BACKGROUND ART Storm and sanitary sewer systems currently employ a network of pipes lo transfer drainage water arid the like from point sources to sewage treatment facilities. Most all pipe networks employ concrete piping that is formed or cast and then cured at a manufacturing facility. These pipe sections must be kept short to minimize their weight.

Longer length piper produced off-site are very difficult to handle and are prone to breakage during shipment. As such, lengths of pipe are limited to about 8' lengths and 8' diameters.

Wlieii installing these short length pipes, a trench musl be dug and provided with a san(l/rock bcd to supporl lie weight of tile pipe and in particular tlie area in which two pipes are joined together with a joint sealing compound. Unfortunately, due to the number of joints and ground shifting the seasons, these joints leak allowing sediment, silt and other debris to enter the pipe. Flow and capacity reductions occur as a result of tile debris impeding flow characteristics. Tlie debris also reduces tlie effective cross-sectional arca of the pipe. As such, pipe with diameters larger than necessary are installed to accommodate the anticipated debris leakage. Another disadvantage of current piping systems is in the overall cost of transporting short, heavy sections of pipe to the location, preparing a proper bed for all the joint locations and joining the short lengths to one another.

Based upon the foregoing there is a need in the art for a concrete pipe that can be provided in long lengths and that reduces the overall cost of installing a pipe network.

Furthermore, there is a need for such a pipe that decreases tlie occurrences of leaks arid that increases the water flow therethrough.

DISCLOSURE OF INVENTION In light of the foregoing, it is a first aspect of the present invention to provide a concrete pipe and method for manufacturing the same.

Still another aspect of tlie present invention is lo provide an inner and outer sleeve that is assembled on silc, wherein concrete is poured between tlie sleeves lo form tlie pipe.

Another aspect of the present invention, as set forth above, is lo provide a spacer ring between tlie sleeves, wherein rebar or other reinforcing rods or cables are placed between the sleeves and thorough tlie spacer ring to provide structural strength for tlie concrete pipe.

Yet another aspect of the present invention, as set forth above, is to provide the spacer rings will interlocking forms that supporl tlie inner and outer sleeves and receive concrete therein.

An additional aspect of the present invention is to provide a concrete pipe wherein a form is provided with the desired length of pipe and wherein the form provides an inner and oulcr surface.

Yet another aspect of the present invention, as set forth above, is provided wherein tlie inner and outer surface of the pipe is formed by an inner arid ouler wall of the Torin, wherein the form has convex members extending between the inner and outer walls with openings therebetween and wherein the convex members nest with the openings between the convex member of an adjacent form.

Still another aspect of the present invention, as set forth above, is wherein the assembled forms and their respective convex members form a conduit along the length of the pipe for receiving concrete or other material for interconnecting the forms.

Yet a further aspect of lie presenl invention, as set forth above, is to insert in the conduit pilot spacers with rebar therethrough or wherein the conduits receive connecting rods that hold the forms in place while concrete is poured between the inner and outer walls.

Still yet another aspect of the present invention, as set forth in both embodiments above, is to provide plurality of elbow forms which may be inserted at one end of a pipe to receive the oppoite end of an adjacent pipe.

Still a further aspect of the present invention is to provide a concrete pipe and method for assembling the same which reduces (lie overall cosl of inslalling a network

of pipes and wherein the assembled pipe improves the fluid over currently known concrete pipes.

The foregoing and other aspects of the invention which shall become apparent as the detailed description proceeds are achieved by a pipe, comprisng: opposed inner and outer surfaces; interconnecting members disposed between the inner and outer surfaces, the interconnecting members and the opposal surfaces forming cavities therebetween; and the cavities receiving concrete terein to form a concrete pipe.

Other aspects of the invention are attained by a method for formimg pipe comprising the slcps of: providing at least two spacer rings; coupling aii inner sleeve with the spacer rings, positioning an outer sleeve the spacer rings, the inner sleeve and outer sleeve having a void therebetween; and filling concrete in void.

Slill other aspects of lie present invention are attained by a method for forming a pipe, comprising the steps of: providing a plurality of interlocking forms, the forms having an inner wall, an outer wall and nesting member interconnecting the inner wall lo the outer wall; interconnecting the pluralily of interlocking forms lo one another by mating the nesting members with one another lo form a pipe, the inner wall arid ilie ouler wall having a void lherobelween; and filling concrele in the void lo form a concrete pipe.

