Title of Invention	PNEUMATIC STRUCTURAL COMPONENT.
Abstract	The invention relates to pneumatic structural element comprised of an essentially cylindrical air-tight hollow body (1) having a radius rh and length Lh and two caps (5), which is manufactured from a preferably textile material that is flexible but has limited stretchability. The side of the hollow body placed under load is provided with a push rod (2) having a length Lh, which is prevented from laterally buckling on the hollow body (1), and both ends of the hollow body are provided with a knob (3). Inside the knob (3), at least one pair of traction elements (4) is joined in a non-positive manner to the push rod (2). The traction elements (4) extend in a helicoidal and opposed manner while revolving around the hollow body (1) with a whole number of revolutions, and they intersect one another at points (8) which are located on a surface line (7) of the hollow body (1) opposite the push rod (2). The push rod (2), the surface line (7) and the longitudinal axis A of the hollow body (1) define a plane E in which the exerted loads and foces are located.

Title of Invention

PNEUMATIC STRUCTURAL COMPONENT.

Abstract

The invention relates to pneumatic structural element comprised of an essentially cylindrical air-tight hollow body (1) having a radius rh and length Lh and two caps (5), which is manufactured from a preferably textile material that is flexible but has limited stretchability. The side of the hollow body placed under load is provided with a push rod (2) having a length Lh, which is prevented from laterally buckling on the hollow body (1), and both ends of the hollow body are provided with a knob (3). Inside the knob (3), at least one pair of traction elements (4) is joined in a non-positive manner to the push rod (2). The traction elements (4) extend in a helicoidal and opposed manner while revolving around the hollow body (1) with a whole number of revolutions, and they intersect one another at points (8) which are located on a surface line (7) of the hollow body (1) opposite the push rod (2). The push rod (2), the surface line (7) and the longitudinal axis A of the hollow body (1) define a plane E in which the exerted loads and foces are located.

