US3751862A

US3751862A - Pneumatically supported structure

Info

Publication number: US3751862A
Application number: US00130758A
Authority: US
Inventors: J Linecker
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-02
Filing date: 1971-04-02
Publication date: 1973-08-14
Anticipated expiration: 1990-08-14

Abstract

A pneumatically supported structure of polyhedral configuration has a plurality of diagonal anchors running between foundation members at the corners of the structure and lying along diagonals thereof. In addition, rigid arches span the foundation members along at least some of the sides and act as supporting members for the flexible skin which is used in sections between the anchors. A double-wall structure may be provided in which the air enters the space between the inner and outer skin and passes out of the space at the base of the structure.

Description

O United States Patent 1 1 1 5 Linecker Aug. 14, 1973 [54] PNEUMATICALLY SUPPORTED 2,797,696 7/1957 Fritsche 135/1 R STRUCTURE FOREIGN PATENTS OR APPLICATIONS [76] Inventor: Josef Linecker, A 5230 Mattighofen, 311,437 11/1955 Switzerland 135/1 R Austria 992,086 10/1951 France 52/2 655,445 4/1929 France 52/2 [22] Filed: Apr. 2, 1971 OTHER PUBLICATIONS [21] Appl' l30758 House and Home, p. 133, 134, Sept. 1956, Eliot Noyes.

[52] us. CI. 52/2, 52/80, 52/88, P im y Ex min r-Frank L- Abbott 135/ 1 R Assistant Examiner-Leslie A. Braun 51 Int. Cl E04b 1/34 ArwmeyKarl E Ross [58] Field of Search 52/1, 2, 80, 86,

52/88; 135/1 R [57] ABSTRACT! A pneumatically supported structure of polyhedral [56] Referenm Cited configuration has a plurality of diagonal anchors run- UNITED STATES PATENTS ning between foundation members at the corners of the 1 818 54s 8/1931 Eriksson 52 2 strucmre and lying alng diagmals 2:782:794 2 1957 White 52/2 rigid arches p the foundation mfimbers along at least 2,823,683 2/1953 South at 135/ R some of the sides and act as supporting members for 1,827,486 10/1931 Paulsen... 52/2 the flexible skin which is used in sections between the 2,297,150 1942 anchors. A double-wall structure may be provided in 2,895,490 7/1959 Dimond 52/ which the air, enters the space between the inner and 2,41 16 1 1/1946 CaP'ta 52,2 outer skin and passes out of the space at the base of the 3,256,895 6/1966 Duquette 52/2 structure R27,232 11/1971 McLorg 52/2 3,059,655 10/1962 Bird 52/2 17 Claims, 22 Drawing Figures Patented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 1 Patented Au g; i4, 1973 5 Sheets-Sheet 2 Patented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 5 Patented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 4 Patented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 5 FIE-2.75

1 PNEUMATICALLY SUPPORTED STRUCTURE FIELD OF THE INVENTION My present invention relates to pneumatically supported structures and, more particularly, to improvements in structures designed to enclose large areas, e.-g. lecture and meeting halls, auditoriums exposition and display stadia, performance theaters, bathing and swimming establishments, and any space-which is to be environmentally controlled or isolated in whole or in part from the atmosphere, wherein at least part of the structural support for the walls is provided by air at a pressure greater than ambient.

BACKGROUND OF THE INVENTION Pneumatically supported structures for the purposes described have gained increasing importance because of the relatively small amount of labor required to erect a large enclosure, because of the fact that the labor involved in such erection need not be highly skilled or highly paid, because minimum previous preparation of the building site is required, and because the cost of materials for the structure is substantially smaller than for rigid-wall prefabricated or custom-built structures.

However, these pneumatically supported structures, which are held up by the introduction of air at a pressure at least slightly above ambient, have some significant disadvantages as they have been constructed heretofore. For example, air loss is a problem which can be countered in conventional systems only by sealing the walls thereof substantially continuously to a foundation or base. This, in turn, increases the cost of preparing the site and may not be technically or esthetically desirable. In some cases, even the shape of the structure is determined by the need to seal the skin to the foundation and ground level and detracts from the usable space within the structure and the appearance thereof from without. The foundation anchorage of the skin continuously along the sides of the structure also re duces the versatility of the enclosure since the shapes in which the enclosure can be provided are limited. Finally, I may note that it is known to provide reinforcement wires or anchors in flexible-wall pneumatically supported structures, generally only at entrance points or in double-hall constructions in the interior, but these anchoring methods have also proved to be unsatisfactory for many purposes. In practical respects, therefore, it can be said that the use of flexible-wall pneumatically supported structures has been severely hampered by prior-art methods of securing the strucutre to the foundation and/or of providing anchoring or reinforcing elements for the walls or roof of the structure.

OBJECTS OF THE INVENTION It is, therefore, the principal object of the present invention to provide an improved pneumatic construction or air-supported structure, especially for large areas, whereby the aforedescribed disadvantages are ob viated.

It is another object of the invention to provide, in a pneumatically supported enclosure, improved means for sealing th junction of the flexible skin with the foundation or support members.

A further object of my invention is to provide an improved system of anchoring the flexible skin of an airsupported structure to a foundation whereby the need for continuous sealing of the skin to the foundation at ground level can be avoided.

