Patent Abstract:
A new conical roof building method provides flat plates having straight abutting edges and curved outer edges. The plates are placed horizontally edge to edge except for a sectoral opening. The plates are welded together to form a flat disc-shaped blank, leaving an open sector of the blank. Radial supports are welded to a top of the disc-shaped blank. A center of the disc-shaped blank is lifted, forming a conical-shaped structure, closing and abutting edges of the open sector and touching edges of the formerly open sector are welded together, completing the forming of the conical roof.

Full Description:
BACKGROUND OF THE INVENTION 
   Placing roofs on large storage tanks and large circular structures is a difficult task which requires constructing and erecting support scaffolding to great heights above the ground and cutting, forming and building supports and plates at precise angles and constructing a precisely shaped supporting frame under the roof before welding of the roof elements together. The construction of domed and conical roofs requires a large amount of time, expense and skilled labor. In many cases support frames must be left enclosed within the roofs. 
   Roofs are constructed atop buildings far from the ground. Tall scaffolding and extra precautions and safety procedures are required. 
   Needs exist for better roof constructions. 
   SUMMARY OF THE INVENTION 
   A new conical roof building method provides flat plates having straight abutting edges and curved outer edges. The plates are placed horizontally edge to edge except for a sectoral opening. The plates are welded together to form a flat disc-shaped blank, leaving an open sector of the blank. Radial supports are welded to a top of the disc-shaped blank. A center of the disc-shaped blank is lifted, forming a conical-shaped structure, closing and abutting edges of the open sector and touching edges of the formerly open sector are welded together, completing the forming of the conical roof. 
   The plates are initially supported on a table structure. Curved outer edge portions of the plates are supported on a shell ring before and during welding of the plates together in a flat form and welding of the radial supports to the top of the disc-shaped blank with the open sector. 
   The blank and the conical-shaped structure are supported on upper edges of the shell ring during the lifting of the center of the disc-shaped blank and the transitioning and transforming of the blank into a conical-shaped roof, and the securing of abutting edges of the open sector. 
   The completed conical roof is supported on the circular upper edge of the shell ring. 
   The conical roof is welded inside and outside along its intersections with the upper edges of the shell ring. 
   The securing edges of the open sector preferably include welding the abutting edges of the sector together. Before welding and securing the edges together, bridging strips are welded across the abutting edges of what formerly was the open sector. 
   A compression ring is welded to upper and inward portions of the radial supports after competing the forming of the conical roof. The compression ring takes some of the compressive load around the central opening in the conical roof. 
   In a preferred embodiment, before and during welding abutted edges of the flat plates together, the beveled edges of the plates are supported on thin copper strips on scaffolds beneath the edges, and the welding is accomplished by welding machines that move over the to of the flat plates. 
   In another preferred embodiment, centers of the plates are supported on plural parallel tables and outer curved edge portions of the plates are supported on a circular upper edge of a shell ring before and during welding of the plates together and welding of the radial supports to the top of the disc-shaped blank. 
   The welding of the radial supports to the top of the disc-shaped blank is accomplished by welding lower edges of angle iron vertical flanges at intervals to the top of the disc-shaped blanks. After completing the forming of the conical roof, the entire edges of the vertical flanges of the angle iron radial supports are fully welded on the conical surfaces of the conical roof. 
   Preferably, a central opening is provided in a center of the blank. In large roofs alternate radial extend from the central opening to the outer curved edge of the blank. Alternate intermediate supports extend from the outer edge of the blank to positions spaced from the central opening. 
   To form the conical shape, the center of the blank is lifted with an element connected to a lifting ring on a bolt extending through the central opening. Usually, the center of the blank is lifted with a crane attached to the lifting ring. The center of the blank may be lifted into a cone shape by extending a vertical ram positioned under the center of the blank. 
