US 3611649 A
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Description (OCR text may contain errors)
Oct. 12, 1971 n. MULLER ETAL 3,611,649
ROOF COVERING SUITABLE FOR SUSPENSION ROOFS Filed Aug. 8, 1969 3 Sheets-Sheet 1 INVI'IN'I'UHS DIETER MULLER FRIEDRICH HANSTEIN Oct. 12, 1971 n. MULLER ETAL 3,611,649
ROOF COVERING SUITABLE FOR SUSPENSION ROOFS Filed Aug. 8, 1969 3 Sheets-Sheet 2 :uiiuiiiiiiiiii/ FIG. 2
LN'VI'ITVI'UHS DIE TER MULLER FRIEDRICH HANSTEIN ROOF COVERING SUITABLE FOR SUSPENSION ROOFS Filed Aug. 8, 1969 Oct. 12, 1971 o. MULLER EI'AL 3 Sheets-Sheet 5 FIG. 3
WVIu'IVIO/(S MULLER ATTORNEYS DIETER FRIEDRICH HANSTEIN I UHHHH HUM" n "H HUN n" HUM unflnnnfl Pllllllllilllllllllll IIIIII 6 4&,%wrMuL //ll/fl United U.S. Cl. 5283 Claims ABS v1 CT OF THE DISCLOSURE An improved suspension roof comprising a polygonal network of bar members, the length of which is substantially equivalent to the length of a side defining a mesh length in a network of mesh members of said suspension roof, at least three of said bar members pivot-ably joining in an intersection member, means for securing said bar members to said intersection member, means for attaching said intersection members to said mesh members, and a covering member in a shape of said polygonal fittingly engaging with said bar and intersection members and supported by said bar members. The described roof structure allows the employment of plastic covering members which may readily be deformed by the stresses imposed on the roof and at the same time provide an easily constructed structure.
This invention relates to roof construction, more particularly to roof covering construction suitable for suspension roofs. Suspension roofs having a variety of cable network supports are known. These cable nets or networks are covered by tarpaulin, plates or the like covering. Moreover, when the covering consists of individual plates, these can be connected together at the joints to form a monolithic or unitary roofing.
For structures of a very large base or surface area, a roof construction consisting of a cable netting has recent- 1y been used which from the ground or a surrounding wall is stretched over the entire base or surface area to be covered and is raised in the manner of a tent by props or columns at one or more points. This construction permits the roofing of areas of practically any desired shape. The inside height can be adapted to the specific requirements as to space by a suitable number and height of the props or columns and these can be selected to be different at different points of a building.
The building of such a roof construction is very simple as compared with the expense heretofore required for large buildings. The steel cable network is placed together flat on the ground, and raised up on the support columns or masts which have previously been erected and anchored in place.
Insofar as such structures are intended only for temporary use as is frequently true for instance for the covering of fairs, exhibitions or the like, a roofing of tent canvases, sheets or the like can, at low expense, be placed over or below the cable netting. For the covering of railways, swimming pools, sports stadiums, factor buildings, large markets or storage places, a permanent waterresistant roof is however indispensable.
An irregular curvature of the cable-netting structure has made it seemingly necessary up to now to use a covering material which can be adapted by its elasticity to the specific curvature of the roof surface or in its condition of use can elastically participate in deformations which take place. Such a roof covering can be built up for instance of a Wood framing, a sealing sheet or ordinary shingles of asbestos cement, wood, etc. The mounting of such a roofing requires a great deal of manual work and thereby does away with the advantage of the cheap substructure which can be used with these roofs.
Furthermore, the sole use of tarpaulins, sheets or the like, in any event does not, in the long run satisfy the demands which are to be made on such a roofing.
The object of the present invention is to achieve a roof covering suitable primarily for suspension roofs and particularly cable nettings formed in tent-like manner, which can be constructed in a simple manner and as well as being permanent and nevertheless can participate in the deformations which occur during construction or use without impairment of its water-tightness.