Still another object of my invention ls the provision of an improved support structure for a pneumatic enclosure which requires only point support or connection to the foundation.

SUMMARY OF THE INVENTION These objects and others which will become apparent hereinafter are attained, in accordance with the invention, with a pneumatically supported structure for single enclosure (single hall) or double enclosure (double hall) or any arrangement of the walls of the enclosure which is generally polyhedral, wherein foundation members are provided along at least the exterior of the structure of corners thereof (vertices of the polygonal plan) while anchoring elements run from these foundation members along diagonals of the plan and cross or are in contact at a crossing point of the diagonals, the flexible skin being provided in sections between these reinforcing elements. Between the foundation members, moreover, along the periphery of the structure, I provide arch-shaped rigid supports adapted to form window or wall elements to which the flexible skin is secured so that, when the skin is stretched by superatmospheric pressure, no stress is applied to the arches, while the arches carry only the weight (at most) of the flexible skin when the interior of the enclosure is deflated. Consequently, in the presence of internal pressure, the anchor elements extending along the diagonal of the structure, take up any outward stress which is transformed into tension on these elements and upon the foundation. No stress, or substantially no stress, is applied to the arch members in the expanded condition of the structure. However, when the pressure within the enclosure falls below ambient, the arches at most take up only the weight of the skin so that the skin hangs from these arches.

The tensioning of the system is preferably so arranged that the skin cannot fall to the floor, even in a condition in which the internal pressure falls to ambient. This may be guaranteed by erecting the arches so that the distance D across which the skin is stretched s2 H +(L/4 where H is the height of the arch and L is the horizontal distance between the arches across which the length D of flexible skin is stretched.

The arches can span the sides of the enclosure from foundation to foundation openly and, because they need not carry any load but their own mass and the weight of the skin in an unstretched state, can extend across long spans. However, even these forces can be taken up in whole or in part by vertical struts or supports spaced along the side and extending between the foundation and the arch. It has been found tobe advantageous, with large spans, to provide the diagonally extending anchors as metal bands or strips or some similar material and to provide networks of such bands between which the fabric or skin can be stretched. In general, the fabric or skin is stretched between pairs of such bands.

According to another feature of the invention, the anchor elements are carried in part, preferably at their crossing points, by extensible removable masts which are extended and placed in position upon erection of the enclosure. The skin is releasably or loosely connected to the supports or arches and may be provided with means enabling the skin to be displaced longitudinally relative to the diagonal elements via sliding shoes, loop arrangements or the like. An air-tight connection can be provided advantageously by a U-section, each bead engageable with the arches and supports, an inflatable tube adapted to be lodged in a groove or a like conventional sealing junction. The connection of the skin with the elongated anchor elements can be effected by loops, shoes, groove arrangements or the like. To erect the structure, the flexible seal or skin is removed from the supports or arches and from the floor and is shifted along the diagonal anchors to the mast which previously has been elongated to raise the anchor elements and stretch the fabric.

It has also been found that pneumatically supported structures which are used to enclose a space at a materially different temperature from that of the ambient atmosphere, require the solution of special problems. The atmospheric temperature may, of course, be higher or lower than that in the interior of the enclosure, especially when the latter is employed to house a swimming pool, curative bath or other body of water. Shower houses and like installations equally are faced with this problem. The additional difficulties arise from the fact that such enclosures have high interior humidity and temperature. When the temperature outside the enclosure is relatively low, the inner surface of a singlewall construction may have a temperature above the dew-point of the interior and condensate may form along this surface. This is especially pronounced when the enclosure houses heated baths and the drawback could not be avoided with conventional air-supply systems. According to the present invention, however, an enclosure faced with this problem is provided with a double-wall construction or with two flexible shells, between which a compartment is created. Advantageously, the skin of the structure is formed from tubular stretches such that individual compartments are provided between the flexible sheets of each strip and the compartments of adjacent strips are separated from one another at their seams. In this'case, I provide inlets and outlets spaced at opposite ends of the elongated compartments for the circulation of air through them. For example, inlet compartments may be provided close to the top of the structure when the strips run upwardly and downwardly, while an outlet is provided close to the base of the compartment from which depleted air is withdrawn. Since the air circulated through the compartment has the same temperature and humidity of the air within the enclosure, the inner face of the double-wall covering does not sustain condensation. The outlets of the compartments, at least along one wall of the structure, may open collectively into a channel formed in the foundation and connected to the aircirculating system. With moderate temperature and humidity differentials between the ambient atmosphere and the interior of the enclosure, recirculation of all or a major part of the air conducted through the compartments is no problem. However, when high-temperature differentials exist across the coverage of the enclosure, I prefer to return only a fraction of the air traversing the compartments to the interior. The balance of the air supplied to the interior of the enclosure may be dry fresh air so that the humidity generated by the pool, showers etc. is reduced.

In hangar-type bathing installations, the cost of elimi nating moisture by disposal of the air generally amounts to about 60 percent of the total heating cost. I have found it to be desirable and advantageous to simplify the venting of moist air into the atmosphere by providing at the top of the structure one or more venting valves communicating between the interior and the atmosphere. In this case, a valve may be provided at the mouth of each flow compartment communicating with the interior so that the valve selectively is operated to vent air from the interior of the structure to the atmosphere or to direct the air along the flow compartments.

