48.

A semi-articulated means for attaching the wing elements 32 to the circular airfoils will now be described in connection with Figs. 8 and'9. In this construction a hinge member may be provided at 60 similar to the hinge above described, with the exception that instead of providing a rigid attachment to the circular rim, the hinge 60 is mounted upon a ing internally of the circular airfoil and pivoted vertically at 62 adjacent the center of the circular airfoil. With this type of structure the circular airfoil becomes of secondary importance in the support of the rectangular airfoils. The hinge at 60 of coursepermits the up and down "flapping motion of the rectangular airfoil and while fabricated arm 61 extend rotation of the circular airfoil about its own axis Also, in the particular construction shown in these figures, a comparatively small number of rigid spokes as at 65 are provided in lieu of the smaller or wire spokes for the circular airfoil as above described. In order to limit to some degree the forward and rearward turning movement of the wing elements 32 about the vertical pivots as at 62, and to yieldingly retain these wing ele ments in a normal position, flexible connections as at 66 may be provided to extend between the hinge members of the adjacent wing elements 32;

As indicated in Figs. 8 and 9, these flexible connections may comprise in part wires or cords with springs interposed, the ends of the wires being attached in suitable eyelets 6'7 formed on the sides of the hinge members. 2

Another arrangement for attaching the rectangular airfoils to the circular airfoil is illustrated in Figs. 10 to 14 inclusive. With this arrangement, a universal joint member is secured in a mounting in the circular wing structure at the root of each rectangular airfoil adjacent to the periphery of ihe circular airfoil. This universal joint permits an up and down or flapping inotion by reason of the rotation of a small shaft or pintle member 68, to which the rectangular wing element is fixed as by arms 69. The central portion of themember 68 is provided with a spherical enlargement 70 and the end portions of the member 68 may be provided with enlarged cylindrical bearing surfaces 71 and 72, which slide respectively in arcuate grooves 73 and 74, these grooves being formed in rigid members as at 75 attached to the peripheral rim of the circular airfoil. The spherical portion '70 is embraced by a member 76 having upper and lower arms as at '77 and '78 respectively, these arms being attached to wires or rods'79 and 80 respectively, in each of which may be interposed a spring as at 81, the rods or wires then extending to points near the center of the circular airfoil where they may be suitably fixed. This mechanism may all be enclosed within suitable housing means as at 82 wihin the circular air foil structure. It may be found desirable to increase somewhat the thickness of the circular airfoil at its. periphery at the areas 83 adjacent the rectangular wing elements in order to accommodate this mechanism andits housing and to provide a flexible shroud over the junction to fair the wing structures.

With the abovedescribed mechanism it will be apparent that when the forces on the wing elements 32 are such as to tend to cause these elements to either lag back of or proceed in ad vance of the rotation of. the circular airfoil, then if such lag or advance becomes effective, the

ange of incidence of the wing element will also be varied. That is, the wing element will be forced to rotate on its own axis because of'the movement of the bearing members 71 and 72 in the slots 73' and 74; these slots being at the same angles to the horizontal, as is indicated in Figs. 11, 12 and 14. In Fig. 11 the parts are shown in normal position whereinthe wing elements 32 extend directly outward radially. In Fig. 12 the parts are shown in the positions assumed when the wing element 32 is moved to a position in advance of the rotation of the circular airfoil,

viewing the parts as indicated in Fig. 10, at 11-11. It will be understood that the rods or wires 79 and 80 W1 h their interposed spring elements cause the member 76 to somewhat yieldingly engage the spherical member'IO while permitting the wing element 32 and its supporting hinge structure to assume its natural position, dependtion of the wing element on its'own a'xis however being restricted to adegree depending upon the angular positions of the slots 73 and 74. When the rotating wing comes to a position of rest, the wing elements 32 will droop down eventually to a position where the arms 69 will contact with and be supported by the lower outer edge of the housing 82 at a point indicated in Fig. 14, at 84. Of course other means such as guy wires may be used to restrict the downward movement of these wing elements but it will be appreciated that such checking or restricting is not an essential funciioning part of the rotating wing mechanism during its operation.

The operation of these rotating wing structures in supporting the airplane in flight will now be described.

