AU2019339595A1

AU2019339595A1 - Construction element

Info

Publication number: AU2019339595A1
Application number: AU2019339595A
Authority: AU
Inventors: Gabriel LAKATOS
Original assignee: Gablok Sa
Current assignee: Gablok Sa
Priority date: 2018-09-10
Filing date: 2019-09-04
Publication date: 2021-03-25
Also published as: DOP2021000037A; MX2021002334A; BR112021004179A2; MA53590A; EP3850168B1; EP4372167A3; ZA202101466B; CR20210107A; EP4372167A2; CN112639232A; WO2020053047A1; CA3111044A1; EP3850168A1; BE1026597B1; EP3850168C0; BE1026597A1; US20210189723A1

Abstract

The present invention relates to a construction element (10) comprising a frame (1) and a block (2) slidable in the frame (1) when subjected to an external force. The block (2) can thus form a tenon between two superimposed frames (1) forming mortises. Construction elements (10) fixed together laterally form modules (100) which can be assembled in offset from one level to another so as to form a wall.

Description

Construction element

Technical field

[0001] The present invention relates to a construction element allowing, for example, the construction of a wall or a vertical panel.

Prior art

[0002] The document US3885363 A describes a construction element comprising a preformed insulation insert placed in a cavity of a concrete frame. Such construction elements can be used to construct a wall by assembling them with mortar for example. This assembly requires precision to ensure that the construction elements are properly aligned and time to place the mortar and also because of this precision.

Summary of the invention

[0003] An object of the present invention is to provide a construction element that is easy and quick to assemble and does not require mortar.

[0004] The invention provides a construction element comprising: • a frame comprising a cavity opening through an upper opening and a lower opening, and • a block arranged to move in a first direction in the cavity under the action of an external pressure and to remain at least partially blocked in the cavity in the absence of external pressure, wherein an upper end of the block is adapted to engage the upper opening of the cavity and is adapted to engage the lower opening of the cavity.

[0005] In the present invention, when two frames are superimposed so that the cavities are aligned, the upper end of the block may be engaged in the cavity of the upper frame while the lower end of the block may be engaged in the cavity of the lower frame. Thus, the block itself serves as a means for fixing and aligning between the construction element and a second identical construction element. It is therefore not necessary to put mortar between two superimposed construction elements.

[0006] Since the block is blocked in the cavity when no force other than gravity is

exerted on it, the fixing between two superimposed construction elements is particularly strong. The

two frames can be considered to be fitted tightly onto the block.

[0007] The fact that the block can be moved in the frame gives flexibility on the relative

position of the block with respect to the frame. In addition, it allows each block to be pushed into the

frame as far as possible during transport, in order to reduce the transport volume and the block to be

at least partially protected by the frame during transport and on the construction site before

construction.

[0008] The block remains locked in the cavity by lateral mechanical compression when

it is not subjected to pressure in the first direction, but it moves relative to the frame when it is

subjected to external pressure in the first direction. The block is designed to be inserted snugly into the

cavity. When a wall is constructed with the construction element, the first direction is preferably a

vertical direction.

[0009] The block can for example be made of a compressible material or have a surface

structure allowing this movement under pressure and blocking in the absence of pressure.

[0010] The block is such that the action of a force causes it to slide in the cavity, but if

it is not subjected to forces other than gravity it is immovably wedged in the cavity. Preferably, human

force is sufficient to make the block slide into the frame.

[0011] For the purpose of this paper, an "external pressure" is sufficient pressure to

move the block in the cavity. The force corresponding to the external pressure is greater than the force

of gravity, so that the block remains immobilized by the frame when it is subjected only to the action

of gravity. The external pressure is preferably a pressure in the first direction.

[0012] Preferably, the construction element is arranged to weigh less than 20 kg, more

preferably less than 15 kg. For example, a prototype of a 300 mm x 300 mm x 300 mm construction

element in which the frame is made of OSB and the expanded polystyrene block is about 4 kg.

[0013] The frame is preferably an object formed of a plurality of flat panels parallel to

the first direction, so as to delimit the cavity in any direction perpendicular to the first direction. For

example, each panel can be formed of a plate. The frame is preferably devoid of grooves on its outer

surface.

[0014] The cavity is designed to allow the block to slide from its lower end to its upper

end.

