Riser Sections and Risers Made Therefrom

Abstract

A riser section having a generally tapered, e.g., frustoconical wall, the riser section having a first connector assembly at one end of the riser section and a second connector assembly at the other end of the riser section.

What is claimed is: 
     
         1 . A tapered riser section comprising:
 a riser body having a tapered wall, said tapered wall having a first end forming a first opening and a second end forming a second, larger, opening;   said first end having a first connector assembly, said second end having a second connector assembly, said first and second connector assemblies being operative to connect adjoining ends of riser sections to form a riser of desired length, respective ones of said riser sections being nestable.   
     
     
         2 . The riser section of  claim 1 , wherein said wall is generally frustoconical. 
     
     
         3 . The riser section of  claim 2 , further comprising:
 an annular, radially inwardly extending lip on said first end and an annular, radially outwardly extending flange on said second end.   
     
     
         4 . The riser section of  claim 3 , wherein said lip comprises an upper, axially facing lip surface and there is at least one key projecting axially from said lip surface and at least one keyhole formed in said lip and said flange has an upper, axially facing flange surface and there is at least one key projecting from said flange surface and at least one keyhole formed in said flange. 
     
     
         5 . The riser section of  claim 4 , wherein there are at least two circumferentially spaced keys on said lip surface, at least two circumferentially spaced keyholes in said lip, at least two circumferentially spaced keys on said flange surface, and at least two circumferentially spaced keyholes in said flange. 
     
     
         6 . The riser section of  claim 3 , wherein said lip has an annular, radially innermost peripheral lip edge and there are a plurality of first locking tabs projecting radially inwardly from said lip edge and said flange has an annular, radially outermost peripheral flange edge, and there are a plurality of second locking tabs projecting radially outwardly from said flange edge, each of said locking tabs having camming surfaces. 
     
     
         7 . The riser section of  claim 6 , wherein said lip first locking tabs comprise a central portion attached to said lip edge and first and second spaced wing portions on opposite sides of said central portion extending upwardly relative to said central portion, said second tabs comprising a central portion attached to said flange edge and first and second spaced wing portions on opposite sides of said central portion extending downwardly relative to said central portion. 
     
     
         8 . The riser section of  claim 7 , wherein respective ones of first tabs on a first riser section are cammed together with respective ones of first tabs on a second, adjacent riser section wherein first ends of said first and second riser sections are connected to one another. 
     
     
         9 . The riser section of  claim 1 , further comprising:
 an annular, radially inwardly extending first rib on said first end, and an annular, radially outwardly extending second rib on said second end.   
     
     
         10 . The riser section of  claim 9 , wherein there is a first annular, axially facing groove formed in said first rib and a second annular, axially facing groove formed in said second rib. 
     
     
         11 . The riser section of  claim 10 , wherein said connector assembly comprises an annular ring having first and second oppositely directed, axially extending annular splines. 
     
     
         12 . The riser section of  claim 9 , wherein there is an annular lip extending radially inwardly from said first rib and an annular flange extending radially outwardly from said second rib. 
     
     
         13 . The riser section of  claim 12 , wherein said rib is provided with a series of circumferentially spaced holes and said flange is provided with a series of circumferentially spaced holes. 
     
     
         14 . The riser section of  claim 3 , further comprising:
 a first, annular, axially projecting spline on said lip and a second annular, axially projecting spline on said flange.   
     
     
         15 . The riser section of  claim 14 , wherein said connector assembly comprises an annular ring being H-shaped in cross-section and having first and second annular axially opposite facing grooves. 
     
     
         16 . The riser section of  claim 9 , wherein said first rib has an annular, axially upwardly facing first groove and said second rib has an annular, axially downwardly facing second groove. 
     
     
         17 . The riser section of  claim 9 , wherein said first annular rib has an annular radially innermost peripheral first rib surface and there are a plurality of first circumferentially spaced, axially upwardly extending hook shaped members depending from said first rib surface, said first hook shaped members having an axially projecting leg portion and a generally radially projecting foot portion, said foot portion being wedge shaped and said second rib has an annular, radially outermost peripheral second rib surface and there are a plurality of second circumferentially spaced, axially downwardly extending hook shaped members depending from said second rib surface, said second hook shaped members having a generally axially projecting leg portion and a generally radially extending foot portion, said foot portion being generally wedge shaped. 
     
     
         18 . The riser section of  claim 3 , wherein said lip has a plurality of circumferentially spaced holes and said flange has a plurality of circumferentially spaced holes. 
     
     
         19 . A riser, comprising:
 a first riser section having a frustoconical wall, a first, smaller end and a second, larger end;   a second riser section having a frustoconical wall, a first, smaller end and a second, larger end;   said first ends of said first and second riser sections having formations projecting as to one and receiving as to another, said second ends of said riser sections having formations projecting as to one and receiving as to another, whereby respective of first ends of first and second riser sections can be connected together; and   a compression assembly to urge said first ends of said first and second riser sections together.   
     
     
         20 . The riser of  claim 19 , wherein one of said formations comprises an annular, axially facing groove on the first end of said first riser section and one of said formations comprises an annular, axially projecting spline on the first end of said second riser section. 
     
