CONCRETE PIPES AND METHODS FOR THE MANUFACTURE THEREOF

Abstract: A concrete pipe and methods for forming the same are presented by this invention. The pipe includes an inner (12) and outer (18) sleeve separated by a spacer ring (14) which creates a void therebetween. Concrete (22) is poured within this void to solidify the pipe structure. The spacer ring (14) is formed by a plurality of interlocking ring forms (28) which have nesting members to allow for the interconnection thereof. In an alternative embodiment, interlocking forms are employed to form both the inner (12) and outer (18) surface of the pipe. These alternative forms provide convex nesting members (28) which form internal conduits between the inner (12) and outer (18) surfaces that accept reinforcing members (16) or connection members to interlock the forms to one another. Concrete (22) is then filled in these conduits and between the void of the inner (12) and outer (18) surfaces to solidify the pipe construction.

Description: CONCRETE PIPES AND METHODS FOR THE MANUFACTURE THEREOF TECHNICAL FIELD The invention herein resides in the art of concrclc pipes and methods for making the same. More particularly, the present invention relates to a concrete pipe which employs structural forms lo fabricate the pipe from concrclc in situ. Specifically, the present invention relates lo a concrete pipe that is constructed on site with same size intcrlockjng forms that receive concrclc therein lo form the pipe, wherein the length of pipe is provided in lengths much longer than normally available. BACKGROUND ART Storm and sanitary sewer systems currently employ a network of pipes to transfer drainage walcr and the like from point sources to sewage treatment facilities. Most all pipe networks employ concrclc piping that is formed or cast and then cured at a manufacturing facility. These pipe sections must be kept short lo minimize their weight. Longer length pipes produced off-site arc very difficult lo handle and arc prone to breakage during shipment. As such, lengths of pipe arc limited to about 8' lengths and 8' diameters. When installing these short length pipes, a trench must be dug and provided with a sand/rock bed lo support the weight of Ihc pipe and in paiticular the area in which two pipes arc joined together with a joint scaling compound. Unfortunately, due lo the number of joints and ground shifting throughout the seasons, these joints leak allowing sediment, silt and olhcr debris lo enter the pipe. Flow and capacity reductions occur as a result of the debris impeding flow characteristics. The debris also reduces the effective cross-sectional area of the pipe. As such, pipes wilh diameters larger than necessary aie installed lo accommodate the anticipated debris leakage. Another disadvantage of current piping systems is in Ihc overall cosl of transporting short, heavy sections of pipe lo 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 lhat reduces the overall cost of installing a pipe network. Furthermore, there is a need for such a pipe that decreases the occurrences of leaks and that increases the water flow therethrough. DISCLOSURE OF INVENTION In light of Ihc foregoing, it is a first aspect of the present invention to provide a concrclc pipe and mclhod for manufacturing the same. Still another aspect of the present invention is lo provide an inner and oulcr sleeve that is assembled on site, wherein concrclc is poured between the sleeves to form the pipe. Another aspect of Ihc present invention, as set forth above, is to provide a spacer ring between the sleeves, wherein rcbar or other reinforcing rods or cables arc placed between the sleeves and through the spacer ring to provide structural strength for the concrete pipe. Yet another aspect of the present invention, as set forth above, is to provide the spacer rings with interlocking forms that support the 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 the inner and outer surface of the pipe is formed by an inner and outer wall of the form, wherein the form has convex members extending between the inner and oulcr walls with openings therebetween and wherein the convex members nest with the openings between the convex members of an adjacent form. Still another aspcel 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 concrclc or other material for interconnecting the forms. Yet a further aspect of the present invention, as set forth above, is to insert in the conduit pilol spacers with rcbar therethrough or wherein Ihc conduits receive connecting rods that hold the forms in place while concrclc 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 pluralily of elbow forms which may be inserted at one end of a pipe lo receive the opposite 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 