CA1190374A

CA1190374A - Roofing structure

Info

Publication number: CA1190374A
Application number: CA000421460A
Authority: CA
Inventors: Ghislain Leurent
Original assignee: Brelan SA
Current assignee: Brelan SA
Priority date: 1981-08-07
Filing date: 1983-02-11
Publication date: 1985-07-16
Also published as: GB2104124B; EP0072382B1; GB2104124A; CH644423A5; EP0072382A1

Abstract

ABSTRACT OF THE DISCLOSURE
A roofing structure, for forming for example a vault, possibly transparent or translucent, is adapted to cover a zone located between two supports generally parallel in a longitudinal direction. This structure is composed of a plurality of juxtaposed roofing plates located at one or more levels, and of hoop elements disposed transversaly between the two longitudinal supports. Each of these hoop elements is constituted by at least two elementary hoop elements comprising a lower hoop element and an upper hoop element superposed on the lower hoop element. The trans-verse edges of the roofing plates are engaged between the lower and upper hoop elements of each pair.
The roofing structure comprises means for provoking the deformation of one of the superposed hoop elements by applying it under pressure against the other and thus ef-fecting gripping of theroofing plates between the superposed elementary hoop elements, without any seal .

Description

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B~CKGROU~D r~F THE I~VENIION

Ihe present inventlon relates to a roofing struc-ture, for example for making a generally transparent or translucent vault for covering a defined zone.
The structure according to the invention makes it possible, particularly but not e~clusively, to make portions of transparent or tr~nslucent surfaces in the roof of a building, the rooFing of corridors, passages, shelters, porches, etc...
Structures of this type are yenerally constituted by a plurality of transparent or translucent plates, For ex-;amyle made of plastics material, fixed by being yripped between hoop elements and possibly crosspieces which de-fine its frame.
~Such structures must cornply with criteria of tiyht--15 ness, aesthetics, ease of assembly and occasionally ease of modification of the structure, for example by adding other surface levels thereto whilst using the structure which has already been positioned. Furthermore, they generally use materials of differente natures which, in particular, pre-sent different coefficients of expansion. When the structure is made, it is therefore necessary to take into account the differences in expansion in the materials assembled toge-ther.
Presently existing structures are described, for ~` 25 example, in US Patents No.2 ~42 073, 3 307 309, 3 325 951, 3 473 27~, 3 434 250 and 3 7~2 120. Some of these structures are constituted by plates of which the transverse edges are housed between superposed curved sect~ons constituting the transverse hoop elements of the structure. These sections are generaly made of metal, steel or aluminium alloy, and a seal may be interposed between a plate and a section or between a plate and each of the superposed sections.
In such a structure the two upper and lower trans-verse sections constituting each hoop element are rendered fast with each other, at each end, by means of a locking screw which is screwed in-an open tubular rib provided on '' '~

q ~ q .~ ~. ~ , ~ o :~r the inner face of the upper sectior). Ihls open tubu3ar rib presents an outer diameter substantially equa~ to the dis-tance separating two ribs provided on the inner face of the lower section and betwen which is eng3ged the open tubular rib fast with the upper section. Consequently, the engage-ment of the locking screw in the open tubular rib provokes the some extent a diametrical expar-sion of the latter ~hich is applied firmly against the two ribs fast with the ]o~er section. Such a structure consequently presents the drawbacl<
of not ensuring a good seal, as the two sections of each hoop element are connected to each other by an effort exer-ted parallel to the plate of which the edge is housed between the two sections.
The above drawback is also met with at the join between the connecting crosspieces perpendicular to the hoop elements and these hoop elements, when these crosspieces are present in the structure. The connection between the cross-pieces and the hoop elements is generally not very water-tight.
SUMMARY OF THE INVENTION

It is an ooject of the present invention to propose a structure which overcomes the above-mentioned drawbacks, which complies with the criteria of seal, aesthetics7 ease of assembly and ease of adaptation of additional walls to a structure which is already in position, and which, moreover, allows free expansion oF the plates with respect to the frame.
~ It is another object of the invention to propose a ;~ structure in which the plates and sections, constituting hoop elements or crosspieces, are assembled together without seals, whilst ensuring a perfect, effective seal.
Yet another object of the invention is to propose a structure in which the assembly of the sections constituting the hoop elements and the sections constituting the connec-ting crosspleces, when the latter are present, is homogene-.

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OUS and the join between the crosspieces and the hoop ele-ments prevents possible inFiltrations of water inside the construction.
To this end, this roofing structureJ adapted for example to form ~ault, possibly transparent or translucent, for covering a zone located between two supports general]y parallel in a longitudinal direction, composed of a plu-rality of juxtaposed roofing plates, located at one or rnore levels, and of hoop elements disposed transversaly between the two longitudinal supports, each of these hoop elements being constituted by at least two elementary hoop elements comprising a lower hoop element and an upper hoop elernent superposed on the lower hoop element, the transverse edges of the plates being engaged between the lower and upper hoop elements of each pair, is characterized in that it comprises means for provoking deformation of one of the superposed hoop elements by applying it under pressure against the ; other and thus effacting qripping of the plates between the ; superposed elementary hoop elements.
According to an embodiment of the invention, the means for provoking deformation of one of the superposed elementary hoop elements comprise means which exert a tan-gential traction at each end of the upper hoop element, each end of the lower hoop element being fast with the adjacent longitudinal support or in abutment thereon, so that the upper hoop element, deformed in traction, exerts a regularly distributed linear pressure on the edges of the roofing plate and the lower hoop element.
According to a variant embodiment, the means provo-king deformation of one of the superposed elementary hoopelements comprise means which exert a tangential thrust at each end of the lower hoop elernent, each end of the upper hoop element being fast with the adjacent longitudinal SUp-port or in abutment thereon, so that the lower hoop element, deformed by thrust, exerts a pressure beneath the roofing plate and the upper hoop element.

