US3559923A

US3559923A - Crash-resistant helicopter

Info

Publication number: US3559923A
Application number: US822199A
Authority: US
Inventors: Alvin Edward Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-05-06
Filing date: 1969-05-06
Publication date: 1971-02-02
Anticipated expiration: 1988-02-02

Abstract

A strong, slightly heavier than air helicopter or like vehicle having: hinged, resilient lifting-propeller blades comprising gas-inflated tubes; a substantially rigid cabin comprising gascontaining tubes and a strong skin means; a landing cushion of easily deformable material which maintains its outer shape in flight; a steering propeller supported in a doughnut-shaped tube that is housed in a strong, streamlined skin; and balloon means at the top of the craft for lightening its weight and stabilizing it against pitching and rolling. The cabin''s main, load-carrying part is cylindrical, or optionally oblong or barrel-shaped; and optionally its tubular members are in stavelike elements having strong, planar sides that are epoxy-glued together.

Description

Unite lif States atent Alvin Edward Moore 916 Beach Blvd., Waveland, Miss. 39576 [21] Appl. No. 822,199

[22] Filed May 6, 1969 [45] Patented Feb. 2, 1971 [72] lnventor [54] CRASH-RESISTANT HELICOPTER 39 Claims, 15 Drawing Figs.

[52] U.S.Cl 244/l7.11,

244/5, 244/l7.l7, 244/17.l9, 244/1 19; 416/84 4l6/229,4l6/241 [51] Int. Cl ..B64C ll/24, B64c 1/00 [50] Field of Search 244/17.11,

Primary ExaminerMilton Buchler Assistant ExaminerPaul Sauberer Atl0rney-Alvin Edward Moore ABSTRACT: A strong, slightly heavier than air helicopter or like vehicle having: hinged, resilient lifting-propeller blades comprising gas-inflated tubes; a substantially rigid cabin comprising gas-containing tubes and a strong skin means; a landing cushion of easily deformable material which maintains its outer shape in flight; a steering propeller supported in a doughnut-shaped tube that is housed in a strong, streamlined skin; and balloon means at the top of the craft for lightening its weight and stabilizing it against pitching and rolling. The cabin's main, load-carrying part is cylindrical, or optionally oblong or barrel-shaped; and optionally its tubular members are in stavelike elements having strong, planar sides that are epoxy-glued together.

PATENTED FEB 2197] Q 7 3559.923

sum 1 or 2 FALVIN EDWARD MOORE,

INVENTOR.

ATTORN EY.

PATENTEU FEB 2 I97! sum 2 [1F 2 FIG.3

AALVI N EDWARD MOORE,

I NVENTOR.

ATTORN EY.

CRASH-RESISTANT HELICOPTER This invention pertains to a lightweight. strong, nearly crashproof vehicle. capable of vertical or nearly vertical takeoff from the ground or water and vertical landing. Some of its basic structure may be used in other craft for example. in boats, submarines. cars, or other types of aircraft, but it is preferably incorporated in helicopters or autogiros.

The very expensive. currently standard helicopters require much lifting power because of their weight, have complicated pitch-changing mechanisms that require motors and complex bearing assemblies, vibrate noisily, and are very subject to damage due to breakage of propeller blades and failure of complex devices, with rather frequent loss of life in crashes. The main objects of the present invention are to eliminate, or at least greatly reduce, these defects, and to produce an inexpensive, relatively safe, slightly heavier-than-air helicopter or autogiro, highly resistant to crashes, which will enable the average man to own and fly an aircraft. Some of the other objects are to provide: l a resilient impeller, especially adapted for use in helicopters, autogiros or submarines; (2) such an impeller in which the centrifugal force and changing aerodynamic force on its rotary blades are balanced without need of pitch-changing motors and complexbearing assemblies; (3) a resilient impeller, not subject to breakage, comprising gas-containing tubular members; (4) a resilient impeller, having strongly inflated tubes of thin, flexible material, having flattened ends; (5) such an impeller having flat-ended tubes that contain pressurized nonaerial gas, each tube capable of being flattened to expel air and then inflated by the nonaerial, pressurized gas (for example. helium or nitrogen), the sealed, flattened ends of the tubes being clamped to a hub and bendable under varying thrust during their rotation; (6) a helicopter or autogiro having: a substantially rigid load-carrying body having a frame of strongly-jointed, thin-metal tubular members; vehicle-stabilizing balloon means; and a lower, shock-absorbing cushion; (7) a cylindrical vehicular body, circular in cross section, made of stavelike elements, each of which has a pair of spaced, strength-providing side supports that are annularly arranged and extend along planes thru the axis of the body and a plurality of strong, gas-containing tubular members, imbedded in foam plastic, inside the side supports.

Other objects and the specific structure of the invention will be apparent from the following specification, and from the accompanying drawings, in which:

FIG. 1 is a top plan view of one form of the invented vehicle, with a portion of its stern being shown as broken away to illustrate the steering propeller and its support and driving means.

FIG. 2 is a detail view in section from the plane 2-2 of FIG. 1.

FIG. 3 is a fragmentary view, in section thru a sidewall of the vehicle, illustrating the fastening of a door or window frame between spaced ends of tubular members.

FIG. 4 is a side elevational view of the vehicle of FIG. 1, with after portions of its cabin and landing cushion broken away and shown in section.

FIG. 5 is a detail view in section thru the cylindrical (or optionally oblong) sidewall, showing one type of the thin metal (or thin, dense plastic) tubular members which optionally may also be used in the lifting propeller.

FIG. 6 is a detail, sectional view showing an optional method of strongly joining cans to form the jointed tubular members.

FIG. 7 is a view in cross section from the plane 7-7 of FIG. 1, but showing a modified form of the landing cushion.

FIG. 8 is a detail view, in section from a plane containing the axis of the cabin, illustrating optional forms of the structure of the round (cylindrical or oblong) part of the cabin, the lightweight, strong, fishtailed, streamlined stern of the craft, the fastening between these two parts (and, optionally, a form of the tubular members that also may be used in the lifting propeller).

FIG. 9 is a detail view, on a reduced scale, showing another form of the cabin-wall assemblage of tubular members.

FIG. 10 is a fragmentary sectional view from the plane 7-7 of FIG. I, showing the round cabin wall as being formed of assembled stavelike elements.

FIG. 11 is a detail view, in section from the plane indicated by the lines 11-11 of FIGS. I and 2. showing one type of the lifting-propeller hinge and associated tubular blades.

FIG. 12 is a detail, top plan view, on a scale larger than that of FIG. 11, partly broken away and in section, of a portion of the blades and hub of a lifting impeller, comprising flattenedend tubes.

