U.S. patent application number 12/420434 was filed with the patent office on 2009-10-22 for compressed-air rigid building blocks.
Invention is credited to Melvin L. Prueitt.
Application Number | 20090260301 12/420434 |
Document ID | / |
Family ID | 41199935 |
Filed Date | 2009-10-22 |
United States Patent
Application |
20090260301 |
Kind Code |
A1 |
Prueitt; Melvin L. |
October 22, 2009 |
Compressed-Air Rigid Building Blocks
Abstract
The outstanding tensile strength of some materials are used in
compression applications by using air pressure to supply the
outward force on an enclosure and by using interior tension members
to maintain the geometry of the air-pressurized structure. The air
pressure on each face of the structure is balanced by the tension
in the tension members. Due to the high modulus of the tension
members, the air-pressurized structures are very rigid. It is the
air pressure that actually supports any load placed on the
structure, but it is the tension members that maintain the geometry
when the load is removed, and the strength of the tension members
determine how much air pressure can be sustained. The mass of
tension material required in such a structure is roughly equivalent
to the amount of filament material required in a cable to support
the same load. The Compressed-air Rigid Building Blocks can be
stacked like bricks to form strong, lightweight walls, buildings,
towers, and other structures.
Inventors: |
Prueitt; Melvin L.; (Los
Alamos, NM) |
Correspondence
Address: |
Melvin L. Prueitt
161 Cascabel St.
Los Alamos
NM
87544
US
|
Family ID: |
41199935 |
Appl. No.: |
12/420434 |
Filed: |
April 8, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61046878 |
Apr 22, 2008 |
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Current U.S.
Class: |
52/2.26 ; 226/91;
249/125 |
Current CPC
Class: |
E04H 15/20 20130101;
F03D 1/04 20130101; F05B 2240/131 20130101; F03D 9/37 20160501;
F03D 9/25 20160501; Y02B 10/30 20130101; Y02E 10/72 20130101; Y02E
10/728 20130101; E04H 2015/205 20130101 |
Class at
Publication: |
52/2.26 ; 226/91;
249/125 |
International
Class: |
E04H 15/20 20060101
E04H015/20; D05B 87/00 20060101 D05B087/00; B65H 57/26 20060101
B65H057/26 |
Claims
1. A compressed-air supported rigid structure, comprising: an
enclosing container for enclosing the compressed air; and an
interior set of tension members that are attached to and pull
inward on the enclosing container walls to counter the outward
force of the compressed air; and a hose for providing compressed
air; and a hose connection for the attachment of the hose; and a
valve for controlling the flow of compressed air; wherein the
tension members extend from each wall of the enclosing container to
the opposite wall of the enclosing container and wherein the
tension members and the compressed air maintain the structural
geometry of the enclosing container to provide the structure with
rigidity and wherein the structure may be folded compactly when the
compressed air is absent and wherein the hose, hose connection, and
valve provide a means of filling the enclosing container with
compressed air to make the structure rigid and releasing compressed
air from the enclosing container and wherein the structure is
designed so that multiple compressed-air supported rigid structures
may be stacked to provide walls, buildings, towers, and other
useful structures.
2. A compressed-air supported rigid structure according to claim 1,
wherein the enclosing container comprises rectangular walls; and
each interior tension member is attached to one enclosing container
wall and extends to and is attached to the opposite enclosing
container wall; and wherein some of tension members extend in
perpendicular direction to the walls to maintain the walls in rigid
configuration; and wherein other tension members extend in diagonal
directions to provide rigidity to the structure against shear
forces; wherein the purpose of the structure is to form a building
block that can be combined with other similar building blocks to
form a wall or other configurations to form a building or tower or
to provide support for a load.
3. A compressed-air supported rigid structure according to claim 1,
wherein the tension members are high-strength, high modulus
filaments, wires, or cords.
4. A compressed-air supported rigid structure according to claim 1,
wherein the side walls are flexible when the compressed air is
released, so that the structure can be collapsed for easy
transportation and shipping and wherein the side walls are rigid
when the compressed air is applied.
5. A compressed-air supported rigid structure according to claim 4,
wherein rigid frames are incorporated upon which the tension
members can be wound during manufacture, and the rigid frames have
hinges on the sides so that the structure can be folded down when
the compressed air is released and wherein a number of said rigid
frames are placed adjacent to each other to form the structure to
which the enclosing container walls are attached.
6. A compressed-air supported rigid structure according to claim 1,
wherein diagonal tension members are cemented to the outsides of
the enclosing walls to provide greater resistance to shear
forces.
7. A compressed-air supported rigid structure according to claim 1,
wherein the top and bottom of the structure are rigid and circular
and are connected by vertical tension members and wherein the
circumference of the structure is a cylindrical surface made of
strong flexible material and having strong horizontal, vertical,
and diagonal filaments cemented to the outside surface.
8. A compressed-air supported rigid structure according to claim 1,
wherein the structure is in circular form with an outer cylindrical
surface of flexible material and an inner cylindrical surface of
flexible material and wherein a top rigid surface extends between
the top of the outer cylindrical surface and the top of the inner
cylindrical surface and wherein a bottom rigid surface extends
between the bottom of the outer cylindrical surface and the bottom
of the inner cylindrical surface and wherein the space between the
two cylindrical surfaces contains many vertical tension members
connected to the top and bottom rigid surfaces, and many horizontal
tension members are perpendicularly connected to the cylindrical
surfaces, and many diagonal tension members are connected to all
interior surfaces, and wherein many horizontal and diagonal tension
members are wrapped around and bonded to the outer cylindrical
surface.