Full Text	The present invention relates to a pneumatic structural component in accordance with the preamble to Claim 1. Several pneumatic structural components in the form of inflatable tube shaped hollow bodies have become known, for example from US 3,894,307 (D1), US 4,712,335 (D2), US 5,735,083 (D3), and FR 2,741,373 (D4). If such a component is loaded transversally, then the aim to be addressed lies principally in containing the tensional and shear forces, without the component collapsing. Whilst solutions are known primarily from D3 and D4, which can contain the tensile forces, in Dl and D2 solutions are published additionally for the containment of shear forces. In D2 the shear forces are contained by numerous carbon fibre rods, which are held in tension between two separately constructed abutments - for instance from reinforced concrete. The pneumatic part of the components described there has the aim only of stabilising the pressure rods against primarily sideways buckling. In Dl several of the components described are joined together parallel to each other into a bridge. The tensile forces are contained by cables led separately underneath, the shear forces by the bridge plates of elements set in rows against each other. Each element itself must here be secured against buckling to two further cables running parallel to the pneumatic elements. In the documents closest to the present invention, D1, D2, arrangements are described which indeed have both tensile and shear elements, but are, however, very expensive both in production and also in application. Apart from this the individual pneumatic elements are only applied as holders of the separation between tensile and shear elements and could be replaced in this function by other light components. The aim of the present invention comprises the production of pneumatic structural components with tensile and shear elements, which can be produced simply and cost effectively, can be easily assembled to complex structural components and constructions such as roofs and bridges and whose erection can also be very quickly accomplished. The addressing of this aim is given in the characterising part of Claim 1 with regard to its essential features, in the following claims with regard to further advantageous features. The subject of the invention is more clearly explained using the attached/drawing by means of several embodiments. Shown are: Fig. la the schematic representation of a first embodiment of a pneumatic structural component in a side view, Fig. 1b the subject of Fig. la in perspective, Fig. 2 a schematic representation of the forces, Fig. 3a, b, c constructional details of the first embodiment Fig. 4a to e various arrangements of tensile elements in developments, Fig. 5 a second embodiment, Fig. 6 a third embodiment, Fig. 7 an example of the application of the first embodiment, Fig. 8a, b, c a fourth embodiment in three views, Fig. 9 an example of the combination of components according to Fig. 8, Fig. 10 a fifth embodiment. Fig. 1 is a schematic representation of a first embodiment of the inventive idea. The component shown here comprises an elongate, essentially cylindrical hollow body 1 inflated with compressed air, of length L and with a longitudinal axis A, which is manufactured from a flexible and airtight material. On its upper side a pressure rod 2 is attached which can be impacted with axial forces. Its ends are formed as nodes 3, onto which two tension elements 4 are fastened in each case. The axial ends of the hollow body 1 carry a cap 5 in each case; for instance one of these caps 5 is equipped with a valve 6 for inflating and deflating the hollow body 1. The two tension elements 4 each embrace the hollow body 1 in the form of a screw with opposite circulating senses for instance once each with a constant pitch. They therefore intersect each other at a position 8 in the centre of a surface line 7 opposite to the pressure rod 2. The pressure rod 2 and the surface line 7 both lie on a plane of symmetry E, which similarly includes the longitudinal axis referenced A of the hollow body 1. The pressure rod 2 is attached onto the hollow body 1 such that for instance in the slack condition of the hollow body 1 it can be pushed in as is shown in Fig. 3a, b. In this way it is secured against sideways buckling. Various types of construction of the nodes 3 are known and familiar to the construction engineer, so that their representation can be omitted here. Fig. 2 shows an example of the loading of the component according to Fig. la, b. A force Fm lying in the plane of symmetry E works on the centre of the pressure rod 2. This is supported in the nodes 3. Neglecting the self weight of the component, then bearing pressures FA work on each node 3. As is known to the specialist, pure pressure forces Fs are now exerted from both nodes 3 on the pressure rod 2 and pure tensile forces Fz in the tension elements 4, whereby the vector components of these tensional forces, which are perpendicular to the plane of symmetry E always compensate to null, however provide a great stiffness and buckling resistance to the component perpendicular to the plane of symmetry E. The limit loading of such a component is obtained in that the surface pressure (in N/m2) of the hollow body 1 caused by the tension of the tension elements 4 must be smaller than the overpressure p acting in the hollow body 1. Fig. 3a, b, c are representations of some constructional details of the hollow body 1. In the cross section according to Fig. 3a the hollow body 1 is set out in separation of functions: an outer skin 10, for instance made from a woven textile assumes the force and tensile loadings. In the interior it hides an airtight tube 11 of a suitable elastomer, which is defined and maintained in form by the skin 10. There are for instance sleeves 12, 13 sewn onto the skin 10, which may be continuous or interrupted. The sleeve 13 accepts the pressure rod 2, the sleeve 12 the tension elements 4, which are set out here as flat ribbons. In the illustration according to Fig. 3b the skin 10 and the tube 11 form a functional entity, which is designated pressure body 14 and for instance comprises a plastics material laminated weave, which is either sewn and sealed, welded or glued in a known manner. As a modification to the sleeves 12, 13 the pressure body 14 carries several loops 15, 16, whereby the simple loops 15 are provided for the tension elements 4, whose position is defined by its characteristic as geodetic lines, the loops 16 for the pressure rod 2 however are produced as so-called capstan loops, which loop around the pressure rod once. In the slack condition of the pressure body 14 the loops 16 are free, the pressure rod 2 can be pushed in without more ado. In the operating condition of the pressure body 14 they are however laid tightly around the pressure rod 2 and thereby prevent its sideways buckling. In accordance with the requirements which are placed upon the component, the