BRIEF DESCRIPTION OF THE DRAWINGS For a complete understanding of the objects, techniques and structure of the invention, reference should be made to the following detailed description arid accompanying drawings wherein: Fig. 1 is a partial-sectional perspective view of a concrele pipe according lo the present invention; Fig. 2 is an elevational end view of an interlocking ring form used in the assembly of a spacer ring; Fig. 3 is a cross-sectional end view of an alternative embodiment of a concrele pipe; Fig. 4 is an elevational erid view of an interlocking form used in (lie alternative embodiment; Fig. 5 is a top view showing two interlocking forms adjacent one another; Fig. 6 is a perspective view of a pilot spacer received within the interlocking form

of the alternative embodiment; Fig. 7 is a perspective view of a lubular member that may be received within the interlocking forms; and Fig. 8 is a perspective view of an elbow form which is inserted into one end of a concrete pipe to allow for connection to an adjacent concrete pipe of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Referring now to the drawing and more particularly to Fig. 1, it can be seen that a pipe accoriding to the present invention is designated generally by the numeral 10.

The pipe 10 includes an inner sleeve or skin 12 that is received within at least one spacer ring 14. A plurality of reinforcing rods, cable, wire or rebar 16 are axially disposcd around the inner sleeve 12. A, outer sleeve or skin 18 is disposed around the spacer rings 14 and the inner sleeve 12 lo form a void 19. A retaining band 20 may be employed around the outer sleeves 18 to connect ends thereof to one another. Concrete 22 is then inserted into the void 19 to fill and interconnect the inner sleeve 12 to the outer sleeve 18. Of course, any type of fill material may be used in place of the concrete, as long as the fill material the structural requirements needed for transferring fluid. Those skilled in the art will appreciate hat the inner sleeve 12 and the oulcr sleeve 18 is typically a polymeric slicer or material that is formable so that ils opposcd edges al least touch or overlap one another iii order lo be welded, [used, bonded with adhesive or the like. Of cpourse, the iner sleeve 12 and the outer sleeve 18 may be provided as an extruded cylinder. It will further be appreciated that the inner sleeve 12 is structurally strong enough to bear the weight of wet concrete as it is poured inlo the void 19. To facilitate the now of concrete through lie void 19 and through lie spacer rings 14, a plurality of holes 24 may be provided in the outer sleeve 18.

Different size holes 24 may be employed. Smaller size holes, about 1/8" diameter, would be used for venting air and demonstrating comleteness of fill. Larger size holes, about 2" in diameter would be used for depositing concrete into the void 19. After the concrete 22 sets, it will be apprecialed that a structurally rigid pipe 10 is formed that can be used to transfer waler, sewage or any other large quantity of liquid material frorii one point to another. It is anticipated that the pipe 10 will be of a relatively smaler diameter of between 16 lo 36 inclies.

Referring now to Fig. 2, it can be seen that an interlocking form 28 is employed in the construction of the spacer ring 14. The interlocking ring form 28 provides an arcuately shaped inner wall 30 and an arcuately shaped outer wall 32. A pair of ribs 34 interconnect tlie inner wall 30 to (lie outer wall 32 and form a cavily 35. As those skilled in the arl will appreciate, the arcs of tlie inner wall 30 arid tlie outer wall 32 are sized depending upon the total diameter of the pipe desired. Protruding nubs 36 extend from both the inner wall 30 and tlie outer wall 32 al a posilion opposite the interconnecting ribs 34. The prolruding nubs 36 serve to position tlie inner sleeve 12 and the outer sleeve 18 away from lie form 28 and also to provide structural strength to the form. Extending from one end of both (lie inner wall 30 and the outer wall 32 is a liook nesting member 40a and 40b, respectively. The other end of the inner wall 30 and the outer wall 32 has extending therefrom a finger nesting member 42a and 42b, respectively. The hook nesting member 40 includes a flange 45 which extends from lie respective wall 30 and 32 inwardly toward the opposite wall. Extending from the flange 45 is a base 46 that is substantially parallel witli the respective inner wall 30 and outer wall 32. A lip 48 extends substantially perpendicularly from (lie base 46 arid is substantially parallel with the nange 45. The flange 45, tlie base 46 arid the lip 48 forrii a groove 50 for receiving the finger nesting member 40 from an adjacent form 28.

When two interlocking fornis 28 are mated with one another, a connection cavily 52 is formed the alternates with the cavity 35 around the diameter of the spacer ring 14.

Those skilled in the art will appreciate that the interlockig ring form 28 is made from a polymeric material which is somewhat flexible, but rigid enough to withstand the weight of concrete that is filled in the void 19 and also the weight of material that is placed over the pipe 10 when the trench holding the pipe is filled in. The interlocking ring forms niay be assembled lo one another by either sliding the finger nesting members 42a and 42b inlo the appropriate grooves 50 or by inwardly flexing lie hook nmesting members 40a and 40b while simultaneously pushing the finger nesting members 42a and 42b outwardly so that the esting members mate with one another.