the overall cost of installing a network of pipes and wherein the assembled pipe improves the fluid flow over currently known concrete pipes. The foregoing and olhcr aspects of (lie invention which shall become apparent as the detailed description proceeds are achieved by a pipe, comprising: opposed inner and oulcr surfaces; interconnecting members disposed between the inner and oulcr surfaces, the interconnecting members and the opposed surfaces forming cavities therebetween; and the cavities receiving concrclc therein to form a concrete pipe. Other aspects of the invention arc attained by a method for forming pipe comprising the steps of: providing at least two spacer rings; coupling an inner sleeve with the spacer rings; positioning an oulcr sleeve around Ihc spacer rings, the inner sleeve and oulcr sleeve having a void therebetween; and filling concrete in void. Still olhcr aspects of the present invention are attained by a method for forming a pipe, comprising Ihc steps of: providing a pluralily of interlocking forms, the forms having an inner wall, an oulcr wall and a 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 to form a pipe, the inner wall and Ihc outer wall having a void therebetween; and filling concrete in the void lo form a concrclc pipe. BRIEF DESCRIPTION OF THE DRAWINGS For a complete understanding of the objects, techniques and structure of Ihe invention, reference should be made lo the following detailed description and accompanying drawings wherein: Fig. 1 is a partial-sectional perspective view of a concrete pipe according to the present invention; Fig. 2 is an clcvalional 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 concrete pipe; Fig. 4 is an clcvalional end view of an interlocking form used in the alternative embodiment; Fig. 5 is a lop 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 tubular member that may be received within the interlocking forms; and Fig. 8 is a perspective view of an elbow form which is inserted inlo one end of a concrclc pipe lo allow for connection lo an adjacent concrete pipe of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Referring now to the drawings and more particularly lo Fig. 1 , it can be seen that a pipe according 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 al least one spacer ring 14. A plurality of reinforcing rods, cable, wire or rebar 16 arc axially disposed around the inner sleeve 12. An oulcr sleeve or skin 18 is disposed around the spacer rings 14 and Ihc inner sleeve 12 lo form a void 19. A retaining band 20 may be employed around the oulcr sleeves 18 lo connect ends thereof lo one another. Concrclc 22 is then inserted into the void 19 to fill in and interconnect the inner sleeve 12 lo the outer sleeve 18. Of course, any type of fill material may be used in place of Ihc concrete, as long as the fill material meets the structural requirements needed for transferring fluid. Those skilled in the art will appreciate that the inner sleeve 12 and the oulcr sleeve 18 is typically a polymeric sheet of material thai is formablc so that its opposed edges al least touch or overlap one another in order to be welded, fused, bonded with adhesive or the like. Of course, Ihe inner sleeve 12 and the oulcr sleeve 18 may be provided as an cxlrudcd 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 into the void 19. To facilitate the flow of concrete through the void 19 and Ihrough the 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" diamelcr, would be used for venting air and demonstrating completeness of fill. Larger size holes, about 2" in diameter, would be used for depositing concrete inlo the void 19. After the concrclc 22 scls, it will be appreciated that a structurally rigid pipe 10 is formed that can be used lo transfer water, sewage or any other large quantity of liquid material from one point lo another. It is anticipated that the pipe 10 will be of a relatively smaller diameter of between 16 lo 36 inches. 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 arcualcly shaped inner wall 30 and an arcualcly shaped oulcr wall 32. A pair of ribs 34 interconnect the inner wall 30 to the outer wall 32 and form a cavity 35. As those skilled in the art will appreciate, the arcs of the inner wall 30 and the oulcr wall 32 arc sized depending upon the lolal diameter of the pipe desired. Protruding nubs 36 extend from bolh the inner wall 30 and the outer wall 32 at a position opposite the interconnecting ribs 34. The protruding nubs 36 serve lo position the inner sleeve 12 and the oulcr sleeve 18 away from the form 28 and also to provide structural strength to the form. Extending from one end of bolh the inner wall 30 and the outer wall 32 is a hook nesting member 40a and 40b, respectively. The olhcr 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 