US3667173A

US3667173A - Hanging roof structure

Info

Publication number: US3667173A
Application number: US38829A
Authority: US
Inventors: Karl Lennart Billgren
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-05-19
Filing date: 1970-05-19
Publication date: 1972-06-06
Anticipated expiration: 1989-06-06

Abstract

A hanging roof structure in which the roof covering is supported by a plurality of lines and tensile forces acting in the lines are taken up by an annular beam of lattice construction, thereby relieving supporting pillars from bending moments.

Description

United States Patent Billgren [4 June 6, 1972 54] HANGING ROOF STRUCTURE FOREIGN PATENTS OR APPLICATIONS [72] Inventor: Karl Lenn'art Billgren, grev Magnigatan 4, 639,689 12/1936 Germany ..52/83 v Stockholm, Sweden 214,193 3/1958 Australia ..52/648 22 Filed: May 19, 1970 OTHER PUBLICATIONS [21] A No; 38,829 Architectural Record Sept. 1936 pg. 236, 237

Civil Engineering, July 1958, pg. 95

[52] U.S. Cl ..52/83, 52/80, 52/648 Primary ExaminerAlfred C. Perham 51 1111. C1. ..E04b 1 342, E04b 1/347 Alwrney-cushmam Darby & Cushman [58] Field of Search ..52/18, 22, 80, 81, 82, 83,

52/246, 648 [57] ABSTRACT A hanging roof structure in which the roof covering is sup- [56] R f Ci d ported by a plurality of lines and'tensile forces acting in the 1 lines are taken up by an annular beamv of lattice construction, UNITED STATES PATENTS thereby relieving supporting pillars from bending moments.

1,141,967 6/1915 Lacoste ..52/82 I 7 Claims, 3 Drawing Figures 20 15 21 23 11 I 3 7 E 31 11 11 13 11 13 1113- I PATENTEnJuu "6 m2 SHEET 2 0F 2 The present invention relates to a hanging roof structure which is supported about its periphery by a load dispersion or equalizing ring of lattice construction and carried by support columns or external wall structures, the central portion of the roof covering being supported by an attachment means which in turn is supported by lines stretched against attachments on the load dispersion ring, and relates in particular to hanging roof structures for buildings of a temporary nature.

In the case of temporary building structures, it is a common desire to maintain construction costs as low as possible. One disadvantage in this respect with hitherto known buildings of the type referred to is that the roof structure is relatively expensive. Although very wide free spans can be obtained with hanging roof structures, the walls of the building spanned by the roof are highly subjected to force moments and lateral forces and must either be anchored very firmly to the ground, the lateral forces then being taken up by the ground attachments, or the walls must be supported with external braces, for example by passing the roof support lines over the walls and anchoring said lines separately in the ground outside the walls.

This incurs additional costs for the ground attachments required to secure the lines.

The object of the present invention is to eliminate the aforementioned disadvantages and is mainly characterized by the fact that the load dispersion ring is in the form of a torsionally rigid lattice structure and that the attachments by which the support lines are secured to the central roof attachment means are situated at the upper outer periphery of the load dispersion ring while at the lower inner periphery of said ring are arranged attachment means for the lines which support the roof covering between the load dispersion ring and the central attachment means. The load dispersion ring is suitably circular in shape with the lines which support the roof arranged radially in respect of said ring. The load dispersion ring is then able to take up all lateral forces or bending moments and the walls are no longer subjected to moments or lateral forces and hence only vertically acting forces need be taken into account when erecting the walls of the building structure. The actual roof covering will hang between the central support attachment means and the outer walls of the building structure, to which walls the peripheral portion of the roof material is suitably attached and supported directly by the load dispersion ring.

The load dispersion ring is constructed of prismatic lattice units which, when seen in plan view, are triangular in shape and each of which include two inner junction points, 9, 9 situated in an upper plane and turned towards the center of the ring and an outer junction point 8 which is remote from the center of said ring, and corresponding junction points situated in a lower plane. The lattice units are secured adjacent to each other and have common upper and lower inner junction points, and corresponding junction points in the two aforementioned planes are mutually connected by means of substantially vertically extending stays. Each upper outer junction point is connected with both of the associated inner lower junction points by means of a diagonal brace and all inner lower junction points and all inner upper and/or all outer upper junction points are mutually connected by means of horizontal braces, which form peripheral annular bars of the load dispersion ring. The lines which support the attachment means are secured to the upper outer junction points and the roof covering supportlines are secured to the inner lower junction points of the load dispersion ring.

