Abstract: A wastewater leaching chamber having asymmetric corrugations running transversely along the length of the chamber, where each transverse corrugation has a wide section on one side and a narrow section on the opposed side of the chamber, such that the corrugation walls run at an angle to the longitudinal axis of the chamber. The widest corrugation side of the chamber has a large straight sidewall, and the corrugation forms an arch which curve across and downward from the top of the straight sidewall to the narrow side of the corrugation at the opposing base of the chamber. The asymmetric arch is comprised of a multi radius curve from the top of the straight side to the opposing base footer.

Abstract: A golf swing training device, comprising a cylindrical rod and a cylindrical sleeve configured to receive the rod. The rod has a first groove located on the rod and a second groove spaced a distance apart from the first groove on the rod. A diameter of the sleeve is larger than a diameter of the rod. The sleeve is configured to rotate around the rod but confined to the distance between the first and second grooves.

Abstract: A vibration damping structure for a heat-transfer tube bundle including columns arranged at an interval and each composed of a plurality of heat-transfer tubes curved in a common plane and arranged in parallel to each other. The vibration damping structure includes a first vibration damping member and a second vibration damping member disposed between the columns so as to intersect the array direction of the columns. The first vibration damping member and the second vibration damping member are disposed at different positions in an axial direction of each heat-transfer tube, and thicknesses of the first vibration damping member and the second vibration damping member in the array direction are larger than an average value of a clearance between the columns under operation.

Abstract: A casing exit joint with guiding profiles and methods for use are provided. In one embodiment, a casing exit joint comprises: a substantially tubular casing joint comprising an inner surface and an outer surface, wherein at least a circumferential portion of the inner surface comprises a plurality of axial inner grooves. In certain embodiments, at least a circumferential portion of the outer surface may comprise a plurality of axial outer grooves. The casing exit joint may be disposed in a wellbore penetrating at least a portion of a subterranean formation, and a cutting tool may cut a window through at least a portion of the casing exit joint. In certain embodiments, the axial inner grooves and/or outer grooves may reduce the amount of milling debris, prevent lateral displacement of the cutting tool, and/or eliminate the need to pre-orient the casing exit joint to achieve the desired exit window.

Abstract: A multimedia stadium soccer goalpost and goal net display. The system includes a rear support-and-multimedia assembly for supporting the net and producing audible and visual effects. The system also includes a stadium soccer goal frame and a net. The rear support-and-multimedia assembly includes at least two upright posts, a rear crossbar, and a multimedia bar system. The two upright posts and the rear crossbar delineate a U-shape and the multimedia bar system is mounted to said U-shape. The multimedia bar system includes a plurality of lights, a plurality of first speakers, a plurality of sponsor display panels, a retractably screen assembly, and a retractably underground projector in order to audible and visually convey content regarding the soccer game and advertisements to the audience. The system also includes a first corner camera, a second corner camera, and a multitude of rangefinder laser-detector video cameras to track, record, and present gameplay live.

Abstract: A pipeline shield is formed of modular pipeline shield panels into a generally tubular shape to fittingly envelope a pipeline. Each panel is formed of a rectangular sheet of durable material formed or formable into an arcuate shape having longitudinal ribs projecting radially from a surface of the sheet and defining longitudinal valleys, and coupling means configured for secure assembly with other modular pipeline shield panels to form the pipeline shield. The pipeline shield reduces or prevents damage from impact or abrasion when the pipeline is lowered into a trench and buried. The longitudinal ribs may extend an entire length of the panel, or may be less than an entire length of the panel and longitudinally staggered to facilitate rolling of the pipeline in a roller cradle during installation. Drainage holes provide for drainage of liquid away from the pipeline or to provide a path for cathodic protection current.

Abstract: The invention relates to a pipe that has a plurality of layers including a main pipe body with opposite inner and outer circumferential surfaces. The pipe further includes an inner layer with an outer circumferential surface that is in integral face-to-face contact with the inner circumferential surface of the main pipe body. The inner layer is formed from a synthetic resin that is more abrasion resistant than the main pipe body.