9. A compressed-air supported rigid structure according to claim 7,
wherein more than one air-supported structure with circular
geometry are cemented onto the top of a flat rigid sheet to make a
larger support structure that may be stacked to make walls, towers,
and other useful structures.
10. A compressed-air supported rigid structure according to claim
1, wherein the horizontal tension members are sheets of strong
plastic, metal, or composite films, and the vertical tension
members are filaments, and wherein the horizontal films are
enclosed on the outside by cementing end sheets to adjacent
horizontal sheets, and the end sheets bulge outward due to air
pressure and allow the structure to be collapsed downward when the
compressed air is released.
11. A compressed-air supported rigid structure according to claim
1, wherein the horizontal, vertical, and diagonal tension members
are sheets of strong plastic, metal, or composite films, and
wherein the vertical tension members are attached to the top and
bottom rigid surfaces, and wherein the horizontal films are
enclosed on the outside by cementing end sheets to adjacent
horizontal sheets, and the end sheets bulge outward due to air
pressure and allow the structure to be collapsed downward when air
pressure is released.
12. A compressed-air supported rigid structure according to claim
1, wherein the internal tension members pass through the enclosing
container walls and are attached to rectangular washers that
distribute the forces over an area of the enclosing container and
wherein the washers are bonded to the enclosing container.
13. A compressed-air supported rigid structure according to claim
1, wherein many of the compressed-air supported rigid structures
are stacked in an overlapping manner to form a tall cylindrical
wall that forms a downdraft convection tower, wherein water
sprayers at the open top of the tower spray water to cool the air
by evaporation, which cool air flows down the inside of the tower
to drive air turbines at the bottom of the tower to produce
electric power and wherein guy wires attached externally to the
tower wall and extend to anchors on the ground and internal radial
cables help to maintain the rigidity of the tower.
14. A compressed-air supported rigid structure according to claim
1, wherein many of the compressed-air supported rigid structures
are stacked in an overlapping manner to form a tall circular wall
that forms an updraft convection tower, wherein solar energy heats
air in a transparent skirt about the bottom of the tower, which
heated air flows up the inside of the tower to drive air turbines
at the bottom of the tower to produce electric power and wherein
guy wires attached externally to the tower wall and extend to
anchors on the ground and internal radial cables help to maintain
the rigidity of the tower.
15. A machine for inserting filaments into a compressed-air
supported rigid structure, comprising: a first set of spools for
holding filaments; and a first structure on which the first set of
spools are mounted; and a first set of needles into which filaments
are threaded for the purpose of passing the filaments through the
top and bottom surfaces of the compressed-air supported rigid
structure; and a first filament capture mechanism for seizing the
filaments after the filaments have been passed through the top and
bottom surfaces by the first set of needles and for attaching the
filaments to the bottom surface; and a first mechanism for moving
the top and bottom surfaces of the compressed-air supported rigid
structure; and a second set of spools for holding filaments; and a
second structure on which the second set of spools are mounted; and
a second set of needles into which filaments are threaded for the
purpose of passing the filaments through the side surfaces of the
compressed-air supported rigid structure; and a second filament
capture mechanism for seizing the filaments after the filaments
have been passed through the side surfaces by the second set of
needles and for attaching the filaments to one of the side
surfaces; and a second mechanism for moving the side surfaces of
the compressed-air supported rigid structure; and a third set of
spools for holding filaments; and a third structure on which the
third set of spools are mounted; and a third set of needles into
which filaments are threaded for the purpose of passing the
filaments through the front and back surfaces of the compressed-air
supported rigid structure; and a third filament capture mechanism
for seizing the filaments after the filaments have been passed
through the front and back surfaces by the third set of needles and
for attaching the filaments to back surface; and a third mechanism
for moving the front and back surfaces of the compressed-air
supported rigid structure; wherein the first mechanism moves the
top and bottom surfaces of the compressed-air supported rigid
structure together, the first set of needles pass filaments through
holes in the top and bottom surfaces, the first filament capture
mechanism seizes the filaments and attaches them to the bottom
surface, the top and bottom surfaces are then moved far apart by
the first mechanism as the first set of spools play out the
filaments, the second mechanism moves the side surfaces of the
compressed-air supported rigid structure together, pressing
together the filaments that extend between the top and bottom
surfaces, the second set of needles pass filaments through holes in
the side surfaces, the second filament capture mechanism seizes the
filaments and attaches them to one of the side surfaces, the side
surfaces are then moved far apart by the second mechanism as the
second set of spools play out the filaments, the third mechanism
moves the front and back surfaces of the compressed-air supported
rigid structure together, pressing together the filaments that
extend between the top and bottom surfaces and the filaments that
extend between the side surfaces, the third set of needles pass
filaments through holes in the front and back surfaces, the third
filament capture mechanism seizes the filaments and attaches them
to the back surface, the front surfaces are then moved apart by the
third mechanism as the third set of spools play out the filaments,
all the surfaces of the compressed-air supported rigid structure
are moved so that their edges are touching as all the spools
tighten the filaments, the filaments are attached and cemented to
the surfaces, and the surfaces are sealed together along their
edges so that the compressed-air supported rigid structure is
leak-proof.