[0015] For example, the frame can be between 100 and 800 mm high, preferably about

300 mm. For example, the frame can be between 100 and 800 mm deep, preferably about 300 mm.

For example, the frame can be between 100 and 800 mm wide, preferably about 300 mm. The panels

of the frame are for example between 10 and 30 mm thick, preferably about 18 mm. The frame can

for example be cubic.

[0016] One function of the frame is to provide the outer panels of the wall. It also

allows the permanent fixing of several construction elements together to form modules that can be

removed from each other. A wall can thus be constructed by placing modules offset from each other,

for example staggered.

[0017] The frame is preferably made of a heat-insulating material.

[0018] Preferably, the upper opening of the cavity is located on an upper end of the

frame and the lower opening of the cavity is located on a lower end of the frame. Preferably, the upper

opening of the cavity is the same as the lower opening of the cavity.

[0019] The block is preferably a solid and filled object. The block is preferably formed

in a homogeneous and isotropic material. The block is thermally insulating. For example, the block can

be made of or comprise expanded polystyrene, graphitized expanded polystyrene, or polyurethane

foam. The block may for example be made of one or more materials having a Young's modulus greater

than 1.0 GPa, preferably between 2.0 and 4.0 GPa, more preferably between 2.5 and 3.5 GPa. The

block is rigid enough to block the frame when partially engaged in the cavity of the frame. The block is

preferably made of a flame-resistant material.

[0020] The block preferably extends between all the lateral panels of the frame so as

to be in contact with them. When partially housed in two superimposed frames, the block is preferably

such that it extends between all the lateral panels of the two frames, so as to be in contact with them.

[0021] Preferably, the height of the block is equal to the height of the frame.

[0022] Preferably, the block extends laterally between several parts of surfaces

forming a triangle, rectangle or square. These surface parts preferably comprise a flat part intended to

contact the inner surface of the cavity and a recessed part to form a chamfer at the upper end of the

block.

[0023] For example, the block may be between 100 and 800 mm high, preferably

about 300 mm. For example, the block can be 100 to 800 mm deep, preferably about 263 mm. For

example, the block can be between 100 and 800 mm wide, preferably about 263 mm. The width of the

block is preferably equal to its depth.

[0024] One function of the block is to form the male part of the arrangement by

interlocking while the frames form female parts. Another function of the block is to provide excellent

thermal and sound insulation.

[0025] In an embodiment of the invention, the cavity and the block are such that the

block can enter the cavity through its lower opening and exit through its upper opening.

Thus, it is possible to slide the block completely out of the cavity.

[0026] In an embodiment of the invention, the difference, taken in absolute value,

between at least one lateral extent of the cavity and a corresponding lateral extent of the block

measured when the block is outside the cavity is less than 3 mm, preferably less than 2 mm, more

preferably less than 1 mm.

[0027] In other words, the lateral extent of the block may be less than, greater than,

or equal to the lateral extent of the cavity, but the difference between these two extents is preferably

less than 3 mm, 2 mm, or 1 mm.

[0028] Thus, the block is intended to be inserted in a particularly tight fit in the cavity.

[0029] For the purpose of this document, a "lateral extent" of an element can be, for

example, its length, width, depth. As the block is intended to be at least partially engaged in the cavity,

a lateral extent of the block generally corresponds to a lateral extent of the cavity: for example, the

width of the block corresponds to the width of the cavity and the depth of the block corresponds to

the depth of the cavity.

[0030] The absolute value of the difference between the lateral extent of the block and

the corresponding lateral extent of the cavity is preferably less than 1% of the lateral extent of the

block, more preferably less than 0.5% of the lateral extent of the block.

[0031] The block may be sufficiently compressible laterally so that its lateral extent

decreases when it is at least partially engaged in the cavity.

[0032] In an embodiment of the invention, the difference, in absolute value, between

the width of the cavity and the width of the block measured when the block is outside the cavity is less

than 3 mm, preferably less than 2 mm, more preferably less than 1 mm and/or the difference, in

absolute value, between the depth of the cavity and the depth of the block measured when the block

is outside the cavity is less than 3 mm, preferably less than 2 mm, more preferably less than 1 mm.

[0033] In an embodiment of the invention, the upper end of the block is chamfered

and/or corners of the upper end of the block are rounded.