Abstract: Rails for drainage channels or manholes are known on which a cover of a channel or of a manhole can be placed. The rail has a horizontal bearing surface (10) extending in a longitudinal direction of the drainage channel or of the manhole and, substantially perpendicular to this bearing face, a rail edge (11) on the inner surface (12) of which the cover can be placed and on the outer surface (13) of which a surface covering can be applied. To increase the strength, it is proposed that the bearing surface (10) and/or the inner surface (12) and/or the outer surface (13) is/are provided with beads (20, 22, 23) over the entire length of the rail (1).

Abstract: A yielding mine roof support is provided which is made in the form of a hollow tube made from an epoxy, phenolic, or polyester fiberglass composite.

Abstract: An impact absorbing pole 5 is disclosed. The pole is formed as a one-piece unit that includes an outer wall 7 and a hollow interior 9 and has a base section 11 for locating the pole below the ground and a pole section 13 for extending upwardly above the ground. The pole is formed so that, in use, the pole can deform above and below ground level when the pole is installed in the ground and is contacted by a vehicle.

Abstract: The invention provides a fluid transfer pipe for filling a cooling circuit of a motor vehicle, and the method for manufacturing said pipe. This pipe includes at least one corrugated bendable portion based on at least one thermoplastic material and which includes a succession of radial reliefs axially spaced so as to form hollows between them, each relief having two frontal regions linked together by an intermediate region, the frontal regions of each relief each having one and the same overall polygonal contour defining at least three straight sections forming flats for this relief and interlinked by rounded sections forming bulges, and the contours of the successive reliefs being adapted to allow for the stripping of the corrugated portion from two hemicylindrical shells of a mold along a single axial stripping plane.

Abstract: The present invention relates to a flexible tube with folding bellows and a plurality of convolutes formed in the wall of the tube and the folding bellows has a convolute which has two opposite bending zones and two restricted elongation zones, where the arrangement has the restricted elongation zones between the opposite bending zones, and the height of the external surface of the convolutes in the restricted elongation zones is below the height of the external surface of the convolutes in the bending zones but still above external surface of the tube, and the wall thickness of the flexible tube in at least one restricted elongation zone in at least one convolute, preferably in all convolutes, of the restricted elongation zones of the tube is specifically greater than the wall thickness in the bending zones.

Abstract: A rotationally molded large-diameter pipe fitting, the wall structure of which is characterized as having a generally smooth interior surface and an exterior surface that is defined by a plurality of axially-spaced circumferentially extending ribs which are monolithically formed and homogeneous with the smooth interior surface of the fitting. The fitting is seamless and modularly designed with integral coupling elements at each terminal end, and with a ribbed wall structure profile capable of withstanding the loads typically found in buried applications with watertight performance requirements, where such ribbed wall structure meets the following dimensions and dimensional ratios: Rib Sidewall Angle (95-105 degrees); Bottom/Top Rib Thickness Ratio (1.80-2.80); Pitch/Rib Height Ratio (1.50-1.95); Rib Height/Fitting Diameter Ratio (0.04-0.09); and Avg. Rib Thickness/Rib Height Ratio (0.28-0.40).

Abstract: An extendable and retractable pressure hose can be constructed comprising an input connector, an output connector, an elastic inner hose, an outer cover, and one or more portions of the elastic inner hose engaged with the outer cover and disposed between the first and second ends of the hose. In such a hose, the input connector and output connector can be connected to each end of elastic inner hose and outer cover.

Abstract: A reinforced pipeline liner designed to facilitate installation and systems and methods for producing and installing a reinforced pipeline liner. A reinforced pipeline liner can comprise a body portion having a layer of matrix material, the layer having an inner surface and an outer surface, and a plurality of interspersed reinforcement structures embedded within the body portion. The reinforcement structures are positioned between the inner surface and outer surface of the layer and circumferentially offset from the other reinforcement structures. Additionally, the body portion may have multiple thicknesses.