16. A machine for inserting horizontal filaments into a
compressed-air supported rigid structure after the vertical
filaments have been inserted, comprising: a vertical row of weaving
shuttles attached to push rods that move the weaving shuttles; and
supports to hold the weaving shuttles at the appropriate height;
and needles with eyelets to hold filaments; and a guide to direct
the needles into holes in a first side face of the compressed-air
supported rigid structure; and catch mechanism to seize the
filaments from the needles and attach them to the face of the
compressed-air supported rigid structure; and spools for holding
filaments; and catch rods which can hold the filaments at the end
of each stroke of the weaving shuttles; and fetch hooks to seize
the filaments from the catch rods and pull them through a second
side face of the compressed-air supported rigid structure; and a
push rod support system to move the push rods and shuttles through
the rows of vertical filaments; wherein the push rod support system
forces the push rods to move the weaving shuttles between rows of
vertical filaments that are attached to the top face and bottom
face of a compressed-air supported rigid structure, and the needles
carrying filaments in their eyelets are guided by the guide into
holes in a first side face of the compressed-air supported rigid
structure where the catch mechanism seizes the filaments and
attaches the filaments to the outside of the first side face of the
compressed-air supported rigid structure, and the weaving shuttles
are withdrawn, and the filaments are passed around one of the catch
rods as the weaving shuttles move to pass down the next row of
vertical filaments, and after all the passes between all the rows
of vertical filaments have been completed, the guide is removed,
and the first side face is cemented to the top face and the bottom
face, and the weaving shuttles, the push rods, and the push rod
support system are removed, and the fetch hooks seize the filaments
from the catch rods and pull them through holes in the second side
face, the catch rods are removed, and the second side face is
sealed to the top and bottom faces, and the filaments are tightened
and sealed to the second side face, and the compressed-air
supported rigid structure is rotated 90 degrees, and the process
described in this claim is repeated to insert the horizontal
filaments that are perpendicular to the horizontal filaments
already inserted.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This claims priority to and the benefit of U.S. Patent
Provisional Application No. 61/046,878, filed Apr. 22, 2008, the
entirety of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] For load-bearing structures, we normally need materials with
high compressive strength. However, in order to use these materials
effectively, large masses are required. A filament, a wire, or a
cable of the material would be useless in the compressive mode.
There are materials that have very high tensile strengths that can
support large loads as a cable, if the support is supplied from
above the load. Unfortunately in practice, most loads are supported
from below. I propose herein a method for using the high tensile
strengths of some materials to support loads in the compressive
mode. This means that building blocks could be much lighter than
the standard load-bearing materials such as masonry bricks,
concrete, or steel beams. (Since "wire" connotes a metal, "string"
connotes a collection of fibers, "yarn" means a large string, and
"cable" is usually applied to a large metal rope, "filament" will
be used in this document refer to the elongated support
member).
[0003] U.S. Patents such as U.S. Pat. Nos. 3,854,253, 4,004,380,
4,676,032, 5,675,938, and 6,584,732 show inflatable structures that
have interior braces, cables, and films to maintain the geometry of
the structure, but they are not constructed to form building blocks
for larger structures. Between the connecting points of the cables
to the outer surfaces, the outer surface material typically bulges
out, due to the air pressure. If these were used as building
blocks, when one block is placed upon another, the bulges would be
springy and would compress so that there would not be sufficient
rigidity for effective building blocks.
[0004] This description also includes the use of the building
blocks for the construction of convection towers, for which I have
four patents with the U.S. Pat. Nos. 5,284,628, 5,395,598,
5,477,684, and 5,483,798.
SUMMARY OF THE INVENTION
[0005] High air pressure in an air bag can support heavy loads, but
they are very compressible (spongy). Now suppose that we have a bag
in the shape of a rectangular box and each face of the box is
maintained in position by air pressure and an array of high tensile
strength, high modulus filaments that run from one face to the
opposite face. The load-bearing surfaces can be rigid or can have
external washers that connect to the filaments. The air pressure
pushes outward, while the filaments pull in. The pressure can be
high inside such a box since the forces on the faces are borne by
the filaments. When a heavy load is placed on the top face, the
tension on the filaments that run from the top face to the bottom
face of the box is reduced, and the load is supported by the air
pressure. Since the filaments are made of a high modulus material
such as Vectran, S-glass, graphite yarn, carbon-reinforced plastic,
or even steel, there will be almost no depression of the box. It
would be quite rigid as long as the external pressure on the top
face did not exceed the pressure of the air inside the box.
[0006] This invention provides a method of utilizing the high
tensile strength of some materials to provide large compression
forces to support loads.
[0007] A box shape is appropriate for many building blocks, but the
use of air pressure in an enclosed surface with internal filaments
or thin films to maintain the shape can take many shapes. This
invention concerns pressurized containers that can be stacked to
make larger structures. They would be quite rigid as long as the
external pressure on the top face did not exceed the pressure of
the air inside the box. We may call it a "Compressed-Air Rigid
Building Block" (CARBB), and it may be much larger than a standard
brick or a building block.
[0008] To prevent gradual deflation by possible small leaks, each
CARBB could have a small-diameter hose attached to it through a
one-way valve. The hose is attached to a pressure tank. Actually,
if it is properly built, it should hold its pressure for years,
just like car tires. If one CARBB is accidentally damaged, it can
be deflated and removed, and another one can be inserted and
inflated. The CARBB's are laid like ordinary bricks with the middle
of each brick placed over the joint of the two bricks below it. See
FIG. 8. For applications in which a narrow column is required, the
CARBB's can be stacked one above the other.