the respective wall 30 and 32 inwardly toward the opposite wall. Extending from the flange 45 is a base 46 that is substantially parallel with the respective inner wall 30 and outer wall 32. A lip 48 extends substantially perpendicularly from the base 46 and is substantially parallel with the flange 45. The flange 45, the base 46 and the lip 48 form a groove 50 for receiving the finger nesting member 40 from an adjacent form 28. When two interlocking forms 28 arc mated with one another, a connection cavity 52 is formed that alternates with the cavity 35 around the diameter of the spacer ring 14. Those skilled in the art will appreciate that the interlocking ring form 28 is made from a polymeric material which is somewhat flexible, but rigid enough to withstand the weight of concrclc 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 may be assembled to one another by either sliding the finger nesting members 42a and 42b into the appropriate grooves 50 or by inwardly flexing the hook nesting members 40a and 40b while simultaneously pushing the finger nesting members 42a and 42b outwardly so that the nesting members male with one another. Those skilled in the art will readily understand from the foregoing structure how the pipe 10 is assembled. Bolh sleeves 12 and 18 may be formed off-site and then assembled with Ihc spacer rings 14 off-site or near the trench. Alternatively, the pipe may be assembled by workers in proximity to Ihc trench by the process described below. In either case, the assembled sleeves 12 and 18 and the spacer rings 14 are situated in thc trench by the workers. When Ihc sleeves arc assembled off-site, workers will assemble the interlocking ring forms 28 lo form a spacer ring 14. It is envisioned that by using the pipe construction methods disclosed herein, that rock/sand beds will only be required at pipe joints. The spacer rings 14 are then placed in ihe trench at predetermined intervals. The inner sleeve 12 is then inserted into the interior of the spacer ring 14. Alternatively, the spacer rings 14 may be formed around the inner sleeve 12. It is envisioned that a horizontal cantilevered beam or "finger" will be positioned al about waist height onto which workers can slip the inner sleeve 12, the spacer rings 14, the rcbar 16, if desired, and the outer sleeve 18. The rcbar 16 may be inserted ihrough 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 cnd-lo-cnd. If desired, the pipe 10 may be assembled in proximity lo 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, concrclc 22 is directed into the void 19 al cither the end of the pipe 10 or Ihrough the strategically placed larger diameter holes 24. Partial backfilling can begin as soon as the weight of the concrete is sufficient lo stabilize the assembled sleeves and spacer rings. Back-filling may be completed when the concrete is set. Referring now lo Figs. 3-5 it can be seen thai an alternative embodiment of a pipe is designated generally by the numeral 60. The pipe 60 is formed by a pluralily of 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 to that of pipe 10; however, use of the forms 62 precludes the need for an inner and outer sleeve. As best seen in Figs. 4 and 5, the interlocking form 62 provides an arcuate inner wall 68 and an arcuate outer wall 70. Opposed edges 72 extend inwardly from the inner wall 68 and the oulcr wall 70 toward one another and are connected by convex nesting members 74. The convex nesting members 74 arc allcmatingly disposed on each edge of the form 62 so as lo form openings 76 therebetween. Therefore, it will be appreciated that when the respective edges of adjacent interlocking forms 62 arc 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 to form a seal. If desired, joint compound may be disposed along the edges 72 lo furthcr enhance the seal between interlocking forms 62. Of course, other means for scaling the interlocking forms C2 may be employed, such as welding, fusing or the like. As best seen in Fig. 3, when the interlocking forms 62 arc assembled lo one another, the arcualc shape of the interlocking form 62 forms the pipe 60. Moreover, the nesting convex members 74 form a conduit 78 which may receive pilot spacers 84 as seen in Fig. 6. Alternating between the conduits 78 arc cavities 86. The pilol spacer 84 includes a tubular member 88 which frictionally receives a reinforcing rod or rcbar 89 therethrough. Extending outwardly from Ihc tubular member 88 arc semi-circular flanges 90 which arc radially disposed in 90" intervals. It will be appreciated that the outer diameter of the flanges is less than the inner diameter of the conduits 78 so as to allow the pilot spacers 84 and associated rcbar 89 lo be received therein. The pilot spacers 84 function to provide