Abstract: It is an object of the present invention to close a slit as easily as possible while suppressing positional displacement of both end edge portions flanking the slit. A corrugated tube includes a corrugated tube body portion formed in a tubular shape in which annular projecting portions and annular recessed portions are alternately formed in a longitudinal direction and a slit is formed in a longitudinal direction; a plurality of first extended pieces provided on one side of both side edge portions flanking the slit in the corrugated tube body portion; and a plurality of second extended pieces provided on the other side of both the side edge portions. The slit is closed in a state where the plurality of the first extended pieces and the plurality of the second extended pieces are disposed on an inner circumferential side of the corrugated tube body portion at different positions.

Abstract: A metal pipe of single piece construction including a wall formed of a single corrugated metal sheet. The sheet has opposing first and second edges extending longitudinally along the sheet. The wall includes a seam that is formed by abutting portions of the first and second edges. The seam extends helically about and along a length of the wall. The sheet has a cross-sectional profile defining 3 corrugation peaks at an exterior wall surface and 3 flat segments, wherein each corrugation peak is separated from an adjacent corrugation peak by a respective one of the 3 flat segments. The sheet has a flattened sheet width of approximately 27 inches and a finished sheet width of approximately 24 inches. The wall defines a pipe diameter of at least 96 inches.

Abstract: The flexible hose of the present invention is crush resistant, burst resistant, and virtually impossible to kink in normal use and is applicable to hoses that are designed for delivering virtually any kind of fluid including water, organic liquids, aqueous based herbicides, aqueous based insecticides, industrial chemicals, beverages, air, industrial gases, vacuum, and the like. The hose design of the present invention is particularly applicable to garden hoses for the delivery of water. In fact, garden hoses having the construction of the present invention are highly resistant to kinking and almost never kink when being used in conventional lawn, garden, and cleaning applications.

Abstract: The invention describes a device and method for making corrugated products. The device can be used with any substrate and includes, at least, first and second drive rollers for driving a middle substrate and a single wall corrugated product. In other embodiments the invention includes upper drive rollers, lower drive rollers and middle drive rollers for driving an upper substrate, a lower substrate and a middle substrate. The middle substrate is driven between the upper and lower substrates at a higher velocity to form flutes that are anchored between the upper an lower substrates thereby forming a corrugated product. The invention also provides for customized corrugated products having multiple fluted substrates in various desirable arrangements. Examples of such products include mattresses, partition panels, other furniture, construction products such as tubes or pipes previously made from metals or concrete.

Abstract: A pipe with a rib includes a pipe portion, and a rib portion formed inside the pipe portion. The rib portion includes a plurality of bent portions in accordance with bending of the pipe portion.

Abstract: A downspout extension has a low-profile to direct rainwater away from a building. A transition adapter can be used to transition from a generally circular or square cross-section of a downspout to a low-profile cross-section of a corrugated duct of the extension. The extension can include internal supports to withstand being stepped on and can have a generally rectangular or trapezoidal cross-section with a longer width than height. The corrugated duct can also be comprised of integrated accordion corrugation sections and transverse non-collapsible ribs to give the corrugated duct extension greater flexibility. The extension can be connected to a downspout using a flexible elbow duct, a downspout connector, and a downspout adapter. The transition adapter of the extension can also be connected directly to a downspout.

Abstract: A pipe joint for plastic pipe includes a bell member and a spigot member. The bell member includes a tubular plastic body wall having a metal reinforcement ring. The spigot member, which is insertable into the bell member, includes a tubular plastic body wall having an internal surface and an external surface and a longitudinal axis and metal reinforcement encased within the tubular plastic body wall. A plurality of plastic ribs extend from the external surface of the tubular plastic body wall and form a gasket channel.