[0034] This chamfer makes it possible to reduce the width and/or the depth of the

block at its upper end so that the block can be easily introduced into the cavity through the lower

opening of the frame, in particular if the lateral dimension of the block outside the cavity is close to the

corresponding lateral dimension of the cavity. For example, the chamfer can be about 1 cm.

[0035] In an embodiment of the invention, the frame comprises lateral panels

delimiting the cavity laterally, and the block is intended to be in mechanical contact with all the lateral

panels of the frame when it is blocked, at least partially, in the cavity.

[0036] This ensures a particularly strong blocking and a particularly good thermal

insulation, since the thermal insulation effect of the block extends over the entire width and depth of

the construction element. Preferably, the block is in mechanical contact with all the lateral panels for

at least 50% or 80% of the height of the block that is in the cavity.

[0037] In an embodiment of the invention, the height of the frame is substantially

equal to the height of the block. For the purpose of the present invention, the "height" of an object is

preferably the maximum distance between the lower end and the upper end of the object.

[0038] In an embodiment of the invention, the frame and the block have a polygonal,

hexagonal, rectangular, triangular or square section in a plane perpendicular to the first direction. The

horizontal section of the frame and the block are preferably rectangular, more preferably square.

[0039] In an embodiment of the invention, the cavity is delimited by flat surfaces

parallel to the first direction.

[0040] Thus, the flat surfaces that delimit the cavity are not inclined with respect to

the first direction. This avoids, in particular, any upward or downward narrowing of the cavity.

[0041] In an embodiment of the invention, the frame is at least partially made of wood

and/or polymer.

[0042] The frame may be in any material comprising wood. It can for example be made

of oriented strand board called, which are sometimes known as OSB. The MDF is also possible. The

frame can also be made of a polymer.

[0043] Preferably, the frame does not comprise concrete. Indeed, concrete panels

should be much thicker than wood and/or polymer panels, which would make the construction

element heavy.

[0044] The invention furthermore provides an assembly comprising a first and a

second construction elements, wherein the frame of the second construction element is placed on the

frame of the first construction element and the block of the first construction element is mechanically blocked in the cavity of the frame of the first construction element and in the cavity of the frame of the second construction element. Preferably, this assembly does not comprise any gluing means between the frame of the first construction element and the frame of the second construction element.

[0045] The invention further provides a construction module comprising a first and a

second construction elements according to any embodiment of the invention, and wherein the frame

of the first construction element is laterally fixed, for example by screwing and/or gluing, to the frame

of the second construction element. The different construction elements of a module are preferably

identical.

[0046] In an embodiment of the invention, the construction module further comprises

a third construction element according to any embodiment of the invention laterally fixed to the frame

of the second construction element. Preferably, the three construction elements of the module are

aligned or arranged in a corner.

[0047] The invention further provides a wall comprising at least three construction

modules according to any embodiment of the invention, at least a first one of the construction modules

comprising:

• a first block located on the one hand in a first cavity of the first construction module

and on the other hand in a cavity of a second of the construction modules, and

* a second block located on the one hand in a second cavity of the first construction

module and on the other hand in a cavity of a third of the construction modules.

[0048] The modules are thus arranged in offset with respect to each other in order to

obtain a particularly solid wall. In addition, the wall may also comprise uprights fixed to several

construction modules. This increases the stability of the wall.

[0049] The wall may also comprise a board to which some of the construction

elements are fixed, with the frame of the construction elements fixed to the board comprising a lower

cutout that receives at least an upper part of the board. The board can be called wall plate.

[0050] The invention further proposes a building comprising at least one construction

element according to any embodiment of the invention, or a module according to any embodiment of

the invention, or a wall according to any embodiment of the invention.

[0051] The invention further proposes a method of constructing a wall or a vertical

panel and comprising the steps of:

(a) providing a first frame comprising a cavity opening through an upper opening and a

lower opening,

(b) providing a second frame comprising a cavity opening through an upper opening and

a lower opening,

(c) providing a block arranged to move in a first direction in the cavity of the first frame

under the action of external pressure and to remain at least partially blocked in the

cavity of the first frame in the absence of external pressure, and to move in the first

direction in the cavity of the second frame under the action of external pressure and

to remain at least partially blocked in the cavity of the second frame in the absence

of external pressure, and

(d) engaging the block in the upper opening of the cavity of the first frame and in the

lower opening of the cavity of the second frame.

[0052] The advantages mentioned for the device apply mutatis mutandis to the

method.