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The different modes of deformation, by traction of the upper hoop element or compression of the lower hoop element, make it possible to apply one of the superposed elementary hoop elernents under pressure against the other, actiny from the ends of these hoop elements. Therefore, contrary to certain existing structures, the fixing rnembers are not distributed over the ~ength of the hoop elements.
Furthermore, it should be noted that the modes of deforma-tion carried out enable the tranverse edges of the plates to lû be gripped between the elementary hoop elements without having to resort to seals. This is mainly due to the fact that the nodes of deformation effect an application under pressure of the upper hoop element ayainst the lower hooper element, or vice versa, which is translated by a substan-tially uniform grip of the transverse edges of the rnaterialsconstituting the structure in the longitudinal and transver-se senseO
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood on reading the following description with reference to the accompanying drawings,in which:
Figure 1 is perspective view of the whole of a structure according to the invention.
Figure 2 is a schematic view in transverse section illustrating the deformation of the upper elementary hoop element, by trsction, with respect to th lower hoop element.
Figure 3 is a schematic view in transverse section illustrating the deformation of the lower elementary hoop element, by thrust with respect to the upper hoop element.
3n Figures 4 and 5 are partial views in section along line A-A of Figure 1, for the mode of deformation shown schematically in Fiqure 2, in the case of structure with one and with two surface levels, respectively.
Fiyures 6 and 7 are partial views in section along 35 line A-A of Figure 1, for the mode of deformation shown schematically in Figure 3, in the case of a structure with one and with two surface levels, respectively.

,, s Figure B is a view in perspective of a variant embo-diment oF the whole of the structurs.
Figure 9 is a schematic view in transverse section illustrating the deformation in traction of the upper hoop element, in the case of the structure of Figure 8.
Figure 10 is a schematic view in transverse section illustrating the deformatior) in thrust oF the lower hoop element, in the case of the structure of Figure 8.
Figures 11 and 12 are partial views in section along lD line C-C of the structure shown in Figure 8, for the mode of deformation schematically shown in Figure 9, in the case of a structure with one and with two surface levels, respecti vely.
Figures 13 and 14 are partial views in section along line C-G of the structure shown in Figure 8, for the mode of deformation shown schematically in Figure 10, in the case of a structure with one and with two surface levels, respecti-;~ vely.
Figure 15 is an exploded perspective view of the end part of the hoop elements shown in Figure 11.
Figure 16 is a view in transverse ssction along lineD-D of Figure 11.
Figure 17 is a variant of Figure 16.
Figure 18 is a view in perspective of a detail of embodiment of the structure shown in Figure 8.
Figure 19 is a partial view in section along line B-B of the structures shown in Figures 1 and 8.
Figures 20, 21, 22, 23, 25, 26 and 27 are views in transverse section through different sections constituting hoop elements.
Figures 24, 28 and 29 are views in perspective of variant embodiments oF the end of upper hoop elements and of lower hoop elements.
Figwre 30 is a view in elevation of an upper hoop element composed of a plurality of portions disposed end to end.

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Figures 31 and 32 are, respectively, view in profile and in elevation of a variant embodiment of the means for deforming the upper hoop element in traction.
Figure 33 i9 a perspective view of the ~hole of a structure presenting connecting crosspieces between the hoops and an openiny.
Figure 34 is a view in longitudinal section through the zone of connection betwecn a crosspiece and hoop ele-ments, this section being made along line B-B of Figure 35.
lû ~igure 35 is a view in transverse section along the line F-F of Figure 3~.
Figure 36 is a view in transverse section along line G-~ of Figure 34.
Figure 37 is a view in section through the zone of connection between the end of an opening and a connecting crosspiece of the structure.
Figure 3~ is a view in section throught the zone of connection oetween hoop elements of the fixed structure.
D~SCRIPTIûN OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, Figure 1 shows a structure 1 in the form of a vault which covers 3 zone defi-ned by two generally parallel longitudinal supports 2~ con-nected or not at their ends by transverse supports 3. The wole of these supports defines for example a cut which pro-jects with respect to the surface of a roof and which defi-nes an opening in this roof which this structure 1 covers.
The upper surface 4 of the supports 2 is substantially hori-zontal. The structure 1 further comprises longitudinal end sections 11 and 19 fast with the supports 2. It also compri-ses hoop elements oriented transversaly with respect to the lonyitudinal direction defined by the supports 2 and spaced out longitudinally. Each of these hoop elements is in fact constituted by at least two superposed elementary hoop ele-ments, namely an upper hoop element 5 and a lower hoop ele-ment 6.

