Wall or casing made of metal stretched over a frame or structure, and construction procedure

A construction of metal walls or closed containers which are used for storage. A wall or shell formed of several sheets of metal (5, 6) juxtaposed at their longitudinal edges (9, 10), resting on longitudinal elements (2, 3) and transverse elements (4). The longitudinal edges of these metal sheets form receptors (13, 14) subject to pressure from transverse movable pushing elements, thereby maintaining one of the edges (9) in abutment with the other (10) and generating lateral, strengthening tension. A method of construction of any individual wall or container by immobilizing sheets of metal (5, 6) along their longitudinal edges (9, 10) on longitudinal elements using opposing transverse force exerted locally and at intervals along the entire length of two adjacent sheets of metal (5, 6).

The present invention concerns a method for constructing a wall formed of a 
succession of juxtaposed forms made of sheets of metal suspended on a 
skeleton or a framework, as well as the wall and the container or shell 
thus formed. 
BACKGROUND OF THE INVENTION 
Silos inside buildings are often made using a skeleton or a framework in 
the general shape of a silo, with an exterior shell made of sheets of 
metal. 
The covering of the silo constitutes its interior wall per se, which is in 
direct contact with the material or the products stored inside. In 
general, the exterior is attached to the skeleton or framework using 
conventional methods such as screws, rivets, or the like, while keeping 
the interior surface as smooth as possible. With this type of 
construction, it is also necessary for the areas with the greatest 
exposure to shocks or the areas with wide spaces between portions of the 
framework to have longitudinal and lateral reinforcements such as girders 
bracing the structure. 
These traditional, prior art designs have numerous drawbacks, particularly 
from the construction perspective, and involve manual labor when 
constructing a silo, which is increased even further by the addition of 
lateral or longitudinal reinforcements. 
A silo with a suspended exterior shell is known in the art and described in 
French Patent Publication No. 2 658 171 in the name of the applicant. This 
silo consists of a succession of metal forms fastened at their upper edges 
onto the longitudinal frame elements, and attached in overlapping 
arrangement at their lower portion in much the same way as roofing tiles 
or shingles are positioned. 
This type of silo eliminates a considerable amount of manual labor and 
offers quite an improvement over traditional silos. In effect, it is 
necessary merely to position the metal forms, which have pre-shaped upper 
edges conforming to the elements of the framework. This is a simple, quick 
job which can be accomplished by a semi-skilled worker. However, certain 
aspects of this type of silo can be improved. 
One such aspect concerns the edges of the sheets of metal, which have 
irregular transverse ridges. The products inside the silo, which are in 
direct contact with these discontinuous areas, may become damaged or even 
stuck to the ridges, depending upon their nature. The irregularities in 
the interior silo surface may also mark the stored products if they are 
made of a deformable, flexible material. This problem often arises during 
storage of products such as plastic bottles, as a fair number of such 
bottles emerge from storage with unattractive striations or marks 
resulting from contact and friction with the edges of the sheet metal. 
This cosmetic flaw is considered serious enough that silos of this type 
are not used by certain producers who bottle their products in plastic 
containers. 
The second aspect concerns the possible formation of linear openings 
between two successive sheets of the metal covering the silo, and in 
general, the development of frequent leaks in such assemblages, allowing 
air and dust to enter. For this reason, this type of silo is unsuitable 
for storing bulk products, particularly food products. 
SUMMARY OF THE INVENTION 
The goal of the present invention is to overcome these disadvantages by 
proposing a method for constructing a wall attached to a framework or a 
skeleton, for example, the wall of a silo-type container or, more 
generally, the shell of any type of container, by juxtaposing successive 
forms made of sheets of metal. 
The invention concerns any wall made of sheets of material, especially 
stainless steel, plastic, or other such material. Some examples are 
separating walls, supporting walls, protective walls, and insulating 
walls, as well as roofs, non-planar, exterior, shingled, reinforcing, or 
protective surfaces. 
In accordance with the present procedure, and according to its principal 
feature, the longitudinal edges of each sheet of material are shaped into 
locking receptor elements; the framework is constructed with a rectilinear 
channel which receives the longitudinal edges of each sheet, and support 
zones are formed in this channel on either side of it and at longitudinal 
intervals along the sheets, wherein two opposing longitudinal edges of two 
adjacent sheets are pushed together and laterally forced against each 
other, causing lateral tension on the sheets, said pushing elements being 
retractable between an active, maintenance position and an inactive, 
inoperative position, in which the edges are no longer joined. If 
necessary, there can also be a means for providing longitudinal tension. 