reinforcement and tensile strength lo Ihc pipe 60 when concrete is received between the inner surface 64 and the oulcr surface 66. If desired, a retaining band 92 may be employed to hold the interlocking forms in a pipe configuration until concrete 99 is received therein and sets. Alternatively, an interconnecting rod 94 as shown in Fig. 7 may be used to interconnect the forms 62 lo one another. The interconnecting rod 94 includes a lube 96 which has alternating openings 98 on cither side thereof. Those skilled in the art will appreciate that the interconnecting rods 94 arc sized to fit within the conduits 78 lo assist in their interconnection. As in the previous embodiment, concrete 99 may be inserted through larger diameter holes 24 lo assist with the distribution of concrete between the inner wall 68 and the outer wall 70. Smaller diameter holes 24 may be used lo vent air and check concrete flow. In assembling the pipe 60, the interlocking forms 62 arc 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. Al this time, either the pilot spacers 84 or the interconnecting rods 94 arc inserted into the conduits 78. Next, a retaining band 92 may be provided around the pipe oulcr surface 66 to hold the interlocking forms in place. Once all the interlocking forms 62 are secured to one another concrete 99 is poured in the appropriate void or opening to solidify the structure. Once the concrclc 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 pourcd-in-placc concrclc collars and scaling rings or by banded gaskets, such that Ihc pipe may be free to change length and pivot in the joint. Alternatively, an elbow form 100 as shown in Fig. 8 may be used. A plurality of elbow forms 100 may be disposed around one end of a pipe 60 so that a pipe may be connected lo an adjacent pipe. The elbow form 100 includes a pipe section 102 from which extends an angle section 104 and a coupling section 106. The pipe section 102 fits between the 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 the coupling section 106 which fits over the end of an adjacent pipe. Those skilled in the art will appreciate that the inner diameter of the coupling section 106 is greater than the oulcr diameter of the adjacent pipe. When filled together, a joint 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 1 10. Bolh walls 108 and 1 10 arc arcualcly shaped so lhal when the forms 100 arc joined sidc-by- sidc, a bcll-moulh coupling is formed to interconnect pipes. Extending inwardly from each wall arc edges 112. Between the edges 1 12 on one side of the form 100 is a convex nesting member 1 14 along the length of the pipe section 102 and the angle section 104, and a concave nesting member 1 16 along the length of the coupling section 104. Between the edges 1 12 of Ihc other side of the form 100 is a convex nesting member 118 along the length of the coupling section 106 and a convex nesting member 120 along the length of the pipe section 102 and the angle section 104. A cap 122 interconnects the lops of inner wall 108, oulcr wall 1 10, edges 1 12, concave nesting member 116 and convex nesting member 120. As seen in Fig. 8, the dimensions of the pipe section 102 arc reduced lo fit into the end of the pipe. When placed side-by-sidc, the concave member 1 14 fits into an adjacent convex member 120 and the convex member 116 receives the adjacent concave member 118. Rebar or olhcr reinforcing members may be placed in (he cavity formed by the nesting concave and convex members lo facilitate interconnecting thereof. Concrclc is received in the cavities and between the inner and outer walls to solidify the elbow form. Vents may be provided in oulcr 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 shippcd lo a sile without the need for heavy duty tractor trailers lo deposit the pipe or for cranes lo lift Ihc pipe off the trailer and into the trench. The present embodiments provide longer lengths of pipe and eliminate the possibility of pipe breakage during shipment. Longer lengths also provide a bcllcr seal since there arc less connections between pipes lo be m;ιdc. By virtue of there being less connections and by providing a more complete seal between the pipes, less sill, debris or olhcr mailer 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 the elimination of a crane lo lift the pi|>c inlo the trench. Thus it can be seen that the objects of the invention have been attained by the struclurc and methods of assembly presented above. While in accordance with the patent statutes, only the best mode and preferred embodiment of Ihc invention has been presented and described in detail, the invention is not limited thereto or thereby. Accordingly, for an appreciation of the true scope and breadth of the invention, reference should be made lo the following claims.