Because the roof can be constructed so that no lateral forces need be taken up on the roof structure support means, the load dispersion ring can be supported in any expedient manner, for example by means of support columns, which enables the building to be designed as desired and places no restriction on the positioningof the walls beneath the roof. Alternatively, the load dispersion ring can be supported by a corrugated wall, in the form of vertical extensions of the outer triangular sides of the lattice units. In addition to the aesthetic value of such a wall, the advantage is also obtained whereby acoustic focus points, which otherwise occur in round or circular building structures, are partially or completely eliminated.

It is suitable that the roof covering support lines are arranged to support the roof continuously between the central support attachment means and the peripheral portions of the roof structure either by causing the roof to rest on the lines or by securing the roof directly below the same.

In accordance with a suitable embodiment of the invention, additional lines are extended between the load dispersion ring, for example from the attachment points of the upper lines, and the points situated between the ring and the central roof support attachment means, which lines prevent the roof from sagging at any point, down to or beneath the level of the peripheral portion of the roof. The object of the extra lines is to cause the roof to slope, to enable water to drain away from the same. 1

The invention will now be described in more detail with reference to the following drawings, which shows an embodiment of the invention in the form of a circular structure,

FIG. 1 showing a sector of a building structure in plan view,

FIG. 2 shows the left portion of a diametrical vertical section through the building structure and FIG. 3 shows a sector of the building structure seen in perspective from beneath and from without.

The cylindrical roof of the building structure is provided in the center thereof with a rigid ring or plate 3 carried by lines 5, which are extended between the plate 3 and a load dispersion or equalizing ring 7 which rests on the outer wall 2 of the building structure. The ring 7 is in the form of an annular space lattice beam comprised of a number of prismatic units which, when seen in plan view, are triangular in shape. Each lattice unit has three junction points located in an upper plane in the beam, namely an outer point 8 and two inner points 9, 9 (FIG. 3). Vertically beneath these junction points, the lattice units are provided with a further three junction points 18 and l9, l9 situated in a lower plane on said beam. Outer and inner vertical stays or

posts

11 and 13 are adapted to connect in pairs corresponding junction points located in the two planes. The lattice units are arranged adjacent each other so that each inner vertical post 13 is common to the

junction points

9 and 19 of two adjacent lattice units. Mounted between the

points

8 and 9 are horizontal stays 15 while a diagonal stay 20 is mounted between the points.8 and 19. All points 8 are mutually connected by horizontal stays 25, which form an outer upper peripheral annular bar of the lattice beam structure. Internal upper and lower peripheral annular bars are formed in a similar manner by stays 2] and 23, which connect together

points

9 and 19, respectively. If extra rigidity is desired, the

comer points

18 and 19 can also be connected together by means of a horizontal stay 17. In extreme cases, particularly in the case of very large structures, a lower, outer connecting annular bar may also be arranged between the junction points 18.

All of the lattice units in the lattice beam structure have the same size. The lattice units can suitably be prefabricated in the factory in a manner whereby they can be transported unassembled to the erection or building site and there assembled. in this connection, the two outer, vertical lattice faces of the units can be pre-manufactured in the factory and transported in a collapsed condition to the erection site together with the two

inner connecting stays

21 and 23 and the upper, outer stays 25 in loose units. The different members can then be bolted together.

The lines 5, which support the central roof covering support attachment means 3, are secured to the load dispersion ring at the upper outer junction point 8 of the lattice units, i.e. at the upper ends of the posts 11. The peripheral portion of the roof covering 1 is secured in a suitable manner between the lattice girder and the outer wall 2 of the building structure. The roof is preferably circular in shape and is extended as far as the posts 11, whereby a circular suspended guttering can be readily installed around the edge of the roof for the purpose of draining rain water. In order to support the roof covering 1 so that it need not beself-supporting between the outer wall and the center 3, a group of lower lines 27, of which a number are shown by dotted lines in FIGS. 1 and 3, are extended between the center attachment means 3 and the junction points 19 of the lattice units. The lines 27 can be drawn under the roof covering 1, which may comprise for example, a glass fiber reinforced plastic material or a laminated wood, whereby the roof covering rests directly on the lines 27. Alternatively, the roof covering 1 may be arranged immediately beneath the lines 27 and attached thereto by means of the requisite number of attachment means.

