Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~070284
CONVERTIBLE STRUCTURAL ELEMENT
FIELD OF THE INVENTION
The present invention relates to a transformable structural element capable of
assuming the shape of a beam to support a load and/or transmit a force and/or
a
couple. This shape can be obtained as desired by the user from components of
the
structural element each having, when they are not assembled, a substantially
flexible
configuration.
A structural element of this kind can be used in numerous applications to
permit the selective formation of a structural element capable of supporting a
load
and/or transmitting a force and/or a couple and having a specific length, the
element
being capable of being retracted into a volume, the space of which is very
much
reduced in relation to this length.
More precisely, but solely by way of example, an element of this type can
form a flagstaff of a given height that can be retracted into a housing
provided in the
ground when the flag is not being flown.
OBJECTS OF THE INVENTION
It is therefore an object of the instant invention to provide a transformable
structural element lending itself easily to mechanization of its
transformation and
capable of supporting substantial loads by the use of two or more units.
BRIEF SUMMARY OF THE INVENTION
The invention thus provides a transformable structural element capable of
assuming a beam-like shape which comprises a first chain, the links of which
mutually articulate and each comprise a hinge pin and at least one link plate
and
means for selectively rendering the articulations between the links rigid to
transform it
into a beam-like structure, said means for rendering rigid comprising a
flexible
connection having a series of locking elements with a fixed distance
therebetween and
where the plate of one link of said chain defines a first support point and a
second
support point opposing the first support point, the first support point of the
link of row
n cooperating with the second support point of the link of row n-1 to contain
a locking
element of said flexible connection when the structural element assumes its
beam-like
shape.
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As a result of these features, the structural element can be used to
selectively
provide a rigid beam starting from a configuration in which the components of
the
element can occupy a different volume from that occupied by the element when
it is
rigid. In a specific case, this space can enter into a volume, the dimension
of which in
the direction in which the rigid beam has to extend is very small compared to
the
length of this beam. In addition, the structural element makes it easily
possible to
choose the length of the beam to the extent that these components can be
assembled
along a shorter or longer length.
The assembly of the structural element can easily be mechanised since the
flexible connection which renders the linked chain rigid can be assembled in
step with
the progression of the length of the beam that is rendered rigid. In addition,
the linked
chain can easily be reinforced by placing several plates side by side for each
articulated link on a same pin, the flexible connection capable of being
assembled
onto all the plates of each link by means of one locking element of this
connection
common to all the plates of a same link of the chain.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention are given in the
following description of non-limiting embodiments with reference to the
appended
drawings, in which:
FIG. 1 is a partial sectional view of a structural element of the invention in
its
rigid configuration and in its most elementary embodiment;
FIG. 2 is a sectional view along the line II-II of FIG. 1;
FIG. 3 shows a preferred embodiment of a structural element of the invention,
the linked chain and the flexible connection (here also a linked chain) being
shown
separately;
FIGS. 4 and 5 are profile views along the arrows IV and V of FIG.3;
FIGS. 6 and 7 show views along arrows VI and VII respectively of FIGS. 4
and 5;
FIG. 8 shows the end of the assembled element;
FIG. 9 is a partially sectional front view of an assembly device for a
structural
element of the invention;
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FIG. 10 is a view along the line X-X of FIG. 9:
FIG. 11 shows the structural element in the course of assembly using the
assembly device;
FIGS. 12 and 13 show diagrammatically a motor device facilitating the
automatic assembly of the structural element of the invention; and
FIGS. 14 and 15 show by way of example two practical applications of the
structural element of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made first of all to FIGS. 1 and 2 which illustrate both the
basic
principle of the invention and its simplest embodiment.
Here the structural element comprises a linked chain 1, three links of which
are shown here, namely the links ...ln-1, ln, ln+l..., it being possible for
the chain to
have as many links as necessary.
The links are articulated in relation to one another by means of pins ...2n-1,
2n, 2n+1... which can be fabricated in any appropriate manner provided the
links are
kept laterally together and of course also able to withstand the loads imposed
on the
element once this has been rendered rigid. In the present embodiment, the pins
can
for example be made in the form of an internally threaded sleeve and provided
with a
radial flange, this sleeve receiving a locking screw.
Each links has a plate ...3n-1, 3n, 3n+l... having a first lateral support
point 4
which is in this case situated in a depression of one of the sides of the
plate, as well as
a second lateral support point 5 defined by a hooked part provided at one of
the
extremities of each plate. As shown in FIG. 1, when the structural element is
assembled, the first support point 4 of any link n of the chain 1 is situated
facing the
second support point 5 of the link of row n-1 of the chain. The cooperating
support
points of two successive links in the chain are thus in opposing positions.