Those skilled in the art will readily understand from the foregoing structure liow the pipe 10 is assembled. Both sleeves 12 arid 18 may be formed off-site and then assembled with the spacer rings 14 off-site or near the trench. Alternatively, the pipe may be assembled by workcrs in proximity to the trench by (lie process described below.

In either casc, the assembled slceves 12 and 18 and the spacer rings 14 are silualed in

the trench by the workers.

When the sleeves are assembled off-site, workers will assemble the interlocking ring forms 28 lo lorni a spacer ring 14. It is envisioned that by using the pipe construction methods disclosed herein, that rock/sand beds will only be required al pipe joints. The spacer rings 14 are then placed in the trench at predetermined intervals.

The inner sleeve 12 is (lien inserted inlo the inlerior of lie spacer ring 14.

Alternatively, the spoacer rings 14 may be formed around the inner sleeve 12. It is envisioned that a horizontal cantilevered beam or "finger" will be positioned at about waisl height onto which workers can slip the inner sleeve 12, the spacer rings 14, the rebar 16, if desired, and the outer sleeve 18. The rebar 16 may be inserted through either the cavities 35 or the connection cavities 52 and axially positioned between the sleeves 12 and 18. The off-site assembled pipes may then be shipped to the trench and connected end-to-end. If desired, the pipe 10 may be assembled in proximity to the trench. The ends of the pipe 10 may be held together by the retaining band 20 or other means, if needed. At this time, concrete 22 is directed into the void 19 at either the end of the pipe 10 or through the strategically placed larger diameter holes 24. Partial back- filling can begin as soon as the weight of the concrele is sufficient lo stabilize the assembled sleeves and spacer rings. Back-filling may be completed when tlie concrele is scl.

Referring now to Figs. 3-5 it can be seen that an alternative embodiment of a pipe is designated generally by tlie numeral 60. The pipe GO is formed by a plurality Or interlocking forms 62 each of which provides a pipe inner surface 64 and a pipe outer surface 66. The pipe 60 provides a construction similar lo that of pipe 10; however, use of the forms 62 precludes tlie necd for an inner and ouler sleeve. As best scen iii l igs.

4 and 5, the interlocking form 62 provides an arcuale inner wall 68 and an arcuate outer wall 70. opposed edges 72 extend inwardly from the inner wall 68 and the outer wall 70 toward one another and are connected by convex nesling members 74. The convex nesting members 74 are alternatingly disposed on each edge of the form 62 so as to form openings 76 therebetween. Therefore, it will be appreciated that when the respective edges of adjacent interlocking forms 62 are mated with one another, the convex nesting member 74 is received within a mating opening 76 of the adjacent form 62. Further, the edges 72 bear against an edge 72 of the adjacent interlocking form 62 lo form a seal. If desired, joint compound may be disposed along the edges 72 lo

further enhance (lie seal between interlocking forms 62. Of course, other means for scaling the interlocking forms 62 may be employed, such as weelding, fusing or the like.

As best seen in Fig. 3, when the interlocking forms 62 are assembled to one another, the arcuate shape of the interlocking form 62 forms the pipe 60. Moreover, the nesting convex members 74 a conduit 78 which may receive pilot spacers 84 as seen in Fig. 6. Alternatng between lie conduils 78 are cavilies 86.

The pilot spacer 84 includes a lubular member 88 which frictionally receives a reinforcing rod or rebar 89 therethrough. Extending oulwardly froiii the tubular member 88 are scmi-circular flanges 90 which are radially disposed in 90° intervals. it will be appreciated that the ouler diameter of the flanges is less than the inner diameter of the conduits 78 so as lo allow the pilol spacers 84 and associaled rebar 89 to be received therein. Tlie pilot spacers 84 function lo provide reinforcement and tensile strength to the pipe 60 when concrete is received between the inner surface 64 and the outer surface 66. If desired, a rclaining band 92 niay be employed lo hold the inlerlocking forms in a pipe configuration until concrele 99 is received therein and sels.

Alternatively, an interconnecting rod 94 as shown iri Fig. 7 may be used lo interconnect the forms 62 tp one another. The interconnecting rod 94 includes a tube 96 which has alternating openings 98 on either side thereof. Those skilled in the art will appreciate that the interconnecting rods 94 are sized to fit within the conduits 78 to assist in their interconnection. As in lie previous embodiment, concrete 99 niay be inserted through larger diameter holes 24 to assist with the distribution of concrete between the inner wall 68 and the ouler wall 70. Smaller diameter holes 24 may be used lo vent air arid check concrete now.