FIG. I3 is a detail view. in section from a vertical plane thru an optional form of the hub and an assembled set of propeller blades that are similar to those of FIG. 12.

FIG. 14 is a view in vertical cross section thru a propeller blade of the type shown in FIGS. 12 and 13.

FIG. 15 is a detail view in section from the lines and planes 15-15 of FIG. 2, on a scale reduced from that of FIGS. 1 and 2, showing one form of joint between a hinge plate of the type shown at 6 in FIG. 11 and flattened-end impeller tubes.

The invention comprises three basic features, each of which may be used with any illustrated forms of the other two basic features: (I) a hinged, resilient lifting propeller, of two optional forms; this impeller is shown in FIGS. 1, 2, I1 and 15 as comprising a metal hinge, and in FIGS. 12 and 13 as having a hinge of flexible, flattened ends of resilient, inflated fabricand-plastic tubes; (2) a lightweight, strong, substantially rigid, round (cylindrical or oblong) load-carrying body portion, 1, optionally made as indicated in FIGS. 7, 8, 9, or 10, hemispherically terminated at the bow, and joined to a fishtailed stern; and (3) a lower, weakly resilient cushion, 2, shown in FIG. 4 as comprising rubber or other flexible foamed plastic, and in FIG. 7 as comprising separate fibers. Optionally, the lifting propeller shaft may be pivoted in a known manner to provide forward propulsion as well as lift, but preferably there is a separate forward propeller, 3.

In FIGS. I, 4, 11 and 15 the lifting propeller is shown as comprising hinges of steel, aluminum alloy or other strong metal. As indicated in FIGS. 11 and 15, each of these hinges has: a plate 4, securely fixed to the metal hub 5', another plate 6 (6' in FIG. 15) that is pivoted with respect to 4; and a hinge pintle, 7, forming part of the pivot bearing of the hinge. The plate 6 is securely fastened to a propeller blade (vane), 8, which comprises tubular members that optionally may be of the type shown in any of FIGS. 5, 6, 8 and 11 to 15. The blade, as indicated in FIGS. 2 and 11 to 15, comprises several juxtaposed rows or tubular members (9 in FIG. 2). In FIG. 11, each tubular member comprises end-joined tubular containers l0, and the rows of these containers are of different diameters, as indicated in FIGS. 2, 14 or 15. These varying diameters are calculated to fit closely within an aerodynamically streamlined skin, 11; and within the skin the tubular members are assembled in the arrangement of FIG. 2 or FIG. 14. The lower surface of the skin 11 is coextensive with the lower edge of the hinge, and preferably also with the lower plate of the hub 5.

Optionally the tubular containers (of FIG. 11 or FIG. 8) may be of strong, dense, resilient or rigid plastic; but preferably they are of thin sheet metal of the thickness of common cansfor example of sheet steel (optionally resilient), aluminum or aluminum alloy. Preferably they are cans of the general type made by can-manufacturing companies and commonly used for holding food, liquids or other materials. Optionally the tubular containers may be filled with foamed plastic, which may be of the closed-gas-cell type; but preferably they contain sealed gas (for example, air, helium, nitrogen, ammonia, or hydrogen mixed with a small amount of combustion-inhibiting gas). This gas may be under pressure well above that of the atmosphere, placed in the can thru an opening (or openings) in it, and then the opening is sealed, preferably around a stopper or closure, with the aid of brazing, welding, solder, or epoxy putty or glue. The cans may be of the type commonly made with soldered lids, or, like paint cans, with lids that snap into a recess; but such recess-filling lids are epoxy-glued, welded or soldered around their annular edges.

both of the can ends. but in quantity production it is preferably a strong, stiffly resilient blade rib. with its outer periphery shaped to conform to the general aerodynamic outline of the blade. and holes in it for later passage of forming foamed plastic. These ribs and the cans preferably are joined in the following way: l a parallel-axis group ofthe cans (four for the blade example illustrated in FIG. 2 or FIG. 14) are placed with their axes vertical in the bottom of a framed fixture, which has rodlike uprights that hold the cans and ribs in their blade-outlining position; (2) a layer of epoxy or liquidrubber (Pliobond) glue is poured or placed on the flat tops of the cans; (3) a resilient rib is laid on the glue; (4) epoxy or liquid-rubber cement is poured or placed on the top of the rib; (5) another set of the cans are placed, with their axes upright on the rib and cement; (6) et seq.; the process is continued to the end of the blade-forming cans; and (7) an end rib of metal. treated wood or dense, strong plastic. shaped like the other ribs, is glued to the outer set of cans. A resilient blade frame thus is made.

The blade is completed by forming the flexible reinforced plastic skin 11 and placing resilient plastic between the skin and tubular members. The skin may be made by wrapping and flexible-cement-gluing textile or metallic fabric or mesh around the cans and ribs. Optionally this mesh may be of finewire spring steel. fine-wire copper network, aluminum mesh or cloth. Preferably it is impregnated and glued, by flexible, liquid-rubber cement (for example, Pliobond) to an outer sheet of resilient rubber before the composite skin is wrapped and glued to the cans and ribs. But optionally the mesh may be first wrapped and flexibly glued to the cans and ribs, and then either sheet rubber is slightly stretched and flexibly-glued around the mesh or the blade frame is placed in a blade-shaping mold and liquid plastic materials (preferably mixed with fiberglas or other plastic-reinforcing elements) are poured into the mold. around the frame. These materials optionally may be the type which forms foamed plastic.

If the blade is not thus finished in a mold, the reinforced plastic skin is drilled or punctured sufficiently to inject formed-plastic liquids into all the spaces around the tubular elements and within the skin; and then the skin is quickly sealed again to prevent loss of the foaming, gas-pressurized liquids. This way of providing insulating plastic (optionally foamed plastic) is preferably utilized in finishing all the structures of the lifting propeller and vehicular body of this invention that comprise tubular members. When these members are of the type shown in FIG. 8 the foaming plastic materials easily pass from a single injection inlet to all spaces around the cans because of the differences in their diameters; and when the containers are of the type indicated in FIG. 11 the end caps in practice project slightly outward from the can cylinders and the foaming plastic also may be put in place thru one hole; but in the blade forms of FIGS. 12 to I5 several plastic inlet holes are usually needed-unless the blade is finished in a mold.