[0009] Large CARBB's would be useful in building large structures
such as convection towers, cooling towers, housings for blimps,
airplanes, military equipment, and farm products such as wheat, and
temporary buildings for special events. Since they are light and
foldable, they can be shipped in the deflated state and inflated at
the site where they will be used. They could be used as temporary
bridge supports in dry streambeds in military applications.
[0010] To give an idea of the kind of load that can be borne by a
CARBB, suppose it is constructed in the form of a cube that is 10
feet on each side and then a pressure of 100 psi is applied inside.
The filaments can be made of Vectran, which has a tensile strength
of 3.2 Giga Pascals (464,000 psi). It would require 235 lbs. of
Vectran for the filaments (with a safety factor of 4) and 600 lbs
of other materials, for a total of 835 lbs. Yet it could support
700 tons (1.4 million pounds) of weight on top of it. Imagine
stacking 14 military tanks on top of an 835 lb. box! Of course, the
compressed air inside the air box weighs 490 lbs., so the total
weight is 1,325 lbs. Its average density of the CARBB is 0.021
gm/cc, including the air. That compares to 0.69 for cardboard and
0.12 gm/cc for balsa wood. The CARBB is much stronger than
cardboard or balsa.
[0011] We could stack such boxes on top of each other to a height
of about 11,000 feet, before the bottom box would begin to
collapse. By tapering the weight (that is, by having the higher
boxes have less mass and less air pressure), they could
theoretically be stacked to over 30,000 feet. We can also increase
the air pressure and put in heavier filaments in order to support
heavier loads. Replacing air with helium allows the construction of
taller towers. For the moment, we are neglecting such things as
wind forces and guy wires.
[0012] For many applications, the CARBB would be much smaller than
10 feet on each side. The advantage of having them large is the
fact that their density is less. A 10 by 10 by 10 foot CARBB would
occupy 1,000 cubic feet. It would require 125 blocks that were two
feet on each side to construct a building block that that occupied
1,000 cubic feet. It would weigh much more, because there would be
much more face material.
[0013] To provide a perspective, we can make a comparison to a
steel cable. An ordinary steel cable, one square inch in cross
sectional area, can safely support 10 tons of weight. If it is
suspended from a crane 100 meters high, the cable will weigh 1,116
lbs. It can support 17.9 times its own weight. Compare this with
the 10 by 10 by 10 foot CARBB. The unit can support 1,080 times its
own weight.
[0014] The U.S. military could use CARBB's as structural material,
since military units often have to move quickly into an area to set
up large temporary buildings. For military purposes, the boxes
might be six feet on each side and weigh 240 lbs. The CARBB's are
transported flat and then inflated on site. They can be stacked to
make walls. What about the roof? Calculations show that if the
CARBB's are designed with sufficient diagonal filaments, they can
be placed on top of the walls to stretch across a 200-foot opening
on the top to form a roof. Rather than having to build CARBB's that
are 200 feet long, shorter bodies can be designed so that they can
be placed end-to-end, and sliding connectors can hold them
together.
[0015] Of course, for building moderate size structures, such as
the military might need, it is not necessary to design the CARBB's
for 100 psi. For example, a CARBB that is 6 by 6 by 12 feet long
that has only 10 psi pressure inside would be able to support 50
tons. If the CARBB's were used to build a wall 60 feet tall, the
weight on the top of each bottom CARBB due to the CARBB's above it
would be a little over one ton. The extra support capacity can be
used to support the roof and possibly intermediate floors. If
heavier loads are required, the pressure can be increased.
[0016] Another application would be tall convection towers. A
company in Australia plans to build a 1,000-meter tall solar power
tower to produce electricity. The tower would be 130 meters in
diameter and would be built of reinforced concrete that is one
meter thick at the bottom. The glass-covered greenhouse around the
base is to be 7 kilometers in diameter, incorporating 38 square
kilometers (15 square miles) of glass to heat the air with solar
energy. The tower will be very heavy (requiring a massive
foundation) and expensive. By stacking CARBB's around in a circle
at the base and continuing to stack CARBB's on top of those, the
tower could be less expensive and far lighter. The proposed
concrete tower would weigh more than 600,000 tons. A tower built of
CARBB's (3 meter wide walls at the bottom) would weigh about 25,000
tons.
[0017] Downdraft convection towers that spray water across the open
top to cool the air can clean air pollution from the atmosphere
while producing electric power. They can be built with CARBB's.
These will be discussed below.
[0018] For wind turbines in the U.S. and around the world, taller
heights mean higher wind speeds and greater power production.
CARBB's could be used to inexpensively build taller wind turbine
towers. The towers could be constructed by laying the CARBB's like
bricks in a circular fashion, or they could be built with circular
CARBB's like that shown in FIG. 10.
[0019] Homes, factories, warehouses, and office buildings can be
built with CARBB's that are especially designed for the purpose.
Hangers at airports represent another application.
[0020] It is therefore an object of the present invention to
provide a rigid box-like structure that is caused to retain its
shape by internal air pressure (or other gas pressure) and by high
strength, high modulus filaments that are attached to opposite
faces of the structure.