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Between the upper and lower hoop elements 5 and 6respectively, are engaged the transverse edges of roofing plates 7, yenerally transparent or translucent. These plates are for example made of a plastic material or a resin and they are supple enough to be cold bent for assembly purposes rhe structure 1 presents one or more surface levels.
In the case of the structure presenting more than one sur-Face level, an intermediate hoop element is interposed bet~
wen an upper hoop element 5 and a lower hoDp elernent 6 of the same pair, all these hoop elements 5, 6, 8 being super-posed. lJnless indicated to the contrary, an interrnediate hoop element ~ shall be considered as an upper hoop element with respect to a lower hoop element 6 and as a lower hoop element with respect to an upper hoop element 5.
The transverse edges of the roofing plates 7 are gripped between the upper hoop elements 5 and lower hoop elaments 6 and the gripping is effected by deformation of one oF the superposed elementary hoop elements and the pres-sure exerted by this deformed hoop element on the other.
This grlpping is effected without the use of members for fixing the hoop elements together, distributed over their length, nor of seals between the plates and the hoop ele-ments. However, this gripping is effected in totally water-tight manner with respect to the interior of the construc-tion, whilst allowing free expansion of the plates and thecollection of the possible infiltration water through the lower hoop element.
Figures 2 and 3 schematically show two modes of deformation of one of the elementary hoop elements allowing such a gripping of the plates.
In Figure 2, the ends 9 and 10 of the lower elemen-tary hoop element 6 are respectively immobilised in position with respec:t to the flange of the longitudinal end section 11 fast with each support, this flange being oriented subs-tantially perpendicularly with respect to the curve definedby the hoop element 6~ This immobilisation may be an abut-ment or it may be ensured by a set screw. In this cas~, it ,~

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is the upper hoop elernent 5 which is deformed and thls de-formation consists in exerting a traction on the ends 12 and 13 of the upper hoop elenent 5, this traction being substan-tially parallel to the tangent to the bottorn point of the curve which it defines. Such a traction i~ sche~e~!r~lly shown by arrows 14 and 15. This traction provokes tensional stresses inside the upper hoop element 5 which is conse-quently applied, by deformation, over the whole of its length, on the lower hoop element 5. This is translated by the appearance of a pressure exerted by the upper hoop ele-ment 5 on the lower hoop element 6, this pressure being perpendicular to each point of the curve defined by the upper hoop element 5. Such a pressure is schematically shown by arrows 16. The transverse edges of the roofing plates 7 which are inserted in and between the elementary hoop ele-ments 5 and 6 are therefore gripped over the whole of their length~
In the variant embodiment illustrated in Figure 3a it is the ends 17 and 18 of the upper hoop element 5 which are respectively immobilised in position, for example with respect to the flange of a longitudinal end section 19 fast with each of the supports 2. This immobilisation may be an abutment or it may be ensured by a screw. In this case, the mode of deformation consists in exerting a thrust on the ends 20 a~d 21 of the lower hoop element 6,this thrust being shown schematically by arrows 22. This thrust is oriented parallel to the tangent to the bottom point of the curve defined by the lower hoop element 6. It provo~es~ over the whole length of the lower hoop element 6, a pressure orien-ted perpendicularly to each point of the curve defined bythe lower hoop element 6, this pressure being shown schema-tically by arrows 23. The lower hoop element 6 is thus ap-plied under pressure over the whole of its length, against the upper hoop element 5 and the edges of the plates are inserted and gripped between the hoop elements 5 and 6.
The two modes of deformation which have just been described enable the assembly between the upper hoop lements 5, the lower hoop elements 6 and the roofing plates 7 to be .- .

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adjusted without having to resort to fixing members distri-buted over the length of the hoop elements, nor to seals, being yiven that a deformation by traction or by thrust is exerted on one hoop element with respect to the other.
Figures 4 and 5 are relative to an embodiment cor-responding to the mode of deFormation shown schematically in Figure 2. In Figure 4~ the end 9 of the lower hoop element is in abutment against a flange 25 of the section 11. A set screw 26 is provided to exert a traction on the end 12 of the upper hop element 5. Th:is screw 26 is oriented parallel to the tangent to the bottom point of the curve of the hoop element 5. Its head abuts on a Flange 27 of the section 11, this flange being oriented perpendicularly to the axis of the screw and offset outwardly with respect to flange 25 For a reason which shall be specified hereinbelow. The threaded part of the screw ~6 is screwed in one or more tapped hou-sings in the end 12 of the upper hoop element 5.
As may be seen in Figure 4, sections 29 are inter-posed betwen the different upper hoop elements 5, these sections Z9 ensuring a longitudinal fixation of the roofing plates 7 in the longitudinal end section 11. This section 29 is of any appropriate form, for example the one shown in Figure 4 which advantageously allows it to be fitted in the end part of the flange 28 of the longitudinal end section 11.
Figure 5 shows a variant of the embodiment shown in Figure 4, in which variant the structure 1 presents two levels of roofing plates. The traction members 30 and 31, such as screws, are preFerably respectively engaged in the ends of the upper hoop element 5 and the intermediate hoop element 8. The end section 11 has substantially the same shape as that described with reference to Figure 4, apart frorn the fact that its flange ~7 has an upper width which constitutes a support surface for the heads of the screws 30 and 31. A section 32 is preferably interposed between the ends of the different successive intermediate hoop elements.

