US3906685A

US3906685A - Roof structure

Info

Publication number: US3906685A
Application number: US545756*A
Authority: US
Inventors: Peter Howard
Original assignee: IMERO FIORENTINO ASSOCIATES IN
Current assignee: IMERO FIORENTINO ASSOCIATES IN; IMERO FIORENTINO ASSOCIATES Inc
Priority date: 1975-01-30
Filing date: 1975-01-30
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

A roof structure has its front and back edge supported by two series of linked truss members which form two arches anchored to the surface to be covered at their bases and sloping upwardly from the surface and outwardly in opposite directions. A number of flexible roof panels are attached between a centrally disposed ring member and the individual truss members of each series to provide the roof covering. Additional means are provided to raise the constituent parts of the roof structure to their operative positions and to maintain the structure in such position.

Description

United States Patent 1 [111 3,906,685 Howard Sept. 23, 1975 [54] ROOF STRUCTURE OTHER PUBLICATIONS [75] Inventor: Peter Howard, New York, N.Y.

, Construction Methods and Equipment, March, 1957, [73] Assignee: lmero Florentino Associates, Inc., pp 170 171 New York, N.Y.

[22] Filed: Jan. 30, 1975 [52] US. Cl. 52/63; 52/82; 52/83; 135/1 D [51] Int. Cl. E04B 1/12 [58] Field of Search 52/83, 82, 745, 63; 135/1 D, 2, 3 C, 4 B

[56] References Cited UNITED STATES PATENTS 2,527,729 10/1950 Hoff 135/1 D 3,028,706 4/1962 Falconer 52/83 3,149,703 4/1964 De Felice... 52/745 3,153,302 10/1964 Wheeler 52/82 3,215,153 8/1963 Haddle 52/80 3,252,469 5/1966 Peake 52/80 3,422,883 1/1969 Daltry 52/83 3,546,831 12/1970 Romo 52/83 Primary ExaminerErnest R. Purser Assistant ExaminerHenry Raduazo Attorney, Agent, or FirmHopgood, Calimafde, Kalil, Blaustein & Lieberman [57] ABSTRACT A roof structure has its front and back edge supported by two series of linked truss members which form two arches anchored to the surface to be covered at their bases and sloping upwardly from the surface and outwardly in opposite directions. A number of flexible roof panels are attached between a centrally disposed ring member and the individual truss members of each series to provide the roof covering. Additional means are provided to raise the constituent parts of the roof structure to their operative positions and to maintain the structure in such position.

12 Claims, 10 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of 6 US Patent Sept. 23,1975 Sheet 3 of6 3,906,685

| I I Hunk- FIG.3

m El US Patent Sept. 23,1975 Sheet4 0.1 6 3,906,685

US Patent Sept. 23,1975 Sheet 5 of6 3,906,685

US Patent Sept. 23,1975 Sheet 6 of6 3,906,685

FIG9

ROOFSTRUCTURE BACKGROUND OF THE INVENTION A large number of shows and musical events are now staged in stadiums and open amphitheaters because of the large seating capacities and ready availabilities of such facilities in many sections of the country. Most of these stadiums and amphitheaters are open to the elements at least in the central area where performers would normally be located for a concert or show, so that they can be seen from a maximum number of seats. It is, therefore, necessary to provide a roof structure over the performing area to provide protection from the weather for the performers as well as to avoid damage to expensive props and instruments. Since stadiums and amphitheaters are customarily utilized for sporting events and only occasionally for concerts and shows, any roof structure must be of a temporary nature and should be easily and quickly set up and removable after a few days or a few performances. Since, in order to perform before differing audiences, performers customarily travel extensively around the country and around the world, it is necessary to construct and take down such a roof structure many times at many different places in the course of each tour.

Customarily, the necessary roof structure will be constructed out of scaffolding by a company located in the area of the planned performance on a custom basis. Such construction requires the use of cranes which must be anchored to the playing surface of the stadium to insure safe operation and the placement of a large number of columns which are utilized to support sections of a canvas roof and which usually extend to the playing surface. Since the playing surface of modern stadiums is often covered with an artificial grasslil e covering rather than grass the driving of any stakes or the mounting of any support structure which would pierce this covering can cause expensive and lasting damage.