[0021] It is another object of the present invention provide a
rigid cylindrical structure that is caused to retain its shape by
internal air pressure (or other gas pressure) and by high strength,
high modulus filaments that are attached to the top and bottom of
the structure and by filaments attached to the outside of the
structure.
[0022] It is another object of the present invention to provide a
rigid box-like structure that is caused to retain its shape by
internal air pressure (or other gas pressure) and by high strength,
high modulus films that are attached to the interior faces of the
structure.
[0023] It is another object of the present invention to utilize
rigid structures for inexpensive construction of convection towers
for the generation of electric power.
[0024] Other objects, advantages and novel features, and further
scope of applicability of the present invention will be set forth
in part in the detailed description to follow, taken in conjunction
with the accompanying drawings, and in part will become apparent to
those skilled in the art upon examination of the following, or may
be learned by practice of the invention. The objects and advantages
of the invention may be realized and attained by means of the
instrumentalities and combinations particularly pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings illustrate embodiments of the
present invention and, together with the description, serve to
explain the principles of the invention. The drawings are only for
the purpose of illustrating preferred embodiments of the invention
and are not to be construed as limiting the invention. In the
drawings:
[0026] FIG. 1 is a cross-sectional side-view schematic of one
embodiment of the present invention showing a structure that is
held rigid by air pressure pushing outward and tension filaments
pulling inward.
[0027] FIG. 2 is an isometric drawing of the CARBB invention
showing a structure that is held rigid by air pressure and internal
tension filaments and showing diagonal filaments on the outside
faces that resist shearing forces.
[0028] FIG. 3 is a schematic side view showing a method of
inserting filaments between the top and bottom faces of a
CARBB.
[0029] FIG. 4 is a schematic side view showing a method of
inserting filaments between the side faces of a CARBB.
[0030] FIG. 5 is a cross-sectional side-view schematic of a single
frame on which tension filaments are wound.
[0031] FIG. 6 is an end view and a top view of part of the frame of
FIG. 5.
[0032] FIG. 7 illustrates a method of inserting filaments into a
CARBB.
[0033] FIG. 8 shows how the CARBB's are laid to form a wall.
[0034] FIG. 9A is a cross-sectional side-view schematic of another
embodiment of the present invention showing a structure that is
cylindrical.
[0035] FIG. 9B is an isometric view of the cylindrical embodiment
of FIG. 9A.
[0036] FIG. 10 is an isometric view of another embodiment of the
present invention, which provides a circular geometry with a
cylindrical hollow inside.
[0037] FIG. 11 is a top view schematic showing how the circular
configurations of FIGS. 9A and 9B or FIG. 10 can be arranged on a
flat sheet.
[0038] FIG. 12 is a cross-sectional side-view schematic of another
embodiment of the present invention showing a structure that
contains horizontal sheets and vertical filaments as tension
members.
[0039] FIG. 13 is an isometric schematic of another embodiment of
the present invention showing a structure that contains horizontal,
vertical, and diagonal sheets as tension members.
[0040] FIG. 14 is a cross-sectional side-view schematic of a
convection tower that uses CARBB modules to construct the walls of
the tower.
DETAILED DESCRIPTION OF THE INVENTION
[0041] FIG. 1 shows one design of a CARBB 1 in cross sectional side
view. The faces 2, 3, 4 and 5 of the CARBB can be made of thin,
tough composite plastic material or other airtight material. The
top face 2 and bottom face 4 can be somewhat rigid. Side faces 3
and 5, as well as the front and back faces (not shown) should be
flexible so that the box can be folded down for shipping.
Horizontal filaments 8 and vertical filaments 9 are shown. The dots
10 represent filaments that run in the third dimension
(perpendicular to the page). The filaments hold the faces in place
against the inside air pressure. In this design, the filaments 9
and 10 run through the side faces and are attached to rectangular
plastic or metal washers, which distribute the force from the
filaments to the face material. Filaments 8 pass through the top
and bottom faces and are attached to the outside of those faces. On
the side faces 3 and 5 (as well as the front and back faces), there
should be small gaps between the rectangular washers so that the
side faces can fold inward to allow the box to be collapsed.
[0042] FIG. 2 shows a perspective view of the box. The encasing
composite material on the faces has diagonal filaments 12 cemented
to the outside of the faces to resist shear forces.
[0043] In order to fabricate such a building block, one method
would be to construct a plastic CARBB with the six faces sealed
together at the edges of each face sheet and hold it in place by
slight inside air pressure against the inside a jig. A rod passes a
filament through holes in one face and continues on to holes in
opposite faces of the box, and the filament is fastened to the
rectangular, tapered washers on the outside of the faces. An
appropriate adhesive seals the washers to the box. This would work
for small boxes, but it would be difficult for large boxes.
[0044] The question is, how are the filaments installed in the box
of FIG. 1 and FIG. 2, if the box is large? There are several ways
in which it may be done. One method is described here. The top face
2 and the bottom face 4 have small holes drilled in them at
appropriate locations for the filaments to pass through. Both faces
are placed in a jig with the top face 2 lying on the bottom face 4,
as shown in FIG. 3. This is just a schematic drawing, showing only
a few spools and filaments. A machine 13 that has many spools 14 of
filaments across top area of the top face 2 and needles (not shown)
pointed downward toward the holes in the top and bottom faces with
the filaments 9 threaded through the eyes of the needles, which
descend so that the needles pass through the holes in the top and
bottom faces. Mechanisms below the bottom face 4 would intercept
the needles and filaments and attach the filaments to the bottom
face, similar to the operation of a sewing machine. The upper part
of the machine would then rise. The top sheet would be raised the
appropriate distance.