It should be noted also that the passage of warm air through the flow compartments also insulates the interior of the structure and reduces substantially the operating cost. The savings produced in this manner are most significant for large hangar-type baths with high air-discharge rates. Thermal calculations have shown that with exterior temperatures of about 5C, the heating of the pool suffices to provide the necessary temperature in the interior of the enclosure so that no additional energy for room heating is required.

During the passage of the discharged air through the flow compartments, the air is cooled and moisture condenses along the outer surface of the covering and can be conducted away by gutters or the like. The outer skin thus acts as a condenser and the outflowing air is dried. The latter air can be totally or partly returned to the heating installation and thereafter to the chamber, if desired, or simply recirculated to the interior of the enclosure.

Even in summer, when the structure is exposed to strong solar radiation, the system of the present invention has significant advantages. The discharged air carries away part of the heat developed in the flow compartments and acts as an insulating medium. It has been found to be advantageous to provide the outer surface of the inner wall of a reflecting material, i.e. to metallize this inner wall. Here, too, pneumatic valves are preferably disposed between the inner and outer walls for fluid-pressure operation to permit the inner wall to collapse onto the outer wall and thereby reduce the insulating effect when part of the solar radiation is to be salvaged for room heating. When a number of valves are provided, or when a valve is inserted for each flow compartment, it is possible to operate the shady side of the enclosure with maximum insulating effect and to reduce the insulating effect at the sunny side to obtain more efficient heating.

it has also been found to be advantageous, in view of the fact that difficulties are encountered in affixing the inner layer to the outer layer of the covering and in joining the adjacent inner layers of respective strips, to provide a bead-forming profile on the outer layer and a fastening member extending along and receiving this profile. The fastening member may have an additional pair of grooves to receive beads of a pair of laterally adjoining inner layers or webs of the covering as well as a further groove between the latter two grooves, to receive the bead of a covering strip adapted to mask the junction of the fabric strips forming the inner layer of the covering. A hollow of the profile or junction member may also be used as a duct for the recirculated'or vented air, as part of the venting valve system mentoned earlier and/or as a service duct through which, for example, electrical conductors may be led.

According to another feature of the invention, the structure consists of at least one window fitted into a wall and preferably conforming in curvature to that of the wall. The window element may be composed of frame members, e.g. profiles, adapted to receive beads of the covering to seal the latter and even provide a seal for both an inner and outer layer of the covering. Preferably, this window element comprises a frame which is spanned by a single translucent sheet or two spacedapart translucentsheets forming an insulating space, the frame having a horizontal pedestal above the outline of which the center of gravity of the window is located. This pedestal may be a plate adapted to be received upon a foundation or to form part of the foundation, but preferably includes means forming a duct for supplying air to the inter-wall space of the covering, removing air from this inter-wall space, delivering air to or removing it from the interior of the structure proper, collecting and conducting away moisture, etc. The orientation of the window such that its center of gravity lies within the outline of the pedestal and, preferably, within the pedestal, permits the window structure to be set upon the ground or the foundation for rapid and convenient positioning and renders the same freestanding while excluding loading of the fabric structure. Advantageously, the frame of the window converges upwardly so that the window may be built in between a pair of upwardly convergent anchors. The outer form of the window corresponds to the surface defined by the generatrices spanning the anchor elements between which the window is built. It will be apparent that this construction allows the window to be inserted without difficulty and permits minimum dimensioning of the window.

Since it has been found to be difficult and expensive to produce window structures of this type from preformed profiles, [prefer to cast the window elements (i.e. the frame) from materials such as concrete and synthetic resin. Instead of metal forms for such casting, however, it has been found to be advantageous to provide bendable forms, e.g. out of a fiberglass/epoxy material, which can be deformed in a supporting structure to correspond to any desired curvature of the wall. By simply modifying the supported structure, a mold of this type can be used for substantially any curvature. The supporting structure is advantageously made from wood.

In summary, the invention comprises basically a pneumatically supported structure with a foundation having anchor points at least at the corners of the polyhedral structure, a flexible skin or covering, e.g. of a rubberized fabric, enclosing the space within the foundation, and a plurality of anchor elements of wire or band configuration spanning diagonally opposite anchor points of the foundation and overlying the covering to retain the latter against outward movement, the anchor elements having a junction point at the intersection of the diagonals, either by virtue of an actual crossover of the elements or by virtue of a simple contact at this intersection point. At least one wall of the structure may be formed by uprights or posts, mounted upon respective foundation members and having free upper ends to which the covering is anchored, or which are held by the covering under some compression. Between the uprights, strips of the covering material are preferably stretched.

A highly important feature of the invention resides in the provision of supporting arches in at least one wall, the arch either spanning the entire wall between the foundation points defining same, or being subdivided into a number of arches which collectively span the wall. In addition, upright members may be provided at spaced locations along the wall for additional support. Important to the present invention is the fact that the inflated structure applies outward stress upon the anchor elements and not significantly upon these arches, so that the covering may be affixed to the latter in a sealing manner but without the force-transmission requirements which might otherwise be expected. The arches need be expected only to support their own weight and the weight of the covering in a deflated state of the structure.