In addition, the building of a roof structure on a custom basis in each location where a show is to be staged is expensive and the roof structure built will be'of varying quality and will provide varying conditions for the performance. It would be desirable to have a roof structure which could be conveniently transported from place to place, both to decrease expense and to insure uniformly good performance conditions at each location. It is not, however, possible for a touring show to take the scaffolding of prior art roof structures from' place to place because of the large number of separate pieces involved in such structures and the resulting complexity in reconstructing the structure at each location.

The present invention solves the above described problems of prior art structures-by providing a roof structure which is portable and which can be raised and supported by a single central support tower. Utilizing the novel roof structure described herein results in savings in both time and money during set up and removal of the structure and saves additional money by avoiding the need for extensive custom construction at each performance location. Since the roof structure is portable the same structure may be used for each performance during the tour and the performers can be assured of a uniform esthetically pleasing performance environment in each location.

SUMMARY OF THE INVENTION A roof structure for covering at least a portion of a surface includes a plurality of truss members linked together end to end to form two series of linked truss members which are arrangeable on the surface to form a substantially regular polygon about an axis passing through the surface when in a first unerected position; hinge means to anchor each end of each of said series of truss members to the surface; a ring arranged within and substantially coaxially with the polygon formed by the truss members; a plurality of flexible roof panels each of which is connected along one side to the ring member and along the opposite side to one of the truss members. First means are provided to raise the ring member to a predetermined height abovethe surface and to support the ring member at said predetermined height, and second means are provided to raise-each of the truss members of said two series of truss members from said unerected position to a predetermined erected position above the surface and to maintain said truss members in said erected position so that each of said series of linked truss members forms an arch which arch slopes upward from said surface and outward from said axis from the bases to the apex.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of the roof structure in erected position.

FIG. I!) is a top schematic view of the arrangement of the linked series of truss sections of the roof structure prior to erection. I

FIG. 2 is a front elevational view of the roof structure in the erected position.

FIG. 3 is a side elevational view of the roof structure in the erected position.

FIG. 4 is a side elevational view of the roof structure in its nonerccted position.

FIG. 5 is a partial top plan view of the support tower for the roof structure taken along plane 5-5 of FIG. 2.

FIG. 6 is a perspective view of the anchoring means for the roof structure.

FIG. 7 is a detailed view taken along plane 7-7 in FIG. 2.

' FIG. 8 is an exploded detailed view of the truss linking means shown in FIG. 7. I

FIG. 9 is a side elevational view of the roof structure with the roof panels removed.

DESCRIPTION OF THE INVENTION The inventive roof structure 10 is shown from the front in FIG. 2. The roof structure 10 is mounted on a raised platform 12 having a horizontal surface 11 so that it covers a stage surface 14 which is supported on surface II. A support tower 16 which is constructed in accordance with known techniques is arranged at the center of the stage 14 on the surface 11 of platform 12 to provide support for roof structure 10 as will be discussed more fully below.

The roof structure 10 includes a number of truss members 18 which are flexibly attached end to end to form two linked series of

trusses

50 and 72. The individual trusses 18 may consist of three

main pipe members

20, 21, 22, as best seen in FIG. 7 which are arranged in a triangular configuration with a number of smaller diameter cross pipe members 24 arranged to provide strength to the triangular truss in a manner well known in the art. Each truss 18 is terminated by an end plate 26 as best seen in FIG. 8 to which the main triangularly arranged

pipe members

20, 21 and 22 of the truss are attached. The trusses 18 are then joined to each other end to end by a clevis and tongue joint as best seen in FIG. 8.

The joint 30 includes a first arched shaped tongue member 32 having an aperture 33 which is mounted on and extends outwardly from a central portion of end plate 260. Two additional similar tongue members 34 and 36 are mounted on end plate 26b so that they are substantially parallel to each other and extend outwardly from plate 26b. Members 34 and 36 include respectively apertures and 37 which are substantially aligned so that the members 34 and 36 form a clcvis end adopted to mate with tongue member 32. Tongue member 32 is inserted between members 34 and 36 and its aperture 33 is aligned with apertures 35 and 37. A bolt 38 is inserted through apertures 35. 33 and 37 and is secured by bolt 40 to formjoint 30 which is rotatable about an axis through bolt 38.

