Arch conduit

A foldable, partially corrugated conduit comprising:

• a first wall which is elongated in one direction and which has a plurality of first corrugations extending generally transverse to said one direction, said first corrugations extending generally between a first wall apex side edge area which extends substantially in said one direction and a first wall terminal side edge area which extends substantially in said one direction;
• a second wall which is elongated in said one direction and which has a plurality of second corrugations extending generally transverse to said one direction, said second corrugations extending generally between a second wall apex side edge area which extends substantially in said one direction and a second wall terminal side edge area which extends substantially in said one direction;
• hinge means connecting said first wall apex side edge area with said second wall apex side edge area, said hinge means providing for said first wall and said second wall to move arcuately generally about the hinge means at least between a folded position in which said first wall terminal side edge area and said second wall terminal side edge area are generally adjacent each other and an unfolded position in which said first wall terminal side edge area and said second wall terminal side edge area are displaced from each other;
• and
• a foldable base which is elongated in said one direction, said base being connected substantially adjacent said first wall terminal side edge area and being connected substantially adjacent said second wall terminal side edge area, said foldable base being foldable at least generally along a first fold area disposed substantially adjacent said first wall terminal side edge area, generally along a second fold area disposed substantially adjacent said second wall terminal side edge area, and generally along at least a third fold area extending in one direction, said third fold area being disposed generally intermediate said first fold area and said second fold area, whereby said foldable base is foldable along at least the first, second, and third fold area as said conduit is moved between the folded and unfolded positions.

A foldable conduit for conveying fluids in a subterranean installation in which a base of the conduit is adapted to be disposed on a generally flat floor of a trench in an unfolded position and in which the trench is adapted to be backfilled over the conduit, the conduit comprising:

• a first side wall which is elongated in a longitudinal direction and arcuate transverse to the longitudinal direction, said first side wall being relatively strong to resist compressive loading forces from the backfill;
• a second side wall which is elongated in the longitudinal direction and arcuate transverse to the longitudinal direction, said second side wall being relatively strong to resist compressive loading forces from the backfill;
• a longitudinally elongated hinge area interconnecting said first side wall and said second side wall at an apex area which is disposed opposite said base, said first side wall and said second side wall being adapted to be moved arcuately about the hinge area between a folded position in which the first and second side walls are generally parallel to each other and an unfolded position in which the first and second side walls have a generally arched cross section;
• said base comprising a foldable material which is adapted to rest in the unfolded position substantially horizontally on and conform generally to the generally flat floor of the trench, said foldable material being sufficiently foldable that but for support received from the floor of the trench the material would fold downward under the weight of conveyed fluids, said base being connected longitudinally in both the folded and unfolded positions with said first and second side walls.

A conduit comprising:

• a longitudinally elongated element having a substantially semiround cross section which has an apex area disposed substantially at the top of the element and a pair of displaced longitudinal terminal side edge areas disposed generally at the bottom of the element, the terminal side edge areas defining a generally planar base area therebetween;
• the elongated element having a plurality of transverse corrugations extending from the apex area to both of said terminal side edge areas;
• said corrugations comprising outward extending peaks and inward extending valleys, the difference between the outward extension of the peaks and the inward extension of the valleys being the height of the corrugations, said peaks defining an outer surface of the elongated element and the valleys defining an inner surface of the elongated element;
• the corrugations having a first height adjacent the terminal edge areas, a second height adjacent the apex area, and between the apex area and the terminal edge areas at each point along the semiround cross section the corrugations having a height which is greater than the first and second heights and varies with the tendency of the elongated element to deflect at the same point along the semiround cross section under subterranean loads.

A longitudinally folded plastic conduit comprising:

• a longitudinally elongated first side wall having a longitudinally extending apex side edge area and a longitudinally extending terminal side edge area, said first side wall being arcuate transverse to the longitudinal direction;
• a longitudinally elongated second side wall having a longitudinally extending apex side area and a longitudinally extending terminal side edge area, said second side wall being arcuate transverse to the longitudinal direction;
• an elongated foldable base operatively connected with the terminal side edge area of the first wall and with the terminal side edge area of the second wall;
• a longitudinal hinge means pivotally connecting the apex side edge areas of the first and second walls;
• and
• the terminal side edge areas of the first and second side walls being disposed substantially adjacent each other, said base being folded substantially between and inside said first and second side walls, whereby the side walls are adapted to pivot about the hinge moving the terminal side edge areas apart which at least partially unfolds the base from inside the first and second side walls.

A corrugated plastic conduit comprising:

• a first corrugated plastic wall which is elongated along a longitudinal axis and arcuate transverse to the longitudinal axis, the first wall having two longitudinally extending edges,
• a second corrugated plastic wall which is elongated along the longitudinal axis and arcuate transverse to the longitudinal axis, said second wall having two longitudinally extending edges, one of said second wall's longitudinally extending edges being integrally connected with one of said first wall's longitudinally extending edges, whereby the first and second walls form an elongated element having a semiround cross section;
• and
• a smooth, flexible plastic base which is thinner than said first and second walls, said base being connected longitudinally adjacent one of the longitudinally extending edges of the first wall and one of the longitudinally extending edges of the second wall, said base being freely flexible at least along the longitudinal axis and transverse to the longitudinal axis.

A corrugated plastic conduit which is disposable in a folded and in an unfolded configuration, said conduit comprising:

• a first corrugated plastic wall which is elongated along a longitudinal axis and arcuate transverse to the longitudinal axis, said first wall having a longitudinally extending apex side edge area and a longitudinally extending terminal side edge area, said first side wall being relatively strong to resist compressive loading forces;
• a second corrugated plastic wall which is elongated along the longitudinal axis and arcuate transverse to the longitudinal axis, said second wall having a longitudinal extending apex side edge area and a longitudinally extending terminal side edge area;
• means for connecting the apex side edge areas of said first and second walls together in such a manner that in the unfolded configuration the terminal side edge areas of the first and second walls are displaced and the connected first and second walls have a generally arch-like cross section transverse to the longitudinal axis, and a generally flat base which is elongated along the longitudinal axis and has a width transverse to the longitudinal axis, said base being foldably connected with the terminal side edge areas of said first and second walls to allow relative folding between the base and the first and second walls, the width of the base limiting the amount by which the terminal side edge areas of said first and second wall can be displaced in the unfolded configuration, whereby the first and second side walls can be folded generally parallel to each other to form the folded configuration of the conduit.