Brief description of the figures

[0053] Other characteristics and advantages of the invention will appear when reading

the following detailed description, for the understanding of which one will refer to the annexed figures

among which:

- Figure la isa vertical section of a construction element according to an embodiment of

the invention,

- Figure lb is a horizontal section of a frame forming part of a construction element

according to an embodiment of the invention,

- Figure 1c is a horizontal section of a block forming part of a construction element

according to an embodiment of the invention,

- Figure id is a three-dimensional view of a construction element according to an

embodiment of the invention,

- Figure 2 is a vertical section of an assembly of two construction elements according to

an embodiment of the invention,

- Figure 3 is a three-dimensional view of a construction module according to an

embodiment of the invention,

- Figure 4 is a vertical section of a construction module according to an embodiment of

the invention,

- Figure 5a is a vertical section of an assembly according to an embodiment of the

invention,

- Figure 5b isa vertical view of a frame that can be used in the assembly of Figure 5a,

- Figure 6 is a vertical view of a wall according to an embodiment of the invention, and

- Figure 7 is a vertical view of a wall according to an embodiment of the invention

comprising a window.

Embodiments of the invention

[0054] The present invention is described with particular embodiments and references

to figures but the invention is not limited by them. The drawings or figures described are only schematic

and are not limiting.

[0055] In the context of this document, the terms "first" and "second" serve only to

differentiate between the different elements and do not imply any order between these elements.

[0056] In the figures, identical or similar elements may bear the same references.

[0057] Figures la to 1d illustrate an example of frame 1 and an example of block 2

which may be part of a construction element 10 according to an embodiment of the invention.

[0058] For the purposes of this description, the first direction 101 is preferably

considered to be a vertical direction.

[0059] The frame 1 comprises a cavity 22. The cavity 22 passes through the frame 1

between an upper end of the frame 1 and a lower end of the frame 1. The cavity 22 is opened by an

upper opening 22a and a lower opening 22b opposite each other.

[0060] The frame 1 comprises lateral panels 23, for example two first panels la (front

and back panels) and second two panels lb (left and right panels). It is preferable that the second

panels lb be blocked laterally between the first two panels la. This can be seen in figure 1b.

[0061] The block 2 is arranged to be mechanically wedged in the cavity 22 when no

external pressure is exerted on it, and to move in the first direction 101 when it is subjected to external

pressure capable of moving it in the first direction 101.

[0062] The block 2 has an upper end 25 and a lower end 26. Preferably, the upper end

25 of the block 2 is arranged to be engaged, according to the first direction 101, in the upper opening

22a and the lower opening 22b of the cavity 22. The upper end 25 of the block 2 can thus engage in the upper opening 22a of the cavity of a first frame 1 and in the lower opening 22b of the cavity of a second frame 1, identical to the first frame 1, and located above the first frame 1.

[0063] More preferably, the entire block 2 can be inserted into the cavity 22 following

the upper end 25 of the block 2. Preferably, the block 2 has a chamfer 21on one edge of its upper end

25, so that it can be easily inserted into the frame 1.

[0064] Preferably, the block 2 is slidable in the frame 1 in the first direction 101, and

its dimensions are chosen so that, in the absence of pressure, the block 2 is mechanically blocked in

the frame 1.

[0065] Preferably, the frame 1 and the block 2 are of square horizontal section, but it

could have another shape while remaining within the purpose of the invention.

[0066] Figure la shows the block 2 partially inserted in the cavity 22 of the frame 1, so

that it protrudes from the cavity 22 at its upper end 25. This figure illustrates the height 51of the frame

1 and the height 52 of the block 2.

[0067] Figure lb illustrates the width 53 of the cavity 22 and the depth 55. Figure 1c

makes it possible, in particular, to illustrate the width 54 of the block 2 and its depth 56.

[0068] Figure 2 shows two stacked construction elements 10. The block 2 of the lower

construction element 10 is partially engaged, with its upper end 25, in the frame 1 of the upper

construction element 10. The construction elements 10 are assembled by interlocking one on top of

the other, offsetting the block 2 with respect to the frame 1, so that the block 2 is partially received in

two frames located one on top of the other.