The

trusses

51, 56, 66 and 71, which are located at each end of each of the two series of

trusses

50 and 72, are attached to the support platform 12 by mounting plates such as 60 and 64 and a coupling 41 as best shown in FlG. 6. Mounting plates 60 and 64 are attached to platform 12 by bolts extending through aper turcs such as 6a and 60b in FIG. 6. The coupling 41 includes a cylindrical collar 42 which is spaced from plate 60 by legs 43. A cylindrical rod 44 extends through and is rotably supported at approximately its midpoint by collar 42. The inner radius of collar 42 is preferably slightly larger than the outer radius of rod 44 so that rod 44 may be rotated within collar 42. A

tounge member 45 having an aperture 46 is mounted at one end of rod 44 while a clcvis end consisting of

tongue members

47 and 48 is attached to the opposite end of rod 44.

Tongue members

47 and 48 include aligned apertures 47:1 and 48a. The tongue member 45 is attached to the clcvis end of a truss such as 51 while the clcvis end 49 of coupling 41 is attached to the tongue end of a truss member such as 56 in the manner described above. After attachment of these end trusses the rod 44 of coupling 41 is rotated through an angle of approximately 90 as the roofstructure is raised into its operational position as further described below.

As is seen in FIG. 1. the roof structure of the present invention includes a total'of 12 truss members of the type described above which are divided into two linked

series

50 and 72 of six trusses each. If desired each series of linked trusses could include more or less trusses than the six shown for illustration. Each series of six trusses forms a support structure for one side of the roof structure 10. The first series of trusses designated 50 in FIG. 1 includes

trusses

51, 52, 53, 54. and 56 which support the forward edge of roof structure 10 of FIGS. 1 and 2. Plates and 64 are mounted on opposite sides of platform 12 aligned with and spaced from the lateral sides of support tower 16. Plates 60 and 64 are used to anchor each of the ends of each of the linked series of trusses to platform 12. The end plates 26 of

trusses

51, 52, 53. 54, S5 and 56 are linked end to end by clcvis and tongue joints 30 as described above. A first end 58 of truss 51 is attached to plate 60 by a hinge coupling 41 which coupling is arranged as described above. Finally, the end 62 of truss 56 is attached to plate 64 on the opposite side of the platform from plate 60 by a similar hinge coupling 41. Both ends of the linked series of trusses 50 are thereby anchored to platform 12. An identical arrangement is used to link

trusses

66, 67, 68, 69, and 71 together to form a second series of trusses 72 which supports the rear side of roof structure 10. Again the free end of the first and last truss of the series, which in this case are

trusses

66 and 71, are attached respectively to plates 60 and 64. As illustrated. properly configured plates 60 and 64 can be used to anchor hingejoints 41 to accommodate end 74 of truss 66 and end 76 of truss 71 so that two mounting plates 60 and 64 may be used to anchor both sides of

truss series

50 and 72 to the platform 12. If desired, separate plates can be used to anchor each end of each series of trusses.

The centrally arranged support tower 16 includes a number of pulleys mounted near the top as best seen in FIG. 5. FIG. 5 shows one halfof the pulley arrangement on tower 16 which also includes the same arrangement on the other side. Two

pulleys

78 and 80 in FIG. 5 are located on the corners of the support tower at a first level and are mounted on support members 79 and 81 which are oriented in the direction of the corners of the support platform. Other pulleys 82. 84, 86, 88 and 90 are mounted at a second higher level on tower 16 and are supported respectively by

support members

83, 85, 87. 89 and 91 which extend radially outwardly from the central axis of the support structure.

A ring shaped member 92 having a central aperture configured to fit around the support tower 16 and be slidablc vertically on the tower is shown in its raised position in FIGS. 1b and 2. The smaller end of a number of substantially

triangular roof panels

94, 96, 98, 100, 102 and 104, which are preferably made of a flexible covering material such as vinyl or canvas, have their smaller apex ends attached about the periphery of ring 92 by any convenient fastening means. lf desired. such fastening means may comprise snaps or removable rings so that the roof panels may be easily removed for storage. The larger base ends of each of these roof panels is attached to one of the truss members 51 through 55 or 66 through 71. Again. if desired, bases ofthc panels may be attached to the trusses by snaps or other means which would facilitate removal of the panels for storage. Adjacent panels. such as 96 and 98 as seen in FIG. 1,.arc configured so that their adjacent sides overlap to provide a continuous roof. For this same reason panels such as 94 and 104 which form the two ends of roof half 72 are configured so that they are larger than the other roof panels and extend a little more than half way across plates 60 and 64 to the adjacent roof panels which are attached to the trusses comprising truss series 50 and which are not shown in FIG. 1.