   A preferred conical roof structure has a conical plate with a central opening and a welded seam running from a lower outer edge of the conical plate to a center of the conical plate. Plural radial supports are welded to the conical plate, and a compression ring is welded to upper surfaces of inward portions of the radial supports around a center of the cylindrical roof. A vent pipe is mounted in the central opening. 
   The radial supports alternate in running from an outer edge of the conical plate to the central opening, and running from an outer edge of the conical plate to positions spaced from the central opening. 
   The roof is self-supporting, and an area inward on an underside of the plate near the curved outer edge is supported on an upper edge of a roof support shell ring. 
   Because of the unusual construction of the new conical roof, the roof may be assembled in a short time with the welding of precut sheets and supports in a flat condition, followed by reinforcing the sheets with radial supports welded to the sheets at intervals. Lifting the center of the roof vertically closes an open sector. Completion of the welding of the former sector edges and the supports on the sheets completes the roof. Welding of the inner and outer circular joints between the upper edge of the support ring and the lower inward surface of the conical roof along circles spaced inward from the outer edge completes the joining of the roof to the underlying structure. The unique construction of the roof is accomplished with a fraction of the cost and time associated with constructing a conical or domed roof on a large circular structure. The new roof is constructed with straight welding. 
   These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the claims and the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a cylindrical ring shell and internal tables for supporting a flat plate of a roof while it is being assembled and constructed from welded parallel plates. The crane and lifting truss is shown placing a plate in position on the supporting table for subsequent welding to the longitudinal edge of the plates already assembled at the rear of the drawing. 
       FIG. 2  is a top plan of the support ring shell and the tables before the roof plates are placed. 
       FIG. 3  is a plan view of tables supporting the plates during assembly of the flat blank. 
       FIG. 4  is an elevation of scaffolds with I beams and shims for supporting seams before and during welding. 
       FIG. 5  is a detail of a scaffold supporting a seam being welded. 
       FIG. 6  is a cross sectional detail of a copper strip below a seam being welded. 
       FIG. 7  is an enlarged cross sectional detail of edges and a copper strip before welding. 
       FIG. 8  is a side view of scaffolds and seam supports. 
       FIG. 9  is a detail of preferred seam supports. 
       FIG. 10  is a detail of a wedge or shim used to finely adjust the support. 
       FIG. 11  shows the roof plates being assembled and welded, with the last plate shown being positioned by a crane. A sector with radial edges that extend from the central opening to the outer edge of the roof plate is left open, as shown at the left. 
       FIG. 12  shows the welding of bottom edges of vertical flanges of radial angle iron support beams to the plate. The support beams are welded at intervals to the plate. The support beams extend inward from the outer edge. Alternating support beams extend to the central opening and to positions spaced from the central openings. 
       FIG. 13  shows the lifting of the center of the roof plate, which causes closing of the sectoral opening. The sector edges are abutted and are held abutted by bridge plates welded across the edges. Then the edges are welded together. At all times the outer edge portion of the roof plate in both its preliminary flat form and in its conical assembled form is supported by the upper edge of the support ring shell. 
       FIG. 14  shows the center being lifted by pushing with an internal ram rather than by pulling with an external crane. 
       FIG. 15  shows the addition of a compression ring on the inside end portions of the long radial supports, and the addition of a vent pipe in the central opening. A safety railing is being installed around the periphery of the roof. A lower outer portion of the roof is welded to the upper edge of the cylindrical support shell, both on the inner surfaces at the upper edge and the outer surfaces of the upper edge. 
       FIG. 16  is a cross sectional view of a roof and wall connection of the present invention showing welding spots. 
       FIG. 17  is a cross sectional view of a roof and wall connection from existing conical roofing showing welding spots. 
       FIG. 18  is a cross sectional view of a roof and wall connection from existing domed roofing showing connections. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a cylindrical ring shell and internal tables for supporting a flat plate of a roof while it is being assembled and constructed from welded parallel plates. The crane and lifting truss is shown placing a plate in position on the supporting table for subsequent welding to the longitudinal edge of the plates already assembled at the rear of the drawing. 