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~ o Figures 6 and 7 relate to ernbodiments corresponding to the mode of deformation shown schematically in Figure 3.
In these figures, the end 3~ of the lower hoop element 6 is subjected to a thrust made with the aid of a screw abutting on a flange of the longitudinal end section 19. The thrust exerted by the screw 35 may possibly be eFfected by a longi-tudinally oriented section 41.
In the embodiments oF Figures 1 to 7, the end of the longitudinal sections 11 and 19 formed by a U-section or.~ien-ted towards the outside of the structure and of which thelower level is located below the level 4 of the support 2, presents means for collecting, chanelling and evacuating the water of condensation of the structure and the water which has possibly infiltrated. ~oreover, the section 11 and 19 presents discharge holes which avoid the water possibly collected by these sections flowing inside the construction.
Figure 8 shows a variant embodiment of a structure 60 in which the longitudinal supports 61 present either an inclined upper face 62 substantially parallel to the tangent to bottom point of the curve of the hoop elements at their ends9 or a substantially horizontal face, in which case the inclination is compens3ted by an appropriate bracket. As in the precedin~ case, the transverse edges of the roofing plates 7 are gripped by deformation oF one oF the superposed hoop elements on the other.
Figure 9 illustrates a deformation by traction at the ends 63 and 64 oF the upper hoop element 5, the ends 65 of the lower hoop element 6 being immobilised with respect to the supports 61, via a bracket for example Figure 10 illustrates a deformation by thrust at the ends 66 and 67 of the lower hoop element 6, the ends 68 of the upper hoop element 5 being immobilised with respect to the supports 61.
The stresses provoked by these deformations are similar to those described respectively with respect to ; Figures 2 and 3.

, , ll Figures 11 to 16 are relative to enbodiments mor~
particularly adapted to the nature oF the s~lpports 61. In figure 11, the end of the lower hoop element 6 is rendered directly fast with the support 61. In other words, longitu dinal sections such as sections 11 or 19, are absent. This connection may be effected for example by screwing the inner face of the hoop element 6, at its end, to the upper surface 62 of the support 51. A seal may posssibly be disposed at that spot. The end 65 of the lower hoop element 6 projects with respect to the suppaort 61. The deformation of the ~Ipper hoop element 5 on the lower hoop element 6, by traction, is preferably effected by means oF an intermediate piece 69 which is illustrated in Figures 15 to 17, relative to a determined embodiment of the hoop elements 5 to 6.
15~eformation by traction is eFfected by means of a screw 7û which is tightened in a tubular rib 71 on the upper hoop element 5, tapped at least at its end part. The lower part of this tubular rib i5 open and, when the hoop elements ~ are superposed, a rib 72 on the lower hoop element 6 enga-; 20 ges in the tubular rib 71. When the screw 70 is tightened, its end 73 exerts a pressure on the end of the piece 69 engaged in the rib 71. As this piece 69 abuts on the end 74 of the rib 72 of the lower hoop element 6, the pressure is transferred to the rib 72 of the lower hoop element 6 and as this lower hoop element is fast with the support 61, the screw 70 therefore e~erts a traction on the upper hoop ele-ment 5 9 abutting on the end of the piece 69. The piece 69 presents a part 75 parallel to the roofing plates and of thickness equal to or slightly less than said plates. It further comprises a rib 76 oriented towards the upper ele-ment 5 and similar to the upper part of the rib 72, this rib 76 engaging in the open tubular rib 71.
In addition, the intermediate piece 69 comprises means for applying the end of the upper hoop element 5 on the end of the lower element 6. These means act from the inside of the hoop elements, which is shown in Figures 15 and 16, or from the outside, as shown in Figure 17. In Figu-res 15 and 16, these means consist oF tWD ribs 78 and 79, in q~

the Form of a C, of whic11 the opening is oriented lateraly towards the outside of the hoop elements. These C-shaped ribs imprison the means for gripping the hoop elements 5 and 6 for the transverse edges of the plates, these means being described hereinafter.
In the case of Figure 17, the means For application of the intermediate piece 69 comprise two C~shaped ribs ~0 and 81 oF which the opening is oriented laterally towards the inside of the hoop elements. These ribs imprison the hoop elements 5 and 6 by abutting respectively on their upper face and on their lower face. The mode of assembly is identical to that described previouslyA
Figure 12 shows a variant of Figure ll for a struc-ture presenting two levels of roofing plates. The principle is similar to that which was described previously and two intermediate pieces 82 and 83 ensure connection of the ends oF the hoops elements 5 and 8, on the one hand, 8 and 6 on the other hand. The screw corresponding to the intermediate piece 82 is tightened in a tapped tubular rib in the upper hoop element 5, whilst the screw corresponding to the inter-mediate piece 83 is tightened in a tapped tubular rib in the intermediate hoop element 8. Furthermore, two longitudinal sections 84 and 85, fitted in each other, preferably present flanges which act, during tightening, like clamps with res-pect to the longitudinal edges of each level of roofingplate and maintain a constant distance betwaen the roofing plates 7, ensuring tightness at this spot between the hoop elements. These sections present, for example, a section simi:lar to that shown in Figure 1~ ith a ~liew to ensuring thightness, a seal 86, single or double, is interposed bet-ween the upper face 62 of the support 61 and the lower face of the roofing plates 7. The seals 86 are disposed between the different hoop elements and ensure tightness between the roofing plates and the support 61.
An embodiment oF the mode of deformation shown sche-matically in Figure lO is shown in Figure 13. In this case, the hoop elements abut on or are deformed with respect to a bracket 87 having a width substantially equal to that of the .