[0069] Figures 3 and 4 illustrate construction modules 100 according to embodiments

of the invention. The construction module 100 comprises several construction elements 10 according

to the invention, for example two construction elements 10 for the module 100 illustrated in Figure 3

and three construction elements 10 for the module 100 illustrated in Figure 4. The construction

elements 10 are preferably fixed together via a lateral panel at a junction 3 between two frames 1, so

that they are at the same height. Preferably, a single plate forms the front panels la of the frames 1 of

several construction elements 10 and a single plate forms the rear panels la of the frames 1 of several

construction elements. Preferably, the blocks 2 of the different construction elements can be moved

independently.

[0070] Figure 5a shows a possible assembly with a construction element 10 according

to an embodiment of the invention. This assembly is in particular advantageous for forming the lowest level of a wall. For example, this assembly may comprise base blocks 8, a hermetic layer 7, a board 5 and construction elements 10.

[0071] The base blocks 8 are for example Ytong blocks aligned in a direction

perpendicular to the plane of figure 5a. The sealing layer 7 is for e.g. made of an EPDM (ethylene

propylene-diene monomer) foil. The board 5, which can be called a wall plate, is preferably fixed by

means for fixing or screws 9 to the base blocks 8. The construction elements 10, with a frame 1 where

the second panels lb are shortened as shown in figure 5b, are arranged so that the board 5 is engaged

between the first panels la and preferably abuts against the lower ends of the second panels 1b.

Means for fixing or screws 6 may be used to fix the first panels la to the board 5.

[0072] Figure 5b illustrates the frame 1 whose second panels lb are shorter than the

first panels la, so as to create a passage 16 arranged to receive at least the upper part of the board 5.

[0073] Figure 6 illustrates a wall 200 comprising modules 100, 100a, 100b, 100c

according to the embodiment of the invention and uprights 4. For reasons of clarity, only certain blocks

are shown. They are shown as dotted lines to indicate that they are hidden inside the modules.

[0074] The modules 100 are preferably arranged vertically offset so that a first part of

an upper module rests on a first lower module and a second part of an upper module rests on a second

lower module. In addition, this allows first 120 and second 130 blocks belonging to a first module 100a

to be located partially in the first module 100a and partially in a second module 100b and third module

100c, respectively. This results in a mechanical coupling between the second 100b and third 100c

modules via the first 100a module.

[0075] At the top of the wall 200, for example, it is possible to cut off the upper ends

of the protruding blocks, or to provide blocks of lower height, in order to finish the wall with a

horizontal surface.

[0076] The uprights 4, which can also be called rafters, are fixed, for example screwed

or nailed, to several superimposed construction elements.

[0077] Figure 7 shows a part of wall comprising a window 11. The window 11 is a part

of open wall. It is delimited, for example, by a lower board 14 at the bottom, an upper board 15 at the

top and lateral construction elements 10. The upper board 15 preferably rests on second panels lb of

two of these lateral construction elements, which can be called first lateral construction elements 10c.

The wall also comprises a lintel 12 located above the tureen board 15 and these first lateral

construction elements 10c. The lintel 12 is a construction module in which central construction

elements 10a have their second two panels lb shorter than their first two panels la, and end construction elements 10b have one of their second two panels lb shorter than their first two panels la. The blocks 2 of the first lateral construction elements 10c are partially inserted into the cavities of the end construction elements 10b.

[0078] In other words, the invention relates to a construction element 10 comprising

a frame 1 and a block 2 that can slide in the frame 1 when subjected to an external force. The block 2

can thus form a tenon between two superimposed frames 1forming mortises. Construction elements

10 fixed together laterally form modules 100 that can be assembled offset from one level to the other

to form a wall.

[0079] The present invention has been described in relation to specific embodiments,

which are of purely illustrative value and should not be considered as limiting. Generally speaking, the

present invention is not limited to the examples illustrated and/or described above. The use of the

verbs "comprise", "include", "consist", or any other variant, as well as their conjugations, can in no way

exclude the presence of elements other than those mentioned. The use of the indefinite article "a",

"an", "one", or the definite article "the", to introduce an element does not exclude the presence of a

plurality of such elements. The reference numbers in claims do not limit their scope.

Claims

1. A construction element (10) comprising: • a frame (1) comprising a cavity (22) opening through an upper opening (22a) and a lower opening (22b), and " a block (2) arranged to move in a first direction (101) in the cavity (22) under the action of an external pressure and to remain blocked at least partially in the cavity (22)in the absence ofexternalpressure, wherein an upper end (25) of the block (2) is able to engage the upper opening (22a) of the cavity (22) and is able to engage the lower opening (22b) of the cavity (22).