materials used can be adapted from a wide range. For the more simple applications, textile materials such as polyester cords and weaves for the tension elements 4 and the armouring of the hollow body 1 are completely sufficient and also cost effective. For the pressure rod 2 itself, simple materials such as for instance bamboo rods can be used. Since the pressure rod 2 is well secured against sideways buckling by the sleeves 13, the pressure rod 2 can also be put together from butt jointed individual pieces. For high loadings however, textile materials of aramid fibres and for the pressure rod 2 composite materials using carbon fibres in a suitable plastics material matrix can be provided. The embodiments represented in Fig. 3a, b, c are not limited in their features; the specialist entrusted with the solution of these details will have many further solutions available to him. The first embodiment of the pneumatic structural component according to Fig. la, b, 2 is preferably suited for a point load in the centre of the component or for a uniformly distributed loading. If the load distribution has to be optimised for other load application positions, then the number of the tension elements 4 can be increased. This is shown by means of Fig. 4a to e. Fig. 4a shows the embodiment of Fig. la, b and Fig. 2 in the development of the hollow body 1. In Fig. 4b each tension element. 4 describes two complete revolutions about the hollow body 1 and is also fastened at L/2 to the pressure rod 2. If the component according to the invention is applied as a bearing beam or an element corresponding to it, then in accordance with the embodiment in Fig. 4b a support is necessary at L/2. Thereby this embodiment corresponds to that in Fig. 4a over half L. The embodiment according to Fig. 4c is an overlay of that according to Fig. 4a and b with regard to the tension elements 4. Since the hollow body 1 is supported by the tension elements 4 as in Fig. 4a at L/2, no central support is required here. Furthermore the preference for point loading at L/2 also disappears. In the embodiment according to Fig. 4d three pairs of tension elements 4 are applied; the component is thereby suited for line loading. At the positions 8 where the tension elements 4 intersect, they are mutually secured against movement. Fig. 4e shows the application of two pairs of parallel mutually parallel tension elements 4. The tension elements 4 not terminating at the ends of the pressure rod 2 are also secured in node elements. This embodiment also emphasises the preference for point loading at L/2. Two embodiments in the form of non-cylindrical hollow bodies 1 are shown in Fig. 5, 6. That in Fig. 5 has a toroidal hollow body 1; the associated pressure rod 2 is then for instance arc shaped. The embodiment according to Fig. 6 is a double cone with for instance arc shaped surface lines. Obviously hollow bodies 1 shaped as a truncated cone are included in the inventive idea. The tension elements of the embodiment according to Fig. 5, 6 are arranged analog to Fig. 1, 2. Obviously all the embodiments according to Fig. 4a to e, suitably adapted here, are similarly in accordance with the invention. Fig. 7 is the representation of an embodiment of the pneumatic structural component according to the invention as in Fig. 1, 2. Several, for instance five, of such components are joined together into a bridge 18. At each end of this bridge 18 a yoke 19 joins together all the nodes 3 on one side of the bridge and directs the applied force FA into the components. The yoke 19 is shown transparent in Fig. 7 with all the technical details omitted, since the construction of such yokes 19 is known to the specialist. Over the components, comprising hollow bodies 1, pressure rods 2 and tension elements 4, wooden planks 20, for instance, are laid at right angles to them and in a known manner joined to each other and to the pressure rods 2. The other end, not shown, of the bridge 18 is constructed in a similar manner. Obviously other known types of decking cover are possible for the bridge, such as perforated steel or other suitable forms and materials. Similarly not shown - since they are state of the art - are the valves 6 and the necessary manifold for simultaneous and pressure equalising inflation of the hollow bodies 1. Fig. 8 is the representation of a further embodiment of the inventive idea. Fig. 8a shows a side view, Fig. 8b a plan view and Fig. 8c a cross section. The hollow body 1 including the various manufacturing modifications is constructed in the same way as that according to Fig. 1. The embodiment according to Fig. 8 has however two pressure rods 2 attached at the sides. Each pressure rod 2 carries a node 3 at each end for the positive engagement of the pressure rod 2 and the tension elements 4. Although with the same diameter of the hollow body 1 its effective height is reduced, at the same time the component according to Fig. 8 (referenced with the reference 22) is however in a position to accept positive and negative bending moments. The reduced maximum load capacity could, if necessary, obviously be compensated for by the choice of a greater diameter for the hollow body 1. The fastening of the pressure rods 2 to the hollow body 1 is effected using analog or identical means as in the first embodiment according to Fig. 1, 2. Otherwise the statements on Fig. 4a - e regarding the tension elements apply also for the embodiment according to Fig. 8. In Fig. 9 an embodiment is shown of a combination of components 22 according to Fig. 8. A multiplicity of such components 22 is arranged adjacent to each other. Each pressure rod 2 accepts the pressure force resulting from the loading of the component 22 in the direction of the vector arrow (loading force FL) in Fig. 9 of two adjacent components 22. For the acceptance of a pressure rod 2 the walls of two adjacent hollow bodies 1 are joined together along two surface lines - by sewing, gluing or welding - whereby a longitudinal running pocket 21 occurs. By the inflation of the hollow bodies 1 the pressure rods 2 pushed into the pockets 21, still slack at first, are clamped between the hollow bodies 1 and are secured against buckling in both directions. With such an arrangement it is possible to create a lightweight roof of great span width, which additionally has the great advantage that both snow loading and lifting wind forces can be withstood. It is further included in the inventive idea to provide the embodiment shown in Fig. 5, 6 with two pressure rods 2 according to Fig. 8. Furthermore such modified components according to Fig. 5 and 8 can also be joined together according to Fig. 9. A convex arched roof can be realised thereby; by changing the radius of curvature of the components according to Fig. 5 and 8 and modification of their length a cupola can be created. Fig. 10 shows a further embodiment of the inventive idea. Here, four pressure rods 2 are arranged at regular spacing around the cylindrical hollow