hoop elements. The bracket 87 presents a flange a8 which is rendered fast, For example by screwing, with the upper face 62 of the support 61. The end of the upper hoop element 5 is rendered fast with the other flange 89 of the bracket 87, for example by means of a screw 90. A screw 919 in combina-tion for example with 3 tapped nut 92, exerts a thrust on the end of the lower hoop element 6, possibly via an inter-mediate longitudinal section 93 of length substantially equal to the width of the hoop elements. One or more seals 94 interposed between the roofing plates and the upper face 62 oF the support 61 and disposed between two consecutive lower hoop elements ensure water-tightness with respect to the interior of the construction.
Figure 14 shows a variant of the embodiment shown in Figure 13, in the case of the structure having two levels of roofing plates. This embodiment is similar to the preceding one, apart from the fact that the flange 89 of the bracket 87 is of longer length. Furthermore, a longitudinal section 95 is interposed between the longitudinal edges oF the roo-fing plates 7, constituting the two levels, and disposedbetween two consecutive intermediate hoop elements ensuring tightness at this spot and the spaced apart relationship between the two superposed plates.
The structure 60 shown in Figure 8 further prefera-bly presents clips 96 for holding the longitudinal edges ofthe roofing plates 7. These holding clips 96 are distributed between cunsecutive superposed hoop elements. Figure 18 shows a non-limiting embodiment of a clip 96 in the form of a flattened C, one arm 97 of whi&h is fast with the upper face 62 of the support 61, for example by screwing. This arm 97 is preferably longer than the oher. The longitudinal edges of the roofing plates 7 are engaged in the groove constituted by the flattened C-shape and are consequently ma:intained therein. It should be noted that the spaced apart relationship between the horizontal arms ~f the C is deter-mined as a function of the thickness of the seals 86 or 94, '7~

so that the longit-Jdirlal edges of the plates exert a subs-tantially constant and uniform pressure on the seals, bet-ween two consecutive assemblies of superposed hoop elements.
Figure l9 illustrates an embodiment of a longitudi-nal end of the structure shown in Figures 1 and ~. At thisspot is located a pair of elementary hoop elements, an upper one 5 and lower Dne 6, between which the transverse edge 4B
of a roofirlg plate 7 is gripped from the inside. On the outside of the structure, a section 49 presents a flange 50 of thickness substantially equal to that of the roofing plate 7 and which is grippecl between the hoop elements 5 and 6. The section 49 further presents a part 51 in the form of an inverted U which is located opposite another part 52, in U-form, of a section 53 fast with the support 3. The upper and lower transverse edges of` a vertical end plate 54 are engaged in the two U-shaped parts 51 and 52 of the sections ~19 and 53. The assembly of the section 49 and more precisely of its flange 50 between the hoop elements 5 and 5 is simi lar to that of the end 48 of the roofing pl~te 7, and the flange 50 is gripped between the hoop elements during tigh-tening, which renders the end piece, constituted by the plate 54 and the section 49, fast with the longi-tudinal structure.
In addition to the deformation means which have just been descrioed, lower and possibly intermeditae hoop ele-ments also comprise guide means which are preferably conti-nuous over their length~ These guide means are generally constituted by at least one rib for one of the hoop ele-ments, which is oriented towards the other hoop element 3~ which is engaged in a groove therein. This groove may be constituted by two paralel ribs or may be obtained by sha-ping the section constituting the hoop element. It should further be noted that the guide means traverse the level defined by the roofing plates 7, between two juxtaposed plates, in order to avoid disconnection of the roofing pla-tes from the hoop elements clue to their free expansion.

Figures 20 to 2B illustrate different variant embo-diments of the cross section of the sections constituting the upper and lower hoop elements. These figures illustrate the means for gripping the p~ates, the guide means and the means for tightening the hoop elements at tlleir ends. The sections of the hoop elenents are generally symetrical ~ith respect to a substantially vertical plane and they present, on either side of this plane, means for gripping the roofing plates 7. These gripping means are preferably constituted by flanges of the sections, opposite for a superposed lower hoop element and upper hoop element, these flanges possibly being reinforced by inner raised edges. The means for tigh-tening the screws, for a deformation by traction or by thrust, are preferably constituted by a tubular rib open over the whole length of the section and tapped at each end.
In the embodiment shown in Figure 28, the means for ; guiding the lower hoop element 6 are in the form of brackets 138 and 139 fast with the support 61 and of which the dis-tance is substantially equal to the width of the lower hoop element 6. The upper hoop element 5 is guided with the aid of the traction screw oF the upper hoop element 5, this screw traversing and abutting on the flange of a bracket fast with the support 61.
Furthermore, the embodiment illustrated in Figure 24 advantageously enables the upper hoop element 5 to be made of a plurality of portions assembled end to end.
By way of example, Figure 30 shows an upper hoop element composed of three portions 144, 145, 146 assembled by screwing or by bolting end to end. This screwing may also be effected as means for deformation of the upper hoop element 5 on the lower hoop element 6. In fact, in this case, it sufFicies to provide a space between the different lugs fast with the upper hoop element 5, such as lugs 141, 142 (Figure 24) and 143 (Figure 29), and to eFfect tighte-ning or bolting for assembling the portions of the upperhoop element, similar to what is effected at the ends of a hoop element.