The central roof support attachment means 3 is situated at a level which is higher than the under side of the lattice girder, i.e. the level of the peripheral portion of the roof, thereby enabling rain water to drain. The height of the lattice girder, and therewith the height of the attachment means 3, must be increased if the diameter of the roof is increased. In order to prevent excessive heights of the lattice girder with wide spans, it is convenient to arrange a further batch of lines 29 (HQ 2) to extend between the upper outer junction points 8 of the lattice units, i.e. the same attachment points for the upper support lines 5, and attachment points 31 of the roof covering arranged in a ring between the attachment 3 and the outer wall 2, for example of a radius reaching to two-thirds or threefourths of the radius of the outer wall. This prevents the roof material from sagging to a lower level than that of its outer peripheral portion.

, If, for example, the building structure is so positioned that the upper surface of the roof is liable to be subjected to wind suction it may be desirable to anchor the roof to prevent it from moving upwards. The roof can be anchored in this respect by means of lines 33, which are arranged to extend radially from the attachments in the roof covering, for example from underneath the aforementioned line attachments 31, to attachment points on the outer wall of the building structure. The lines 33, however, need not be provided in the same number as the remaining lines and neither need they be uniformly distributed over the whole building structure. Normally, only certain portions of the roof are subjected to wind suction and it is sufficient only to anchor these portions by lines 33.

The lattice units are suitably pre-fabricated in one or more standard sizes, according to a system of modules. When constructing a roof structure, in accordance with the invention, it is then only necessary to join the requisite number of lattice units in juxtaposed relationship to form a ring of the requisite diameter in order to obtain a covered floor surface. The reason why a plurality of sizes maybe desirable is that the loads acting on the lattice units greatly increase with increased building dimensions, whereby larger buildings require very strong lattice units, which in turn would be unnecessarily heavy, clumsy and expensive for small building structures.

7 Only a few sizes, however, are necessary. By means of the aforementioned module system, the roof structure can now be constructed in principally the same manner for buildings which vary greatly in size. The smallest roof which can be constructed in this way is triangular in shape, in which the sides of the triangle are formed by the inner faces of the prismatic lattice units. The roof thus obtains the same size as the lattice units. The upper limit in size is a question of dimensioning, but it has been found that buildings containing essambly halls seating eight thousand people, for example, can be provided with a roof constructed in accordance with the invention without losing the adyantages gained by a light and inexpensive lattice work structure while at the same time retaining all the remaining advantages of the roof structure One of great advantage with the roof structure, according to the invention, is that the shape of the actual building when seen in plan view is not dependent on the shape of the roof, which is suitably circular. The shape of the building in plan can thus be of any expedient form, for example semicircular, triangular or rectangular and the building may be open or closed as desired. This advantage-is obtained by the fact that the lateral forces to which the

roof support lines

5, 27 and possible also lines 29 are subjected are all taken up and dispersed in the form of peripherally acting forces by the load dispersion ring 7. The load or force dispersion ring thus transmits no lateral forces or moments to the walls of the building, and hence the ring, if desired, can be supported on columns, whereby the walls of the building can be arranged in any desired manner. If the floor area covered by the roof is to be used to a maximum for a closed building volume, the building is provided with a circular outer wall of the same radius as the outer posts 11 of the lattice units. Circular buildings of this type have the disadvantage of acoustic focus points. This can be avoided if the outer'wall of the building is corrugated instead of being smooth, for example by extending the outer and inner posts 1 1 and 13, respectively, of the lattice units to form support pillars, between which corrugated outer walls can be arranged. If so desired, the building can be erected on sloping ground.

Further connecting stays can be arranged between the outer lower junction points 18 of the lattice units. if an extra rigid lattice girder is desired, for example if the roof is to be designed to carry heavy loads of snow. Snow loading can otherwise be eliminated in a known manner, by using a roof material which is heat permeable, so that the snow can melt and drain away.

The roof can be erected in position in a number of different ways. For example, the lattice girder can be assembled together at its position on top of the walls of the building,

' whereafter the roof covering is either secured to the lattice girder or to the outer wall of the building structure. The center section of the roof with the central support attachment means 3 is then lifted to the intended height by means of a central pole or lifting jack, whereafter the support lines are tightened in sequence to the required tension. Alternatively the lattice girder can be assembled on the ground before erecting the walls of the building and the whole roof structure completed at ground level. The completed roof structure is then lifted on jacks to the required height and the walls thereafter erected in position.

If the load on the support lines 5 is too great, the number of lines may be doubled by arranging extra support lines between the lines 5. The extra lines are then secured between the central attachment means 3 and the junction points 9.