DESCRIPTION OF THE DRAWING The above and other objects features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which;

FIG. 1 is a diagrammatic vertical cross-section of a double-wall structure according to the present invention:

FIG. 1a is'a perspective view of another similar structure; FIG. 1b is a detail of a modification;

FIG. 2 is a plan view of the arrangement of FIG. 1;

FIG. 3 is a diagram representing a plan view of a polyhedral structure, according to the invention, which has sides inclined to the rectangularly adjoining sides;

FIG. 4 is a vertical cross-section through a gassupported structure in which a secondary support is provided for the flexible skin;

FIGS. 5 7 are detail views in cross-section through the anchoring elements, for example, along the line V V in FIG. 2 showing the connection to the diagonally running anchor elements to the flexible skin;

FIG. 8 is a cross-section through a portion of an arch member according to the present invention, e.g. along the line VIII VIII of FIG. 2, drawn to an enlarged scale;

FIG. 9 is a side-elevational view of an open enclosure with removable support mast;

FIG. 9a is a plan view of the latter enclosure;

FIG. 10 is a vertical cross-section of the left-hand side of a hemispherical air-supported double-wall enclosure;

FIG. 11 is a view similar to FIG. 10 showing the double-wall structure in a somewhat collapsed state;

FIG.,12 is a partial plan view of the venting valve of this structure;

FIG. 13 is a cross-section taken generally along the line XIII XIII of FIG. 12 and showing the venting valve in a closed condition wherein, however, the valve between the interior of the enclosure and the doublewall chamber is open;

FIG. 14 is a detail cross-sectional view, drawn to an enlarged scale, showing the connection of the inner and outer shells via a connecting profile;

FIG. 15 is a vertical section through a window element for use in a pneumatically supported structure according to the invention;

FIG. 16 is an elevational view thereof;

FIG. 17 is a cross-section through the profile members forming the window element;

FIG. 18 is a plan view of a door element having a rotatable door mounted in a framelike structure; and

FIG. 19 is a side-elevational view, in cross-section, of a spacer interposable between the inner and outer shells or skins.

SPECIFIC DESCRIPTION Referring first to FIG. 1a in which a rectangular enclosure, eg a bathing or swimming enclosure of square plane, is represented in diagrammatic perspective view, it can be seen, that the basic elements of the pneumatically supported structure 200 include foundation at the corners or

vertices

201, 202, 203 and 204 of each rectangular unit. In FIGS. 1 and 2, the locations of the foundations and the structure thereof are shown in greater detail. For the purposes of FIG. 1a, however, it will suffice to observe that each of the foundations consists merely of a footing and a post rising from the footing to grade level. Along the wall 205, moreover, there are provided individual footing for each of a plurality of vertical posts 206 which are vertically spaced along this side of the structure and reach upwardly to support a concrete arch 207 (FIG. 8) when the arch is intended to span especially large distances between the

foundations

201 and 202. The space between each pair of posts 206 may be closed by a strip of the flexible skin (e.g. rubberized fabric) forming the walls of the enclosure.

A pair of diagonally extending anchoring elements 208 and 209, respectively bridging foundation posts 202 and 204 and foundation posts 201, 203, intersect and are joined at the contact point 210 in a manner similar to that represented at 20 in FIG. 2. It should be understood, of course, that the diagonally extending elements need not cross as shown in FIG. 1a, but may merely be connected at the diagonal intersection point as shown at 211 in FIG. lb.

The members 208 and 209 may have the configurations illustrated in FIGS. 5 7 and may be connected to the skin in a similar manner. The members 208 and 209 are bridged by rubberized fabric strips 212, which may be seamed at 213 in the usual manner, to provide a fluid-tight roof-and-wall structure for the enclosure. Along the rim 214 of the arch 207, however, the skin, represented generally at 215, is clamped, preferably with a corrugated sealing arrangement as shown in FIG. 8.

It is important to note that the connection does not apply significant stress to the arch 207 which need merely take up the weight of the skin when the pressure within the enclosure falls. In the embodiment illustrated in FIG. 1a moreover, the wall 205 is shown to be open. More commonly, door and window structures may be provided (FIGS. 18) or the wall will simply be closed and a conventional door or other opening arrangement provided for access to the interior of the enclosure. Another wall 216 of the enclosure may be formed by an arch 217 which is anchored at the foundation points 201, 202 but is inclined outwardly to the vertical by contrast with the arch 207 which lies in a vertical plane. The space between the arch and the edge 218 of the skin 215 bridging the quadrant defined by wall 216 and anchors 208, 209, is built by strips of rubberized fabric skin represented at 219. The seam between the roof and the additional strip 219 is also represented at 218 and may be supported by a further concrete arch if desired. If the concrete arch 219 is prestressed, I may provide vertical members 220 under tension along generatrices of the substantially cylindrical surface defined by the arch 217, to place the latter under tension in the vertical direction. Of course, these vertical members 220 may be used also when the arch 217 is not under prestress but merely is subjected to the weight of the fabric skin as the pressure within the enclosure falls. The regions between member 220 are spanned by rubberized fabric strips 221.

The rear wall 222 of the enclosure is defined by a rigid arch 223 having no intermediate supports, but spanning the gap between foundation points 203 and 204. As with the other arches already described, the connection between the skin and the arch is accomplished with the system illustrated in FIG. 8. A rigid antechamber 224 may be provided in an outwardly bulging rigid structure which also supports the junction 225 with the flexible skin. An arch such as that shown at

sides

205, 216 or 222 may also be provided at this junction, where the antechamber is air-supported as well.