The structural element also comprises a flexible connection 6 formed here of a
band 7 on which are provided at different points cylindrical studs,...8n-l,
8n, 8n+1...
extending perpendicularly from one of the lateral faces of the band, that is
the one
which, when the structural element is assembled, is located adjoining the
linked chain
1. As a result, the pins of these studs extend parallel to the pins of the
links of the
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chain 1 when the structural element assumes its beam-like shape. The flexible
connection can, for example, be a reinforced rubber band.
Each stud ...8n-1, 8n, 8n+1... is provided with an end flange 9 (FIG.2)
adapted
to lock the chain laterally after assembly and thus to consolidate the
structural
element. The distance between the studs 9 is the same as between the pins
...2n-1, 2n,
2n-1...
It follows from the foregoing description that the structural element of the
invention can adopt two configurations, namely a flexible configuration in
which the
chain 1 and the flexible connection 6 are disassociated and another
configuration in
which the element constitutes a rigid beam depending on the way in which its
two
components are assembled. In this rigid configuration the element is able to
withstand a load/or transmit a force and/or a couple.
To explain the operation and to simplify the description (FIGS. 1 and 2), it
should be noted that the structural element is assembled and positioned within
a
system of orthogonal coordinates x-y-z, the axis z of which is vertically
oriented and
the axis x is directed along the length of the beam which constitutes the
structural
element.
Both the chain 1 and the flexible coupling 6 can be rolled up, for example on
a
suitable drum, from which they are unrolled to assemble the structural
element. The
chain 1 can obviously be rolled around a drum, the axis of which is oriented
along the
direction y, that is parallel to that of the pins ...2n-l, 2n, 2n+1...
In the case of the flexible connection 6, it will firstly be understood that
it can
have a very low mechanical resistance in both directions y and z: under these
conditions it can be made of a band of completely flexible material.
Nonetheless, the
beam formed by the structural element would then only have a specific
mechanical
resistance in the direction z, the forces of stress C being directed
downwards. The
beam would then therefore be able to support a load provided this was
compatible
with the resistance of the chain. On the other hand, if this load C acts in
the opposite
direction, the beam would not present any resistance since the structural
element
would be disassembled immediately. It should be noted here that the structural
element is constrained at its extremity, as shown to the left of FIG. 1.
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~However, if the connection 6 is only laterally flexible, that is if it can be
rolled
around a drum the axis of which is vertically oriented (direction z), the
structural
element would then present a resistance to flexion in both directions along
the
direction z, provided of course that the load limits are not exceeded. It will
be seen
herein below that in other embodiments of the invention the flexible
connection 6 will
be made in a different manner to give the structural elements resistance
properties that
are identical for the two orientations of the load along the axis Z.
It will also be noted that the studs ...8n-1, 8n, 8n+1... ultimately serve to
lock
the articulations between the links of the claim 1.
It should be noted that the orientation of the structural element described
hereinabove in the system of coordinates x-y-z is solely selected for purposes
of
illustration, the structural element having entirely analogous properties,
regardless of
its orientation in space.
FIGS. 3 to 8 show the preferred embodiment of the invention. In this case, the
structural element is also composed of a linked chain 10 and a flexible
connection 11,
where these two components have exactly the same shape. In other words, the
flexible connection 11 is also composed of a linked chain identical in all
points to the
chain 10. For this reason only the chain 10 will be described in greater
detail below.
More specifically, the chain 10 comprises a succession of links 12 each
comprising a pin 13 and at least one plate 14. In the embodiment shown, each
plate
14 is arranged alongside an identical parallel plate 14a, an interspace 15
being
provided between the plates forming the narrowest links. In addition, each
plate has
two points of support 4 and 5, as shown in the embodiment of FIGS. 1 and 2.
The interspace 15 provided on the pin of each linked chain 10 or 11 is equal
to
the thickness of the two plates 14 or 14a so that when the two chains are
assembled to
form the structural element, they are interleaved with one another (see FIG.
8) to form
a coherent assembly. It will be noted that for the same purpose the pins 13
are
extended on one side of each chain over a distance 16 equal to the interspace
15, plus
a very small length by which the axle projects on the other side of the chain.
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In addition, the pins 13 also project by a small distance beyond the opposing
lateral face of each chain to form guide members 17 the purpose of which will
be
explained below.