Prior to flight, the rotating wing structures must be placed in rotation, but once in rotation the motion of the airplane through the air will auto-rotation. This initial rotation may' be secured from the airplane engine through the use of suitable shaft and clutch mechanisms, such for example as have heretofore been used in connection with the autogyro. Such mechanism is disconnecied after the required speed of rotation is secured and before the airplane starts its flight. Initial rotation may also be imported manually if desired or merely by deflecting a current of air from the airplane propeller on to the rotating elemen's. When the rotator wing elements are placed in rotation as above described, centrifugal force tends to throw the wing elements 32 upwardly into horizontal positions. As the airplane starts its flight by taxiingover the ground at increasing speed, the air flow through the rotating wing structures increases. This causes the lift of the circular airfoil, as well as that of the wing elemen s 32, to build up until the airplane is carried up into theair in flight.

As previously stated, each rectangular wing functions similarly to an airplane wing when gliding and auto-rotation is the result of the constraint of the glide to a circular flight path. The lift on the rectangular airfoils tends to swing (or cone) them upward and this is counter: acted by the centrifugal force of the rectangular airfoils due to the rotation. The resultant of the centrifugal and lift forces of the rectangular airfoils essentially cancel in the plane of rotation, and are additive in the vertical, applying lift to the structure.

In horizontal flight, it will be readily understood that the rate and direction ,of the airflow over the rectangular airfoils varies as the wing structure rotates. 0n the advancing side, the relative velocity between air and airfoil increases until the rectangular airfoil under considerationis at right angles to the path of flight. It then decreases until the individual airfoil is again at right angles to the path of flight on the retreating side of rotation.

As the lift of an airfoil is a function of air lution. Various other forms only travel at a fore obvious rectangular ing rotation, positions. The arrangement shown in Figs. 10 to 14 inclusive is adapted to accomplish this purpose. The form of the guides or slots 73 and 74 is so chosen as to vary the angle of incidence of the wing elements 32with the advance or retreat of the airfoil, as above described, in such a manner as to equalize the lift throughout revoof mechanism might also be provided for accomplishing the result as regards varying the angle-of incidence in such manner that the wing is free to flap and to pivot and whereby such pivoting brings into action a turning mechanism that varies the angle of incidence. I

With the above described constructions the use thatif the angle of incidence of the airfoils may be properly varied durof relatively long and heavy auto-rotating rectangular airfoils is avoided. With such long airfoils as heretofore used, although the outer ends thereof travel at a relatively high speed and with high efficiencies, theinner portions which can low rate of speed, are much less effective, especially where no central circular airfoil is provided. The speed of rotation of'such been relatively low-at about 125 R. P. M. However, with the constructions embodying my inmay be much greater-for example 300 R. P. M. or more-and comparable lifts secured from smaller rotating wing structures. In addition, the greatest horizontal speed of the airplane may be small in relation to the rotational velocities of the auto-rotatableairfoils. If the velocity due to rotation is great, and that due to forward advance in flight is small, the variation in lift on any individual rotating airfoil will be small during its revolution, thereby making possible smooth stable flight with a high degree of efliciency for the rotating wing elements. The support given by the circular rotating airfoils at the center of the rotating structures serves to substantially increase the support afforded by the auto-rotatable elements. The above described arrangement, having a minimum of two rotor wings, permits ready access and egress from the cockpit or cabin of the plane either in flight oron the ground, even while the wings are rotating. This arrangement also provides a compact symmetrical structure in which the parts may be easily replaced, serviced or inspected. The relatively small diameter of the circular airfoil permits retaming the variations of the center of pressure within controllable limits while still permitting elements also makes it convenient to use the dihedral mounting, assuring proper banking. on the-turns.

However, my invention in various ofits phases is adaptable to machines having more than two of the auto-rotatable structures. .FQL example, inFlgs- 15 to 1'7 inclusive, 1 have shown a machine of the pusher type having sweep-back'lower wing panels, the conventional upper wing panels being replaced by auto-rotatable structures as at 90 and 91 constructed similar .to the rotatable structures above described and also designed to rotate in opposite directions as arrows. .[nv addition, I have provided at 92 a third and preferably somewhat smaller auto-rotatable element also of similar construction and mounted in advance of the forward end of the cabin in a constant lift may be secured at all long auto-rotatable airfoils heretofore used has.

vention as above described, the speed of rotation the use of relatively high and efficient rotor. speeds. The use of a pair of the auto-rotatable indicated by the a position somewhat lower than, the structures 90 and 91. As is indicated in Fig. 17, the shaft upon which the structure 92 rotates may be mounted so as to be tiltable forwardly or rearwardly' by suitable means'such as indicated at 93, manually operable from the control stick in the same manner that conventional elevator surfaces are operated.