In assembling the pipe 60, the interlocking fornis 62 are placed adjacent one another and a minimal force is applied to insert the convex nesting members 72 into the corresponding receiving openings 76. this is continued until the last interlocking form 62 completes the diameter of the pipe. At this time, either the pilot spacers 84 or the interconnecting rods 94 are inserted into the conduits 78. Next, a retaining band 92 may be provided around the pipe outer surface 66 to liold the interlocking forilis in place.

Once all (lie interlocking forms 62 are secured lo one another concrete 99 is poured in the appropriate void or opening to solidify the structure. Once the concrete has set, the trench in which the pipe is held may be filled in.

Both pipe embodiments 10 and 60 may be joined by using poured-in-place concrete collars and scaling rings or by banded gaskets, such that the pipe e may be free lo change length and pivot in the joint. Alternatively, an elbow form 100 as sliown in i;ig. 8 may be uscd. A plurality of elbow forms 100 may be disposed around one end of a pipe 60 so that a pipe may be connected to an adjacent pipe. The elbow form 100 includes a pipe scclion 102 from which extends an angle section 104 and a coupling section 106.

The pipe section 102 fits between (lie pipe inner surface 64 and the pipe outer surface 66 of the pipe 60. The angle section 104 provides a transition from the pipe section 102 lo (lie coupling section 106 which fits over the end of an adjacent pipe. Those skillcd in the art will appreciate that the inner diameter of the coupling section 106 is greater than the outer diameter of the adjacent pipe. When fitted together, a joinl scaling compound may be used to interconnect one end of a pipe lo an end of a pipe which employs the elbow forms 100.

Each elbow form 100 provides an inner wall 108 and an outer wall 110. Both walls 108 and 110 are arcuately shaped so that wlien the forms 100 are joined side-by- side, a bell-mouth coupling is formed lu interconnect pipes. Extending inwardly form eacli wall are cdgcs 112. Between the edges 112 on oiic side of lie foriii 100 is a convex nesting member 114 along the length of the pipe section 102 and the angle seclion 104, arid a concave nesting nieniber 116 along lie length of the coupling scclion 104. Between the edges 112 of the other side of the form 100 is a convex nesting member 118 along the length ofg the coupling sction 106 and a convex nesting member 120 along the length of the piJ)e section 102 arid the angle section 104. A cap 122 interconnects the lops of inncr wall 108, outer wall 110, edges 112, concave nesting member 116 arid convex nesling member 120. As scen in Fig. 8, the dirnensioiis of lie pipe section 102 are reduced lo fit inlo lie end of the pipe. When placed side-by-side, the concave member 114 fits into an adjacent convex member 120 and the convex member 116 receives the adjacent concave member 118. Rebar or other reinforcing members may be placed in the cavity fornied by the nesting concave and convex members lo facilitate interconnecting thereof. Concrete is received in the cavities arid between the inner and outer walls to solidify the elbow form. Vents may be provided in outer wall 110 if needed.

These embodiments provide several advantages over existing concrete pipe and methods for assembling the same. First, the polymeric interlocking forms are easily

shipped to a site without the need for heavy duly tractor trailers lo deposit the pipe or for cranes to lift the pipe off the trailer and into the treanvch. The present embodiments provide longer lengths of pipe arid eliminate the possibility of pipe breakage during shipments. longer lengths also provide a better seal since there are less connections between pipes pipes to be made. By virtue of there being less connections and by providing a more complete seal between the pipes, less silt, debris or other matter enters the completed pipe. This enhances the flow characteristics of the fluid flowing through the pipe. Additionally, by using a polymeric or plastic inner sleeve or surface, the coefficient of friction between the water and the surface is greatly reduced over pipe constructions which have a concrete inner surface. Finally, these embodiments present a total reduced cost over known methods of laying and constructing pipe network systems. This is by virtue of their being less interconnecting joints, a reduction in the amount of rock/sand needed for preparing the bed upon which the pipe rests, less time spent joining pipes together and eliminating of a crane to lift the pipe into the trench.

Thus it can be see seen that the objects of the invention have been attained by the structure and methods of asseiiibly presented above. While in accordance with the patent statues, only the best mode and preferred embodiment of the invention has been presented and described in detail, the invention is not limited thereto or thereby.

Accordingly, for an appreciation of the trues scope and breadth of thge invention, reference should be made to the following claims.