In a step of the above-outlined method before joining the cans to the ribs the hinge plate 6 may be fastened to the radially inner set of cans by bolts 14, the flat heads of which are glued in flared holes thru plate 6. The nuts 16 are held in slim sockets, inserted thru holes 18 in the blades inner-end cans, and screwed tightly on the bolt threads by turning the socket. But the currently preferred way of fastening the cans to this plate 6 is, before step (1) of the above method, to place the apertured plate, with the pintle removed, in the base of the fixture (the bottom of which is formed to permit the can-engaging surface of the plate 6 to be horizontal) cover it with a layer of epoxy putty or glue, and thus cement the first group of cans (with glue-filled holes in their base end-caps) to the plate. This epoxy putty or glue, which penetrates and sets in the holes of both the plate and the end-caps, has strength comparable to or exceeding that of steel.

The hub 5 is fixed to the propeller drive shaft 20 by a ring of welding, 22, to the hinge plates 4 by bolts 24. and to the removable hub cover 26 by large screws, schematically indicated at 28. When the blades are placed in position and fastened to the hub by inserting and end-fastening the pintles 7 in the hinges. the lifting propeller thus formed is strongly. stiffly resilient. has a simple long-lasting pivot bearing, and permits the blades to hinge up, balancing the centrifugal force and aerodynamic thrust on them when, in rotation, they ad vance against the relative wind of the crafts forward motion.

Instead of cans like 10, having in each row equal diameters, cans of unequal diameters of the type shown in FIG. 8 may be utilized. These have recessedjindented end-caps. In an end recess of each larger can the end-cap of a smaller can is nested; and (when used in an impeller) these end-caps are resiliently glued together by air-setting liquid-rubber cement.

Another type of tubular member that optionally may be used to form the blades is illustrated in FIGS. 13 to-IS. The flattenedend tubes here shown may be joined to the hub by a metal hinge, one plate of which is shown at 6 in FIG. 15; or, as in FIGS. 12 and 13, they may be directly attached to the hub in such a way as to provide flexible hinges by their radially inner flat ends. In FIG. 12, the elongated,

inflated tubes

30 and 31 are shown to have such flattened hubward ends, respectively indicated at 34, 35. 36 and 37. These flat ends are formed. at each end of each tube, by flattening and thoroughly. sealingly bonding together the two contiguous flat plies, so that the middle part of the tube, containing foamed plastic or (preferably) pressurized gas. remains circular, and from a point well spaced from each end of the tube the curved tube walls arcuately flare outward on two sides and arcuately flare inward on two other, orthogonally located sides. As shown in FIG. 13, the flared wall portions of the smaller tube 38 are flattened to the same plane at 39, and the similar flared wall portions of the larger tube 30 would taper to the same plane if, as is optional, the flatted portions of the two tubes stopped and met at a line thru the axis of the bottom hub plate 40 (and thru the axis of the propeller shaft that later in the manufacture is weldedto plate 40). But as shown the bonded flattened portions 42 of trailing edge tube 38 extend thru and are strongly glued to overlying flattened portions of leadingedge tube 30. The similar glued-together four flat plies of the pair of tubes that are orthogonally arranged'with respect to

tubes

30 and 38 are shown at 44 (plies of the smaller tube) and 46 (overlying plies of the larger tube). The leading-edge tube of the left-hand sct'of tubes in FIG. 13 (not shown in section) is illustrated at 48. The smaller right-hand tube whose flattened ends are glued within those of tube 48 is not seen in FIG. 13; but in FIG. 12 two such orthogonally arranged pairs of tubes are shown. They are supported in a hub that is fixed to the propeller shaft 50 by welded bars 51. The sectional plane indicated, normal to propeller shaft 50 and to the axis of the hub, passes thru

flat plies

36 and 37, which extend over and are epoxy-glued to plies 34 and 35. The plies fit in varyingdepth recesses in the upper end of the hub sides, between projections 52 which jut upward from the bottom plate of the hub and may be curved on their peripheral surfaces 53. Closely overlying and holding the plies (and the epoxy putty of varying thickness over them), there is a strong, metal cover plate 54 which is bolted orscrewed to projections 52, and optionally also thru the plies to the bottom plate. In FIG. 13 the similar cover plate 56 is fastened to the hubs bottom plate by bolts 58.

The resilient tubes of FIGS. 12 to 15 optionally may be made of fabric and flexible plastic, for example of two cloth plies impregnated and coated with rubberlike rubber-tire cas' ings or water hose. The fabric may be cloth or fine-wire mesh of spring-steel, copper, aluminum, or aluminum alloy. In lieu of this construction, they may be made of rubber-coated, solid, very thin spring-steel sheet or thin aluminum or copper sheet, covered with resilient rubber (for example molded rubber or an air-setting coat of Pliobond-type rubber cement). When they are of fabric and rubber they are preferably provided with repeatedly usable gas-inlet valves (60. in FIG. I); but when of solid metal they are permanently inflated with gas. The gas used may be air or any of the above-named nonaerial gases; it is under pressure well above that of the atmosphere. preferably in the range of l0 to 30 pounds per square inch.

In FIG. 15. the flattened ends of the tubes are shown as extending along upright planes-instead of in the horizontal arrangement of the tubes of FIGS. 12 and 13. At each end of the blade the flattened and sealed end of each of the elongated cylindrical tubes is formed (bent, pressed or die-formed to the side) in a right angle to the axis of the tube. When it is made of thin resilient metal its hubward end is annealed before it is thus shaped; and when the tube comprises resilient rubber or other thermoplastic material its hubward end is sufficiently heated to slightly plasticize it just before that end is pressed or die-formed into the bracing angle.

In any event the flange or brace 62 thus formed is securely fastened to the hinge plate 6', which is similar to plate 6 of FIG. 11. Epoxy glue or putty is applied to the contiguous surfaces of the flanges 62 and plate 6, some of it penetrating holes 64 for extra holding power; and optionally bolts of the type shown at 14 in FIG. 1 1 may be extended thru the holes 64 and registering holes in flanges 62 and nuts 16 screwed tightly against the flanges.

Formation of skin means and plastic within it and around the tubes, in the manner described above, completes the blade of the type of FIG. 15. Preferably the part 65 of this plastic, adjacent to the hinge, is epoxy, reinforced with fiberglas fibers or other finely divided reinforcing elements.