The present invention also relates to a wall or an exterior shell obtained 
according to the preceding method and consisting of juxtaposed sheets 
covering a skeleton or a framework formed of assembled horizontal or 
vertical elements, characterized in that the longitudinal edges of each 
sheet are shaped into receiving or blocking structures, and in that the 
skeleton has rectilinear channels which receive the opposing longitudinal 
edges of the two adjacent sheets, said receiving channels comprising 
support zones which laterally contact the two opposing edges using 
retractable pressure elements, and in that the longitudinal edges are 
laterally forced against each other by these elements. 
If fine sheets of material are used, longitudinal tension means are also 
provided. 
The present invention also concerns a more elaborate or extensive object or 
product, such as a silo or in general, a container, a shelter, a building, 
or the like, consisting of a skeleton and a cover. 
According to one of its advantages, the instant invention eliminates any 
transverse edges, particularly edges projecting from the interior silo 
surface, which exert pressure on the products inside the silo and damage 
them. 
Further specific advantages of the invention are as follows: 
the sheets of material are not punctured or rough; 
the edges and the sheets of covering material are connected in the same 
plane; 
the complete absence of joints eliminates any possibility of 
bacteriological contamination; 
in the case of a silo, the structure is sealed and therefore can be used in 
numerous applications, particularly pressurized silos; 
the seal can be reinforced using single or multiple longitudinal edges with 
interlocking shapes; 
the permanent lateral tension of the metal, which may be augmented by 
longitudinal tension when necessary, provides adequate rigidity, and thus 
thin sheets of metal can be used, eliminating the need for supplemental 
reinforcing means to be soldered or screwed on. 
But the main feature of the invention consists of reduced labor costs for 
building a wall, a shell, or a unit formed on a base of walls such as a 
silo (although it is not limited to a silo), because it can be constructed 
quickly by semi-skilled workers. 
The constructed units are also airtight because they do not require the 
sheets of covering material to be overlapped.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
In general, the present invention applies to a silo formed of juxtaposed 
sheets of metal immobilized on a skeleton or an exterior framework and to 
the method of constructing the silo. For a better understanding of the 
invention, the first description concerns the formation of a wall with a 
smooth interior surface on an exterior skeleton, with sheets of juxtaposed 
metal attached to the skeleton, immobilized by gripping means at various 
locations along their edges, using lateral tension supplemented by 
longitudinal tension when needed. 
The description will begin with an incomplete base or elementary wall. 
Obviously, the elementary wall is duplicated laterally to form the lateral 
surface of the silo and its covering. 
A skeleton which will become the frame 1 of the silo or other closed 
storage unit is constructed using girders such as elements 2 and 3 and 
vertical elements or posts such as frame posts 4 connected to each other 
by soldering or assembled by other mechanical means. 
These assembled elements are the supporting unit for the adjacent 
juxtaposed sheets of metal 5, 6, which are generally quite long. 
At horizontal intervals determined by the thickness of the metal, there are 
vertical, rectilinear receptor channels in the skeleton, such as channel 7 
(FIG. 4) and within the channels, at vertical intervals, depending upon 
the degree of rigidity desired, there are transverse support zones such as 
zone 8 supporting two sheets of metal 5, 6. Within these zones on the 
skeleton, two adjacent sheets of metal 5, 6 with homologous longitudinal 
edges 9, 10 are applied against each other along said opposing 
longitudinal edges and held in this position, one edge being maintained 
against the other by the opposing forces originating from movable, 
transverse opposing elements 11, 12. 
To accomplish this, opposing longitudinal edges 9 and 10 on the two 
adjacent sheets of metal form homologous receptors 13, 14 which are 
juxtaposed, and which are immobilized and blocked by pressure elements 11 
and 12 exerting a counter-force. 
Longitudinal edges 9, 10 may be shaped in various ways, as will be seen in 
detail below. In the preferred embodiment of the invention, receptors 13 
and 14 form longitudinal wings such as wings 15, each having a contact 
surface 16 obtained by bending the edge of the sheet at a right angle and 
then forming a blocking return 17, also bent at a right angle, but 
perpendicular to the contact surface. 
The appropriately shaped longitudinal edges cooperate in each transverse 
support zone 8 with the opposing elements 11 and 12, which, according to 
the preferred variation, are constructed in the form of retractable 
immobilizing elements and which are attached near receptor 13 or 14 
surrounding their front extremities. 
At the level of each transverse support zone 8 there are two longitudinal 
edges 9 and 10 which can be joined to two movable elements 18 and 19 
holding pressure elements 11 and 12, which are attached elastically so as 
to exert pressure on one another. 