[0045] We now have two rigid sheets at the top and bottom and rows
of vertical filaments 9 extending between the two sheets. The whole
assembly is then rotated 90 degrees to the left, and the faces 2
and 4 are separated further. See FIG. 4. Note that the machine 13
is now on the left. Face 3 is placed below the filaments 9, and
face 5 is placed above the filaments 9. Face 3 is raised as face 5
is lowered. The filaments 9 are pressed between the two faces 3 and
5 as the spools 14 allow the filaments to be extended. Faces 3 and
5 have holes in them for the passage of the filaments. Face 3 has
rectangular washers cemented to its bottom matching the position of
the holes. Face 5 has rectangular washers cemented to its top over
the holes. While faces 3 and 5 are pressed together, machine 15,
which is similar to machine 13, and spools 16 holding filaments
pass the filaments 8 through holes in faces 3 and 5 by needles (not
shown). The filaments are attached to the bottom of face 3. Then
face 3 is lowered while machine 15 and face 5 are raised.
[0046] The process of the preceding paragraph is repeated, except
that the whole assembly is rotated into the page of the drawing,
and the front and back faces of the CARBB are placed above and
below all the filaments. The front and back faces are moved
together to press all the filaments 8 and 9 between them. Another
machine then passes filaments through the front and back faces, the
filaments are connected to one of the faces, and the faces are
moved apart. All of the faces are moved into the appropriate
positions, and all the filaments are tightened and cemented to the
outside of the faces. The faces are sealed along all the edges. The
finished BARBB can then be inflated.
[0047] Each CARBB has an inflation connection and valve, and a
connection for a small diameter hose to maintain pressure (not
shown).
[0048] Another way of positioning the filaments is to wind the
filaments onto a plastic (or metal) frame 20 as shown in FIG. 5.
The frames are constructed of narrow strips that might be two
inches wide (in the direction normal to the page of the drawing)
and perhaps 3/16 of an inch thick. Vertical 9, horizontal 8, and
diagonal filaments 7 are wound around the frames. Many of these
frames are then placed adjacent to each other. The top, bottom, and
sides of the plastic casing (faces) of the CARBB are then epoxied
to the outside of the frames and sealed at the corners. That will
take care of four faces of the box. Filaments will need to be
passed through the other faces by rods. If each rod has a
streamlined body at its front end, it will be guided through rows
and columns of filaments as it presses against those filaments.
Finally the end plastic sheets are sealed to the side sheets. The
whole process can be automated in a factory.
[0049] The advantage of having the diagonal filaments is that they
provide resistance to shear forces about the axis normal to the
page. The CARBB's can be oriented so that the probable direction of
greatest shear forces will be resisted. Shear forces in other
directions can be resisted by diagonal filaments on the outside of
the box.
[0050] The frames 20 have hinges 21 on side strips 25 and 26 so
that the CARBB's can be folded down for transporting to the
location of use or for storage. The side encasing material must be
flexible in order to permit the folding of the box. The top and
bottom of the box can be rigid. Alternatively, in order to make
side strips easily foldable, side strips 25 and 26 can be made of
flexible material that have rigid rectangular washers where the
filaments are attached.
[0051] FIG. 6 shows detail of part of the frame. The filaments 7,
8, and 9 are wrapped into slots 22 in the frames and tightened to
specified tension while the frames are held in a jig. When the
frames are stacked adjacent to each other, they fit together with
overlaps 23 and 24.
[0052] Another way to put the filaments into the CARBB is
illustrated in FIG. 7. The top face 2 and the bottom face 4 of
CARBB can be put together as shown in FIG. 3. The filaments are
passed through and attached to the bottom face. Then the two faces
are moved to their normal finished positions, and the filaments 9
are cemented to the outside of the top face. In FIG. 7, the left
face 3 is then placed on the left. A vertical row of shuttles 80
attached to rods 82 are inserted from the right and pass down
between the rows of vertical filaments 9. The rods 82 are moved by
support 83. For the first pass through, horizontal filaments 8 are
attached to the first vertical catch rod 84. There is one vertical
catch rod 84 at the right of each row of vertical filaments 9. From
there filaments 8 pass through the eye of the needles 81 and then
go back to spools 87. Alternatively, the shuttles 80 could contain
the spools of filaments. The shuttles 80 are supported by supports
86 and roller 89.
[0053] When the shuttles 80 reach the left side, an inserted guide
85 guides the needles into the holes 88 in the left face 3. After
the needles pass through left face, a mechanism (not shown) seizes
the filament above the needle and attaches it to the surface of
face 3. Then the shuttles are withdrawn to the right. The support
83, along with the rods, shuttles, and the spools, move one row
toward the viewer in the drawing. As it moves toward the viewer,
the filament passes around the next catch rod 84. On the left, the
guide 85, which has slots in the side to let the filaments pass
through, also moves toward the viewer to line up with the next row
of holes 88. Then the shuttles move again to the left to install
the next row of horizontal filaments 8. This process continues
until all the horizontal filaments are installed. The guide 85 is
removed, and the left face 3 is moved into contact with the top
face 2 and bottom face 4 and cemented to them.