   As shown in  FIG. 1 , a cylindrical support structure with a circular upper edge is first constructed by welding curved plates in vertical welds at longitudinal ends of the curved plates. 
   The cylindrical ring shell is generally indicated by the numeral  1  and is formed from a series of vertical plates  3  which are curved around a vertical axis. Vertical welds  7  join longitudinal end edges  5  of the plates. A circular upper edge  9  of the cylindrical support shell supports the roof. Tables  11  with legs  13  are mounted inside the cylindrical ring shell  1  to support the elongated roof plates  23  as they are assembled and welded along their longitudinally extending lateral edges  25 . 
     FIG. 1  also shows a crane sheave  27  lowering an elongated plate  29  into position next to previously welded plates  23  shown in the back. A truss  31  has several supports  33  for holding the longitudinally extending plate  29  as it is placed in position. A sectoral opening  41  with radial side edges  43  and  45  is left open when forming the flat roof plates. A central opening  47  is formed in the middle plate and has a welded collar  49  for receiving a lifting assembly during construction and holding a vent pipe after construction. Welding machines  51  may be used to weld the joints  25  between abutting lateral edges of the plates  23 . 
     FIG. 2  is a plan view of the assembled and welded roof shells or plates  23  showing open sector  41  with edges  43 ,  45 . 
     FIG. 3  is a top plan view of the welded roof plates or sheets supported by the support ring shell, and the support tables  91  put in place before the roof plates  23  are placed and edges are welded. 
     FIG. 4  shows preferred supports  101  with upper I beams  103  and leveling shims or wedges  105  to support plate seams. The ring shell  1  is shown mounted on a concrete base  107 . Ring shell  1  also supports the plates. 
     FIG. 5  is a detail of an I beam  111  on top of a support. Wedges  105  hold a copper strip  113  against an inside of edges  25  of plates  23  before and during welding. 
     FIG. 6  is a detail of the copper strip  113  with a groove  117  beneath the seam edges  25 . The copper strip  113  is about ⅜″ thick and about 2″ wide, as shown in  FIG. 7 . Sheet edges  25  are beveled so that the welding may be done from the flat top of the assembled sheets  23 . The copper strip assures complete fusing of the edges  25 . 
     FIGS. 8 and 9  show a different seam support  121  with u-shaped support tops  123  for holding the I beams  111  against the copper strip  113  with the aid of wedges  105  for precise welding. Tops  125  of the U&#39;s may be spot welded  127  to the roof sheets  23  to hold the edges  25  together during their welding. The support ring shell is shown supporting the edges of the flat roof structure. 
     FIG. 10  shows a shape of one possible wedge  105 . 
     FIG. 11  shows the roof plates  23  being assembled and edges  25  being welded, with the last plate being positioned by the crane. A sector with radial edges  43 ,  45  that extend from the central opening  47  to the outer edge of the roof plate is left open, as shown at the left. 
   As shown in  FIG. 11 , the flat plate blank  21  is fully assembled with the lowering into place of the last curved edge plate  51 . The sector  41  has been left open with spaced radial edges  43  and  45 , as indicated by the person  53  who is standing within the open sector. 
   The open sector  41  extends to the central opening  47 . Radial supports  61  have been provided for radially arranging on the flat roof plate  21 . 
     FIG. 12  shows the welding of bottom edges of vertical flanges of radial angle iron support beams to the plate. The support beams are welded at intervals to the plate. The support beams extend inward from the outer edge, and alternating support beams extend to the central opening  47  and to positions spaced from the central opening. 
   As shown in  FIG. 12 , the radial supports  61  have all been welded in place on the roof plate  21  by interval welding at the lower edge of vertical flanges  63  of the angle iron supports  61 . Outer ends  65  of the angle iron supports extend to the outer edge of the flat plate  21 . Alternate supports  67  and  69  have inner edges  71  and  73 . The inner edges  71  of the long supports  67  extend to the central opening  47 . The inner edges  73  of the shorter supports  69  extend to positions spaced from the central opening. 