More specifically, these support zones 8 are provided within and along each 
vertical receptor channel, the base of which is defined by a vertical 
element 4. Said channel 7 forms a housing for the two opposing 
longitudinal edges 9 and 10 on two adjacent sheets 5 and 6. Transverse 
support zones 8 are provided at vertical intervals and each have two 
pressure elements 11 or 12 in the form of two locking elements located 
opposite each other, with movable elements 18 and 19 acting as removable 
locks exerting counter forces upon the contact surfaces 16 of the two 
adjacent longitudinal edges and thus forming a minimal relative seal. 
The arrows in FIG. 10 show how air passes between the connecting edges 
through an air outlet which would be necessary, for example, in the case 
of a pressurized silo. 
This relative seal can be improved by forming contact surfaces 16 into 
complementary shapes, either by die-stamping or some other hot or cold 
metal shaping technique. The complementary forms may be U-shaped (FIG. 
14), V-shaped (FIG. 15), single or double C-shaped (FIG. 17), or whatever 
other single, double, or multiple combination of these shapes is 
appropriate. 
In the embodiment shown, the movable support elements 18, 19 each function 
as locks but do not block movement. 
Each lock consisting of movable element 18 or 19 is, for example, generally 
parallelepiped in shape with a front portion 20 of various shapes, for 
example, straight and flat, with or without a connector 21, or bisected, 
or with a central flat portion 23, or some other suitable shape, as shown 
in FIGS. 11 through 13. The rear surface of these pressure elements 
extends into a tail 24 in the shape of a rod with a helicoidal spring 25 
blocked on one side by the rear surface 26 of the lock and on the other 
side by a support bracket 27 attached to the adjacent skeleton girder 2 or 
3. Supporting bracket 27 has a passageway for rod 24, which extends 
through the passageway and even beyond it. The path of the spring is 
preferably blocked by a lateral stop (not shown) when the spring is 
extended. 
In accordance with the variation shown, each lock is translationally guided 
by three successive adjacent walls of adjacent skeleton girder 2, 3, 
which, along with the adjacent vertical element, define an outlet opening 
28 for the lock. 
Naturally, a person skilled in the art might conceive other designs for the 
pressure elements, the lock, its housing, passageway 28, or the support 
zones. 
The arrows and dashed lines in FIG. 9 are schematic representations of the 
slight convex shape 29 of the metal sheets when they are not laterally 
extended, that is, when adjacent longitudinal edges 9 and 10 are not 
connected. This drawing also shows how it is possible to interject a 
cleaning tube 30 between the two edges, previously separated with a tool 
31, for example, a flat edged tool 32 (FIG. 8). 
The procedure for attaching a wall or the like consists first of forming 
and shaping the longitudinal edges on sheets of metal 5, 6 which are equal 
in length to the finished height of the final object, and then 
constructing the skeleton or framework 1 from girders 2, 3 and vertical 
elements 4, forming support zones 8 at longitudinal and transverse 
intervals along receptor channels 7 to accommodate longitudinal edges 9, 
10 of the metal sheets; the opposing metal sheet edges are forced against 
one another by counteracting forces directed toward the contact plane of 
the corresponding edge and directed towards each other by pressure 
elements 11, 12. 
According to the preferred embodiment, these forces act as elastic recall 
forces when abutting longitudinal edges 9, 10 of each metal sheet 5, 6 and 
forcing them against each other. 
More specifically, longitudinal edges 9, 10 of the metal sheet are shaped 
by forming a right angle into a contact surface 16 and also forming a 
blocking return 17 by bending it into a right angled. This receptor unit 
is attached to each movable element 18, 19 of pressure elements 11, 12; 
then the adjacent receptor piece is attached in the same way to the 
opposing movable piece. These opposing elastic forces push the movable 
pieces against each other at the rear by contacting the adjacent edges of 
metal sheets 5, 6. 
Each sheet of metal is maintained in transverse position by elements 
holding one edge 9 to the other 10, placed at regular or irregular 
intervals along the edges, but sufficiently close together to produce 
enough lateral tension for the lateral support and rigidity needed. 
If needed, there can be specific elements (not shown) providing 
longitudinal tension which, when associated with lateral tension, provide 
the rigidity necessary for using thin sheets of metal. 
This technique makes it possible to use thin metal sheets because the 
lateral tension caused by pressure in the support zones provides enough 
rigidity for supporting a silo or resisting other stress on the wall 
during normal use. 