VEHICULAR BODY As indicated in FIG. 7, the load-carrying part of the body comprises round (cylindrical or oblongpreferably cylindrical) main gas-containing

tubular members

66 and 67, which optionally may be of any of the forms shown in FIGS. 5, 6 and 8 to 15. In each instance foamed plastic, 68, preferably surrounds the tubular members, within skin means of strong material, comprising inner and outer skins that form the inner and outer surfaces of the arcuately-shaped middle part of the cabin. As shown in FIG. 8, the outer skin of the preferably cylindrical body portion and of the fishtail stern portion comprises three skin layers: wire or strong fiberglass mesh 70 (preferably expanded metal, for example, expanded steel lath or expanded-aluminum network); stucco 71, impregnating and coating mesh 70 (preferably portland or mortar cement, mixed with a fine, lightweight aggregate such as vermiculite, pumice or cinders, but optionally of epoxy, mixed with such aggregate or with cedar, cypress or redwood sawdust); and an outermost flexible sheath, '72 (preferably comprising flexible rubber or other flexible plastic, which may be applied in the form of glued plastic sheet material, or as liquid-rubber cement of the Pliobond-type mixed with reinforcing, thickening fibers or particles. Preferably, rubber sheet is epoxy-glued to the stucco. The inner skin may be made like the outer one (with or without an innermost layer of the flexible rubber 72); or it may be formed in the manner of skin 11.

These skins are supported by a lightweight, strong frame of tubular members, which may be in any of the disclosed tubular forms. As shown in FIG. 8, each tubular member is a row of end-joined cans, 74 and 75, of different diameters. The end caps of each of the smaller cans 75 are seated in and strongly bonded by epoxy, other strong glue or putty (or brazing or welding) 76, to the recessed end caps of adjacent larger cans. The resultant row is a jointed tubular member, having great strength at its joints, and having, between the numerous joints, lightweight, thin, gas-containing walls (optionally strengthened by pressurized gas, which may have a pressure well above that of the atmosphere). This gas may comprise air, helium, nitrogen, ammonia, hydrogen or other nonaerial gas or mixture.

These tubular members, having a strength-to-weight ratio that equals or exceeds that of nature-joined bamboo. are closely juxtaposed, preferably contiguous at their joints, and are arranged in the arcuately-shaped middle portion of the cabin. This cabin (which is preferably circular but optionally may be oblong in middle cross sections) optionally comprises tubular members of the end-joined cans or of any of the other tubular-member forms of this invention; and it may be made, as illustrated in FIG. 8, in the following way: (A) Cutting a wide piece of plywood (or metal or edge-joined planks that are glued together at their edges with epoxy or other strong cement) into the arcuately or circularly shaped cabin-end wall element 78. Although in some vehicles this element may have a door in it for access into the stern portion, it is preferably solid. A similar wall element is cut for the forward end of the main, middle-cabin space; this element has the same outer size and shape as 78, but is formed with a door in its middle part. for access into the bow portion of the cabin. (B) Cutting an arcuate piece, 80, of wide, strong metallic mesh (for example of expanded aluminum, expanded steel (metal lath) or hardware cloth), having a curved periphery similar to that of wall element 78, but extending outward from the periphery of 78 by a distance equal to the largest outward extent of the tubular members (equal to the diameter of the larger containers 74 when end-jointed cans form the tubular members), and gluing this piece 80 to element 78 with epoxy putty or other strong adhesive. A similar piece of mesh 81 (FIG. 1), of the same outer size and shape, is cut and strongly bonded with epoxy or other adhesive to the solid forward wall element, with a door hole that registers with that in the last-named element. (C) Placing a removable holder between the element 78 and the forward solid-wall element, and temporarily fastening it to these elements and the associated pieces of mesh in such a way as to hold them (only during assembly of the tubular members) in parallel positions, spaced apart by the desired length of the main load-containing space, with their centers on the desired axis of the cabin. This temporary holder may be a jig or fixture element or a plurality of rods, with screwthreaded ends extended thru holes in the spaced pair of solid endwall elements and associated pieces of mesh and clamped to these elements by pairs of nuts that are screwed toward each other, (D) Annularly placing the tubular members on the peripheries of the solid endwall elements and fastening their ends on these peripheries and against the closely juxtaposed outer rims of the associated pieces of mesh. This fastening is by means of epoxy putty or other strong adhesive, and in the form of FIG. 8, optionally and preferably, also with use of a bolt 82 at each end of each tubular member. This bolt may be fastened to each terminal can-end cap before this cap is soldered or otherwise bonded to the cylindrical can wall; or, as shown in FIG. 8, it may be inserted thru a hole 83 in each rowterminal can of each jointed tubular member, placed thru an end-cap hole and the adjacent mesh and clamped there by the nuts 84 and 85. The bolts and the optional nuts on them that are contiguous to the can ends are preferably bonded to these contiguous end-caps by epoxy or other strong adhesive, 86.

Where a side door opening or hatchway (88 in FIGS. 3 and 4) is located, tubular members 89 are fastened to each side of the door or hatch frame and to

elements

80 and 81. This fastening may be by epoxy or strong adhesive and also, optionally, by bolts and nuts 90 that are similar to 82 and 84. (E) Stuccoing the

mesh

80 and 81 with material comprising portland cement or epoxy adhesive (this is an optional step since its equivalent may be done in step (B) above, with thick adhesive or other cement). (F) Forming the above-described pair of arcuate, wire-mesh skin elements 70, outward and inward of the tubular members, with similarly arcuate, integral portions of the mesh, projecting rearward and forward of the upright pieces of mesh (and of the tubular-member ends) sufficient distances to form the fishtail stern and the arcuately streamlined bow cabin portions. (G) Cutting slits in the forward projection of this mesh, parallel to the axis of the cabin, aft to the upright mesh 81; placing a streamline-shaped mandrel within the projection and against 81. bending the slitted mesh portions into the desired approximately streamlined bow shape; wiring or strongly sewing together the overlapped parts of these portions, from element 8] forward to the approximate place for a window; cutting out mesh to form the window opening; and inserting and epoxy-puttying a curved plexiglass window in the opening. (H) Cutting a hole for the steeringpropeller support 91 in the top of the rear projection of the mesh that is aft of element 80; and placing a pair of upper and lower curved dies or clamp parts. curved in the shape indicated at 92 in FIG. 4, over and under this rear projection and clamping it into the streamlined fishtail shape shown in FIGS. 1 and 4. If the mesh is of resilient metal or of nonresilient metal and covered or coated and impregnated with resilient rubber or other resilient plastic) the rear projection automatically, resiliently assumes the curved. approximately streamlined, fishtail shape 92-93, even when only its aftermost edge portion 94 is clamped by narrow clamps into a narrow horizontal line; but if the projection is not elastic the above-described, wider, curved clamp parts are preferably used. In any event, this narrow flattened stern portion 94 is strongly bonded over and impregnated with epoxy or other strong putty or adhesive. (I) The above-described stucco is now applied on and into the outer and inner parts of the mesh. And after this stucco dries or sets the outermost, flexiblerubber layer 72 of the composite cabin skin means is strongly glued on the stucco. (This layer 72 is optional; if desired it may be eliminated, as indicated in FIG. (J) Small holes are drilled in the cabin skin means; and the middle, main part of the cabin is now finished by pouring mixed foamed-plastic liquids thru the holes and around the tubular members, thus further strengthening and insulating this part of the cabin wall. (K) The deck 95-95' is formed by: gluing together (preferably with epoxy putty or cement) a plurality of gascontaining tubular elements at the base of the curved interior wall of the main part of the cabin and of the bow (preferably the elements 96 are filler pieces of bamboo; and the whole of the assembled tubular elements preferably fills nearly all the space below the deck surface); covering these elements with epoxy or other strong cement (for example portland or mortar cement) mixes with fine, lightweight aggregate; and (preferably) slightly imbedding textile or metal fabric in the cement before it sets or dries. (L) Strengthening the cabin bow with braces and/or extra interior layers of stucco on additional wire mesh. (M) If desired, thus strengthening also the fishtail stern of the cabin.

