U.S. patent number 3,751,862 [Application Number 05/130,758] was granted by the patent office on 1973-08-14 for pneumatically supported structure.
Invention is credited to Josef Linecker.
United States Patent |
3,751,862 |
Linecker |
August 14, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
PNEUMATICALLY SUPPORTED STRUCTURE
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.
Inventors: |
Linecker; Josef (A 5230
Mattighofen, OE) |
Family
ID: |
22446180 |
Appl.
No.: |
05/130,758 |
Filed: |
April 2, 1971 |
Current U.S.
Class: |
52/2.18; D25/21;
52/2.24; 135/97; 52/80.1; 135/124; D25/17; 52/2.17; 52/88;
135/119 |
Current CPC
Class: |
E04H
15/20 (20130101); E04H 2015/205 (20130101); E04H
2015/207 (20130101) |
Current International
Class: |
E04H
15/20 (20060101); E04b 001/34 () |
Field of
Search: |
;52/1,2,80,86,88
;135/1R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
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311,437 |
|
Nov 1955 |
|
CH |
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992,086 |
|
Oct 1951 |
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FR |
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655,445 |
|
Apr 1929 |
|
FR |
|
Other References
House and Home, p. 133, 134, Sept. 1956, Eliot Noyes..
|
Primary Examiner: Abbott; Frank L.
Assistant Examiner: Braun; Leslie A.
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 air-supply 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 air-supply means for delivering air to said
enclosure.
Description
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 reduces 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 obviated.
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 air-supported 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 1s 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 2 .sqroot. H.sup.2 +(L.sup.2 /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 to be 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
single-wall 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
air-circulating 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 eliminating
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 5.degree.C, 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 spaced-apart translucent sheets 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 free-standing 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, I 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 gas-supported
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 double-wall 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, e.g. 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. 1b.
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. 15 - 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 corners 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 left-hand 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 20 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 right-hand 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, (right-hand side in FIG. 1)
and a number of such elements are provided, the structure will have
a circular configuration.
In FIG. 4, I 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 geodesic-domed 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 11a, 11b, extending over more than 180.degree. of the
circumference 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 formed with a convex portion 11c 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 12. 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 11e in contact with the covering 1 and a
pair of overhanging portions 11f and 11g which retain the bands.
FIG. 7 shows an arrangement in which the covering 1 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 14a 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. 9a, 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 101 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 125 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 130 which likewise extends the entire
length of the seam and is provided with a longitudinally 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 130c 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, permits 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 nail-like 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.
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