Abstract: A metal pipe of single piece includes a wall formed of a single corrugated metal sheet. The sheet has opposing first and second edges extending longitudinally along the sheet. The wall includes a seam formed by abutting portions of the first and second edges. The seam extends helically about and along a length of the wall. The wall has an interior wall side and an opposing exterior wall side. The metal sheet has an interior wall side and an opposing exterior wall side. The interior wall side defines an inner wall surface of the wall, and the exterior wall side defines an outer wall surface of the wall. The sheet has a sinusoidal cross-sectional profile defining 5 corrugation peaks at the inner wall surface and 5 corrugation peaks at the outer wall surface. The sheet has a flattened sheet width of approximately 27 1/4 inches and a finished sheet width of approximately 23 inches.

Abstract: A metal pipe of single piece construction including a wall formed of a single corrugated metal sheet. The sheet has opposing first and second edges extending longitudinally along the sheet. The wall includes a seam that is formed by abutting portions of the first and second edges. The seam extends helically about and along a length of the wall. The sheet has an interior wall side and an opposing exterior wall side. The interior wall side defines an interior wall surface of the wall. The exterior wall side defines an exterior wall surface of the wall. The sheet has a sinusoidal cross-sectional profile defining 3 corrugation peaks at the interior wall surface and 3 corrugation peaks at the exterior wall surface. The sheet has a flattened sheet width of approximately 27 inches and a finished sheet width of approximately 21 inches. The wall defines a pipe diameter of at least 96 inches.

Abstract: An endoscope shaft made of a composite tube comprises an external tube and an internal tube which is softer and more resilient compared to the external tube as well as a helical spring for stiffening the composite tube. According to the invention, the helical spring in the relaxed state has an outer diameter which is larger than the inner diameter of the internal tube. Furthermore the helical spring is inserted in the internal tube preferably loosely at a spring bias, whereby it is radially pressed against the internal tube.

Abstract: In a double-layered construction corrugated tube 23 of a wire harness 21 which are provided on an outer side of a high voltage cable 22, an outer corrugated tube 26 is formed without a slit. In addition, an inner corrugated tube 27 is formed so as to be inserted from one end to the other end of the outer corrugated tube 26 with the high voltage cable 22 accommodated therein. The inner corrugated tube 27 is formed so that a pitch P1 between adjacent ridge portions 38 thereof is narrower than a pitch P2 between adjacent groove portions 30 of the outer corrugated tube 26.

Abstract: A metal pipe of single piece construction including a wall formed of a single corrugated metal sheet. The sheet has opposing first and second edges extending longitudinally along the sheet. The wall includes a seam that is formed by abutting portions of the first and second edges. The seam extends helically about and along a length of the wall. The sheet has an interior wall side and an opposing exterior wall side. The interior wall side defines an interior wall surface of the wall. The exterior wall side defines an exterior wall surface of the wall. The sheet has a sinusoidal cross-sectional profile defining 3 corrugation peaks at the interior wall surface and 3 corrugation peaks at the exterior wall surface. The sheet has a flattened sheet width of approximately 27 inches and a finished sheet width of approximately 21 inches. The wall defines a pipe diameter of at least 96 inches.

Abstract: A decoupling element for a conduit includes an interior hose made of metal and a corrugated exterior hose surrounding the interior hose, with a hollow-cylindrical gap formed between the corrugated exterior hose and the interior hose. At least one damping element is arranged in the gap, with the damping element(s) constructed of a woven fabric made of a high-temperature-resistant material and having an outside surface with at least one bulge, wherein the bulge positively engages with a corrugation of the exterior hose. The exterior hose may be a membrane bellows. The woven fabric may be a metallic material. The at least one damping element covers, along the rotation axis, preferably a proportional length of at least 20% of the hollow-cylindrical gap and has preferably a static stiffness in the radial direction of less than 100 N/mm.