     FIG. 13  shows the lifting of the center  47  of the roof plate  21 , which causes closing of the sectoral opening  41 . The sectoral opening edges  43 ,  45  are abutted and are held abutted by bridge plates welded across the edges  43 ,  45 . Then the edges  43 ,  45  are welded. At all times the outer edge portion of the roof plate in both flat  21  and conical  81  forms is supported by the upper edge of the support ring shell. 
   As shown in  FIG. 13 , a hook-lifting ring  74  has been secured in the central opening by extending the shaft  75  of the O-ring through the central opening  47  and attaching a plate beneath the central opening with a nut. A hook  77  on sheath  27  of crane  79  lifts the ring and forms the roof into its finished conical shape  81 . During the lifting of the center of the roof, a circular inner portion of the roof spaced inward from the outer edge  83  rests on the upper edge of the cylindrical wall  1 . Lifting the center of the roof closes the sectoral opening  41  shown in  FIGS. 1 and 2 . The abutting radial edges of the closed sector are bridged with steel strips that are welded in place, and then both radial edges  43  and  45  are welded together. The lower edges of the vertical flanges  63  of the radial supports  61  are welded continuously to the roof plate surface  81  on both sides of the flanges  63 . The joint of the conical roof  81 , with the circular upper edge of the cylindrical support wall, is welded inside and outside. 
     FIG. 14  shows lifting the center of the flat roof  21  with a ram  131 . 
     FIG. 15  shows the addition of a compression ring  85  on the inner edges  71  of the long radial supports  67 , and the addition of a vent pipe  87  in the central opening  47 . A safety railing  91  is being installed around the periphery of the roof. The lower outer portion of the roof is welded to the upper edge of the cylindrical support shell, both on the inside surfaces of the upper edge and the outer surfaces of the upper edge. 
   As shown in  FIG. 15 , a conical compression plate  85  is welded to the upper surfaces of the angle iron supports  61  near their inner edges  71 . A curved vent pipe  87  is welded to the central opening. Finally a safety railing  91  is welded along the outer edge  83  of the conical roof  81 . 
   The assembled roof is self-supporting. The roof holds its own conical shape and is supported only by the upper edge of the cylindrical support ring  1 . 
     FIG. 16  is a cross sectional view of a roof and wall connection of the present invention showing welding spots. A roof  141  is attached to side walls  143  by welding  145  the inside and outside connection between the wall  143  and roof  141 . 
     FIG. 17  is a cross sectional view of a roof and wall connection from existing conical roofing showing welding spots. In prior systems, a conical roof  147  was connected to a wall  149  by use of a bracket  151  that was welded  153  to both the conical roof  147  and to the wall  149 . However, this process often results in rust forming at the connection  155  between the conical roof  147  and wall  149 . 
     FIG. 18  is a cross sectional view of a roof and wall connection from existing domed roofing showing connections. In prior systems, a domed roof  157  rested on top of a shelf  159  in a wall  161 . 
   Because of the unusual construction of the new conical roof, the roof can be assembled in a short time with the welding of precut sheets in a flat condition, followed by the interval welding along lower edges of radial supports to the welded roof plates. Lifting of the center of the roof vertically closes the open sector. Bridge strips are welded across the abutted radial edges before complete welding of the edge. Completion of the welding of the radial roof support beams, adding and welding a compression ring, completes the roof. Welding inner and outer circular joints between the upper edge of the support ring  1  and circular portions of the lower surface of the conical roof  81  spaced inward from the outer edge  83  holds the roof in place. 
   The unique construction of the roof is accomplished with a fraction of the cost and time associated with constructing a cylindrical or domed roof on a large circular structure, and is constructed with straight welding. 
   While the invention has been described with reference to specific embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention, which is defined in the following claims.

Technology Classification (CPC): 4