In reference to the drawings, the present invention is illustrated in the figures, wherein like numbers designate like elements or elements functioning in substantially similar manner and wherein:
FIG. 1 is a perspective drawing of the novel roof construction;
FIG. 2 is a perspective drawing of an intersection member of the present invention with certain elements added and the whole illustrated in an expanded perspective;
FIG. 3 is a crosssection of the intersection member along the axis AA of FIG. 2;
'FIG. 4 is a cross-section of the intersection member along line B-B of FIG. 2.
Referring now to the drawings, the invention is accomplished by a roof covering consisting of a polygonal network of rigid bars 2 illustrated in FIGS. 1 and 2, the length of which bars correspond essentially to the length of the side of the cable 11 netting: meshes shown in FIG. 2 or a multiple thereof and which bars 2 are pivoted to each other at the points of intersection at intersection members 3 shown in FIG. 1, the spaces between the bars being covered by panel-shaped or shell-shaped building elements 4, preferably of light building materials, which materials are adapted in their contour to the shape of the meshes and are supported movably with respect to the bars in the plane of the roof.
The bars may be connected at their ends to connecting pieces or intersection members shown in detailed manner in FIG. 2 provided in the region of the intersections, or better still, the bars and the connecting pieces have a trough-like or U-shaped cross-section shown in FIG. 3 which is open towards the top and into which there engage the covering elements 4 which are provided with a downwardly bent edge 4a.
In the 45 wedge which is formed by an intersection of an imaginary extension of the bars, the connecting pieces or intersection members 3 of themselves are developed in the manner of a bellows 5 aligned radially to a centerpoint of the intersection member.
The extensions 3a of the intersection member are shaped to extend in trough-like manner enveloping from below the bar ends and seal the same in water-tight manner. This can suitably be eifected in the manner that the intersection members 3 consist of an elastic material, for instance rubber, plastic or the like and are provided with steel inserts 7 embedded in the intersection member and shown by dashed lines in FIG. 2 to take up the bar forces. These steel inserts may suitably consist of striplike parts 7 arranged on or in the bottom of the intersection member and connected at one end to the end of the bar, for instance bolted to same such as shown in FIG. 4 and on the other end pivoted to a ring 8 illustrated in FIG. 2 lying in the central part of the connecting pieces or intersection member. The pivoting of this insert is achieved by suitable means such as another, small ring 9 perpendicular to the plane of the large, central ring 8, which small ring is attached to the ring 8 and insert 7.
The extensions 3a of the intersection members can be provided with sealing lips as shown in FIGS. 3 and 4 attached or shaped thereon; the upper edges of the bars 2 as well as the intersection members can bear sealing strips 10 shown in FIG. 3 for the placing of the covering elements 4 thereon.
The roof covering in accordance with the invention is so constructed on the basis of its very design that it is capable of taking up or distributing in the network itself the stresses which occur. However, it can also be laid on an existing cable network roof and fastened to same. In such case, the bars advisedly lie above the cables and the intersection members 3 in the region of the cable junctions.
The covering elements 4 themselves are advantageously cupola-shaped shown partially in FIG. 3 with an edge strip 4b extending in the plane of the roof and a downwardly bent edge perpendicular shown in FIG. 3 to this plane.
In accordance with the invention the main advantage of the present roof covering resides in its development as a polygonal network with bars pivotly connected at the points of intersection and covering elements which correspond in contour and size to the meshes of the netting. As a result of this development, the roof covering is movable in all directions, at least in the orders of magnitude encountered with these roofs in respect to the angular deformations of the netting or the vertical displacements of the individual junctions forming a mesh. These deformations are absorbed by the covering material which material is elastic within certain limits or are compensated for by the movable support of the covering elements with respect to the network bars.