2. The construction element (10) according to claim 1, wherein the cavity (22) and the block (2) are such that the block (2) can enter the cavity (22) through its lower opening (22b) and exit through its upper opening (22a).

3. The construction element (10) according to any one of the preceding claims, wherein the difference, taken in absolute value, between at least one lateral extent (53; 55) of the cavity (22) and a corresponding lateral extent (54; 56) of the block (2) measured when the block (2) is outside the cavity (22) is less than 3 mm, preferably less than 2 mm, more preferably less than 1mm.

4. The construction element (10) according to any one of the preceding claims, wherein the difference, in absolute value, between the width (53) of the cavity (22) and the width (54) of the block (2) measured when the block (2) is outside the cavity (22) is less than 3 mm, preferably less than 2 mm, more preferably less than 1mm and/or the difference, in absolute value, between the depth (55) of the cavity (22) and the depth (56) of the block (2) measured when the block (2) is outside the cavity (22) is less than 3 mm, more preferably less than 2 mm, more preferably less than 1mm.

5. The construction element (10) according to any of the preceding claims, in which the upper end (25) of the block (2) is chamfered and/or in which corners of the upper end (25) of the block (2) are rounded.

6. The construction element (10) according to any one of the preceding claims,

wherein the frame (1) comprises lateral panels (1a, 1b) delimiting the cavity (22) laterally, and wherein the block (2) is intended to be in mechanical contact with all the lateral panels (1a, 1b) of the frame (1)

when it is blocked, at least partially, in the cavity (22).

7. The construction element (10) according to any one of the preceding claims, in

which the height (51) of the frame (1) is substantially equal to the height (52) of the block (2).

8. The construction element (10) according to any one of the preceding claims, in

which the cavity (22) is delimited by flat surfaces parallel to the first direction (101).

9. The construction element (10) according to any one of the preceding claims, in

which the frame (1) is at least partially made of wood and/or polymer.

10. An assembly comprising a first and a second construction elements (10) according to any one of the preceding claims, wherein the frame (1) of the second construction element (10) is

placed on the frame (1) of the first construction element (10) and the block (2) of the first construction

element (10) is mechanically blocked in the cavity (22) of the frame (1) of the first construction element

(10) and in the cavity (22) of the frame (1) of the second construction element (10).

11. A construction module (100) comprising a first and a second construction elements

(10) according to any one of claims 1 to 9, wherein the frame (1) of the first construction element (10)

is laterally fixed, for example by screwing and/or gluing, to the frame (1) of the second construction

element (10).

12. The construction module (100) according to the preceding claim, further

comprising a third construction element according to any one of claims 1 to 9 laterally fixed to the

frame (1) of the second construction element (10).

13. A wall (200) comprising at least three construction modules (11) according to claim

11or 12, at least a first one (100a) of the construction modules comprising:

" a first block (120) located, on the one hand, in a first cavity of the first construction module (100a) and, on the other hand, in a cavity of a second (100b) of the

construction modules; and

" a second block (130) located on the one hand in a second cavity of the first

construction module (100a) and on the other hand in a cavity of a third (100c) of

the construction modules.

14. A building comprising at least one construction element according to any one of

claims 1 to 9, an assembly according to claim 10, a module according to any one of claims 11 to 12 or

a wall according to claim 13.

15. A method of constructing a wall (200) or a vertical panel and comprising the steps

of:

(a) providing a first frame (1) comprising a cavity (22) opening through an upper opening

(22a) and a lower opening (22b), (b) providing a second frame (1) comprising a cavity (22) opening through an upper

opening (22a) and a lower opening (22b),

(c) providing a block (2) arranged to move in a first direction (101) in the cavity (22) of

the first frame (1) under the action of an external pressure and to remain blocked at least partially in the cavity (22) of the first frame (1) in the absence of external

pressure, and to move in the first direction (101) in the cavity (22) of the second frame

(1) under the action of an external pressure and to remain blocked at least partially

in the cavity (22) of the second frame (1) in the absence of external pressure, and

(d) engaging the block (2) in the upper opening (22a) of the cavity (22) of the first frame

(1) and in the lower opening (22b) of the cavity (22) of the second frame (1).