body 1. Each pressure rod 2 has again at each end a node 3, into which for instance two tension elements 4 are fastened in each case. For greater clarity in Fig. 10 each pair of tension elements associated with a pressure rod 2 is given the same signatures. The pressure rods 2 are secured against buckling in the azimuthal direction of the cylindrical hollow body 1 and against radial buckling outwards by sleeves (analog to the sleeves 13 according to Fig. 3), and against radial buckling inwards by the excess of pressure in the hollow body 1. In this way an extraordinarily light and axially highly loadable component arises. By suitable and well known means it can be ensured that the axial pressure load on all four pressure rods is evenly distributed. WE CLAIM: 1. A pneumatic structural component comprising an airtight elongate hollow body (1) inflatable by compressed air and made of flexible material; at least one pressure rod (2); and at least one pair of tension elements (4), characterized in that - the at least one pressure rod (2) is disposed onto the hollow body (1) along a surface line and is secured against displacement and buckling by sleeve type elements (13,16), - the at least one pair of tension elements (4) are fastened at both ends of the at least one pressure rod (2), the pressure rod (2) having a node (3) for fastening the pressure rod (2) in a mutual positive engagement with the tension elements (4), - the at least two tension elements (4) are each configured in the form of a screw contra-rotating around the hollow body (1) and intersecting each other on a surface line (7) of the hollow body (1) opposite to the pressure rod (2), - the nodes (3) are designed to accept bearing pressure. 2. A pneumatic structural component as claimed in claim 1, wherein the hollow body (1) comprises an airtight laminated tensile weave and at least one valve (6) for inflation and deflation. 3. A pneumatic structural component as claimed in claim 1, wherein the tensile weave forms an outer skin (10), and an airtight tube (11) of an elastomer is provided for inserting in the outer skin (10). 4. A pneumatic structural component as claimed in claim 2 or claim 3, wherein the atleast one pressure rod (2) is configured at least in one piece, which runs along the surface line (7) of the hollow body (1), and wherein the ends of the nodes (3) are so designed to accept bearing forces transversal and at right angles through a longitudinal axis of the hollow body (1). 5. A pneumatic structural component as claimed in claim 4, wherein the atleast one pair of tension elements (4) is joined to the pressure rod (4) with positive engagement, and wherein the tension elements (4) each constitutes a whole number of circuits around the hollow body (1). 6. A pneumatic structural component as claimed in claim 5, wherein the tension elements (4) each constitutes one circuit around the hollow body (1). 7. A pneumatic structural component as claimed in claim 4, wherein two pairs of tension elements (4) are provided and joined to the nodes (3) in positive engagement with the pressure rods (2), and wherein each pair of tension elements (4) comprises a whole number of circuits around the hollow body (1). 8. A pneumatic structural component as claimed in claim 7, wherein one pair of tension elements (4) constitutes one circuit, the other pair of tension elements (4) comprises two circuits, around the hollow body (1). 9. A pneumatic structural component as claimed in claim 4, wherein more than two pairs of tension elements (4) are present and joined to the nodes (3) in positive engagement, and wherein each pair of tension elements (4) constitutes a whole number of circuits around the hollow body (1) 10.A pneumatic structural component as claimed in claim 2 or claim 3, wherein two pressure rods (2) are provided and are fastened along two opposing surface lines (7) of the hollow body (1) against buckling, wherein the nodes (3) are so designed that they join each pressure rod (2) with the pair of tension elements (4) associated with them in positive engagement and are adapted to accept transverse bearing forces, and wherein the bearing forces are at right angles to a plane (E) in which the pressure rods (2) and the longitudinal axis of the hollow body (1) lie. 11.A pneumatic structural component as claimed in claim 10, wherein the hollow body (1) has an essentially cylindrical form. 12. A pneumatic structural component as claimed in claim 10, wherein the hollow body (1) is essentially in the form of a torus. 13.A pneumatic structural component as claimed in claim 10, wherein the hollow body (1) is conically formed at least on one side. 14.A pneumatic structural component as claimed in claim 11 or 12 or 13, wherein for each pressure rod (2) one pair of tension elements (4) is provided and joined in the nodes (3) in positive engagement with the associated pressure rod (2), and wherein the tension elements (4) each constitutes a whole number of circuits around the hollow body (1). 15. A pneumatic structural component as claimed in claim 11 or 12 or 13, wherein for each pressure rod (2) more than one pair of tension elements (4) are provided and are joined with positive engagement in the associated nodes (3), and wherein each pair of tension (4) constitutes a whole number of circuits around the hollow body (1). 16. A pneumatic structural component as claimed in claim 2 or claim 3, wherein four pressure rods (2) are provided and fastened against buckling to the hollow body (1) along the surface lines (7) lying apart from each other by 90°, wherein at least one pair of tension elements (4) is provided per pressure rod (2) and joined with positive engagement in-the nodes (3) of the pressure rod (2), wherein each pair of tension elements (4) has a whole number of turns about the hollow body (1), and wherein the nodes (3) are designed for the acceptance of forces running axially to the hollow body (1). The invention relates to pneumatic structural element comprised of an essentially cylindrical air-tight hollow body (1) having a radius rh and length Lh and two caps (5), which is manufactured from a preferably textile material that is flexible but has limited stretchability. The side of the hollow body placed under load is provided with a push rod (2) having a length Lh, which is prevented from laterally buckling on the hollow body (1), and both ends of the hollow body are provided with a knob (3). Inside the knob (3), at least one pair of traction elements (4) is joined in a non-positive manner to the push rod (2). The traction elements (4) extend in a helicoidal and opposed manner while revolving around the hollow body (1) with a whole number of revolutions, and they intersect one another at points (8) which are located on a surface line (7) of the hollow body (1) opposite the push rod (2). The push rod (2), the surface line (7) and the longitudinal axis A of the hollow body (1) define a plane E in which the exerted loads and foces are located.