In accordance with the invention, the roof covering 4 consists of a large number of similar individual units which are prefabricated in a simple manner and assembled at the place of erection. The network formed therefrom may have triangular, rectangular, and particularly and preferably square, pentagonal or even round shapes, but at all times identical meshes. Only with roofs of complicated shape, such as for instance tent roofs are structural parts necessary which differ to a slight extent from the normal regular polygonal development of the meshes. In the case of a steel cable netting with network fields at right angles when flat, the tent-like erection leads at the point of intersection to an angular displacement which the covering elements must also be able to take into account.
As can be envisioned from the disclosure herein, even in the case of complicated shapes of roof, after erecting more than 80% of the network, the mesh fields remain substantially at right angles and that particularly simple roofs substantially have only right-angle fields. If the bars and the intersection members are sufficiently wide, i.e. have a width equal to about 10% of the mesh width, then the angular tolerance is sufficiently large to cover 85 to 90% of all network fields with square cover elements. Only the remaining 10 to of the fields are covered with covering elements of approximately diamond shaped section. Since a certain angular tolerance exists also for this construction, it is possible to utilize only a few standard shapes of covering elements.
In further reference to the drawings, and as an amplification of the foregoing, the network as illustrated consists of a network of steel cables 11 with square meshes when the roof is flat. This development has the advantage that for the covering only square covering elements 4 are required and that the individual parts 4 of the roof covering can be kept of smaller dimensions since the forces which occur are taken up by the substructure. Fundamentally any desired netting structure is possible, as it can be completely independent of the existence or development of the supporting netting structure. Thus, as mentioned before, the meshes of the roof covering network can be triangular, square, hexagonal, octagonal or even round.
The bars 2 of the network are developed in the embodiment shown in FIG. 2 by way of example as rails or channels of U-shaped profile open upwardly, i.e. towards the top. Thus, these bars simultaneously serve to lead rainwater away on the inside of the rails. Moreover, in order to obtain temperature control by spraying water onto the surface of the roof covering or else by spraying water or suitable chemicals to contribute to the fire resistance of the roof covering these bottom channels may be produced with fluid pipelines or conduits. The crosssection of the bars 2 can be, besides the trough shape with an upwardly opening channel, also polygonal, round or more or less W-shaped. For the fastening of the bars 2 to the steel cables 11 existing cable connectors such as shown in FIGS. 2 and 4 as item 12 can be used or sheet metal clamps employed which surround the steel cable 11. These cable connectors 12 are connected, e.g. by bolting with a bolt 13 to the bottom of the bars 2. The cable connector 12 has a spacer 12a provided for proper securing of the bars 2 to the cable. The length of the bars 2 corresponds to a planar dimension of a single mesh of the netting or a multiple thereof.
In order to obtain a roof covering which is airtight and watertight an elastic sealing strip 10 is placed on the arm ends of the bars 2 which strip 10 is preferably tapered upwardly to a sharp point or tongue.
The connecting pieces 3 or intersection members have the function of connecting the bars which come together at anetwork intersection point (hence, an intersection member), in a manner which causes the same to be capable of bearing tensile stresses and distribute these loads as well as be watertight. Since the angles at which the bars 2 come together are not the same at every point of the network, the connecting piece 3 must be designed to be pivotable in such a manner that it adjusts to the specific angles of the intersection of the bar network and can participate in changes thereof.
In order to satisfy these requirements, the intersection members preferably consist of an elastic material in which there are embedded the previously discussed steel insert to take up and transmit the tensile forces. As material for the connecting pieces, rubber, chlorinated rubber, silicone rubber, polyurethane elastomers, non-rigid PVC or polyethylene are suitable. The steel inserts preferably consist of strip-shaped parts 7 which are brought on one end into force locked connection with the bars 2, for instance by bolting as shown in FIG. 4, and on the other end are pivotally connected to a ring 8 which is arranged at the centerpoint of the intersection member 3.