[0054] On the right, the shuttle mechanism (80, 82, 83, and 87) is
removed. The right face 5 (shown in FIG. 1) is put into place, and
a mechanism from the right side of the right face inserts hooks
through the holes and seizes the filaments that are held by the
catch rod 84 and pulls them through the holes. The catch rods have
grooves in the right side so that it is easy to snag the filaments.
After all the filaments 8 have been drawn through the holes, the
catch rods 84 are removed, and the right face 5 is moved against
the top face 2 and bottom face 4 and sealed into place. The
filaments 8 are drawn tight and attached to the right surface of
face 5.
[0055] The assembly is then rotated about the vertical axis 90
degrees counterclockwise. The back face is placed to the left along
with the guide 85. The supports 86 are removed from between the
shuttles, because they would interfere with the filaments 8. The
shuttles are guided by moving down the channels, which are
surrounded by the vertical and horizontal filaments. The catch rods
84 are put in place on the right. The shuttles are inserted from
the right, and the process described in the proceeding paragraphs
insert the remaining filaments. Finally the front and back faces
are cemented in place.
[0056] This method would work for the design shown in FIG. 1. It
would also work for the design in which filaments 7, 8, and 9 are
put in place by the frames of FIG. 5. In some cases, the diagonal
filaments would be pushed out of the way by the shuttles.
[0057] FIG. 8 shows one method of building a wall or other
supporting structure with CARBB's. The CARBB's 1 can be stacked
like bricks.
[0058] Another embodiment (30) of a CARBB is shown in FIG. 9A and
FIG. 9B. FIG. 9A shows a cross sectional side view of a cylindrical
enclosure that has filaments 9 running in the axial direction to
support the circular faces 33 and 34 against internal air pressure.
FIG. 9B gives an isometric view of the outside of this embodiment.
Filaments 32 are wrapped around the cylinder 35 in a
circumferential direction to support the side pressure. Diagonal
filaments (not shown) cemented to the outside of cylinder 35 resist
shear forces. The cylinder 35 should be made of flexible material
so that the CARBB can be folded down for shipping. Cylinder 35 is
sealed to the rigid top 33 and the rigid bottom 34.
[0059] This cylindrical embodiment can be easily fabricated in a
factory. The top face 33 and the bottom face 34 should have small
holes for the filaments at appropriate locations. Both are placed
in a jig with the top face lying on the bottom face. A machine that
has many spools of filaments across a circular area and needles
pointed downward toward the holes in the top and bottom faces with
the filaments threaded through the eyes of the needles can descend
so that the needles pass through the holes in the top and bottom
faces. Mechanisms below the faces would intercept the needles and
filaments and attach the filaments to the bottom face. The upper
part of the machine would then rise. The top sheet would be raised
the appropriate distance, and the filaments would be attached to
the top face. The holes would be sealed and the filaments would be
cemented to the top face 33 and bottom face 34. The side enclosure
35 would then be sealed to the top and bottom sheets.
[0060] For narrow towers, like those that support wind turbines,
the CARBB's could be constructed in a circular design 36 as shown
in FIG. 10. The interior would be constructed of frames like that
in FIG. 5, but the outer part of each frame would be wider than the
inner part, since the radius and the circumference of the circular
design are larger on the outside. There would be vertical,
horizontal, and diagonal filaments inside. The horizontal filaments
run radially. Since the outside cylinder 37 has a larger area than
the inside cylinder 38, there might be concern that the radial
filaments would pull more strongly towards the outside, but there
will be filaments wrapped circumferentially around the outside
cylinder 37 that will counter this extra force.
[0061] FIG. 11 shows a method of grouping CARBB modules such as
design 30 in FIG. 9 or design 36 in FIG. 10. The modules can be
attached to a bottom rigid sheet 39. In this way, the circular
CARBB's can be assembled to function as building blocks similar to
those of FIG. 2 and can be stacked like those of FIG. 8.
[0062] Another design that makes it easy to fold the CARBB flat is
shown in side view cross section in FIG. 12. The air pressure on
the CARBB's sides is countered by horizontal thin film sheets 41 of
material with high tensile strength. The internal air pressure on
the top 44 and bottom 45 are supported by filaments 42. The outer
edges of the sheets are sealed together by end sheets 43 that are
cemented to the horizontal sheets 41. Air pressure forces them to
curve outward. This design is fabricated by laying the bottom face
45 of the CARBB on the factory assembly mechanism and then laying
the first horizontal sheet 41 on the bottom face 45 and sealing the
first sheet 41 to the bottom face with the end sheets 43. While
that sheet lays flat on the bottom, the second horizontal sheet 41
is laid on top of the first sheet 41 and sealed to the first
horizontal sheet with other end sheets 43. This process is
continued until the last horizontal sheet 41 is sealed to the top
face 44 of the CARBB with end sheets 43. The top face 44 and the
bottom face 45 can be somewhat rigid and have many small holes in
them for the attachment of the filaments 42. With the whole
assembly lying flat, needles pass through the holes in the top face
44 and are forced down through the horizontal sheets 41 with
filaments 42 in the eyes of the needles. Mechanisms below the
bottom face catch the filaments 42 and attach them to the bottom
face 45. When this process is finished, air pressure raises the top
to full height while spools reel out the filaments. The filaments
are then attached to the top, and the holes where the filaments
pass through are sealed.
[0063] An alternative to the design shown in FIG. 12 would be to
use sets of filaments in place of the horizontal sheets. The sets
of filaments would be laid upon the bottom face 45 and attached to
the end sheets 43 in a manner similar to the description in the
previous paragraph. An advantage of the horizontal sheets 41 is
that they provide resistance to shear forces about the vertical
axis.