FIGS. 5, 6, 9 and 10 indicate other optional forms of the cabin-wall structure. In the form of FIG. 5 the tubular members are corrugated. They may be of molded plastic; or as shown they may comprise cylindrically bent pieces of corrugated thin metal (for example of aluminum alloy or steel). Optionally they may be made of corrugated metal sheet of the type used in roofs or trailer structures, but in sa smaller vehicles its thickness is preferably thinner than such material that is now commonly sold. These tubular members of FIG. 5 may be elongated and have sealing end caps only at

elements

80 and 81; or optionally each corrugated member 97 comprises cans of the general type shown in FIG. 8 or FIG. 6. In FIG. 6 the cans are of the same diameter and have welded, brazed or epoxy-glued end caps that are strongly bonded together in the tubular member by epoxy or other strong putty or glue, 98, which comprises a thin adhesive layer between the contiguous surfaces of the end caps. Alternatively, these end caps may be bonded by welding or brazing; or, when they are in tubular members of the type shown in FIG. 11, they may be joined by resilient rubber, air-set from liquid rubber cement of the Pliobond type.

FIG. 10 shows a cabin wall made of separate, bondedtogether, stavelike construction units. Each of these members comprises: an inner, strength-providing piece 99, of plywood (or other wood or metal or reinforced plastic); a pair of planar side pieces, 101, of similar material, epoxy-glued or otherwise fixed to piece 99; a plurality to tubular members, 102, of any of the above-described types; and epoxy or other strong putty or glue between the closely adjacent portions of each adjoining pair of the tubular containers. Preferably the tubular elements are continuously and interbracingly nested together, and have surfaces in contact with the side pieces 101; and optionally gas-containing filler elements of the type shown at 96 (bamboo or the like) may be used to further fill out the space between pieces 99 and the outer cabin skin. As illustrated, the elongated pieces 99 are planar; but optionally they may be curved to form, together, a cylindrical or oblong inner cabin wall; or they may be barrel-curved staves, in which event the members 102 are outwardly curved in fore-and-aft direction, and the outer cabin skin means is barrel-curved.

The stavelike members are joined in a cylindrical or oblong cabin wall by gluing them together with epoxy or other strong adhesive, 104, and then enveloping them in composite outer skin means. This skin means may be of the type shown in FIG. 8; or may comprise: an inner, annular, very thin sheath 106, of aluminum alloy, copper, steel (optionally spring steel) or strong, waterproofed textile or metallic fabric; and an outer, flexible sheet or coating 108 of rubber or other plastic. In any event, the stavelike members preferably are supported in assembly by solid-wall elements like 78 of FIG. 8. Foamedplastic materials are poured around the tubular members and the cabin is otherwise finished as above described. 9

FIG. 9 indicates another way of bracingly nesting a plurality of inner and outer tubular members, between skins of the type illustrated in FIG. 8 or FIG. 10. Here the inner tubular members are shown as of smaller diameter than the similar outer members. They are glued together at their contiguous surfaces; the skins are formed; and then foamed-plastic liquids are poured between the skins.

STEERING PROPELLER FIGS. 1 and 2 show the structure for supporting and driving the steering propeller 108. Element 110 optionally may be gearing, driven by' a shaftfrom the forward main engine; but preferably it is a fluid or electric motor, receiving hydraulic fluid or electric current via line 111, which is connected to a forward source of fluid or electric power, driven by a main engine. The streamlined housing of element 1 10 is firmly fixed to streamlined upper and lower struts, 112 and 113, which may be a single, shaped hollow tube, or optionally may comprise several small-diameter, sealed, cylindrical tubes, inflated with gas at a pressure well above that of the atmosphere, and covered with foamed or other plastic, within a streamlined strut skin.

Struts

112 and 113 are also strongly bonded to a tubular, doughnut-shaped support, comprising an outer skin, 114, and inner reinforcing means. This reinforcement may consist of stitfly resilient or rigid foamed plastic, 115, or as indicated in FIG. 1 may comprise a plurality of interbracing, doughnutshaped tubes 116, of thin metal or dense plastic, inflated with one of the above-described, highly pressurized gases, and surrounded by foamed or other plastic, within the enveloping skin. The doughnut-tube-bracing element 118, comprising a strong skin of metal (or of the above-described type of stuccoimpregnated mesh) provides a streamlined fairing for the after end of the doughnut-shaped support.

This support is further braced and strengthened by: (l the contiguous edges of the above-described hole in the top of thecabin skin means and epoxy putty or other adhesive which strongly bonds the curved surface of the support skin to these edges; (2) the lower contact between the bottom surface of the support and the skin of the fishtailed stern, together with epoxy or other putty, 119, between those two portions (its thickness is exaggerated in FIG. 4; in practice there is contact); and (3) the gas-cell-containing foamed plastic that is injected under pressure as foaming liquids thru a small,v quickly sealable hole in the after part of the cabins outer skim Preferably all the foamed plastic of this invention is of this closed-gas-cell type and is thus put in place under gaseous pressure via quickly-scalable apertured means.

LANDING CUSHION The vehicle preferably comprises a lower, shock-absorbing cushion, that is adapted for landing on ground or in the water. This member comprises: an outer, flexible, waterproof skin, 122, (optionally an integral part of an overall fabric-andplastic skin, 135), that remains in the generally symmetrical shape shown in FIGS. 4 and 7 when the vehicle is in the air, but readily flexes out of this shape on landing contact with the ground or water; inner shock-taken means that optionally may comprise the integral, readily flexible foamed plastic 123 of FIG. 4 or fibers or the like 124, as indicated in H0. 7, housed within a very flexible, generally cylindrical skin, 125; and four flexible tubes 126, inflated with one of the above-named gases at a pressure well above that of the atmosphere, which preserves the shape of the cushions outer skin while the craft is in the air. Further streamlining and shape-preserving means for the skins comprise an after fairing which has a flexible skin and flexible foam plastic (shown in FIG. 4 at 128) in this skin, and resilient foamed plastic, 129, within skin [22. An optional shape-preserving means is shown in FIG. 7 at 130; it is a flexible tube, inflated with gas, annularly curved at the nose of the cushion, and having after ends that are joined in a line at the cushion 's streamlined stern.