Claims: What is claimed is: 1. A pipe, comprising: opposed inner and outer surfaces; interconnecting members disposed between said inner and outer surfaces, said interconnecting members and said opposed surfaces forming cavities therebetween; and said cavities receiving concrete therein to form a pipe. 2. The pipe according lo claim 1 , further comprising: at least one spacer ring disposed between said inner and oulcr surfaces, wherein said inner surface is an inner sleeve received within said spacer ring and wherein said outer surface is an outer sleeve positioned around said spacer ring. 3. The pipe according lo claim 2, wherein said spacer ring comprises a pluralily of forms interconnected at their respective edges. 4. The pipe according to claim 3, wherein each one of said pluralily of forms comprises: an inner wall; an oulcr wall; al least one rib interconnecting said inner wall and said oulcr wall; and a first nesting member extending from an edge of al least one of said inner and oulcr walls that nests with a second nesting member that extends from an edge of al least one of said inner and outer walls. 5. The pipe according to claim 4, wherein said first nesting member extends from each of said inner and outer walls lo nest with said second nesting member which extends from each of said inner and outer walls, said inner and oulcr walls farming said cavities for receiving rcbar therein. 6. The pipe according to claim 1 , further comprising: an interlocking form having an inner wall that forms said inner surface and an outer wall that forms said outer surface, said inner and oulcr walls having a nesting member interconnecting each edge thereof, each said nesting member received in an adjacent interlocking form. 7. The pipe according lo claim 6, wherein said nesting member comprises a pair of opposed edges extending inwardly from said inner and oulcr walls, and a pluralily of convex members interconnecting said opposed edges, there being an opening between said convex members to receive convex members from adjacent interlocking forms. 8. The pipe according to claim 7, wherein said convex members form a conduit when said interlocking forms arc connected, said conduit receiving a plurality of pilot spacers carrying rcbar. 9. The concrete pipe according lo claim 7, wherein said convex members form a conduit when said interlocking forms arc connected, said conduit receiving a tube with openings. 10. The concrclc pipe according to claim 1 , further comprising a plurality of elbow forms having a pipe section and a coupling section, each said pipe section connected to an end of the pipe, wherein said coupling section receives an end of an adjacent pipe. 11. A method for forming a pipe comprising the steps of: providing al least two spacer rings; coupling an inner sleeve with said spacer rings; positioning an outer sleeve around said spacer rings, said inner sleeve and said oulcr sleeve having a void therebetween; and filling concrete in said void. 12. The method according to claim 11, wherein said step of providing comprises the steps of: providing a plurality of interlocking ring forms, each said ring form having an inner wall, an oulcr wall, at least one rib interconnecting said inner wall to said oulcr wall, and a nesting member extending from one of said inner and outer walls to receive an adjacent ring form; and interconnecting said plurality of interlocking ring forms to form said spacer ring. 13. The method according lo claim 12, wherein prior lo said filling step the method provides a step of inserting at least one reinforcing member between said inner and oulcr walls of said spacer rings. 14. The method according to claim 13, further comprising Ihe slcp of inserting between said inner and outer sleeve a pluralily of elbow forms which have a coupling section for receiving an end of an adjacent pipe. 15. A method for forming a concrete pipe, comprising the slcps of: providing a plurality of interlocking forms, said forms having an inner wall, an oulcr wall, and a nesting member interconnecting said inner wall lo said outer wall, said inner wall and said outer wall having a void therebetween; interconnecting said pluralily of interlocking forms to one another by mating said nesting members with one another lo form a pipe; and filling concrete in said void to form a concrete pipe. 16. The method according lo claim 15, wherein said slcp of interconnecting includes the steps of forming a conduit with said nesting members, and inserting a pilot spacer with a reinforcing member into said conduit. 17. The method according to claim 15, wherein said step of interconnecting includes the slcps of forming a conduit with said nesting members and inserting a tube with openings therein. 18. The method according to claim 17, further comprising the step of inserting between said inner and outer walls a pluralily of elbow forms which have a coupling section for receiving an end of an adjacent pipe.

Inventors: BJERKE WILLIAM M, MAJNARIC ANTON B, BJERKE, WILLIAM, M., MAJNARIC, ANTON, B.
Applicants: MAJNARIC TECHNOLOGIES INC, MAJNARIC TECHNOLOGIES, INC.
Application year: 1998
Main classification: F16L9
IPC codes: F16L9