When the structural element is in its non-assembled shape, the chains 10 and
11 have a flexibility oriented in such a way that their links are freely
articulated about
the pins 13. The pins 13 are nonetheless axially locked each time in aligned
holes of
the two plates of a same link respectively. Considering FIG. 5 (left hand
side), the
plates 14-A and 14a-A of the link are rotatably integral about the pin 13-A of
this link
whereas these same plates turn freely about the pin 13-B of the link B, the
plates 14-B
and 14a-B of which are rotatably integral with the pin 13-B and so on, along
the entire
length of the chain.
This means that each claim can be rolled around a drum the axis of rotation of
which is parallel to the pins 13. It is therefore simple to retract the two
chains in a
reduced space the perpendicular dimension of which to the pins of the chains
is small
in relation to the length of the structural element when this is in its
assembled
configuration.
This may easily be achieved by hand by progressively hooking the links of the
claims 10 and 11 to one another, while at the same time interleaving them as
shown in
FIG. 8. In this configuration the structural element is very robust and
virtually
becomes a single beam. The loads which can be supported by this element are
obviously a function of the materials used and the dimensioning of the parts.
Moreover, the robustness can easily be increased by providing links formed of
plurality of parallel plates, the distances between which are selected to
obtain an
interlacing of the two chains as shown in FIG. 8.
To facilitate the mode of assembly it is possible to use an assembly device,
one embodiment of which has been shown in FIGS. 9 and 10.
The assembly device comprises two plates 20 and 21 secured by four small
columns 22 and fixed to one another by screws 23. The opposing faces of the
two
plates 20 and 21 each present a guide channe124 into both sides of which two
junction
channels 25a and 25b terminate. These channels are designed to guide the ends
17 of
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the pins of the two chains 10 and 11 forming the structural element of the
preferred
embodiment of FIGS. 3 to 8.
FIG. 11 illustrates how assembly is effected using the assembly device of
FIGS. 9 and 10. The two chains 10 and 11 are introduced between the plates 20
and
21, the outer faces of the outer plates of their links sliding on the opposing
faces of the
plates 20 and 21. The pins of the links are then guided into the channels 25a
and 25b
with regard to chains 10 and 11 respectively and then assembled in the common
guide
channe124.
During the relative movement of the chains 10 and 11, on the one hand, and
the assembly device on the other, the links of the chains are progressively
hooked into
one another in such a way that the structural element becomes a rigid beam on
emerging from the device.
FIGS. 12 and 13 show on the basis of skeleton diagrams how the assembling
and disassembling operations of the structural element can be effected.
FIG 12 relates to an assembly, the principle of which is similar to the device
of
FIGS. 9 and 10. However, in this case, the channels 24 and 25a, 25b are
flanked by
chain wheels 26a and 26b, the indentations 27 of which are designed to retain
the
extremities 17 of the pins 13 of the linked chains 10 and 11.
By turning the chain wheels 26a and 26b in one or other direction it is
possible
to achieve the assembly (arrow fl) or disassembly (f2.) of the structural
element.
FIG. 13 shows a motorized example of this assembly device. Each chain
whee126a, 26b is rotatably integral with a toothed wheel 28a, 28b which mesh
with
one another and with a motor pinion 29 coupled to a motor 30. It is of course
also
possible to drive the pinion 20 using a handle.
FIGS. 14 and 15 show two applications of the invention in diagrammatic form.
FIG. 14 shows a flagstaff which can be retracted into a box 31 embedded in
the ground. The box contains two drums 32 about which are rolled the linked
chains
10 and 11 respectively. An assembly device 33 analogous to that shown in FIG.
12
and associated with the motor device shown in FIG. 13 is placed between the
drums.
FIG. 15 shows the application of the invention to a sun blind adapted to be
mounted, for example, to the facade of a building. An assembly device 34
provided
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with its motor device 35 is mounted in the middle of a frame 36 into which the
blind
can be rolled up. The linked chains 37 and 38 of the structural element are
housed in
sheaths 39 and 40 placed above the frame 36. When the blind needs to be
unrolled,
the structural element is assembled to form, on emerging from the assembly
device, a
horizontal beam which makes it possible to stretch the blind. It suffices of
course to
reverse the direction of rotation of the motor device 35 to retract the blind
and
disassemble the structural element. Various other applications hereof are
obviously
also possible.
Finally, it will be noted that the beam obtained after assembly of the
structural
element does not necessarily need to be rectilinear. An element of this kind
could, in
fact, be designed of rigid structure, but curved to a greater or lesser extent
by carefully
choosing different lengths for the links of the chain.
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