All the skins of the cushion are of fabric (preferably of nylon or other strong cloth), impregnated and coated with flexible plastic, which preferably is rubber.

BALLOON MEANS The top part of the vehicle preferably comprises balloon means that aids in stabilizing the craft against pitching and rolling and in holding it upright after landing. As indicated in FIGS. 1 and 4, this means comprises'two balloons with their adjacent ends 132 in contact with the propeller-shaft tube 134, which projects upward between them to the top level of the balloon means.

Around the entire middle portion of the craft, comprising the balloons and the cylindrical parts of the cabin and the cushion, there is wrapped a strong, foam-plastic-filled fabric, 135, of nylon or the like, impregnated and coated with flexible plastic. This envelope comprises streamlined fairing skins 136; its top is rearwardly extended and joined at 137 to the skin 114 of the steering-propeller support; and its bottom 138 is heavily coated with tough rubber of the type used in automobile tire treads, to take the wear of landing. This envelope completes the outer form of the vehicle.

POWER MEANS.

The crafts power plant preferably comprises: a gasoline or lightweight diesel engine, 140, mounted in the nose of the craft, driving the forward propeller thru a clutch; a pump incorporated in the engine housing, driven by the engine; hydraulic-fluid lines 142 and 111; the controllable-speed, liftpropeller-driving hydraulic motor 144 (supported on a cabin partition, 146, or 144; and the motor 110 which drives the steering propeller.

In the appended claims, unless otherwise qualified, the word impeller" signifies a vehicle propeller, or autogiro or other fluid impeller; the word fluid-dynamic" means aerodynamic or hydrodynamic; the expression tubular member signifies: a single tube or a plurality of end-connected tubular articles, of any cross-sectional shape; gaseous material": gas, gaseous mixture or foamed plastic of the closed-gas-cell type; gas": pure gas or mixture of gases; plastic: rubber or any other type of plastic; and the word fluid" signifies air or water.

1 claim:

1. A vehicle, comprising:

, a cabin, having a load-containing space and a thrust beara rotary lifting impeller, subject to fluid-dynamic lifting force during its rotation in a fluid, having: a shaft in said thrust bearing, transmitting lift via said bearing to said cabin; a plurality of resilient, fluid-dynamic blades, ex-

tending transversely of the axis of said shaft; and a hinge between each of said blades and the shaft, permitting upward pivoting of said blade away from a plane normal to the axis of the shaft, under said lifting force, and against centrifugal force on the blade, tending to position it in said plane;

each of said blades comprising: a flexible, streamlined, skin;

within said skin, a plurality of juxtaposed tubular members, each of which is circular in cross sections over a sub stantial portion of its length, said members having a plurality of different diameters in said circular-in-cross-section portions, with a smaller-diameter one of said portions being near the trailing edge of the blade, and at least one of said portions having a diameter larger than that of said smaller-diameter portion and located between the blades leading edge and said smaller-diameter portion; and gaseous material inside each of said tubular members.

2. A vehicle as set forth in claim 1, in which said gaseous material is gas at a pressure approximately equal to that of the atmosphere.

3. A vehicle as set forth in claim 1, in which said gaseous material is gas, under pressure well above that of the atmosphere.

4. A vehicle as set forth in claim 1, in which said gaseous material comprises gas that is lighter than air.

5. A vehicle as set forth in claim 1, in which said gaseous material comprises closed-gas-cell, foamed plastic.

6. A vehicle as set forth in claim 1, in which each of said blades has a planar, platelike element, comprising metal, at its end adjacent to said hinge, and said hinge comprises: a rigid element, fixed to said platelike element; a rigid element, fixedly connected to said shaft; and a pivot bearing between said rigid elements.

7. A vehicle asset forth in claim 1, in which each of said hinges comprises a flexible element of sufficient strength to withstand its disruption by said centrifugal force.

8. A vehicle as set forth in claim 7, in which: each of said blades comprises an elongated flexible tube, and said flexible element of each of said hinges comprises a flattened end portion of said tube and resilient adhesive bonding together the flat plies of said flattened end and sealing an end of the tube.

9. A vehicle as set forth in claim 1 in which each of said blades comprises an elongated flexible tube, having walls of impeller-strength-providing material, having a middle portion that is circular in cross sections and an end portion at each end of said middle portion, said end portion comprising: a curved part that has an integral junction with said middle portion, that, in a plane containing the longitudinal axis of the tube, curvingly flares outward on each side of the tube s axis, and in a plane normal to said first-named plane curvingly tapers toward the said axis of the tube; and a flattened-end portion, integrally joined with the shaftward end of said curved part, comprising two parallel, flat edges of said curved-part end and bonding material between said flat edges, sealing said shaft ward end of the tube.

10. A vehicle as set forth in clam l, in which: said tubular members comprise tubes having flexible walls; each of said tubes is filled with a portion of said gaseous material; and said gaseous material imparts resiliency to said tube walls.

11. A vehicle as set forth in claim 10, in which said gaseous material comprises gas under above-atmospheric pressure.

12. A vehicle as set forth in claim 10, in which said gaseous material comprises closed-gascell, foamed plastic.

13. A vehicle as set forth in claim 1, in which said cabin is round in cross sections normal to its longitudinal axis over a substantial portion of its length, and has a substantially rigid wall between its exterior and said load-containing space, said rigid wall comprising: a plurality of tubular cabin-frame members, connected together in a cabin-strength-providing framework; gaseous material in each of said members; and means strongly connecting said members together.

14. A vehicle as set forth in claim 13, in which: said impeller blades are entirely located in ambient fluid above said cabin;

at least their major portions, during their rotation come within the space between vertical projections of the ends of said round-in-cross section cabin portion; and, during their rotation, major portions of the blades extend outside the space between vertical projections of the sides of said round-in-cross section cabin portion, thus vertically moving fluid to and beyond and below the curved borders of said cabin portion.