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In addition, as visible in particular in the embo-diments shown in Fiyures 20 to 29, the lower hoop element 6 presents one or more channels. The or each channel is defi-ned by ~he flanges constituting the gripping means, the 5 lo~er wall of the lower hoop element 5 and part of the guide means. These channels are water-tight over th~ length of the hoop element. They channel the water which might possibly infiltrate between a roofing plate 7 and a hoop element. The longitudinal support sections naturally present approprlate means for evacuating this water, for example, water outlet orifices. Thus, these channels contribute to the tightness of the structure, as they evacuate the water coming from the outside which might infiltrate between the roofing plates and the hoop elements, more particularly the upper hoop element.
~ oreover, it will be noted in Figures 20 to 29, that the means for guidiny the upper and lower hoop elements are not in contact, in order to avoid a thermal bridge between the air outside the constuction and the air inside and thus to eliminate to a maximum the risks of water of condensation forming inside the construction.
The modes of deformation which were previously des-cribed mainly use screws. However, this is not limiting and any other device for exerting a traction on the upper hoop element or a pressure on the lower hoop element is suitable.
Figure 29 shows a threaded rod 143 which is longitudinally welded to the end ot the upper hoop element 5 and whereon a nut (not shown) is screwed for tensioning the upper hoop element.By way of example, Figures 31 to 32 show a device oF
the lever and spring type 9~.
Figure 33 shows a structure 150 whose span requires ; lengths of plates which render the assembly of the structure expensive and difFicult. It presents roofing plates 7 which are juxtaposed both in the longitudinal direction and in the transverse direction. The plates are joined in the trans-verse direct:ion by means of hoop elements 151, similar to those which have been described. The join of the roofing plates 7 in the lDngitudinal directiDn i6 effected ùy means ;

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of connecting crosspieces 152. These crosspieces connect two assemblies of successive superposed hoop elements an~ their number depends on the span oF the structure. The connecting crosspieces further enable opening parts such as window 153 to be rnade, by definirlg, in a longitudinal direction, the periphery of the opening anci that of the window itself, the hoop ele~ents 151 defining the opening in the transverse direction. The hoop elementc; are of any appropriate nature and for example are shaped as illustrated in Figs 20 to 29.However, the lower hoop element presents a longitudinal tubular reinforcing charnber 173 in its lower part (Fig. 34).
Figs 34 to 36 show in transverse section the cross-piece sections and the conrlection between a crosspiece and the hoop elements, in the case of the crosspiece presenting two surface levels. Figs 34 and 35 show an upper hoop ele-mrnt 5, a lower hoop element 6 and an intermediate hoop element 8O The connecting crosspiece presents, in register with the hoop elements, an upper section 155, a lower sec tion 156 and an intermediate s~ction 154. The sections of the crosspiece, as well as the hoop elements, grip the edges of roofing plates 7.
The crosspiece sections 155, 156 and 154 are super-posed and maintained in position with respect to one another by guide means.
2S The upper section 155 i5 approximately in the form of a very open upturned V, of which the ends of the two arms 15a and 159 constitute part of the gripping means for the upper level of the roofing plates 7.
The lower section 156 is approximately in the Form 30 of a U of which the ends of the two arms 160 and 161 consti-tute part of the means For gripping the lower level of the roofing plates 7.
The intermediate crosspiece section 154 is approxi-mately in the form of an H, of which the upper and lower 35 ends of the arms 162 and 163 are respectively opposite the ends of arms 158, 160 and 159, 161 and constitute a comple-ment for the means gripping the roofing plates 7.

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~ he guide means are constituted, for the lower sec-tion 156, by a central rib 1~3, oriented longitudinally with respect to the crosspiece, which is engaged in a rib 164, in the form of an upturned U, on the intermediate element 154.
The rib 164 extends vertically by a single rib 165, in the axis of the rib 143~ and which engages in a rib 156, in the form oF an upturned U, on the upper section 155. It will be noted that the means for guicling the sections 154, 155, 155 are in the same longitudinal plane, which enables the sec-tion 155 to be directly fitted in the section 156 in thecase of one level of roofing plates.
In addition, the single ribs 143 and 165 and the upturned U ribs 164 and 156 associated therewith preferably do not present any mechanical contact with one another, so as to avoid any thermal bridges.
The ends of the arms of the ribs 164 and 166, in the form of an upturned U, extend laterally by respective flan-ges 167, 168. The upper face of the flanges 167 and 168 is located at a level equal to or slightly higher than the 2û level of the lower face of the roofing plates 7. The thick-ness of the flanges 167 and 16R is substantially less than the thickness of the roofing plates 7 disposed at their ; level. Further~ore, the lower face of the lower section 156 ~- of the crosspieces presents at least one projecting rib. ~y way of illustration, two ribs 169 and 170 have been shown in Fig. 35. The dimensions of the sections constituting the crosspiece are determined so as to be in relation with those of the hoop elements oF which they ensure connection, mainly in height. The purpose of these ratios b*tween the dimen-sions is to ensure continuity between the longitudinal and transverse ~ones of grips of the edges of the rooFing pla-tes.
The connection between a crosspiece and the super-posed hoop elements is effected by fitting or gripping the ends of the crosspiece sections in the hoop elements and between the superposed hoop elements.