What I claim is:

1. In a hanging roof structure of a type which is supported at its periphery by a load dispersion ring of lattice construction and which is supported at its center by an attachment means, with the attachment means being supported by supporting cables secured between the load dispersion ring and the attachment means, so that the structure can function as a roof covering when carried on support columns or an outer wall of a building being covered thereby, the improvement in said roof structure comprising:

a load dispersion ring in the form of a torsionally rigid, three-dimensional lattice structure constructed of prismatic lattice units which, when seen in plan view, are triangular in shape, each lattice unit further including:

two inner comer junctions (9) facing the center of the load dispersion ring and an outer comer junction (8) facing away from the center of the load dispersion ring, all of said junctions being located in an upper plane,

two inner (19, 19) and one outer (18) corner junctions located in a lower plane and corresponding to the junctions described for said upper plane,

substantially vertically extending struts (11, 13, 13) connecting said corresponding corner junctions in said upper and lower planes,

diagonal braces (20, 20) connecting each upper outer comer junction (8) with each lower inner comer junction (19) of a lattice unit,

said lattice units being secured adjacent to each other with common upper and lower inner comer junctions,

horizontal braces connecting said lower inner comer junctions to form a lower inner peripheral ring (23) of said load dispersion ring,

horizontal braces connecting said upper inner comer junctions to form an upper inner peripheral ring 21 of said load dispersion ring, and

said supporting cables extending between said central attachment means and said load dispersion ring being secured to said upper outer comer junctions and to said lower inner corner junctions.

2. The roof structure of claim 1 and including horizontal braces connecting said upper outer comer junctions (8) to form an upper outer peripheral ring (25) of said load dispersion ring.

3. The roof structure of claim 1, characterized in that 'said supporting cables strung between said central attachment means and said lower inner corner junctions of the load dispersion ring support a roof covering continuously with the roof covering resting on the supporting cables.

4. The roof structure of claim 1, characterized in that said supporting cables strung between said central attachment means and said lower inner comer junctions of the load dispersion ring support a roof covering continuously with the roof covering being attached directly beneath the supporting cables.

5. The roof structure of claim 1, characterized in that said lower outer comer junctions are connected together with the aid of horizontal braces which form an outer lower circumferential ring of the load dispersion ring.

6. The roof structure of claim 1, characterized in that said load dispersion ring is supported by a corrugated wall in the form of vertical extensions of the outer faces of the triangular lattice units.

7. The roof structure of claim 1, characterized in that additional cables are strung between said load dispersion ring and points situated between the load dispersion ring and said central attachment means to prevent a roof covering from hanging down at any point to a level which is equal to or beneath the level of the peripheral portion of the roof.

Claims

1. In a hanging roof structure of a type which is supported at its periphery by a load dispersion ring of lattice construction and which is supported at its center by an attachment means, with the attachment means being supported by supporting cables secured between the load dispersion ring and the attachment means, so that the structure can function as a roof covering when carried on support columns or an outer wall of a building being covered thereby, the improvement in said roof structure comprising: a load dispersion ring in the form of a torsionally rigid, three-dimensional lattice structure constructed of prismatic lattice units which, when seen in plan view, are triangular in shape, each lattice unit further including: two inner corner junctions (9) facing the center of the load dispersion ring and an outer corner junction (8) facing away from the center of the load dispersion ring, all of said junctions being located in an upper plane, two inner (19, 19) and one outer (18) corner junctions located in a lower plane and corresponding to the junctions described for said upper plane, substantially vertically extending struts (11, 13, 13) connecting said corresponding corner junctions in said upper and lower planes, diagonal braces (20, 20) connecting each upper outer corner junction (8) with each lower inner corner junction (19) of a lattice unit, said lattice units being secured adjacent to each other with common upper and lower inner corner junctions, horizontal braces connecting said lower inner corner junctions to form a lower inner peripheral ring (23) of said load dispersion ring, horizontal braces connecting said upper inner corner junctions to form an upper inner peripheral ring 21 of said load dispersion ring, and said supporting cables extending between said central attachment means and said load dispersion ring being secured to said upper outer corner junctions and to said lower inner corner junctions.

2. The roof structure of claim 1 and including horizontal braces connecting said upper outer corner junctions (8) to form an upper outer peripheral ring (25) of said load dispersion ring.

3. The roof structure of claim 1, characterized in that said supporting cables strung between said central attachment means and said lower inner corner junctions of the load dispersion ring support a roof covering continuously with the roof covering resting on the supporting cables.

4. The roof structure of claim 1, characterized in that said supporting cables strung between said central attachment means and said lower inner corner junctions of the load dispersion ring support a roof covering continuously with the roof covering being attached directly beneath the supporting cables.

5. The roof structure of claim 1, characterized in that said lower outer corner junctions are connected together with the aid of horizontal braces which form an outer lower circumferential ring of the load dispersion ring.