Abstract: A device for manufacturing a flat profile corrugated tube includes a supplying portion for pushing out and supplying a molten resin material in the form of a sheet, a pair of metal molds for molding a profile corrugated tube, a driving mechanism portion capable of changing postures of the pair of metal molds into receiving postures in which the metal mold surfaces are opened and can receive a sheet-formed molded body supplied from the supplying portion and molding postures in which the metal mold surfaces are closed, and changing the postures of the pair of metal molds into the molding postures after the sheet-formed molded body supplied from the supplying portion is received in the receiving postures, and an adhesion molding portion for causing the sheet-formed molded body supplied from the supplying portion to adhere to the metal mold surfaces of the pair of metal molds taking the receiving postures.

Abstract: A tubular structure having a multi-layer, strength-enhanced first end segment, a multi-layer, strength-enhanced second end segment, and a flexible segment intermediate said multi-layer strength-enhanced first end segment and said multi-layer, strength-enhanced second end segment is provided. Methods for manufacturing tubular structures are also provided.

Abstract: A duct for enclosing post tension reinforcing tendons includes a first closed circumference conduit having at least one minimum internal radius. The conduit includes at least one corrugation including two longitudinally spaced apart end members wherein a radial outer surface of each end member defining at least one external radius. A reduced diameter portion is disposed between the two end members. The reduced diameter portion defining at least one intermediate radius larger than the at least one minimum internal radius and smaller than the at least one external radius.

Abstract: A method for treating wastewater in a leaching field comprises forming and burying in soil a continuous curve arch shape cross section injection molded thermoplastic leaching chamber. The chamber has inwardly curving sidewalls perforated with closely spaced horizontal slots and peak corrugations which are closely spaced apart on about 8 inch center-to-center distance or less. The chamber configuration in combination with certain plastic material properties and thickness provide strength sufficient to meet regulatory requirements when the soil above the buried chamber is subjected to load.

Abstract: The present invention relates to a method for the manufacture of a connection between a corrugated tube and a further body, wherein the further body has a bore having a bore diameter which is smaller than the outer diameter of the corrugated tube, with the method including the step of drawing or pressing the corrugated tube into the bore.

Abstract: Fluid line and method of making fluid line that includes an inner contour structured with wave peaks and wave troughs. Each wave peak has a front flank and a rear flank, and the front flanks are structured with an inclination angle, relative to a longitudinal axis, shallower than an inclination angle of the rear flanks.

Abstract: Methods and apparatus for transmitting a fluid through the core of a metal sandwich structure. Improved metal sandwich sheet structures include a formed metal core that is brazed, welded, or bonded to two outer flat metal sheets at a series of interleaving surface regions. The inventor has recognized that fluids (e.g., liquid and/or gaseous substances) can be transmitted through the cavities of these structures in order to accomplish thermal conduction or as a means of servicing particular regions of a building, vehicle, device, or other work of construction.

Abstract: A multi-layer bell is formed from the outer shell of a multi-layer pipe in a secondary process, thereby allowing the extrusion process to be conducted at normal speeds. The bell may include a strain limiting membrane fused or mechanically secured between the outer shell extrusion layer and the inner liner extrusion layer, increased hoop or circumferential stiffness. This invention allows the extrusion process to be in its simplest form, with no adjustments to the corrugator or extruder speeds.

Abstract: An umbilical (2) has a center tube (4) that is a steel tube, and that the cross section of the center tube (4) at the extremity of the umbilical (2) is made corrugated on a length that extends substantially from the extremity to a distance from the extremity so that fatigue strain on non corrugated parts of the steel tube is avoided when the extremity of the umbilical (2) is inserted into a bend stiffener (1).

Abstract: A metal pipe of single piece includes a wall formed of a single corrugated metal sheet. The sheet has opposing first and second edges extending longitudinally along the sheet. The wall includes a seam formed by abutting portions of the first and second edges. The seam extends helically about and along a length of the wall. The wall has an interior wall side and an opposing exterior wall side. The metal sheet has an interior wall side and an opposing exterior wall side. The interior wall side defines an inner wall surface of the wall, and the exterior wall side defines an outer wall surface of the wall. The sheet has a sinusoidal cross-sectional profile defining 5 corrugation peaks at the inner wall surface and 5 corrugation peaks at the outer wall surface. The sheet has a flattened sheet width of approximately 27¼ inches and a finished sheet width of approximately 23 inches.