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Ihe lower section 156 presents, at each end, a pro-~jecting part 171 which is constituted by the lower Face and the lower part of the arms o~ the IJ. This part 171 i5 fitted in an oriFice 172 in the lateral wall of the lower hoop element 6J said oriFice being of substantia~ly corresponding form. This orifice is pierced in the lateral wall with a w3tertight tubular chamber 173 located in the lower wall of the lower hoop element 6. The lower edge of the orifice 172 is located at a sufficient distance above the lower face oF
lû the tubular chamber 173, in order to allow the water recove red by the connecting crosspiece to flow inside the lower hoop element 6. For the upper section 155 and the interme-diate section 154, the flanges 16~ and 167 extend beyond the ends of these sections and constitute respective projections 15 174 and 175. The projections 174 and 175 are loca-ted subs-tantially at the level of the roofing plates 7 and they extend respectively between the upper hoop element 5 and the intermediate hoop element ~ and between the intermediate hoop element ~ and the lower hoop element 6.
In the projecting part 171 of the lower section 156, the projecting ribs 169 and 170 each present a notch 176 which overlaps the lower edge of the orifice 172 provided in the lateral wall of the lower hoop element 6, which avoids disconnection when the structure is assembled.
Thus, the different sections constituting a cross-piece are fitted in the hoop elements or between the hoop elements and the assembly of the hoop elements by deforma~
tion, by traction or by thrust brings about assembly of the sections constituting the crosspiece and the grip of the 3û roofing plates 7 between the hoGp elements and between the sections of each crosspiece.
The central open tubular rib of the lower section 156 may possibly be tapped at the ends so as to render this section 156 fast with a door upright, window, etc It should be noted that the roofing plates 7 are mounted directly between the sections constituting a cross-piece, without resorting to seals9 and they allow free ex-pansion.

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In the same way as the hoop elements, the crosspiece present means for collecting and evacuating possible water infiltrating from the outside,which might infiLtrate between the rooFing plates and the sections constituting the cross-pieces.
As for the hoop elements, channels are defined for the sections constituting a crosspiece and in particular the lower section 156 and the interrnediate section 154. These channels are laterally defined by the flanges of the sec-tions and by the ribs constituting the guide means. They aredefined in their lower part by the lower part of the sec-tions. It should be noted that, at the level of the lower section, the projecting part 171 extends the channels of this section inside the tight tubular chamber 173. In this way7 the running water which may infiltrate in the sections of the crosspiece towards the lower section 156 is channel-led and evacuated towards the outside through the watertight tubular chamber 173 of the lower hoop element 6, which is provided at each of its ends with rneans for evacuation to the outside.
A crosspiece is generally incined transversaly, being given that it follows the curvature of the hoop ele-ments at the point of connection. In this way, the water which may infiltrate accumulates only on one side of the crosspiece, i.e. the side oriented towards the top of the slope. In Fig. 35, it has been assumed that the left-hand side of the Fiyure is oriented towards the slope. It is therefore necessary to provide orifices for evacuating the infiltration water from the intermediate section 154 towards the lower section 156. The means for chanelling the running water towards the section 156 comprise, for the intermediate section 154, orifices 177 which are pierced in the horizon-tal arm of the H formed by this section and on the left-hand side of Fig. 35. These orifices 177 allow the water which tnay infiltrate between the upper level of the roofing plates 7 and the upper section 155 to flow in the direction of the lower part of the lower section 156.

The orifices 177 in the interrncdiate section 154 located on the right-h~nd side of Fig. 35, i.e. towards the lower level of the slope are equipped with funnels 179 wich define, with each orifice 177, a watertight channelling tube opening out oeneath the level of the roofing plates 7 of the lower level. In this way, the possible infiltration water is directly channelled towards the channels of the lower sec-tion 156 without risk of infiltration between the upper face of the roofing plate 7 of the lower levei and the lower edge of the flange 163 of the intermediate section 155.
At the ends of the intermediate section 154, stops 178 hermetically obturate the water evacuation channels defined by this section. These stops are for example asem-bled at the horizontal part of the ~-1, by screwing.
The channels of the lower section 156, and more particularly the channel oriented towards the top of the slope, channel the water towards the interior of the water-tight tubular chamber 173 of the lower hoop element 6, whence it is evacuated towards the outside. It should be noted that the channels of the lower section 156 open out in the watertight tubular chamber 173 at a level at least equal to the level which the water might reach in this chamber, so as to avoid saturation or overflow of this chamber.
In this way, tightness is ensured inside the cons-truction, as all the water likely to infiltrate between theroofing plates and the hoop elements or the crosspiece sec-tions is evacuated towards the outside via the interior of the hoop elements and the crosspiece sections.
Furthermore, the lower section 156 of the crosspiece is pre~erably laterally provided with two g~ltters lal and 182 which collect the water of condensation of the struc-ture. These gutters extend in the projecting part 171 and open out in the tight tubular chamber 173 via the opening 172. In this way, the water of condensation is also collec-ted, channelled and evacuated.
Fig. 37 schematically shows the connection betweenan opening, such as the window 153 shown in Fig. 33, and a crosspiece which defines the opening in a longitudinal di-3~