The manner in which the roof structure is assembled and mounted over the stage 14 will now be described with reference to the above described parts. The rect angular supporting platform 12 is first constructed by means well known in the art. The support tower 16 is then firmly anchored to the center of the platform 12. Central tower guide cables 106., 1 08, and 112 are connected from the upper corners of the substantially square tower 16 to the nearest corner of rectangular platform 16. These cables are preferably attached to platform 12 through turnbucklcs 114, 116., 118 and 120 to permit the tension of each of the tower guide cables to be adjusted to insure that the central tower 16 is properly positioned and firmly anchored on the platform 12.

The trusses 18 are then arranged on thesurface of i the platform and are connected to each other by clevis and tongue joints 30 and the first and last end of each series of trusses, such as ends 51 and 56 of series 50 in FIG. 1 are attached respectively. to plates 60. and 64 by a coupling 41 as shown in FIG. 6. FIG. 1b shows the schematic arrangement of

truss series

50 and 72,after link-ing the individual trusses and attachmentof the Y linked series of trusses to plates 60 and 64 by coupling members 41. prior to raising the two sides of the roof structureto their operative positions in a manner to be described below. The individual truss sections form a substantially regular polygon when linked and attached to platform 12 which in this case has twelve sides with a break between the two linked series formed by plates 60 and 64. The regular polygon approximates a circle having its center at the central axis of tower 16. In the illustration shown, 12 identical triangular trusses l7 feet 6 inches-in length have. been usedand the radius of the circle approximated by the resulting polygon is "35 feet. The distance between plates 60 and 64 is-approximately 70 feet which is, therefore, the distance spanned by the roof structure 10. as illustrated. Longer distances can be spanned by roof. structures in accordance with this invention if more or longertruss members 18 are utilized in each series of linked truss members. Utilizing a roof structure of the above dimensions, a platform sixth feetin depth can be covered in its central area, as best shown in FIG. 1, which illustrates the "roof structure 10 in its erected operative position.

members in each of the seriesof linked

truss members

50 and 72. Each of these cables runs over one of the upper level pulleys such as 82, 86, 88 and 90' of FIG. 5 and thence down, into the central tower 16 where they are attached to suitable hoisting means such as winches .whichare not shown but are well known in the art. The suspension cable arrangement for the truss members would be as follows for some of the truss members shown. Cable 122 would pass over pulley 82. Cable 123 would pass over pulley 84. Cable 124 would pass over pulley 86.This arrangement would be contin ued around both sides of the central support tower 16,

so that eachof the truss suspensioncables would pass over a pulley to tensioning means within the tower 16.

Tent ring suspension cables 136 through 139 are attached to four points spaced substantially summetrically about the tent ring 92. These tent ring suspension cables pass respectively over the pulleys on the lower level of 1G. 5 two of which are shown as 78 and 80 and two of which are similarly arranged on the side of the tower 16 which is not shown in FIG. 5. As in the case of the truss suspension cables after passing over the

pulleys

78 and 80 the tent ring suspension cables are attached to tensioning means such as winches within tower 16 which are not shown.

The tent ring and the trusses are then pulled upward from the platform 12 -by applying tension. to the truss suspension and tent ring suspension cables/By this means the tent ring 92 is raised to the position shown in FIG. 2 carrying with it the smaller apex ends of each of the roof panels such as 104. 102 and in FIG. 3, and truss members such as 54, 55, 56, 69, 70 and 71 as seen in'FlG. 3 are raisedfrom the position of FIG. lb to their operative positions as seen in FIGS. la, 2 and 3. FIG. 4 shows

truss members

54, 55 and 56 immediately prior to raising them to their operative positions with

truss suspension cables

124, and 126 attached. Once in their operative positions the truss members making up the linked series of

truss members

50 and 72 form arches which are anchored at their bases oneach side to plates 60 and 64 and slope respectively upward and outward toward the forward and back edge of the platform 12 so that roof structure 10 covers as much of the central area of platform 12 as possible to provide a large unobstructed viewing area at both the front and back of the platform 12. thereby providing an extensive usable performance area for the stage 14 as best seen in FIG. 2.

To provide increased stability against wind forces additional truss guide wires and 151 are attached between

joints

160, 161, 163, 164, 165,166, 168 and 169 and the platform 12. Each of the truss guide wires is preferably attached to the platform 12 through a turnbuckle such as 170 through 181 so that the tension on each truss guide wire is adjustable to provide proper stability and positioning of the truss sections which make up the linked

truss series

50 and 72. The additional support afforded by the truss guide wires will now be discussed in detail with reference to joints and 161.