Abstract: A pipe joint for plastic pipe includes a bell member and a spigot member. The bell member includes a tubular plastic body wall having a radially outer side including a pair of spaced apart circumferentially extending ribs and a metal reinforcement ring located between the ribs. The tubular plastic body wall includes a circumferential plastic ring portion extending between the ribs and radially exterior of the metal reinforcement ring to encase the metal reinforcement ring within the tubular plastic body wall. A radial gap may be provided between the plastic ring portion and the metal reinforcement ring to accommodate differing thermal shrinkage rates as between the two different materials. The spigot member, which is insertable into the bell member, includes a tubular plastic body wall having an internal surface and an external surface and a longitudinal axis and metal reinforcement encased within the tubular plastic body wall.

Abstract: A fluid line includes at least one corrugated section having wave peaks and wave troughs and at least one tie rod arranged in at least one portion of the corrugated section and being coupled to plural wave peaks. A method of making the fluid line includes forming at least one corrugated section at an end area or beginning area of a generally cylindrical section of the fluid line.

Abstract: A metallic tubular structure having an inner surface providing a passage for conveying fluid or vapor, an outer surface, a multi-layer, strength-enhanced first end segment, a multi-layer, strength-enhanced second end segment, and a flexible segment intermediate the multi-layer, strength-enhanced first end segment and the multi-layer, strength-enhanced second end segment, the metallic tubular structure comprising: a first inner metallic tubular member, the inner surface thereof providing a fluid- or vapor-conveying passage for conveying fluid or vapor therethrough, the first inner metallic tubular member longitudinally extending the entire length of the metallic tubular structure, the first inner metallic tubular member comprising one or more metallic layers; a second metallic tubular member circumferentially disposed on the outer surface of a first end of the first inner metallic tubular member, the second metallic tubular member longitudinally extending a predetermined distance on the first inner metallic tu

Abstract: A composite strip 10 windable to form a helical pipe for transporting fluid is disclosed. The composite strip comprises: an elongate plastic strip 11 having a base portion 12, the base portion 12 having an upper side defining an outer face 15; and at least one lengthwise extending composite rib portion 20 upstanding from the outer face 15 of the base portion 12. The rib portion 20 has a distal end 23 remote from the base portion 12. The composite rib portion comprises: an elongate inboard reinforcing member 30 disposed within or adjacent to the base portion 12; an elongate outboard reinforcing 40 member disposed within the distal end 20 of the rib portion 20 parallel to the inboard reinforcing member 30; and an elongate intermediate plastic web 23 portion extending between the inboard and outboard reinforcing members 30, 40. When wound into a helical pipe, the composite rib portion 20 reinforces the pipe against radial crushing loads.

Abstract: Modified-profile metal strips, and annular and spiral metal pipes and other products formed from such strips. The strips comprise a plurality of spaced longitudinal ribs of size and transverse location selected to increase the strength of a given thickness or gauge of the strip and the associated strength of a product formed from the strip.

Abstract: A filler pipe, wherein a flow path for a fluid is formed through multiple resin materials being extruded simultaneously and wherein a corrugated part is shaped through peaks and valleys disposed continuously, comprises an outer layer formed from a high density polyethylene, a barrier layer formed from EVOH with superior resistance to fuel permeation, and an inner layer, formed from high density polyethylene. The structure is such that d<L when the depth from the apex of the peak to the bottom of the valley is defined as d, and the distance from the apex of the peak to the barrier layer is defined as L.