While the invention has been described in detail with respect to particular preferred examples, it will be understood by those skilled in the art after understanding the invention that various changes and further modifications may be made without departing from the spirit and scope of the invention, and it is intended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A rotating wing structure comprising a disclike freely rotatable airfoil and a plurality of auto-rotatable wing elements hinged thereto along lines substantially tangent to the periphery there- 0 2. A rotating wing structure comprising a disclike centerportion, a plurality of substantially radially extending wing elements at the periphery thereof, and means for mounting said wing elements for pivotal movement about vertical axes at the mid portion of the structure, and also pivotal movement about horizontal axes extending transversely of the wing elements.

3. A rotating wing structure/comprising a disclike center portion, a plurality of substantially radially extending wing ery thereof, means for mounting said wing elements for pivotal movement about vertical axes at the mid portion of the structure, and also-pivotal movement about horizontal axes extending transversely of the wing elements, and means controlled by said last described pivotal movement for tilting said wing elements about axes extending in a generally radial direction.

4. A rotating wing structure comprising a disclike center portion having a plurality of autorotatable wing elements extending from the periphery thereof, and means for mounting said wing elements in respect to said central portion,

"permitting pivotal movement of said wing elements about substantially horizontal axes extending transversely of said wing elements, and means under the control of such pivotal movement for varying the angle of incidence of said wing elements by and in accordance with such pivotal movements;

5. An airplane comprising a fuselage, propeller means mounted thereon, wings of the sweepback type extending therefrom, auto-rotatable airfoil structures mounted at each side of said fuselage in spaced relation to said wings, and another auto-rotatable airfoil structure mounted substantially on the longitudinal axis of the fuselage. 6. A rotatins wing structure comprising a rotatable disc-like element having a plurality of wind driven airfoils located at spaced points around its periphery, the direction in which said airfoils extend in respect to said periphery-being variable with variations in the air forces thereon, and means housed within the'disc-like element for interconnecting adjacent airfoils whereby variations in the position of one of them causes a force to be applied to the adjacent airfoils tending to vary the positions of the latter. 1

7. A rotating wing structure'comprising a free- Iy rotatable disc-like element having a plurality of wind driven airfoils located at spaced points around its periphery, said element having the form in cross section of a symmetrically uniformly cambered lifting surface, each of said airfoils being mounted pivotally about an axis extending in a generally perpendicular direction in respect to said element whereby the direction in which each airfoil extends in respect to said periphery is variable with variations in the air forces thereon.

8. A rotating wing structure comprising a disclike freely rotatable airfoil and a plurality of auto-rotatable wing elements protruding from its periphery and hinged to the disc-like airfoil along lines extending transversely of said wing elements.

9. A rotating wing structure comprising a disclike freely rotatable airfoil and a plurality of auto-rotatable wirig elements protruding from its periphery and hinged to the disc-like airfoil along lines extending transversely of said wing elements, said lines extending substantially parallel to the general plane of the disc-like airfoil.

10. A rotating wing structure comprising a freely rotatable surface, substantially a surface of revolution, shaped like a discus, said rotatable surface having the form in cross section of a symmetrically uniformly cambered lifting surface such that when in flight at various angles of incidence in the neighborhood of the horizontal, the center of pressure against the struc- -ture remains substantially constant, and a plurality of wind driven airfoils located at spaced points around the periphery of said rotatable surface.

11. A rotating wing structure comprising a freely rotatable surface, substantially a surface of revolution, shaped like a discus with symmetrical uniform cambered upper and lower surfaces whose maximum camber is at theaxis and having a plurality of wind driven airfoils secured thereto adjacent its periphery, said airfolls being attached pivotally and being free to assume various positions depending upon centrifugal force and the force of air-currents thereon.

SELDEN T. WILLIAMS.

Images