Guide wires

142 and 141 are attached to joint 160 to form two sidesof a triangle with joint 160 at its apex. Guide wire 141 is also attached to one corner of rectangular platform 12 and guide wire 142 is attached to a more central area of the side of platform 12. Junetion 161 is attached to guide wire 140 which is in turn attached to the corner of platform 12 at the same point of attachment as guide wire 141. A similar arrangement is utilized to support

junction

163 and 164; 165 and 166; and 168 and 169 as best seen in FIG. 1. No support structures extend across the large open areas at the front and back of the stage so that the roof structure 10 provides unobstructed views of both the front and back portions of the stage.

As constructed in accordance with the embodiment described herein the support tower 16 extends 32 feet above the platform 12 and the apex at

joints

162 and 167 of the arches forming the sides of roof structure 10 are nineteen feet above the level of the platform 12. The base of .the arches formed by the two seriesof linked trusses 50 and 72 join the platform at an angle of approximately 33 /2 and the arches extend transversely upward and outward at a substantially uniform angle of 33 /2" from their bases at plates 60 and 64 to their apexes at

joints

162 and 167.

Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the inven tion and appended claims.

I claim: 1. A roof structure for coveringat least a portion of a support surface including a plurality of truss members;

linking means to join individual ones of said truss members end to end to form a first and a second series oflinked truss members, said series of linked truss members forming a polygon arranged substantially symetrically about an axis on said surface when said truss members are in an unerectcd position;

anchoring means to hold each end of each of said series of linked truss members to said support sur ,face;

a ring member arranged within and substantially coaxially with said polygon defined by said linked truss members in said unerected position;

a plurality of flexible panels having a first side connected to said ring member and the side opposite said first side connected to one of said plurality of linked truss members;

first means to raise said ring member to a predetermined height above said support surface; and

second means to raise said truss members in both of said linked series of truss members from said unerectcd position to an erected position at predetermined heights above said support surface so that said first and second series of truss members from respectively a first and a second arch, each of said arches sloping upwardly from said surface and outwardly from said axis from the base to the apex of said arches.

2. A roof structure as claimed in claim I in which said linking means includes a plurality of clevis and tongue joints and in which said anchoring means includes a roatable clevis and tongue joint.

3. A roof structure as claimed in claim 1, including cables extending each of said series of truss members and said support surface.

4. A roof structure as claimed in claim 1, in which said first means includes a first plurality of pulleys mounted at a first height above said surface and a first plurality of suspension cables attached to said ring member, said suspension cables passing over said pulleys. and in which said second means includes a second plurality of pulleys mounted at a second height which is greater than than said first height above said surface and a second plurality ofsuspension cables. said second plurality of suspension cables being attached to points along each of said series of linked truss members and each of said second series of suspension cables passing over one of said second plurality of pulleys.

5. A roof structure as claimed in claim 4, including means to apply tension to said first and said second pluralities of suspension cables to move said ring member to said predetermined height and said truss members to said erected position.

6. A roof structure as claimed in claim 1, in which the bases of each of said arches join said surface at an angle of approximately 33.5".

7. A roof structure as claimed in claim 1, in which each of said arches extends upwardly from said surface at a substantialy uniform angle from the bases to the apex.

8. A roof structure for covering a portion of surface which structure is adopted to be supported by a single support tower arranged substantially along an axis perpendicular to said surface;

a plurality of truss members;

linking means to join said truss members end to end to form a first and second series of linked truss members, said first and second series of linked truss members forming respectively first and second arches, each of said arches sloping upwardly from said surface and outwardly from a plane extending through said axis;

mounting means adjacent to said plane to anchor the bases of each of said arches;

a ring member arranged coaxially about said tower at a predetermined height above said surface;

a plurality of flexible panels each having a first side connected to said ring member and a second side opposite said first side connected to one of said truss members;

first support means to hold said ring member at said predetermined height; and

second support means adopted to support each of said arches.

9. A roof structure as claimed in claim 8, in which said first support means includes a first plurality of pulleys arranged about said tower at a first vertical distance above said surface and a plurality of Cables. each of said cables being attached to said ring member and extending over one of said pulley, and in which said second support means includes a second pluralitly of pulleys arranged about said tower at a second vertical distance above said surface. said second distance being greater than said first distance. and a second plurality of cables attached respectively to a plurality of points along said series oflinked truss members and extending respectively over one of said second plurality of pulleys.