In FIGS. 1 and 2, which illustrate principles of the present invention in somewhat greater detail, I have shown a two-unit hangar-type bathing enclosure for a swimming pool or like recreational facility or for a curvative pool or spring for medical or therapeutic treatment. The structure illustrated in FIGS. 1 and 2 comprises six foundation footings 23 at the comers of the squares defining the rectangular plan view of the structure. Each pair of diagonally opposite foundation footings 23 is spanned by a diagonally extending anchor wire or band (FIGS. 5 7) between which the individual segments or strips of the covering material 1 is provided.

The covering material may be applied as described in connection with FIG. 1a and have seams running generally horizontally (FIG. 2). These strips may also be of double-wall construction as will be apparent hereinafter.

The front-side closure of the structure may be provided with supporting arches in an open manner or may be closed with an antechamber 4 best seen at the lefthand side of FIGS. 1 and 2. Alternatively, a supporting arch may be provided along this side and the antechamber 4 composed of a flexible covering. The flexible covering in all of the embodiments hereafter described preferably consist of rubberized fabric which may be metallized for radiation reflection as previously discussed.

All or any of the walls may, moreover, be provided with vertical posts 5 between the covering 1 and the floor, the posts being resistant to bending and serving as a support for the cover. The covering 1 can, of course, span the gaps between the post 5 as illustrated in FIG. 2 or may terminate at the tops of the posts so that additional material is provided in strips between them.

Preferably at least one wall of the structure, generally all of the walls thereof, is provided with an arch such as that shown at 3 spanning the rear foundation members 23 (FIG. 4). The arch may be free standing (right rear in FIG. 2) or may be provided with supporting uprights 7 (left rear FIG. 2), the covering being sealingly anchored to the arches (FIG. 8). For large spans, it has been found to be economical to provide the vertical supports or studs 7 between the arch and the ground. In this case, the arch may even be dimensioned such that it need not carry even its own weight. In any event, the arches 3 are so constructed and arranged that, upon failure of the internal pressure, the covering hangs freely between the arches without contacting the ground. Furthermore, this condition permits, as shown in broken lines at the left-hand side of FIG. 1, the dimensioning of the covering and the anchor elements such that inflation of the structure bellies out the covering beyond a plane joining the arches. This is especially desirable for small and medium spans and does not materially increase the stress applied to the arches.

With large spans, I have found it to be advantageous to provide the individual covering surfaces 1 with double curvature, i.e. curvature in two mutually orthogonal planes, whereby the walls of the structure are curved upwardly to the top or apex of the structure at which the diagonally extending anchor elements are joined.

Furthermore, I may provide one or more arches 3 (extreme right in FIGS. 1 and 2), especially for large spans, which are tilted outwardly (i.e. lie in planes inclined to the horizontal) from which vertical elements 8 extend downwardly to the ground under tension. The tension elements 8 are intended to take up the stress applied to the arch upon failure of the pressure within the enclosure. It will be understood that the term arches as here used and illustrated is intended also to include shell or door structure to which the fabric covering is connected along an arc.

As shown in FIG. 2, air-inlet openings are provided in the inner layer of the double-wall covering 1 when the structure makes use of flow compartments between the layers for insulation and air circulation as previously described. The air then flows in the direction illustrated by arrows 21 from each horizontally extended flow compartment to openings at the vertical seams, downwardly to an air duct 22 which is provided along the foundation. From duct 22, the air is led through air-return piping to a heating plant.

In FIG. 3, I show an arrangement in which the structure is not strictly rectangular. The left-hand side of the structure is a rectangular portion which, at the righthand side is transformed into a parallelogram and eventually terminates in a trapezoid. The structure is generally describable as a polygon with foundation points at least at some corners or vertices of the polygon. In this case, the anchor elements 2 extend along diagonals so that intersections may be provided at the top of the structure. However, two or more anchors 2a, for example, may meet at each connection point. In this case several cross-overs are provided for each anchor element with anchor elements from a number of other foundation points. It follows that the structure according to the present invention can be triangular, square or rectangular or, generally, polyhedral. With a single arch-forming outer wall or window element according to the invention, various polyhedral structures can be built with unlimitedly increasing size. Furthermore, the polygonal section may extend at any angle so that extreme versatility in configurations is possible. When the arch members are tilted outwardly, moreover, (righthand side in FIG. I) and a number of such elements are provided, the structure will have a circular configuration.

In FIG. 4, l have shown, in cross section, another structure partly represented in FIG. 2, in which a rigid secondary structure 9 is provided within the primary structure to support the covering 1 when the latter relaxes by reduction of the pressure within the enclosure. In this case, the arches 3 can have substantially smaller dimensions since they need not even take up a significant load of the flexible covering. The internal structure 9 is a lattice work of metal bars with a geodesicdomed configuration or a simple ladder array of bars as represented in FIG. 4. The covering bulges outwardly into a smooth arcuate configuration upon inflation of the structure, but falls upon the internal structure 9 and between the bars thereof as shown 'in FIG. 4 at 1, when the pressure is reduced or withdrawn. The rigid secondary structure 9 need be dimensioned only to take up the weight of the covering and can be of very light construction. It has been found to be advantageous to provide the rigid structure 9 with hinge joints, at least along the top of the structure and with feet guided in rails so that the pneumatic structure can be erected simply by opening out the internal support 9 and can be closed by folding the latter. Such an arrangement has been found to be desirable in bathing enclosures which, for the summer, may be opened partly to permit direct access of fine weather to the bathing area. In this embodiment, I also show that the foundation comprises an air-supply duct 25 along the inner edge of the enclosure through which the air is introduced into the interior of the enclosure. The air may pass into the flow compartments as described in connection with FIGS. 1 and 2 and thence into a collecting duct 24 which may register with the interwall compartments of the structure. The arrangement of

ducts

24 and 25 permits control of fluid flow in a simple manner without mechanical devices for air supply and return.