[0064] Another alternative embodiment similar to FIG. 12 is shown
in FIG. 13. The tension support is provided by vertical 51,
horizontal 52, and diagonal sheets 53 of strong plastic film. This
configuration of sheets can be formed by extrusion of the plastic
through a die. The isometric drawing shows the direction of
extrusion. When the plastic exits the die, it already has the
vertical, horizontal, and diagonal sheets. Only two diagonal sheets
are shown, but diagonal sheets can actually be placed to meet all
the intersections of the vertical and horizontal sheets. The
extrusion units are cemented to the top rigid face 55 and bottom
rigid face 56. If the end sheets 54 are not part of the extrusion,
they can be added by cementing onto the horizontal sheets 51.
[0065] For large assemblies, the extrusions can be made in smaller
units and can then be cemented together. For example, each
extrusion unit might be one foot square in cross section with
two-inch spacing between the vertical sheets and two-inch spacing
between the horizontal sheets. If the CARBB is to be six feet long
by three feet wide by three feet tall, it would require nine of the
extruded units (each six feet long) to fill the interior. Holes in
the interior sheets would allow air to flow throughout the
interior.
[0066] The advantage of the design of FIG. 13 is that, in addition
to the strong tension forces applied to the outside faces of the
box by the interior sheets, there are strong forces to resist any
shear stresses. The end sheets 54 on the side allow the unit to
collapse downward when the air pressure is removed. To attach end
sheets to the front (nearest the viewer in the drawing) and back,
the extrusion is allowed to extend a little beyond the intended
face of the box, the vertical and the diagonal sheets are cut back
slightly, and end sheets are cemented to the horizontal sheets.
Since interior sheets are thin, heavier and more rigid sheets 55
and 56 are cemented to the top and bottom. The end sheets should be
thicker and tough to prevent abrasive objects from damaging the
unit.
[0067] If the sheets in a 6 by 3 by 3 feet CARBB are 5 mils thick
with two-inch spacing between sheets and the material has a density
similar to Spectra 2000, the weight on the interior sheets would be
41 lbs. If the tensile strength is 30,000 psi, the maximum
allowable air pressure would be 150 psi. With a safety factor of
three (air pressure=50 psi), the CARBB could support 129,600 lbs. A
warehouse wall 120 feet long could support 1,296 tons. The complete
6 by 3 by 3 foot CARBB would weigh 100 lbs. With the compressed air
at 60 psi, it would weigh 120 lbs. It can support 1,300 times its
own weight.
[0068] Since the CARBB's are so light, there might be a concern
that CARBB's might be blown off a wall built with CARBB's by the
wind. For some applications, Velcro could be applied to the top,
bottom, and ends of the CARBB's to secure them together. For other
applications, straps can tie them together and anchor them to a
concrete foundation.
[0069] Rigid CARBB's that use air pressure to provide support and
internal filaments that have high tensile strength and high modulus
can be used to build towers, such as those that support wind
turbines.
[0070] One of the important applications of CARBB technology is the
construction of convection towers, either downdraft or updraft. A
downdraft convection tower, such as that shown schematically in
side view cross-section in FIG. 14, works well in low-humidity
areas where water is available. Water is sprayed across the open
top of the tower by a water spraying system 61. That cools the air
and makes it dense. The air falls down the inside of the tower and
turns air turbines 62 at the bottom of the tower to generate
electricity. The diffuser 63 improves the efficiency of the
turbines.
[0071] The cylindrical wall 60 is made by stacking CARBB's in
brick-like manner (FIG. 8). Guy wires 65 and radial cables 66 add
to the rigidity of the tower wall. These can be steel cables, or
they can be made of some of the new lightweight, high-strength
filament materials. Structural supports 67 are built to support the
wall above the turbines.
[0072] A downdraft convection tower that is 1,000 meters tall and
500 meters in diameter can generate 1,000 megawatts of electric
power when the relative humidity is 20% or less. But building a
tower of that size is quite expensive by using the standard
materials and methods. The value of CARBB can be illustrated by
comparing it with concrete and steel construction. Consider the
CARBB's to be 10 by 10 by 10-foot cubes, as described above with
air pressure of 100 psi. The cube would weigh 1,325 lbs, including
the compressed air. A cube of the same size made of concrete would
weigh 150,000 lbs. The foundation for a 1,000-meter tall concrete
tower would be enormous.
[0073] As mentioned above, with a CARBB top face force of 1,440,000
lbs, it could support CARBB's that are stacked to a height of
10,000 feet. Since the tower is only 3,280 feet tall, the pressure
can be lowered considerably.
[0074] Whereas a 1,000 meter tall concrete and steel tower would
require several years to complete. Such a tower that is built with
CARBB would require about five months. The blocks can be inflated
at the base of the tower. Lightweight lifting units on top of the
wall can raise the CARBB to the top and quickly place it on top of
the wall. A number of crews of three workers each can make the
tower grow rapidly. When one row is finished, the lifting unit can
be placed on an uninflated CARBB, and the inflation of the CARBB
will lift the lifting unit to the next level. For concrete towers,
it requires a lot of energy to lift the concrete, and then after
the concrete is poured, time must be allowed for it to harden.
After that, the concrete forms must be dismantled and reset.
* * * * *