     
         21 . The riser section of  claim 20 , wherein said groove has an annular seal ring disposed therein. 
     
     
         22 . The riser section of  claim 20 , wherein said second ends of said first and second riser sections have formations projecting as to one and receiving as to the other. 
     
     
         23 . A riser, comprising:
 a first riser section and a second riser section, said first riser section having a first smaller end and a second larger end, said first smaller end having an annular, axially facing first groove, said second riser section having a smaller diameter end and a larger diameter end, said smaller diameter end having an annular, axially facing second groove;   an annular spline having a first axial end and a second axial end, said first axial end being received in said first groove, said second axial end of said spline being received in said second groove; and   a compression assembly to urge said smaller ends of said first and second riser sections together.   
     
     
         24 . The riser section of  claim 22 , wherein there is a first seal ring disposed in said first annular groove and a second seal ring disposed in said second annular groove. 
     
     
         25 . A riser, comprising:
 first and second riser sections having frustoconical walls, said first riser section having a first, axially projecting spline at a first end of said first riser section, said second riser section having a second, axially projecting spline at a first end of said second riser section, an annular, H-shaped ring having a first, axially facing opening for receipt of said first annular spline and a second, axially facing opening for receipt of said second annular spline; and   a compression assembly to urge said first ends of said first and second riser sections together.   
     
     
         26 . A riser, comprising:
 first and second riser sections having frustoconical walls, said first riser section having a first, annular rib with a first annular, axially facing groove, said second riser section having a second, annular rib with a second annular, axially facing groove, said first and second axially facing grooves being in register with one another;   a seal ring disposed in said first and second annular grooves; and   a compression assembly to urge said first and second riser sections together.   
     
     
         27 . A riser, comprising:
 a first riser section and a second riser section, said first riser section having a smaller diameter end and a larger diameter end, said larger diameter end having an annular, axially facing, first groove, said second riser section having a smaller diameter end and a larger diameter end, said smaller diameter end having an annular, axially facing, second groove;   a connecting ring, said connecting ring having a base with a first surface and a second surface, a first annular, axially projecting spline extending from said first surface and a second, axially projecting spline extending from said second surface, said first spline having a diameter substantially the same as a diameter of said first groove, said second spline having a diameter substantially the same as the diameter of said second groove, said first spline being receivable in said first groove, said second spline being receivable in said second groove; and   a compression assembly to urge said first and second riser sections together.   
     
     
         28 . A below-ground accessible structure buried at a desired depth below grade, comprising:
 a subsurface structure having at least one opening;   a riser having a first end operatively connected to said opening in said structure and a second end accessible from above-ground so as to provide access into said structure, said riser comprising:
 at least two riser sections, each of said riser sections having a frustoconical wall with a first end and a second end; and 
 a connector for connecting adjacent ends of said first and second riser sections. 
   
     
     
         29 . The riser section of  claim 1 , further comprising:
 a first, annular, radially inwardly extending flange on said first end and a second, annular, radially outwardly extending flange on said second end, said first flange having a top surface and a bottom surface, there being a first, annular, axially facing clip groove in said top surface, and said second flange having a top surface and a bottom surface, there being a second, annular, axially facing clip groove in said bottom surface.   
     
     
         30 . The riser section of  claim 29 , wherein there is a first plurality of generally U-shaped clips connecting the first ends of adjacent riser sections and a second plurality of generally U-shaped clips connecting the second ends of adjacent riser sections. 
     
     
         31 . The riser section of  claim 29 , wherein said generally U-shaped clips comprise a body and first and second spaced arms extending laterally outwardly from said body, each of said arms having an inwardly facing dog, said dogs forming a slot therebetween. 
     
     
         32 . The riser section of  claim 30 , wherein the dogs on one of said first and second arms of said first plurality of clips are received in said first clip groove of said riser section, the dogs on the other of said first and second arms of said first plurality of clips are received in the first clip groove of an adjacent riser section, and the dogs on one of the first and second arms of said second plurality of clips are received in said second clip groove of said riser section, and the dogs on the other of said first and second arms of said second plurality of clips are received in the second clip groove of an adjacent riser section. 
     
     
         33 . The riser section of  claim 31 , wherein said first and second fingers are elastically connected to said body. 
     
     
         34 . The riser section of  claim 29 , wherein said first flange has a first annular seal ring groove on said bottom surface of said first flange and said second flange has a second, annular seal ring groove on said top surface of said second flange. 
     
     
         35 . The riser section of  claim 1 , wherein said first end has a first annular, radially inwardly extending lip, and said second end has a second annular, radially outwardly extending lip. 
     
     
         36 . The riser section of  claim 35 , wherein there is a first plurality of circumferentially displaced latches connected to the interior of said wall adjacent said first end and a second plurality of circumferentially displaced latches connected to the exterior of said wall adjacent said second end, each of said latches comprising a body portion attached to said wall, an elastic arm attached to said body portion and extending axially beyond said first end in the case of said first plurality of latches and axially beyond said second end in the case of said second plurality of latches, said arm having a radially projecting dog, said dog projecting toward said wall and having an undercut surface, said first and second lips having an annular, axially facing angled surface, the angle of said undercut and the angle of said angled surface being generally complementary.