Full Text

The present invention relates to a pneumatic structural
component in accordance with the preamble to Claim 1.
Several pneumatic structural components in the form of
inflatable tube shaped hollow bodies have become known, for
example from US 3,894,307 (D1), US 4,712,335 (D2), US
5,735,083 (D3), and FR 2,741,373 (D4). If such a component
is loaded transversally, then the aim to be addressed lies
principally in containing the tensional and shear forces,
without the component collapsing. Whilst solutions are known
primarily from D3 and D4, which can contain the tensile
forces, in Dl and D2 solutions are published additionally for
the containment of shear forces.
In D2 the shear forces are contained by numerous carbon
fibre rods, which are held in tension between two separately
constructed abutments - for instance from reinforced
concrete. The pneumatic part of the components described
there has the aim only of stabilising the pressure rods
against primarily sideways buckling.
In Dl several of the components described are joined
together parallel to each other into a bridge. The tensile
forces are contained by cables led separately underneath, the
shear forces by the bridge plates of elements set in rows
against each other. Each element itself must here be secured
against buckling to two further cables running parallel to
the pneumatic elements.
In the documents closest to the present invention, D1,
D2, arrangements are described which indeed have both tensile
and shear elements, but are, however, very expensive both in
production and also in application. Apart from this the
individual pneumatic elements are only applied as holders of
the separation between tensile and shear elements and could
be replaced in this function by other light components. The
aim of the present invention comprises the production of
pneumatic structural components with tensile and shear
elements, which can be produced simply and cost effectively,
can be easily assembled to complex structural components and
constructions such as roofs and bridges and whose erection
can also be very quickly accomplished.
The addressing of this aim is given in the
characterising part of Claim 1 with regard to its essential
features, in the following claims with regard to further
advantageous features.
The subject of the invention is more clearly explained
using the attached/drawing by means of several embodiments.
Shown are:
Fig. la the schematic representation of a first
embodiment of a pneumatic structural component
in a side view,
Fig. 1b the subject of Fig. la in perspective,
Fig. 2 a schematic representation of the forces,
Fig. 3a, b, c constructional details of the first embodiment
Fig. 4a to e various arrangements of tensile elements in
developments,
Fig. 5 a second embodiment,
Fig. 6 a third embodiment,
Fig. 7 an example of the application of the first
embodiment,
Fig. 8a, b, c a fourth embodiment in three views,
Fig. 9 an example of the combination of components
according to Fig. 8,
Fig. 10 a fifth embodiment.
Fig. 1 is a schematic representation of a first
embodiment of the inventive idea. The component shown here
comprises an elongate, essentially cylindrical hollow body 1
inflated with compressed air, of length L and with a
longitudinal axis A, which is manufactured from a flexible
and airtight material. On its upper side a pressure rod 2 is
attached which can be impacted with axial forces. Its ends
are formed as nodes 3, onto which two tension elements 4 are
fastened in each case. The axial ends of the hollow body 1
carry a cap 5 in each case; for instance one of these caps 5
is equipped with a valve 6 for inflating and deflating the
hollow body 1.
The two tension elements 4 each embrace the hollow body
1 in the form of a screw with opposite circulating senses for
instance once each with a constant pitch. They therefore
intersect each other at a position 8 in the centre of a
surface line 7 opposite to the pressure rod 2. The pressure
rod 2 and the surface line 7 both lie on a plane of symmetry
E, which similarly includes the longitudinal axis referenced
A of the hollow body 1. The pressure rod 2 is attached onto
the hollow body 1 such that for instance in the slack
condition of the hollow body 1 it can be pushed in as is
shown in Fig. 3a, b. In this way it is secured against
sideways buckling. Various types of construction of the
nodes 3 are known and familiar to the construction engineer,
so that their representation can be omitted here.
Fig. 2 shows an example of the loading of the component
according to Fig. la, b. A force Fm lying in the plane of
symmetry E works on the centre of the pressure rod 2. This
is supported in the nodes 3. Neglecting the self weight of
the component, then bearing pressures FA work on each node 3.
As is known to the specialist, pure pressure forces Fs are
now exerted from both nodes 3 on the pressure rod 2 and pure
tensile forces Fz in the tension elements 4, whereby the
vector components of these tensional forces, which are
perpendicular to the plane of symmetry E always compensate to
null, however provide a great stiffness and buckling
resistance to the component perpendicular to the plane of
symmetry E. The limit loading of such a component is
obtained in that the surface pressure (in N/m2) of the hollow
body 1 caused by the tension of the tension elements 4 must
be smaller than the overpressure p acting in the hollow body
1.