The use of an elastic material for the intersection member makes possible in simple fashion a water-impermeable seal with respect to the bars 2 which terminate at the intersection member. In this connection, the contact surface between the extensions 3a of the intersection member 3 and the bars 2 are provided with ribs 14, i.e. these are advisedly transversely ribbed so that sealing ribs 14 are produced. These ribs are shown in FIGS. 2 and 4. The connecting of the bars 2 with the intersection member 3 is effected in the examples as shown by bolts 13 which serve at the same time to fasten the cable clamps 12 to the steel cables 11. The bars 2 are provided at their ends with slots 2a in order to facilitate adaptation to different lengths. For the bolt attachment, there can first of all be provided a cover plate 15 which is held fast by nuts 16. When the bolts 13 are used at the same time for fastening the cover elements a resilient holding strap 17 is placed to span the U-shaped channel which is held fast by another nut 16 and a covering cap nut 18 as shown in FIGS. 1, 2 and 4.
In order to make possible in theregion of the sealing of intersection members 3, adaptation to possible changes in angle of the network, gussets or bellows 5 between the extensions 3a are preferably developed in the illustrated form directed radically to the centerpoint of the intersection member 3. In order to obtain suflicient rigidity in these regions also, steel inserts in the form of round rods 19 shown by dashed lines in FIG. 2 can be provided here also, one end thereof extending into the protruding parts of the bellows 5 and the other end being fastened to the central ring 8. The upper edge of the intersection member 3, in the same way as the sealing strips of the bars 2, can be provided with an upwardly tapering tongue which serves to provide a seal for the covering elements by bearing against the same as shown in FIGS. 2 and 4.
The intersection member 3, instead of being made of elastic materials with steel inserts, can also be made of thin metal sheets, for instance by deep-drawing. Suitable metals are zinc, aluminum, copper, or else, lead. The extensions are in this case covered on their inside with an elastic sealing material and supported on the outside by a strong steel strap, in this embodiment the bellows are developed with sharp edges and in such a manner that an inwardly extending fold in the bottom passes into an outwardly protruding fold in the upwardly extending channel part.
The actual roof covering is formed by the covering elements 4. These consist preferably of an opaque to glassclear weather-resistant material. Acrylic plastic having glass-like properties is excellently suited. Other suitable materials are sheet metal, asbestos cement, wood-fiber chipboards, plywood or fiberboard, in which connection the latter must be provided with a weather-resistant coating, for instance of tar. Glass windows can also be inserted in covering elements of this type.
The covering elements 4 are advisedly developed in cupola shape in order to obtain suificient rigidity. As previously mentioned, the cupolas extend towards the edges. An edge strip 4b extends in the plane of the roof; and another edge strip 4a, an extension of the first, is bent downwardly perpendicular to this plane. With this cupola shape and with an angular cross-section, excellent rigidity is obtained in the plane as well as perpendicular thereto.
When the covering elements 4 consist of translucent to transparent material, for instance of acrylic plastic, having glass like properties, it may be advisable to make a part of the roof colored, clouded or opaque in order to prevent excessive radiation from the sun. It may also be advisable to install in the roof covering a pipeline or conduit preferably extending in the hollows of the bars 2 or below same in order to provide an opportunity for spraying water or other similar cooling materials onto the roof surface through nozzles. In this manner good temperature control of the covered space can be obtained. Furthermore, it is possible, when roofing closed, heatable premises to use double-shell covering elements and also to develop the bars or channels 2 as multiple shells or provide them with an insulating covering.
The four corners of the covering elements will not always lie in a plane in the finished roof covering or when the roof is in use; roof motions will occur, particularly as a result of external influences such as wind, snow or the like, resulting in a canting of the covering elements. The stresses which occur in this connection are taken up without damage by the materials employed, provided the curvature of the cupola is not too great. For particularly strong stresses, available are suitable covering elements which are made of pre-stretched acrylic material.
