Reinforced plastic pipe

A length of plastic pipe comprising:

• a tubular wall having a first end portion, a middle portion, and a second end portion,
• said middle portion having a generally round transverse cross-section, a uniform mean internal diameter for the longitudinal extent thereof, a plurality of integral, exterior peripheral circular reinforcing flanges disposed at spaced intervals along the longitudinal axis of the tubular wall to provide stiffening, and a plurality of integral longitudinal reinforcing ribs disposed at spaced intervals about the external circumference of the tubular wall to provide stiffening, the height of said circular flanges being equal to the height of said longitudinal ribs,
• said first end portion having a generally round transverse cross-section and presenting a threaded male section having a plurality of protuberant helical thread rib segments on the exterior of said tubular wall, each thread rib having one side surface perpendicular to the exterior surface of said tubular wall for carrying the longitudinal threading bearing forces and one side surface disposed at an angle to, and merging with, the exterior surface of said tubular wall, each thread rib segment extending for a portion of the circumference of said wall thereon, said first end portion further having, between the distal end thereof and said threaded male section, a cylindrical end portion containing an annular groove in the exterior surface of said tubular wall and having a resilient gasket disposed within said annular groove,
• said second end portion having a generally round transverse cross-section, the maximum exterior diameter of said second end portion being equal to the diameter of said middle portion of said tubular wall as measured to the peripheral edges of said circular flanges and longitudinal ribs thereby providing aligned longitudinal support points when said pipe is layed on a support surface, said second end portion presenting a threaded female section having a plurality of indented helical thread groove segments in the interior surface of said tubular wall, each groove segment having one side surface perpendicular to the interior surface of said tubular wall for carrying the longitudinal threading bearing forces and one side surface disposed at an angle to, and merging with, each groove segment extending for a portion of the circumference thereon, whereby said second end portion is adapted to receive a first end portion of another length of similar pipe which is inserted therein and turned for causing threading engagement between the threaded male and female sections to establish a connection therebetween.

A plastic pipe arrangement comprising:

• a first pipe length and a second pipe length connected with said first pipe length, each said pipe length comprising a tubular wall having a first end portion, a middle portion, and a second end portion;
• said middle portion having a generally round transverse cross-section, a uniform mean internal diameter for the longitudinal extent thereof, a plurality of integral, exterior peripheral circular reinforcing flanges disposed at spaced intervals along the longitudinal axis of the tubular wall to provide stiffening, and a plurality of integral longitudinal reinforcing ribs disposed at spaced intervals about the external circumference of the tubular wall to provide stiffening, the height of said circular flanges being equal to the height of said longitudinal ribs;
• said first end portion having a generally round transverse cross-section and presenting a threaded male section having a plurality of protuberant helical thread rib segments on the exterior of said tubular wall, each thread rib segment having one side surface perpendicular to the exterior surface of said tubular wall for carrying the longitudinal threading bearing forces and one side surface disposed at an angle to, and merging with, the exterior surface of said tubular wall, each thread rib segment extending for a portion of the circumference of said wall thereon, said first end portion further having, between the distal end thereof and said threaded male section, a cylindrical end portion containing an annular groove in the exterior surface of said tubular wall and having a resilient gasket disposed within said annular groove;
• said second end portion having a generally round transverse cross-section, the maximum exterior diameter of said second end portion being equal to the diameter of said middle portion of said tubular wall as measured to the peripheral edge of said circular flanges and longitudinal ribs thereby providing aligned longitudinal support points when said pipe is alyed on a support surface, said second end portion presenting a threaded female section having a plurality of indented helical thread groove segments in the interior surface of said tubular wall, each groove segment having one surface perpendicular to the interior surface of said tubular wall for carrying the longitudinal threading bearing forces and one surface disposed at an angle to, and merging with, the interior surface of said tubular wall, each groove segment extending for a portion of the circumference of said wall thereon, said second end portion of said first pipe length receiving the first end portion of said second pipe length which is inserted therein and turned for causing threading engagement between the threaded male and female sections to establish connection therebetween, said longitudinal reinforcing ribs on each pipe length being in alignment for thereby indicating full threaded engagement of said first and second pipe lengths.