Fig. 3a, b, c are representations of some constructional
details of the hollow body 1. In the cross section according
to Fig. 3a the hollow body 1 is set out in separation of
functions: an outer skin 10, for instance made from a woven
textile assumes the force and tensile loadings. In the
interior it hides an airtight tube 11 of a suitable
elastomer, which is defined and maintained in form by the
skin 10. There are for instance sleeves 12, 13 sewn onto the
skin 10, which may be continuous or interrupted. The sleeve
13 accepts the pressure rod 2, the sleeve 12 the tension
elements 4, which are set out here as flat ribbons.
In the illustration according to Fig. 3b the skin 10 and
the tube 11 form a functional entity, which is designated
pressure body 14 and for instance comprises a plastics
material laminated weave, which is either sewn and sealed,
welded or glued in a known manner. As a modification to the
sleeves 12, 13 the pressure body 14 carries several loops 15,
16, whereby the simple loops 15 are provided for the tension
elements 4, whose position is defined by its characteristic
as geodetic lines, the loops 16 for the pressure rod 2
however are produced as so-called capstan loops, which loop
around the pressure rod once. In the slack condition of the
pressure body 14 the loops 16 are free, the pressure rod 2
can be pushed in without more ado. In the operating
condition of the pressure body 14 they are however laid
tightly around the pressure rod 2 and thereby prevent its
sideways buckling. In accordance with the requirements which
are placed upon the component, the materials used can be
adapted from a wide range. For the more simple applications,
textile materials such as polyester cords and weaves for the
tension elements 4 and the armouring of the hollow body 1 are
completely sufficient and also cost effective. For the
pressure rod 2 itself, simple materials such as for instance
bamboo rods can be used. Since the pressure rod 2 is well
secured against sideways buckling by the sleeves 13, the
pressure rod 2 can also be put together from butt jointed
individual pieces.
For high loadings however, textile materials of aramid
fibres and for the pressure rod 2 composite materials using
carbon fibres in a suitable plastics material matrix can be
provided.
The embodiments represented in Fig. 3a, b, c are not
limited in their features; the specialist entrusted with the
solution of these details will have many further solutions
available to him.
The first embodiment of the pneumatic structural
component according to Fig. la, b, 2 is preferably suited for
a point load in the centre of the component or for a
uniformly distributed loading. If the load distribution has
to be optimised for other load application positions, then
the number of the tension elements 4 can be increased. This
is shown by means of Fig. 4a to e.
Fig. 4a shows the embodiment of Fig. la, b and Fig. 2 in
the development of the hollow body 1. In Fig. 4b each
tension element. 4 describes two complete revolutions about
the hollow body 1 and is also fastened at L/2 to the pressure
rod 2. If the component according to the invention is
applied as a bearing beam or an element corresponding to it,
then in accordance with the embodiment in Fig. 4b a support
is necessary at L/2. Thereby this embodiment corresponds to
that in Fig. 4a over half L.
The embodiment according to Fig. 4c is an overlay of
that according to Fig. 4a and b with regard to the tension
elements 4. Since the hollow body 1 is supported by the
tension elements 4 as in Fig. 4a at L/2, no central support
is required here. Furthermore the preference for point
loading at L/2 also disappears.
In the embodiment according to Fig. 4d three pairs of
tension elements 4 are applied; the component is thereby
suited for line loading. At the positions 8 where the
tension elements 4 intersect, they are mutually secured
against movement. Fig. 4e shows the application of two pairs
of parallel mutually parallel tension elements 4. The
tension elements 4 not terminating at the ends of the
pressure rod 2 are also secured in node elements. This
embodiment also emphasises the preference for point loading
at L/2.
Two embodiments in the form of non-cylindrical hollow
bodies 1 are shown in Fig. 5, 6. That in Fig. 5 has a
toroidal hollow body 1; the associated pressure rod 2 is then
for instance arc shaped.
The embodiment according to Fig. 6 is a double cone with
for instance arc shaped surface lines. Obviously hollow
bodies 1 shaped as a truncated cone are included in the
inventive idea.
The tension elements of the embodiment according to Fig.
5, 6 are arranged analog to Fig. 1, 2. Obviously all the
embodiments according to Fig. 4a to e, suitably adapted here,
are similarly in accordance with the invention.
Fig. 7 is the representation of an embodiment of the
pneumatic structural component according to the invention as
in Fig. 1, 2. Several, for instance five, of such components
are joined together into a bridge 18. At each end of this
bridge 18 a yoke 19 joins together all the nodes 3 on one
side of the bridge and directs the applied force FA into the
components. The yoke 19 is shown transparent in Fig. 7 with
all the technical details omitted, since the construction of
such yokes 19 is known to the specialist.
Over the components, comprising hollow bodies 1,
pressure rods 2 and tension elements 4, wooden planks 20, for