15. A vehicle as set forth in claim 13, in which each of said cabin-frame members is strongly jointed and comprises: a plurality of sealed, end-joined, curved container walls, each of which contains a portion of said gaseous material; connecting means between and strongly joined to the adjacent ends of each adjoining pair of said curved container walls, comprising at least one platelike element and means strongly bonding together said adjacent ends and said platelike element.

16. A vehicle as set forth in claim 15, in which cross sections thru the peripheries of said curved container walls are circular, and said peripheries in cross section comprise circles of different diameters.

11 17. A vehicle as set forth in claim 13 in which each of said cabin-frame members comprises a sealed, elongated tube having walls of dense material and containing a portion of said gaseous material.

l8. A vehicle as set forth in claim 17, in which said walls have a thickness of less than 0.02 of an inch, and said gaseous material imparts strength to the walls.

19. A vehicle as set forth in claim 13, in which said gaseous material comprises gas at a pressure above that of the atmosphere.

20. A vehicle as set forth in claim 13, in which said gas is lighter than air.

21. A vehicle as set forth in claim 13, in which the gaseous material in said cabin-frame members comprises closed-gascell, foamed plastic.

22. A vehicle as set forth in claim 13, in which said cabinframe tubular members comprise sealed tubular walls that have a thickness less than 0.02 of an inch and are of material comprising metal, and said gaseous material is gas at a pressure well above that of the atmosphere.

23. A vehicle as set forth in claim 22, in which said gas is lighter than air.

24. A vehicle as set forth in claim 13, in which said cabinframe members comprise sealed tubes, each of which has a pair of flattened and sealed ends, and said gaseous material in the tubes has resiliency and adds strength to the walls of said tubes.

25. A vehicle as set forth in claim 1, in which said thrust bearing is in a middle portion of said cabin, said middle portion is below said impeller and has a maximum horizontal width that is less than the combined lengths of two of said impeller blades, and in which said vehicle further comprises a shock-absorbing cushion that is below and attached to said middle portion and has a maximum horizontal width that is no greater than that of said middle portion.

26. A vehicle as set forth in claim 25, comprising an aerostatic, balloon means above and attached to said cabin middle portion, and in which said vehicle comprises a flexible sheath of strong material which envelops the said balloon, cabin middle portion, and cushion.

27. A vehicle as set forth in claim 26, in which said cushion comprises fibrous material, and in which at least the portion of said sheath that covers said cushion comprises waterproof material and prevents the entry of water among said fibers.

28, A vehicle, having a load-carrying cabin, said cabin comprising:

a cabin-strength-providing skin, comprising a sheet of stiffly flexible material;

a middle cabin portion, having a load-containing space,

round in cross sections normal to the longitudinal axis of the cabin, comprising, within a forward part of said skin: a

substantially rigid forward wall, at the forward end of said middle portion; a substantially rigid after wall, at the after end of said portion; extending between said walls and inclosing said load-containing space, a curved side wall. endlessly curved in planes normal to said axis, having cabin-strenght-providing framework comprising a plurality of juxtaposed, tubular members, with their axes curvingly arranged around said axis; gaseous material in each of said tubular members; and foamed plastic around each of the tubular members and between them and said skin;

a substantially streamlined nose portion of the cabin. comprising a nose-strength-providing skin;

a substantially streamlined, generally tishtail-shaped cabinstern portion, defined by a fishtail-shaped after part of said first-named skin, said after part having: integral, curving, top, side and bottom portions; a flattened, generally horizontal after end; and, in each cross section normal to the said longitudinal axis, a total peripheral extent that is at least as large as the total peripheral extent of the said after wall; said Fishtail-shaped part of the cabin-strength-providing skin tending to hold its generally streamlined flshtail shape, with: its said flattened after end in planar horizontal condition; its 'top and bottom portions curvingly tapering in height from said flattened after end, forward and upward to said after wall: and its sidewalls curvingly flaring outward in increasing horizontal extent across said axis from said after wall to said flattened after end.

29. A vehicle as set forth in claim 28, adapted to move in a fluid which surrounds it, comprising means, connected to said cabin, for exerting a lift on the cabin.

30. A vehicle as set forth in claim 29, in which said lift-exerting means comprises a fluid-dynamic impeller.

31. A vehicle as set forth in claim 30, in which said fluid is air and said fluid-dynamic impeller is aerodynamic.

32. A device asset forth in claim 31, in which said vehicle is a vertical-takeoff aircraft, said impeller is a lifting propeller, and said vehicle comprises motive means and power-transmission means connected to said motive means and to said propeller.

33. A vehicle'as set forth in claim 28, adapted to move in a fluid which surrounds it, comprising: a lifting impeller haying a plurality of blades, each of which has a framework comprising hollow tubular members and gaseous material in said lastnamed tubular members; and a rotary shaft; said impeller further comprising hinge means between said shaft and each of said blades.

34. A vehicle as set forth in claim 33, further comprising aerostatic, balloon means, having a center of lift above the center of gravity of the vehicle.

35. A vehicle as set forth in claim 28, comprising aerostatic, balloon means, exerting a lift on said cabin that is centered above the center of gravity of the vehicle and provides an attitude-stabilizing force on the vehicle.

36. A vehicle as set forth in claim 28, comprisinga shockabsorbing cushion, located below and attached to said middle cabin portion, havinga maximum width not greater than that of said middle portion, and in which said vehicle comprises a flexible sheath of strong material that surrounds said middle portion and cushion.

37. A vehicle as set forth in claim 36, in which said cushion comprises fibrous material and at least the portion of said sheath that is below said longitudinal axis comprises waterproof material and protects said fibrous material from entry of water.

38. A vehicleas set forth in claim 32, in which an after part of said cabin-strength-proyiding skin has an opening at its top, elongated in a fore-and-aft direction, comprising: a propellersupporting skin, closely fitting in said opening, having a streamlinedly-curved upper part that extends well above an upper part of said cabin-strength-providing skin and a bracing lower part that extends downward from said opening and within said last-named, cabin skin, into close proximity with a lower part of said cabin skin; means strongly fastening said cabin and propeller-supporting skins together along the line of 39. A vehicle as set forth in claim 38. in which the said means connecting the propeller and propeller-rotating means comprises streamlined struts. fixed to a generally toroidal inner portion of the said propeller-supporting skin.

