US2751172A - Flexible kite - Google Patents

Description

June 19, 1956 G. s. ROGALLO ET AL 2,751,172

FLEXIBLE KITE Filed Nov. 17, 1952 2 Sheets-Sheet 1 FIG.!

IN V EN T 0R 5. G'E/FTAUDE SI/GDf/V P0614110 Fig/$11475 MEZ Vl/V R0601! 0 HTTOAA EY June 19, 1956 s, ROGALLO HAL 2,751,172

FLEXIBLE KITE Filed NOV. 17, 1952 2 SheetsSheet 2 Cfi '7 2,751,172

the recessing effects a birdlike shape to the rear of the kite and the general configuration in flight is somewhat similar to what is now known as the flying-wing type of Patented June 19, 1955 2,751,172 5 aircraft.

KITE The area adjacent the nose may be folded along the FLEXIBLE lines 30 to increase stability and rigidity. Gertrude Sugden Rogallo and Francis Melvin Rogallo, Various apertures are provided at the leading edges Warwick, Va. such as the apertures 32 and 34 for securing bridle strings as indicated in dotted lines, such as 36 and 38. Application November 1952 Sena] 320897 Reference to Fig. 1a the mode of attachment of the 3 Claims. (Cl. 244-153) bridle strings will be understood; each bridle string being This invention relates to kites and more particularly and serve to prevent the string from pulling out therefrom.

to kites having no rigid structural elements, of the type set as will be understood from consideration of Fig 1 forth generally in our United States Patent 2,546,078 of Additional bridle strings 46 and 48 are provided for the March 20, 1951. trailing edges and these strings may be ad ustably secured In the patent referred to hereinabove is disclosed a at a series of apertures which are spaced and designated kite of generally quadrilateral shape and comprised of a as L, M, and S, indicative of light, medium, and strong light, flexible material having a crevice longitudinally of winds. the kite body for strengthening and Iigidifying the struc- The bridle strings descend below the kite to a common ture. We have now found upon further research and exjuncture 52 and the main control string 54 descends from periinentation that it is possible to construct a kite of the juncture 52 down to the operator. flexible material such as paper, cellophane, etc. wherein It will be noted that in addition to the three apertures the kite body forms a single continuous arch angularly L, M, and S, a fourth aperture 64 is provided for each transverse of the oncoming wind and that such construcseries. The string is first threaded through aperture 64, tion affords unexpected stability in flight as well as enthence through L for a light Wind; for a medium Wind the hanced lifting power Further, our improved construction string is further threaded through M, and finally for a effects easier control of the kite in flight and results in an strong Wind the string is further threaded through S. overall simplification in manufacture and operability not The same scheme is used for securing the tail 67 to a hitherto suspected as Well as afiording an economy in line 65, wherein a pair of apertures '70 are provided 111 the that a lighter and cheaper material is usable. kite body as shown.

Accordingly, it is the object of our present invention to With reference to Fig. 2, the arch of the airfoil is de picted, the cross-section of the arch being understood to be suitable material which will be exceedingly cheap to ma ugenerally transverse of the oncoming air although at an facture and prepare for flight and which will be easily conang t r a mln d by the angl of attack 74 trolled in flight as well as effecting good flying characas Seen 011 teristics.

40 Thus our kite is operative by virtue of a positive lift Other objects and features of the invention will be achieved, and is a true airfoil, the angle of attack being apparent in the subsequent description, adjustable by selecting the number Of apertures L, M, S

In general, our improved kite utilizes substantially the through Which the hridles are threadedsame principles as heretofore taught in our prior patent. It Will he noted that a Single, Continuous Com-Cally This principle envisages the provision of an airfoil sur- Shaped arch transversely of the longitudinal axis 76 is face of a flexible nature such that it can expand and conachieved, the P being Substantlany at the Hose 12 and tract in accordance with the strength of the oncoming or that y Vlftue 0f the fleXlhlhtY and feslhehey of the klte support ng an o a t tak advantage f l ht ourients, material the lobes of the kite on either side of the longiwhile at th ame tu m t a bl angle f tudinal axis can expand or contract in accordance with attack with respect thereto as controlled and guided by a the Strength of the oncoming Thus a light breeze Will plurality of bridle strings secured at various points ad- Permit the natural resiliency 0f the material to Present a jacent to leading d ili d larger airfoil support area than a strong wind. This A detailed description of our invention will now be etteet is more Pronounced than that found the ongiven in onjun tio with th d d d i in struction of our prior patent and, of course, far surpasses which:

any equivalent effect experienced in conventional kites. Fig. 1 shows a plan view of the top side of the kite flat- Further, a Surprising degree of stability is achieled y the tened out to reveal structural details. Structure- Fig. 1a is an enlarged detail of a string attachment ele- Various substitutions of material y he made, g-, mem plastic ferrules, plastic strings, plastic kite body of poly- Fig, 2 i a View showing the kite as it would appear in ethylene, and so forth, commensurate with light weight flight and being a forward view thereof. and feldahl'hty for compact Storaige- Fi 3 is a side i f the i in fli ht It Will be appreciated that the basic novelty and con- With reference to Figs 1 through 3, our improved struction of our kite is not limited to uses as a toy, but kite comprises a generally d il t n shaped alrfoil could, in fact, be expanded to more serious purposes such 10 f i bl fl xibl d li h i l as he t f as radar targets, parachutes, underwater tow devices, airleading edges 14 and 16. The trailing edges of the kite are Having thus described our invention We are aware that generally designated as 18 and 20, shown in brackets, many Cha ges e p which terminate in a tail area 22.

The trailing edges are concavely recessed at 24 and 26 addition to the gene so as to reduce the lift at the tail area which improves and 0th stability and makes use of a lighter tail possible. Further to persons skilled in the art seek to be limited to the precise embodiment shown herein except as set forth in the appended claims.

We claim:

1. A kite comprising an airfoil member of a flexible material having sweptback leading edges meeting at a forward point and trailing edges joining corresponding leading edges at lateral wing points, said trailing edges meeting at a tail area and being recessed to reduce the rearward tail surface, the arrangement thus presenting the appearance of a flying wing; means for attaching bridle strings to edges of said airfoil member, said bridle strings being joined at a point and exerting simultaneous tension on respective edges to form a single arch across said airfoil member in an airstream, said airfoil being held longitudinally tilted in flight by said bridle lines to effect an angle of attack, wherein the shape of said arch varies as the strength of the supporting wind and said angle of attack.

2. A kite comprising an airfoil member of flexible material capable of being arched by a supporting airstream and being shaped so as to effect a conical arch of the surface thereof transversely across the airfoil member, the crest of said arch being the longitudinal axis of said airfoil member, and bridle strings attached to said airfoil member on opposite sides of the longitudinal axis serving to guide and control said kite and present the surface thereof at a suitable angle of attack, wherein said airfoil member is comprised of paper-like material, having leading edges in a swept-back arrangement meeting at a forward point, said point being provided with folds radiating therefrom for stifiening of the area adjacent said point.

3. A kite comprising an airfoil member of flexible material capable of being arched by a supporting airstream and being shaped so as to effect a conical arch of the surface thereof transversely across the airfoil member, the crest of said arch being the longitudinal axis of said airfoil member, and bridle strings attached to said airfoil member on opposite sides of the longitudinal axis serving to guide and control said kite and present the surface thereof at a suitable angle of attack, including means for securing said bridle strings to said airfoil member at selective points thereof to vary the angle of attack depending on the strength of wind encountered.

References Cited in the file of this patent UNITED STATES PATENTS

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