Abstract: A metal bellow tube has sectional shapes of a ridge and a valley in a bellows-shaped tube wall of a metal bellows tube that are made to be V-shaped. As a result, a metal bellows tube with significantly improved bending fatigue resistance compared to conventional ones is provided. In addition, by this metal bellows tube and a tubular metal braid covering the outside of the tube, a flexible tube for a high-pressure fluid can be constituted. Consequently, a high-pressure fluid exceeding 20 MPa, particularly even a superhigh-pressure fluid of 70 MPa, can be transferred safely without transmitting the molecules of the fluid.

Abstract: The present invention relates to a method for making a plastic drainage pipeline reinforced by steel strips, comprising the steps of (1) steel strips and plastic being integrated to form a composite profile having ribs reinforced by steel strips; (2) the composite profiles being transported to an installation site; (3) the composite profiles being wound, and simultaneously the edge of the profile being melted and welded to form plastic drainage pipes reinforced by steel strips; and (4) a spigot joint being made at one end of the pipe. The present invention also relates to a plastic drainage pipe made by the method, comprising a plastic pipe body and reinforcing ribs integrated with the plastic pipe body as a whole, wherein the ribs of the plastic pipe are reinforced by steel strips enwrapped by the plastic. The present invention also provides an apparatus for making the plastic drainage pipe reinforced by steel strips.

Abstract: A coupling for three-wall, corrugated pipe, the pipe including a corrugated wall having a plurality of primary corrugations, is disclosed. The coupling includes a first pipe section having disposed at one end a bell portion, the bell portion having a bell portion of corrugated wall and an outer wall; a second pipe section having disposed at one end a spigot portion, the spigot portion having a spigot portion of corrugated wall between an inner wall and an outer wall; and a gasket disposed in a groove extending around a circumference of the spigot portion and engaged between the bell portion of corrugated wall and the spigot portion of corrugated wall. A three-wall, corrugated pipe section, and method for assembling a plurality of three-wall, corrugated pipe sections, are also disclosed.

Abstract: The present invention relates to a reinforced undersea unit pipe element (1) suitable for being laid empty at great depth. The element includes a tubular wall, having at least one external peripheral reinforcing element (6, 7) creating a plurality of localized zones on the outside surface of the wall, the radial distance (d1) between the outside surface of the pipe and the longitudinal axis (XX?) of the wall in the zones being greater than the outside radius (R) of the tubular wall portions lying between the successive zones in the longitudinal direction (XX?), two successive ones of the zones being spaced apart in the longitudinal direction (XX?) of the tubular wall by a distance (D) equal to ½ to 4 times the outside diameter (d) of the tubular wall portions, the successive zones preferably being spaced apart regularly.

Abstract: A continuous curve arch shape cross section corrugated injection molded thermoplastic chamber is provided and includes a body having a multiplicity of peak and valley corrugations running along the curve of the arch shape, wherein the multiplicity includes opposing sidewalls, each having a foot, opposing chamber ends connected to the body, the ends shaped to form joints with the ends of like chambers, a multiplicity of sprues, within spaced apart valleys, at elevations intermediate the foot and apex of the chamber, wherein each sprue has a first runner running upwardly alone the valley in direction of the apex, and a second runner running downwardly along the valley toward the foot, a base runner connected to the bottom of the second runner, running lengthwise along the foot of the chamber; and at least one third runner connected to the base runner and running upwardly along a peak adjacent the valley.

Abstract: A continuous curve arch shape cross section leaching chamber made of molded thermoplastic has closely spaced corrugations and sidewalls, portions of which are perforated with horizontal slots. Either or both of the slot height and the local wall thickness of the sidewall portion which defines the slots may vary with slot elevation from the base. The chambers are free of interior and exterior strengthening ribs. They provide high interior storage volume and high leaching area in combination with low mass or weight of plastic material. An exemplary 34 inch wide chamber has more than 1.5 cubic feet of water storage volume per foot, less than 4 pounds weight of thermoplastic material per foot, and at least 30 square inches of slot-provided leaching area per foot.