As previously noted, the skin or covering of the structure of the present invention bulges outwardly against the anchor elements 2. I have found that suitable anchor elements may be formed of pairs of wire as illustrated in FIG. 5. In this construction, two parallel wires 10 constitute an anchor element, the wires being interconnected by spacer and profile members 11, preferably of an elastically yieldable material. Member 11 comprises a pair of recesses ll a, lib, extending over more than 1Y0 ot" the cir cumference of the wires 10 and preferably having a diameter slightly less than that of the wire so that each wire 10 can be snapped into one of the recesses and is held therein by the inherent resiliency of the body. Between the wires 10, the web of member 11 is fonned with a convex portion 1110 which bears upon the covering 1 or may be connected directly to the latter. Furthermore, I have pointed out the advantage in some systems, of affording relative movement to the anchor elements and the covering 1, to which end the members 11 may be shoes affixed to the covering and slidably receiving wires 10 while preventing them from shifting relative to one another.

In FIG. 6, I have shown another embodiment of the anchor elements which here comprises a stack of metal bands or strips H2. The metal bands or strips, of course, increase the compartment surface between anchoring element and the covering for improved support against internal pressure and permit the junction points or intersection to be of small overall thickness. The anchorage of the wires 10 and the bands 12 in the foundation members 23 is effected by screw or bolt junctions. As in the system of FIG. 5, the shoe 11d has a curved portion lie in contact with the covering 1 and a pair of overhanging portions II If and 11g which retain the bands. FIG. 7 shows an arrangement in which the covering l is secured to the anchor elements so that the individual strips of fabric span pairs of such anchored elements. More specifically, the strips overlap and have loops folded around the beads 13 of respective profiles which have webs 13 in overlapping relationship. Bolts may be provided as shown at 14 to secure the profiles together which simultaneously constitute the anchor elements (for members 13) while sealingly connecting the stretches of the fabric. One or more rubber sealing strips 140 may, of course, be provided between the overlapping members to prevent air leakage from the scene.

In FIG. 8, I have shown in cross section the arch-like wall or window member which may be provided at 3 as previously described. A prefabricated channel 15 of substantially U-shaped cross section and of concrete is mounted upon the vertical posts 7. The reinforcing rods of these posts, or tie members, extend into the channel 15 and are there received within a reinforcing basket 26 which is introduced into the channel after the

prefabricated members

7 and 15 have been mounted as shown. Concrete 16 is cast into the channel and the upper surface of the concrete layer is shaped by an appropriate striker to have a longitudinally corrugated configuration as represented at 17. With the aid of an elastic strip or gasket 18 of similar configuration, a metal band 19 may press the edge of the covering 1 against the gasket 18 and the concrete support and can seal the structure. Bolts may be anchored at spaced locations in the concrete for retaining the band 19.

In FIG. 9 and FIG. 90, I have shown another arrangement in which opening and closing of the structure is facilitated. In this embodiment, a mast 27, which is longitudinally extensible, is provided at the crossover or intersection point of the anchor elements 2. Furthermore, guy wires 28 are provided between the mast and the arch elements 3. Props 29 are provided to hold the anchor elements 2 away from the arches 3. For opening the structure, the edge 30', 30", 30" of the covering is released from one or more of the arches and the mast 27 raised. Thus the anchor elements and the unopened fabric surfaces remain stretched while the covering 1, as shown in broken lines is shoved upwardly to expose the area therebelow to the exterior.

FIGS. 10 14 show a double-wall arrangement in which the outer supporting layer 101 of the covering is underlain by an inner foil 102 which is shown to run parallel to the outer layer. The inner shell is sealed to the foundation to close off the enclosure. Pneumatic valves are provided at the top of the dome 117 of the arrangement at which the air-flow compartments between the covering layers 10] and 102 terminate. In fact, the dome 117 of the system may be a rigid shaft.

As best seen in FIG. 10, the rigid shell is provided with closed upper valves blocked by member 118 above the outer covering layer and communicating with the atmosphere, and open valves 119 communicating between the interior of the enclosure and the interwall space. At the base of the enclosure, the interwall space communicates via discharge valve 121 with the atmosphere or a return duct 122, the latter leading to the heating plant. In a manner similar to that shown in FIG. 4, the foundation also includes an air-supply duct 123 through which the pressurizing and ventilating air is delivered.