The manufacture of covering elements from acrylic material does not afford any technical difficulties even with corner angles of other than 90. These elements are made of fiat slabs by heating these above the softening point of the employed acrylic and pressure blowing into the shape of a cupola with compressed air through a frame which fits at edges of the element. Similarly, these elements can be vacuum drawn into the desired shape. After cooling, these elements retain the cupola shape. Cupolas of different corner angles can be made by means of a frame whose sides are pivotly connected at corners and which frame can adjust itself accordingly to any desired angle.
The mounting of the roof covering in accordance with the invention is extremely simple. In the example described by way of illustration in FIGS. 1, 3 and particularly FIG. 4, four cable sockets 12 with upwardly extending screw bolts 13 are screwed onto the steel cables at each point of intersection of the steel cable network which is spread out flat on the ground. The intersection members 2 are now attached in such a manner that one screw end extends through a borehole 3b in each of the four extensions 3a of the intersection member. Thereupon the bars 2 are inserted in such a manner that these extend at both ends into a separate intersection member and guide the screw ends through the slots Zn on the bar ends. For the fastening of the bars, washers, lock washers, nuts and lock nuts are placed on the same. Only after this preliminary work is the steel cable netting placed on the supporting masts and anchored. In this connection, at the same time, the intersection members are shaped corresponding to the corresponding netting angles. The roof structure is then immediately ready to receive the covering elements. After the covering elements 4 are placed in the bar or channel member 2, holding straps 17 preferably consisting of stainless steel are merely placed over the bolt ends and fastened by a nut. The bolt end is advisedly protected with a bolt cap nut 18.
What is claimed is:
l. An improved suspension roof comprising a network of mesh members and a polygonal network of bar members, the length of which is substantially equivalent to the module length of a side defining a mesh length in the network of mesh members of said suspension roof, at least three of said bar members pivotably joining in an intersection member, means for securing said bar members to said intersection member, means for attaching said intersection members to said mesh members, and a covering member in a shape of said polygon fittingly engaging with said bar and intersection members and supported by said bar members.
2. The improved suspension roof as in claim ll wherein said bar members define an upwardly and exteriorly to said roof extending U-shaped channel.
3. The improved suspension roof as in claim 2 wherein on said bar member a sealing lip is provided on each of said upturned edges of said U-shaped channel.
4. The improved suspension roof as in claim 2 wherein bridging means are provided for spanning the legs of said U-shaped channel to secure said roof covering to said bar member.
5. The improved suspension roof as in claim ll wherein the intersection member is comprised of a center piece means to which said means for securing said bars are pivotably engaged, gusseting means to accommodate structurally occurring displacement of said bar members relative to each other, first sealing means for tightly engaging said bar members, and second sealing means for engaging said roof covering.
6. The improved suspension roof as in claim 5 and wherein the intersection member is an elastic material and the centerpiece means and the means for securing said bar members to said intersection member are a metal insert in said intersection member.
7. The improved suspension roof as in claim 5 and wherein the means for securing said bar members to said intersection member is a steel strip pivotably engaged to said centerpiece and rigidly secured to said bar members.
8. The improved suspension roof as in claim 1 wherein the polygonal network is defined by cable members and the intersection members are attached thereto at intersections of said cable members.
9. The improved suspension roof as in claim 8 and wherein the bar members are attached to said intersection members and placed above said cable members.
10. The improved suspension roof as defined in claim 1 and wherein the covering member has a first edge strip extending in a plane in which the roof lies, and a second edge strip integral with said first edge strip extending per- 7 pendicular to said plane defined by said first edge and 3,327,443 6/1967 Gay et a1. 52-460 fittingly resting on said bar members. 3,410,039 11/1968 Brezina 52-83 X 3,488,899 1/1970 Schultz et al. 52-14 References Cited UNITED STATES PATENTS 5 PRICE C. FAW, JR., Primary Examiner 3,063,521 11/1962 Fuller 528l X X'R' 3,090,613 5/ 1963 Bechtold 52-80 X 3,323,820 6/1967 Braccini 5281 X 5214, 80, 222, 639