Claims

1. A vehicle, comprising: a cabin, having a load-containing space and a thrust bearing; a rotary lifting impeller, subject to fluid-dynamic lifting force during its rotation in a fluid, having: a shaft in said thrust bearing, transmitting lift via said bEaring to said cabin; a plurality of resilient, fluid-dynamic blades, extending transversely of the axis of said shaft; and a hinge between each of said blades and the shaft, permitting upward pivoting of said blade away from a plane normal to the axis of the shaft, under said lifting force, and against centrifugal force on the blade, tending to position it in said plane; each of said blades comprising: a flexible, streamlined, skin; within said skin, a plurality of juxtaposed tubular members, each of which is circular in cross sections over a substantial portion of its length, said members having a plurality of different diameters in said circular-in-cross-section portions, with a smaller-diameter one of said portions being near the trailing edge of the blade, and at least one of said portions having a diameter larger than that of said smaller-diameter portion and located between the blade''s leading edge and said smaller-diameter portion; and gaseous material inside each of said tubular members.

7. A vehicle as set forth in claim 1, in which each of said hinges comprises a flexible element of sufficient strength to withstand its disruption by said centrifugal force.

9. A vehicle as set forth in claim 1 in which each of said blades comprises an elongated flexible tube, having walls of impeller-strength-providing material, having a middle portion that is circular in cross sections and an end portion at each end of said middle portion, said end portion comprising: a curved part that has an integral junction with said middle portion, that, in a plane containing the longitudinal axis of the tube, curvingly flares outward on each side of the tube''s axis, and in a plane normal to said first-named plane curvingly tapers toward the said axis of the tube; and a flattened-end portion, integrally joined with the shaftward end of said curved part, comprising two parallel, flat edges of said curved-part end and bonding material between said flat edges, sealing said shaftward end of the tube.

10. A vehicle as set forth in clam 1, in which: said tubular members comprise tubes having flexible walls; each of said tubes is filled with a portion of said gaseous material; and said gaseous material imparts resiliency to said tube walls.

12. A vehicle as set forth in claim 10, in which said gaseous material comprises closed-gas-cell, foamed plastic.

14. A vehicle as set forth in claim 13, in which: said impeller blades are entirely located in ambient fluid above said cabin; at least their major portions, during their rotation come within the space between vertical projections of the ends of said round-in-cross section cabin portion; and, during their rotation, major portions of the blades extend outside the space between vertical projections of the sides of said round-in-cross section cabin portion, thus vertically moving fluid to and beyond and below the curved borders of said cabin portion.

16. A vehicle as set forth in claim 15, in which cross sections thru the peripheries of said curved container walls are circular, and said peripheries in cross section comprise circles of different diameters. 11 17. A vehicle as set forth in claim 13, in which each of said cabin-frame members comprises a sealed, elongated tube having walls of dense material and containing a portion of said gaseous material.

18. A vehicle as set forth in claim 17, in which said walls have a thickness of less than 0.02 of an inch, and said gaseous material imparts strength to the walls.

20. A vehicle as set forth in claim 13, in which said gas is lighter than air.

21. A vehicle as set forth in claim 13, in which the gaseous material in said cabin-frame members comprises closed-gas-cell, foamed plastic.

22. A vehicle as set forth in claim 13, in which said cabin-frame tubular members comprise sealed tubular walls that have a thickness less than 0.02 of an inch and are of material comprising metal, and said gaseous material is gas at a pressure well above that of the atmosphere.

23. A vehicle as set forth in claim 22, in which said gas is lighter than air.

24. A vehicle as set forth in claim 13, in which said cabin-frame members comprise sealed tubes, each of which has a pair of flattened and sealed ends, and said gaseous material in the tubes has resiliency and adds strength to the walls of said tubes.

27. A vehicle as set forth in claim 26, in which said cushion comprises fibrous material, and in which at least the portion of said sheath that covers said cushion comprises waterproof material and prevents the entry of water among said fibers. 28, A vehicle, having a load-carrying cabin, said cabin comprising: a cabin-strength-providing skin, comprising a sheet of stiffly flexible material; a middle cabin portion, having a load-containing space, round in cross sections normal to the longitudinal axis of the cabin, comprising, within a forward part of said skin: a substantially rigid forward wall, at the forward end of said middle portion; a substantially rigid after wall, at the after end of said portion; extending between said walls and inclosing said load-containing space, a curved side wall, endlessly curved in planes normal to said axis, having cabin-strenght-providing framework comprising a plurality of juxtaposed, tubular members, with their axes curvingly arranged around said axis; gaseous material in each of said tubular members; and foamed plastic around each of the tubular members and between them and said skin; a substantially streamlined nose portion of the cabin, comprising a nose-strength-providing skin; a substantially streamlined, generally fishtail-shaped cabin-stern portion, defined by a fishtail-shaped after part of said first-named skin, said after part having: integral, curving, top, side and bottom portions; a flattened, generally horizontal after end; and, in each cross section normal to the said longitudinal axis, a total peripheral extent that is at least as large as the total peripheral extent of the said after wall; said fishtail-shaped part of the cabin-strength-providing skin tending to hold its generally streamlined fishtail shape, with: its said flattened after end in planar horizontal condition; its top and bottom portions curvingly tapering in height from said flattened after end, forward and upward to said after wall: and its sidewalls curvingly flaring outward in increasing horizontal extent across said axis from said after wall to said flattened after end.

32. A device as set forth in claim 31, in which said vehicle is a vertical-takeoff aircraft, said impeller is a lifting propeller, and said vehicle comprises motive means and power-transmission means connected to said motive means and to said propeller.

33. A vehicle as set forth in claim 28, adapted to move in a fluid which surrounds it, comprising: a lifting impeller having a plurality of blades, each of which has a framework comprising hollow tubular members and gaseous material in said last-named tubular members; and a rotary shaft; said impeller further comprising hinge means between said shaft and each of said blades.

36. A vehicle as set forth in claim 28, comprising a shock-absorbing cushion, located below and attached to said middle cabin portion, having a maximum width not greater than that of said middle portion, and in which said vehicle comprises a flexible sheath of strong material that surrounds said middle portion and cushion.

38. A vehicle as set forth in claim 32, in which an after part of said cabin-strength-providing skin has an opening at its top, elongated in a fore-and-aft direction, comprising: a propeller-supporting skin, closely fitting in said opening, having a streamlinedly-curved upper part that extends well above an upper part of said cabin-strength-providing skin and a bracing lower part that extends downward from said opening and within said last-named, cabin skin, into close proximity with a lower part of said cabiN skin; means strongly fastening said cabin and propeller-supporting skins together along the line of said opening and in the area of said close proximity; means for rotating a steering propeller; means strongly connecting said propeller-rotating means to said propeller-supporting skin; and a vehicle-steering propeller, supported and driven by said propeller-rotating means.

39. A vehicle as set forth in claim 38, in which the said means connecting the propeller and propeller-rotating means comprises streamlined struts, fixed to a generally toroidal inner portion of the said propeller-supporting skin.