In the detail view of FIG. 13, a valve structure is shown in somewhat greater detail. In FIG. 11, however, the system has been illustrated with the valve 118 in an open condition and valve 119 closed. When valve 119 is closed, air is prevented from circulating through the interwall compartment and is, instead, released directly into the atmosphere. In this case, the inner covering layer is no longer supported by air within the interwall space and collapses against the outer covering layer 101. Opening of valve 119 permits air to flow into the wall space and, consequently, spreads the covering

layers

101 and 102 apart. The valve member 118 may have an oval cross section (FIG. 13) to block the vent opening. The edge of the outer covering layer 101 extends beneath the valve member 118 and grips the latter. A pressure drop within the chamber will cause atmospheric pressure on the left-hand side of the valve member 118 to shift to the right and cause it to fall into the trough 124 formed as an extension upon the inner wall covering layer 102. The space 126 ensures release of the valve by suction and re-engagement under pressure. Projections 127 may be provided to permit the flow cross section to be established with considerable accuracy and to allow draining of condensate, and proper choice of the materials for the valve housing and the ball valve block 118 will suffice to permit any degree of blockage and control that may be necessary. The member serves as a collecting shield for condensate developing along the inner surface of dome 117 and delivers such condensate to the trough 124 from which it may flow through the channel between the covering layers to the foundation.

In FIG. 14, I have shown a system for joining a pair of inner fabric strips 129 and 102 together and to an outer covering 1. The device comprises a bead-forming element thermally bonded or vulcanized to the outer covering layer 1 along the entire seam. Between the bead 128 and the

strips

102, 129, I dispose an intermediate profile member which likewise extends the entire length of the seam and is provided with a longitu dinally extending groove in which the bead 128 is received. A pair of

grooves

130a and 130b receives the beads 129 of the inner covering layers to be joined along the strip. A further groove 130s receives the bead of a cover strip 31 which masks the junction FIGS. 15 and 16 are directed to yet another feature of the invention in which a rigid window element 33 is formed with a base plate 34 provided with air-discharge openings 35. The base plate 34 extends beneath the rearwardly bent upper portion of the frame and the center of gravity of the entire structure preferably lies within the outline of this base plate or within the latter proper. The external periphery of the frame is formed with a channel in which the flexible covering 101 can be held by a tension wire 109. Sealing may be provided by a profile 36 of some suitable material such as rubber which is fitted into the annular groove. The frame is also provided with an internal groove in which the window elements, preferably an outer shell 108 and an inner shell 107 of plexiglass, can be fixed. The arch shape of the window frame 33, which corresponds to a doubly-curved surface in effect, pennits the tension wire 109 to press against the frame uniformly at all locations. Tensioning screws 37 lock the wire 109 in place and hence also fix the covering to the window structure. The base plate 34 engages laterally against the frame element to resist the inward pressure applied by the bottom-span wire 109. The window element is preferably cast from a synthetic resin or concrete in an elastic form 38 of a fiber-glass reinforced polyester resin which is positioned by angle members 39 mounted upon a wooden support structure 40. Securing the mold to the support structure and positioning the mold is the function of the screws 42'. The necessary grooves or ridges of the form may be provided by appropriately dimensioned parts 38 which are assembled to define the casting cavity.

In FIG. 18, I show a cross section of the bottom or base connection of the pneumatically supported structure. The outer covering layer 101 is provided along its lower rim with a loop in which a stiffening profile 42 extends. The approximately round cross section of this profile is clamped from the exterior of the covering 101 and by screws 44 and nuts 45 fastened to the foundation 34a. By twisting or tilting the profile about its longitudinal axis, the loop of the covering 101 is stretched between the round portion of the profile to the tilted profile portion. The stretched loop portion is pressed against a ridge 46 of the foundation element to provide an absolutely leakproof seal between the foundation and the covering. Thin-wall elements 47 are set upon the foundation 34a and carry the inner covering layer 102 to provide a tight connection between the inner covering layer and the foundation. Slots 48 are provided in the foundation to communicate with the interwall compartments and conduct the discharged air into the return duct.

FIG. 19 shows a spacer of insulating elastic material of light weight, such as foam, synthetic resin or an elastomer. This spacer has a central portion with an elongated nose 49 turned toward the inner edge and a short nose 50 which carries a shell 51. The latter, with its edge lying against the outer edge, also defines an insulating air space 52. This spacer is placed upon a naillike pin 53 fastened to the outer wall. The inner shell is connected to the same pin. Equalization openings are also provided in shell 51.

The improvement described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the invention except as limited by the appended claims.

I claim:

1. A pneumatically-supported structure, comprising a polyhedral foundation having a plurality of spaced apart anchor joints with pairs thereof defining sides of the structure; elongated anchor elemntts spanning diagonally opposite anchor points under tension and secured to said foundation said anchor elements meeting at a diagonal intersection; and a flexible gas-retentive covering enclosing the space within said foundation and retained against outward force by said elements upon internal pneumatic pressurization of the enclosure, said covering being formed by flexible segments each spanning the space between two such anchor elemnts, adjacent segments being seamed along said anchor elements and said anchor elements being received within said covering; and means for maintaining an air pressure along an internal surface of said covering greater than atmospheric pressure.

2. The pneumatically-supported structure defined in claim 1, further comprising a plurality of genreally vertical posts spaced apart along at least one of said sides and spanned by said cover.

3. The pneumatically-supported structure defined in claim 1, further comprising at least one rigid arch spanning anchor points along at least one of said sides and sealingly connected to said cover.

4. The pneumatically-supported structure defined in claim 3, further comprising a plurality of vertically extending posts spaced horizontally apart along said one of said sides and reaching from the ground to said arch for supporting same.