rection. This crosspiece which is indicated by reference lB3in Fig. 33l is similar to the crosspiece which was describecl with reference to Figs 34 and 36, apart from the fact that the upper section 18~ is truncated on the opening side. On the other hand, the roofing plates located on the opening side are absent and the plate of the lower level is replaced by a shim 185. At its ends, the crosspiece 183 presents the same means for fitting in the hoop elements and for gripping between the hoop element as the one described previously.
The connection between the crosspiece and the end of the opening i5 rendered substantially watertight by Means of seals which are preferably three in number and which are indicated in Flg. 37 by reference 186, 187 and 188. The seal 185 abuts on the flange 162 of the intermediate section 154 and, at each of its ends, on the upper face of the upper hoop element 5 of the fixed structure. The seal 187 abuts on the upper part of the upper section 184, as well as on the upper face of the upper hoop element 5 of the fixed struc-ture. Seals 186 and 187 are flexible and housed in cavities 189 and 190 which are defined for example by the flanges of a section fast with the end of the opening 153. These two seals thus render the lateral part of the opening structure watertight at this spot.
The seal 188 is itself preferably in the form of a lip. It is semi-rigid and abuts against the wall of the gutter 181 of the lower section 156. This seal 188 effects an insu~ation between the inner and outer parts of the cons-truction and thus avoids water of condensation inside the construction to a maximum.
Fig. 38 schematically illustrates the connection between the hoop elements 5, 6 and 8 of the fixed structure and hoop elements 191, 192 and 193 of the opening structure.
This connection comprises two U shaped sections 194; 195 disposed head to tail. The section 194 is gripped between the upper hoop element 5 and the intermediate hoop element 8 of the fixed structure whilst the section 195 is gripped between th0 upper hoop element 191 and the intermediate hoop element 193 of the window. The section 195 of the window is naturally above the section 194 of the fixed structure and overlaps one of its arms.
A seal 196 is housed in the section 195, thus avoi-ding that the rain water penetrate inside the constructionif the section 194 is filled faster than it can discharge the collectecl water.
Tightness is also ensured by two similar seals 197 and 198, the seal 19~ being gripped between the interrnediate hoop element ~ and the upper hoop element 6 of the fixed structure and the seal 197 being gripped between the inter-mediate hoop element 193 and the lower hoop element 192 of the opening. The external rounded face of seal 198 closely engages the external arm o-F the section 195 of the opening whereas the external rounded face of seal 197 closely enga-ges the external arm of section 194 of the fixed structure when the opening is closed. Thus these seals 197 and 198 allow a double isolation with respect to the exterior and the seal 198 avoids that the major part of rain water pene-trates into the section 194 provided to this end to collectand discharge this water.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Roofing structure, for covering a zone located between two supports substantially parallel in a longitudinal direction, comprising a plurality of juxta-posed roofing plates located at at least one level, hoop elements positioned transversely between said two longitudinal supports, each of these hoop elements being constituted by a pair of elementary hoop elements comprising a lower hoop element and an upper hoop element superposed on the lower hoop element, said roofing plates each having transverse edges engaged between said lower and said upper hoop elements of each pair, means for provoking the deformation of one of said superposed hoop elements by applying it under pressure against the other of said hoop elements and thus effecting gripping of said roofing plates between the superposed elementary hoop elements, and guide means across the level defined by the juxtaposed roofing plates, said guide means comprising, on one of said hoop elements, at least one rib which is oriented towards the other hoop element and engaged in a groove therein, without any contact between said rib and said groove in order to avoid a thermal bridge between the air outside the structure and the air inside.

2. Structure according to Claim 1, wherein the guide groove is constituted by a tubular rib open over the whole length of the section and tapped at each end, said groove being a part of the means provoking a deformation of one of the superposed hoop elements.

3. Structure according to Claim 1, comprising connecting crosspieces between said hoop elements and extending perpendicularly thereto, said connecting cross-pieces being composed of superposed sections comprising mutual guiding means between which are engaged the longitudinal edges of said roofing plates; and said means provoking deformation of one of said superposed elementary hoop elements with respect to the other also provoke the assembly in compression of said superposed sections constituting said connecting crosspiece.

4. Structure according to Claim 3, wherein the lower section of a crosspiece comprises, at each of its ends, a projecting part fitting in a corresponding orifice in the lateral wall of the lower hoop element, this orifice being at a height ensuring continuity between the zone of gripping of the transverse edge of a plate between the hoop elements and of its longitudinal edge between the sections of the crosspiece, the projecting part presenting anchoring means with respect to the lower hoop element.

5. Structure according to Claim 4, wherein the projecting part has a cross section substantially in the form of a U and, on its lower face, at least one notch fitting on the lower edge of the orifice provided in the lateral wall of the lower hoop element.

6. Structure according to Claim 3, wherein the upper section of said connecting crosspiece has at each end a projecting part of thickness less than or equal to the thickness of said roofing plates and the upper face of said upper section is located at the level of the upper face of said roofing plates and is engaged between two superposed hoop elements.

7. Structure according to claim 6, wherein the lower section of said connecting crosspiece includes means for channelling the water of infiltration towards said projecting part which ensures communication with the hollow part of said lower hoop element.

8. Structure according to Claim 3, wherein said upper section is provided with a guiding rib of upturned U section; a rib on said lower section being engaged in said guiding rib; and the part of said upper section projecting inside said hoop elements being constituted by the extension of the lower part of the rib of said guiding upper section.

9. Structure according to Claim 3, comprising at least two superposed levels of roofing plates having transverse edges engaged between superposed upper, intermediate and lower elementary hoop elements and having longitudinal edges engaged between superposed upper, intermediate and lower sections of a connecting crosspiece; said intermediate section being pierced with orifices ensuring flow of the water of infiltration towards the lower section of said crosspiece; and at each end of said intermediate section means hermetically obturating the water evacuation channels defined by this intermediate section.