10. A roof structure as claimed in claim 10, including additional cables extending respectively from said surface to points along said series of linked truss members. and means to adjust the tension on each of said additional cables.

11. A roof structure as claimed in claim 8, in which said linking means includes a plurality of hinged couplings disposed between adjacent ends of said truss members making up each of said linked series of truss members. and said mounting means includes a rotatable hinged coupling connecting the bases of each of said arches to said surface.

12. A roof structure as claimed in claim 11 in which said hinged couplings are clevis and tongue joints.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5.906.685 Dated September 25. 1975 Inventor(s) Peter H ward It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 7, line 56, "roatab le" should be rotatable.

Column 7, line 58, after "extending" insert -between-. Column 7, line LI-7, after "greater" should be only one (1 "than".

Column 8, line i, "substantialy" should be --substantially--.

Bignzd and Sealed this sixteenth Day Of December 1975 [SEAL] A ttes t:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Patents and Trademarks

Claims

1. A roof structure for covering at least a portion of a support surface including a plurality of truss members; linking means to join individual ones of said truss members end to end to form a first and a second series of linked truss members, said series of linked truss members forming a polygon arranged substantially symetrically about an axis on said surface when said truss members are in an unerected position; anchoring means to hold each end of each of said series of linked truss members to said support surface; a ring member arranged within and substantially coaxially with said polygon defined by said linked truss members in said unerected position; a plurality of flexible panels having a first side connected to said ring member and the side opposite said first side connected to one of said plurality of linked truss members; first means to raise said ring member to a predetermined height above said support surface; and second means to raise said truss members in both of said linked series of truss members from said unerected position to an erected position at predetermined heights above said support surface so that said first and second series of truss members from respectively a first and a second arch, each of said arches sloping upwardly from said surface and outwardly from said axis from the base to the apex of said arches.

2. A roof structure as claimed in claim 1 in which said linking means includes a plurality of clevis and tongue joints and in which said anchoring means includes a roatable clevis and tongue joint.

4. A roof structure as claimed in claim 1, in which said first means includes a first plurality of pulleys mounted at a first height above Said surface and a first plurality of suspension cables attached to said ring member, said suspension cables passing over said pulleys, and in which said second means includes a second plurality of pulleys mounted at a second height which is greater than than said first height above said surface and a second plurality of suspension cables, said second plurality of suspension cables being attached to points along each of said series of linked truss members and each of said second series of suspension cables passing over one of said second plurality of pulleys.

6. A roof structure as claimed in claim 1, in which the bases of each of said arches join said surface at an angle of approximately 33.5*.

8. A roof structure for covering a portion of surface which structure is adopted to be supported by a single support tower arranged substantially along an axis perpendicular to said surface; a plurality of truss members; linking means to join said truss members end to end to form a first and second series of linked truss members, said first and second series of linked truss members forming respectively first and second arches, each of said arches sloping upwardly from said surface and outwardly from a plane extending through said axis; mounting means adjacent to said plane to anchor the bases of each of said arches; a ring member arranged coaxially about said tower at a predetermined height above said surface; a plurality of flexible panels each having a first side connected to said ring member and a second side opposite said first side connected to one of said truss members; first support means to hold said ring member at said predetermined height; and second support means adopted to support each of said arches.

9. A roof structure as claimed in claim 8, in which said first support means includes a first plurality of pulleys arranged about said tower at a first vertical distance above said surface and a plurality of cables, each of said cables being attached to said ring member and extending over one of said pulley, and in which said second support means includes a second pluralitly of pulleys arranged about said tower at a second vertical distance above said surface, said second distance being greater than said first distance, and a second plurality of cables attached respectively to a plurality of points along said series of linked truss members and extending respectively over one of said second plurality of pulleys.

10. A roof structure as claimed in claim 10, including additional cables extending respectively from said surface to points along said series of linked truss members, and means to adjust the tension on each of said additional cables.

11. A roof structure as claimed in claim 8, in which said linking means includes a plurality of hinged couplings disposed between adjacent ends of said truss members making up each of said linked series of truss members, and said mounting means includes a rotatable hinged coupling connecting the bases of each of said arches to said surface.