5. The pneumatically-supported structure defined in claim 3 wherein said arch lies generally in a plane inclined outwardly from said enclosure, said structure further comprising a plurality of vertically extending tension elements reaching from the ground to said arch.

6. The pneumatically-supported structure defined in claim 3 wherein a plurality of such arches are provided along respective sides of the structure, said arches and said covering being so constructed and arranged that said covering is supported by said arches above grade level upon depressurization of said enclosure.

7. The pneumatically-supported structure defined in claim 1,. further comprising an interior framework within said enclosure for supporting said covering upon depressurization of said enclosure.

8. The pneumatically-supported structure defined in claim 1, further comprising an elongated supporting mast within" said enclosure and movably acting upon said anchor elements for maintaining at least parts of the length thereof under tension while enabling a portion of said enclosure to be opened to the atmosphere.

9. The pneumatically-supported structure defined in claim 1 wherein said covering is formed with a plurality of discrete air-flow compartments, further comprising means for inducing a flow of air from the interior of said enclosure through said compartments, and duct means for collecting the air traversing said compartments.

10. The pneumatically-supported structure defined in claim 9, further comprising valve means in an upper portion of said enclosure for selectively connecting the interior of said enclosure to said compartments and to said atmosphere.

11. The pneumatically-supported structure defined in claim 10 wherein said duct means forms part of said foundation, said foundation further comprising airsupply means for delivering air to said enclosure.

12. The pneumatically-supported structure defined in claim 1, further comprising a window element receivable in said enclosure and comprising a base plate, and a frame member rising from said base plate and curved to conform to the configuration of said enclosure, said frame member being spanned by at least one shell, the central gravity of said window element lying within the outline of said base plate.

13. The pneumatically-supported structure defined in claim 1 wherein said anchor elements each comprise a pair of parallel wires and means for holding the wires of each pair together.

14. The pneumatically-supported structure defined in claim 1 wherein said anchor elements each comprise a plurality of bands and means for holding the bands of each element together.

15. A pneumatically supported structure comprising a foundation, a flexible covering overlying said foundation, means for maintaining a pressure along an inner surface of said covering in excess of atmospheric pressure to pneumatically support said covering, said covering being of double-wall construction and forming passages between walls thereof, said passages running downwardly from locations close to the top of said structure to locations close to the bottom thereof, and means for circulating air through said structure and said passages whereby air enters said passages at said locations close to the top of said structure and emerges from said passages close to the bottom thereof, said structure being further provided with openings around said foundation for admitting fresh air to the entrance of said structure.

16. A pneumatically-supported structure, comprising a foundation having a plurality of spaced apart anchor points with pairs thereof defining sides of the structure; elongated anchor elements spanning diagonally opposite anchor points and secured to said foundation; a flexible gas-retentive covering enclosing the space within said foundation and retained against outward force by said elements upon internal pneumatic pressurization of the enclosure; and at least one rigid arch spanning anchor points along at least one of said sides and sealingly connected to said cover; said arch being provided with a sealing edge formed with longitudinally extending corrugations, a sealing strip overlying said edge, and means for maintaining one edge of said covering in sealing engagement with said strip.

17. A pneumatically-supported structure, comprising a foundation having a plurality of spaced apart anchor points with pairs thereof defining sides of the structure; elongated anchor elements spanning diagonally opposite anchor points and secured to said foundation; a flexible gas-retentive covering enclosing the space within said foundation and retained against outward force by said elements upon internal pneumatic pressurization of the enclosure; a window element receivable in said enclosure and comprising a base plate, and a frame member rising from said base plate and curved to conform to the configuration of said enclosure, said frame member being spanned by at least one shell, the center of gravity of said window element lying within the outline of said base plate; and a tension wire extending around said frame member for anchoring same to said covering, and a further wire spanning said frame member at the lower end thereof for retaining said frame member against said base plate.

11. The pneumatically-supported structure definein claim 10 wherein said duct means forms part of said foundtaion, said foundation further comprising airsupply means for delivering air to said enclosure.

* t l v W105" UNITED STATES PATENT OFFECE QERTEFECATE 0F CQRRECTION Potent No. 3q'75lA862i V I Dated 14 Aug U31. 197,3

Inventor-(s) Josef LINECKER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading, between lines "[21]" and "[52]", the folbowing insert be made 7 v "K301 PoREIGN'APPLicATIoN PRIORITY BATA 2 Am-n 1970 Austria 3027/70 2'1 August'1970 Austria'7791/70 signed and sealed this 12th day of March 1974.

(SEAL) Attest: v

EDWARD MQFLETCHERQJR. I e c. MARSHALL DANN Attestipg Officer-- A I A Commissioner of Patents

Claims

7. The pneumatically-supported structure defined in claim 1, further comprising an interior framework within said enclosure for supporting said covering upon depressurization of said enclosure.

8. The pneumatically-supported structure defined in claim 1, further comprising an elongated supporting mast within said enclosure and movably acting upon said anchor elements for maintaining at least parts of the length thereof under tension while enabling a portion of said enclosure to be opened to the atmosphere.

11. The pneumatically-supported structure defined in claim 10 wherein said duct means forms part of said foundation, said foundation further comprising air-supply means for delivering air to said enclosure.

11. The pneumatically-supported structure definein claim 10 wherein said duct means forms part of said foundtaion, said foundation further comprising air-supply means for delivering air to said enclosure.