instance, are laid at right angles to them and in a known
manner joined to each other and to the pressure rods 2. The
other end, not shown, of the bridge 18 is constructed in a
similar manner. Obviously other known types of decking cover
are possible for the bridge, such as perforated steel or
other suitable forms and materials.
Similarly not shown - since they are state of the art -
are the valves 6 and the necessary manifold for simultaneous
and pressure equalising inflation of the hollow bodies 1.
Fig. 8 is the representation of a further embodiment of
the inventive idea. Fig. 8a shows a side view, Fig. 8b a
plan view and Fig. 8c a cross section. The hollow body 1
including the various manufacturing modifications is
constructed in the same way as that according to Fig. 1. The
embodiment according to Fig. 8 has however two pressure rods
2 attached at the sides. Each pressure rod 2 carries a node
3 at each end for the positive engagement of the pressure rod
2 and the tension elements 4. Although with the same
diameter of the hollow body 1 its effective height is
reduced, at the same time the component according to Fig. 8
(referenced with the reference 22) is however in a position
to accept positive and negative bending moments. The reduced
maximum load capacity could, if necessary, obviously be
compensated for by the choice of a greater diameter for the
hollow body 1. The fastening of the pressure rods 2 to the
hollow body 1 is effected using analog or identical means as
in the first embodiment according to Fig. 1, 2. Otherwise
the statements on Fig. 4a - e regarding the tension elements
apply also for the embodiment according to Fig. 8.
In Fig. 9 an embodiment is shown of a combination of
components 22 according to Fig. 8. A multiplicity of such
components 22 is arranged adjacent to each other. Each
pressure rod 2 accepts the pressure force resulting from the
loading of the component 22 in the direction of the vector
arrow (loading force FL) in Fig. 9 of two adjacent components
22. For the acceptance of a pressure rod 2 the walls of two
adjacent hollow bodies 1 are joined together along two
surface lines - by sewing, gluing or welding - whereby a
longitudinal running pocket 21 occurs. By the inflation of
the hollow bodies 1 the pressure rods 2 pushed into the
pockets 21, still slack at first, are clamped between the
hollow bodies 1 and are secured against buckling in both
directions. With such an arrangement it is possible to
create a lightweight roof of great span width, which
additionally has the great advantage that both snow loading
and lifting wind forces can be withstood.
It is further included in the inventive idea to provide
the embodiment shown in Fig. 5, 6 with two pressure rods 2
according to Fig. 8. Furthermore such modified components
according to Fig. 5 and 8 can also be joined together
according to Fig. 9. A convex arched roof can be realised
thereby; by changing the radius of curvature of the
components according to Fig. 5 and 8 and modification of
their length a cupola can be created.
Fig. 10 shows a further embodiment of the inventive
idea. Here, four pressure rods 2 are arranged at regular
spacing around the cylindrical hollow body 1. Each pressure
rod 2 has again at each end a node 3, into which for instance
two tension elements 4 are fastened in each case. For
greater clarity in Fig. 10 each pair of tension elements
associated with a pressure rod 2 is given the same
signatures. The pressure rods 2 are secured against buckling
in the azimuthal direction of the cylindrical hollow body 1
and against radial buckling outwards by sleeves (analog to
the sleeves 13 according to Fig. 3), and against radial
buckling inwards by the excess of pressure in the hollow body
1. In this way an extraordinarily light and axially highly
loadable component arises. By suitable and well known means
it can be ensured that the axial pressure load on all four
pressure rods is evenly distributed.
WE CLAIM:
1. A pneumatic structural component comprising an airtight elongate hollow
body (1) inflatable by compressed air and made of flexible material; at
least one pressure rod (2); and at least one pair of tension elements (4),
characterized in that
- the at least one pressure rod (2) is disposed onto the hollow body (1)
along a surface line and is secured against displacement and buckling by
sleeve type elements (13,16),
- the at least one pair of tension elements (4) are fastened at both ends of
the at least one pressure rod (2), the pressure rod (2) having a node (3)
for fastening the pressure rod (2) in a mutual positive engagement with
the tension elements (4),
- the at least two tension elements (4) are each configured in the form of a
screw contra-rotating around the hollow body (1) and intersecting each
other on a surface line (7) of the hollow body (1) opposite to the pressure
rod (2),
- the nodes (3) are designed to accept bearing pressure.
2. A pneumatic structural component as claimed in claim 1, wherein the
hollow body (1) comprises an airtight laminated tensile weave and at least
one valve (6) for inflation and deflation.
3. A pneumatic structural component as claimed in claim 1, wherein the
tensile weave forms an outer skin (10), and an airtight tube (11) of an
elastomer is provided for inserting in the outer skin (10).
4. A pneumatic structural component as claimed in claim 2 or claim 3,
wherein the atleast one pressure rod (2) is configured at least in one