It is also important to note that the edges of the metal sheets can be 
dismantled or removed with the same extraordinary ease and speed as they 
are attached. It is necessary merely to insert an instrument such as a 
tool 31 with a flat edge 32, a flat rod, or the end of a screwdriver, 
through the narrow slot between two successive sheets 5, 6; after a 
quarter rotation, the connecting edges will separate enough to admit the 
tip of a nozzle or of a suction or diffusion element 30 on a cleaning 
and/or disinfecting tool. 
The method of the invention offers a structure which can be assembled or 
disassembled with exceptional speed by a semi-skilled individual. The 
total hourly labor costs for assembling a wall or the like are therefore 
greatly reduced in proportion to the time required for the operation. 
The following description concerns a silo type container used in one 
application of the invention, with reference to FIGS. 18, 19, and 20. 
As the drawings show, the silo has one lateral surface 33 consisting of 
longitudinal walls 34 and transverse walls 35, each formed of a lateral 
succession of juxtaposed sheets of metal, with edges shaped according to 
the method described above. 
The walls are juxtaposed and assembled on the skeleton or framework poles 
by locking and immobilizing them, as well as forcing one edge against 
another with pressure elements 11 and 12 forming two opposing locks. 
The metal sheets are joined to each other at their corners using angled 
posts such as element 36. 
This construction method is used not only for the walls forming lateral 
surface 33, but also for base 37 and upper cover structure 38, which will 
now be described. 
Upper cover structure 38 is shown in detail in FIG. 19. 
It consists of a network 39 of upper girders 40 and upper crossbars 41 
forming a horizontal armature; on the sub-surface there are attached the 
juxtaposed metal sheets with shaped longitudinal edges held by the lock 
provided for the walls of the lateral surface. This network 39 is 
connected to the upper portion of the lateral surface walls 34 and 35 in 
the following manner. The upper girder 40 of each lateral surface wall 42 
is formed of a succession of upper surfaces of horizontal elements and the 
extremities of the skeleton posts, defining between them receptor channels 
7. The upper girders 42 of the longitudinal lateral surface walls 34 are 
closed by a flat tubular element 43 also forming a mechanical retaining 
edge. This element 43 is integral with upper girder 40 adjacent to the 
upper covering structure 38 appearing in FIGS. 18 and 19. 
The connection at the crests of the two consecutive lateral surface walls, 
as shown in FIG. 21, is formed around an angled pole 36 flanked on each of 
its interior lateral surfaces by vertical tubular contact elements 44 and 
45, which are shorter than the sides of angled pole 36, so each one forms 
a space 46 adapted to hold longitudinal edge 9 or 10 of each metal sheet 
on the end of the lateral walls. This structure is symmetrical with angled 
pole 36. 
Silo base 37 has a horizontal wall 47 or an inclined wall 48. These walls 
are connected in a different way, depending upon whether they involve a 
horizontal base (FIG. 22) or an inclined base (FIG. 23). 
If the base has a horizontal wall 47, the connection between base 37 with 
an element of lower edge 49 is identical to the connection holding angled 
pole 36 to the lower edge of the adjacent vertical sheet by longitudinal 
edge 9, 10 of the base sheet on the edge element. 
A tubular element 45 forms a space 46 as with the connection on angled pole 
36. 
With an inclined base 48, the connection is more complex. The lower edge 49 
is formed of two elements 50 and 51 forming an upside down "L". Wall 48 of 
the inclined base diagonally abuts vertical element 51 of lower edge 49 
using an annexed, wide angle end support 52 integral with peripheral 
element 49 of the base wall. The metal sheets of the adjacent lateral wall 
and inclined base wall 48 are sealed at their extremities. For example, 
note that on the sheet of the lateral wall, one extremity 53 forms a right 
angle, while the sheet of the base wall has a projecting overhang. 
The descriptions above concern a conventional silo type container, with a 
base that is either horizontal or inclined. However, various other shapes 
and other types of containers are possible using the same construction and 
design techniques. 
In addition, but only when necessary, the invention provides an 
supplemental means of applying longitudinal tension to the metal sheets. 
This is a specific requirement when using thinner sheets of metal. 
Permanent longitudinal tension can be achieved in various embodiments of 
the invention. 
This tension or rigidity is present in the case of the separating wall 54 
of the silo shown in FIG. 20. Separating wall 54 is formed of a lateral 
succession of several metal sheets 55, 56 with their longitudinal edges 
57, 58 folded and overlapping each other so as to form a longitudinal, 
vertical, flat housing 59 for a core or a metal layer 60 in the form of a 
flat metal piece acting as a reinforcement or strengthening element. 