piece, which runs along the surface line (7) of the hollow body (1), and
wherein the ends of the nodes (3) are so designed to accept bearing
forces transversal and at right angles through a longitudinal axis of the
hollow body (1).
5. A pneumatic structural component as claimed in claim 4, wherein the
atleast one pair of tension elements (4) is joined to the pressure rod (4)
with positive engagement, and wherein the tension elements (4) each
constitutes a whole number of circuits around the hollow body (1).
6. A pneumatic structural component as claimed in claim 5, wherein the
tension elements (4) each constitutes one circuit around the hollow body
(1).
7. A pneumatic structural component as claimed in claim 4, wherein two
pairs of tension elements (4) are provided and joined to the nodes (3) in
positive engagement with the pressure rods (2), and wherein each pair of
tension elements (4) comprises a whole number of circuits around the
hollow body (1).
8. A pneumatic structural component as claimed in claim 7, wherein one pair
of tension elements (4) constitutes one circuit, the other pair of tension
elements (4) comprises two circuits, around the hollow body (1).
9. A pneumatic structural component as claimed in claim 4, wherein more
than two pairs of tension elements (4) are present and joined to the
nodes (3) in positive engagement, and wherein each pair of tension
elements (4) constitutes a whole number of circuits around the hollow
body (1)
10.A pneumatic structural component as claimed in claim 2 or claim 3,
wherein two pressure rods (2) are provided and are fastened along two
opposing surface lines (7) of the hollow body (1) against buckling,
wherein the nodes (3) are so designed that they join each pressure rod
(2) with the pair of tension elements (4) associated with them in positive
engagement and are adapted to accept transverse bearing forces, and
wherein the bearing forces are at right angles to a plane (E) in which the
pressure rods (2) and the longitudinal axis of the hollow body (1) lie.
11.A pneumatic structural component as claimed in claim 10, wherein the
hollow body (1) has an essentially cylindrical form.
12. A pneumatic structural component as claimed in claim 10, wherein the
hollow body (1) is essentially in the form of a torus.
13.A pneumatic structural component as claimed in claim 10, wherein the
hollow body (1) is conically formed at least on one side.
14.A pneumatic structural component as claimed in claim 11 or 12 or 13,
wherein for each pressure rod (2) one pair of tension elements (4) is
provided and joined in the nodes (3) in positive engagement with the
associated pressure rod (2), and wherein the tension elements (4) each
constitutes a whole number of circuits around the hollow body (1).
15. A pneumatic structural component as claimed in claim 11 or 12 or 13,
wherein for each pressure rod (2) more than one pair of tension elements
(4) are provided and are joined with positive engagement in the
associated nodes (3), and wherein each pair of tension (4) constitutes a
whole number of circuits around the hollow body (1).
16. A pneumatic structural component as claimed in claim 2 or claim 3,
wherein four pressure rods (2) are provided and fastened against buckling
to the hollow body (1) along the surface lines (7) lying apart from each
other by 90°, wherein at least one pair of tension elements (4) is provided
per pressure rod (2) and joined with positive engagement in-the nodes (3)
of the pressure rod (2), wherein each pair of tension elements (4) has a
whole number of turns about the hollow body (1), and wherein the nodes
(3) are designed for the acceptance of forces running axially to the hollow
body (1).
The invention relates to pneumatic structural element
comprised of an essentially cylindrical air-tight hollow body (1)
having a radius rh and length Lh and two caps (5), which is
manufactured from a preferably textile material that is flexible
but has limited stretchability. The side of the hollow body
placed under load is provided with a push rod (2) having a length
Lh, which is prevented from laterally buckling on the hollow body
(1), and both ends of the hollow body are provided with a knob
(3). Inside the knob (3), at least one pair of traction elements
(4) is joined in a non-positive manner to the push rod (2). The
traction elements (4) extend in a helicoidal and opposed manner
while revolving around the hollow body (1) with a whole number of
revolutions, and they intersect one another at points (8) which
are located on a surface line (7) of the hollow body (1) opposite
the push rod (2). The push rod (2), the surface line (7) and the
longitudinal axis A of the hollow body (1) define a plane E in
which the exerted loads and foces are located.

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Patent Number

225236

Indian Patent Application Number

IN/PCT/2001/01114/KOL

PG Journal Number

45/2008

Publication Date

07-Nov-2008

Grant Date

05-Nov-2008

Date of Filing

22-Oct-2001

Name of Patentee

AIRLIGHT LIMITED

Applicant Address

VIA CROCE 1, CH-6710 BLASCA

Inventors:

#	Inventor's Name	Inventor's Address
1	PEDRETTI MAURO	VIALE CATTORI 8, CH-6900 LAGANO

PCT International Classification Number

E04H 15/20

PCT International Application Number

PCT/CH2001/00107

PCT International Filing date

2001-02-19

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	583/00	2000-03-27	Switzerland