Each reinforcement 60 exerts tension on the metal sheet using a tractive 
element. This may consist of threaded rods 61 each passing through a 
connecting support 62 which connects, at intervals, both beams 63 and 64 
of a transverse girder located above the transverse separating compartment 
54. The lower extremity of each threaded rod is connected to the upper 
extremity of each reinforcement 60. On the body of the threaded rod there 
is a screw-washer unit 65 contacting the upper transverse supporting 
surface of connection 62 traversed by threaded rod 61, thereby exerting 
vertical pressure which can be adjusted by positioning the screw. 
This tension is transmitted to the adjacent metal sheet, since each 
reinforcement 60 is immobilized against the sheet by two bolts or screws 
66, 67 with pointed ends. 
This tension means associated with each reinforcement 60 is described with 
reference to separating wall 54. It can, of course, be used also with 
longitudinal walls 34 and transverse walls 35 on the lateral surface of 
the silo. 
Separating compartment 54 is connected to the lateral surface in the 
following manner. 
The longitudinal edges of the end sheets of metal are folded and maintained 
at the level of a connecting assemblage 68 on the lateral surface. The 
double thickness of the folded edge 69 of the vertical edge of sheet 55 
rests between two opposing skeleton posts 4. The end sheet of metal 55 of 
separating wall 54 passes between the two opposing longitudinal edges 9 
and 10 of two nearby sheets of metal on the lateral surface and is gripped 
and immobilized between these edges by the counteracting forces of the 
pressure elements. This effect is augmented by the presence of a lower 
oblique edge 70 formed of two parallel tubular elements 71 and 72 which 
hold the metal between them with tightening elements, such as bolts (not 
shown). 
The method of forming and constructing a silo according to the invention 
consists first, of constructing an exterior skeleton or frame 1 using 
horizontal girders 2, 3 and posts 4, maintaining separations between the 
extremities of the horizontal elements to create receptor channels 7 to 
receive longitudinal edges 9, 10 of the metal sheets, and second, of 
positioning the locks of pressure elements 11 and 12 and placing the metal 
sheets on the structure. The length of the sheets is at least equal to the 
height of the lateral surface walls. 
Next, the connections at the angled posts 36 and the lower connections 
between the lateral surface walls and the base wall are made. 
If an upper covering structure is desired, the upper peripheral edge is 
then positioned using a flat tubular element above upper beam 42 of 
longitudinal lateral walls 34. Next, the upper covering structure is 
constructed in the same manner as the lateral surface walls, and the 
sheets of metal are positioned and immobilized using the restraining 
locks. 
If needed, a separating compartment 54 is attached, using no vertical 
posts, but using reinforcements 60 connected to an upper girder 63, 64 by 
an element exerting tension on the metal sheets. 
Insofar as the metal sheets are concerned, their longitudinal edges 9, 10 
are shaped into a right angle forming a contact surface 16 with an angled, 
blocking return 17. This receptor form is attached to each movable piece 
18, 19 of the locks, and then the adjacent receptor form is attached in 
the same way to the opposite movable piece. The opposing elastic forces 
push the movable pieces against each other by rear contact with the 
adjacent edges of metal sheets 5, 6. 
Each sheet of metal is transversely maintained by elements fastening one 
edge 9 to the other edge 10 spaced at regular or irregular intervals along 
its length, but close enough together to produce enough lateral tension 
for the desired support and rigidity. 
As indicated, if necessary, specific means can be provided to produce 
longitudinal tension, one example being the separating compartment 
referred to above, and these elements, in association with lateral 
tension, provide additional rigidity when using thin sheets of metal. 
This technique makes it possible to use thin sheets of metal because the 
lateral tension supplied by the locks in the support zone imparts 
sufficient rigidity to support the silo contents. 
It should be noted that not only are the locks quickly and easily placed on 
the skeleton or framework elements provided for that purpose, but the 
metal sheets are just as easily positioned. Therefore, it is quick and 
easy to disassemble or move the structure. To separate or disengage the 
edges of the metal sheets, one need only insert an instrument or a tool 31 
with a flat end, or a flat rod, a screwdriver tip, or other suitable 
instrument through the narrow slot between two successive sheets of metal 
5, 6, rotating the instrument a quarter turn to separate the connecting 
edges enough to admit a spray, aspiration or diffusion tip or nozzle 30 
for cleaning and/or disinfecting the structure. 
The invention features an exceptionally rapid method of silo 
assembly/disassembly that can be accomplished using semi-skilled labor. 
Thus, the total labor costs for constructing the unit are greatly reduced 
in proportion to the hours required and the skill of workers employed. 
Finally, the only technical assistance needed to construct such a unit is a 
detailed set of instructions.