Patent Publication Number: US-2006012165-A1

Title: Modular connection system

Description:
This application is a continuation of U.S. Provisional Patent Application Nos. 60/588,857 filed Jul. 16, 2004 and 60/667,000 filed Mar. 31, 2005 entitled Modular Connection System. 
    
    
     TECHNICAL FIELD  
      The present invention relates to pipe connections and more particularly, relates to a modular pipe connection system and method.  
     BACKGROUND  
      There currently exist many devices for connecting a pipe to an opening in a concrete structure such as a tank, manhole, or utility vault. One category of these known devices are expanded-in-place (EIP) systems that include a rubber boot having an expandable band at one end creating a seal between the rubber boot and the structure and a contractible band at the other end of the to be connected. These known EIP devices have several limitations.  
      For example, structures such as septic tanks and utility vaults are often manufactured with pre-configured connection points, i.e., the pipe connections leading into and out of the structures are often the same. In order to reduce the manufacturing and installation costs of these structures, it is desirable to be able to produce them having a plurality of predefined and arranged openings within the structure in order to facilitate the pipe connection.  
      Traditional EIP connection systems cannot be installed during the manufacturing process when the structure is cast in the forms. As a result the known EIP connection systems must be installed in the production facility or in the field. This requires a hole/opening to be drilled or cast within the structure during the manufacturing process or in the field which can increase labor costs and introduce installation problems due to installer error and varying level of skill and experience.  
      Moreover, known EIP connection systems are intended only two make a connection between the structure and a pipe and cannot easily form a plug. Consequently, if a structure with openings already in place is manufactured and not all the openings are utilized, the known connection systems cannot effectively be used to plug the opening in the structure. This creates a further impediment to creating a structure with openings already in place. As a result, each structure must be individually designed in order to create the desired number and arrangement of openings (thereby increasing labor costs and production times) or individually created after the structure has been manufactured (thereby increasing the labor and installation costs).  
      Another feature of known EIP connection systems is the use of expandable bands. Because of the moving parts and the overall complexity of the expandable bands, they are expensive to manufacture, thus increasing the overall price of the connection system. In order for the expandable band to create sufficient expansion pressure to seal between the boot and the opening of the structure, the expandable band must be made of a relatively heavy gauge, non-corrosive material such as stainless steel, thus further increasing the costs.  
      Accordingly, it is desirable to have a connection system that can be molded or cast in place in concrete during the manufacture of the structure, thereby reducing the manufacturing and installation costs of the connection system. The connection system should preferably be able to be made watertight and effectively form a plug in the event that an opening is not utilized. Additionally, the connection system should be less expensively produced than known EIP connection systems.  
      It is important to note that the present invention is not intended to be limited to a system or method which must satisfy one or more of any stated objects or features of the invention. It is also important to note that the present invention is not limited to the preferred, exemplary, or primary embodiment(s) described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims.  
     SUMMARY  
      According to one embodiment, the present invention features a modular connection assembly for use with an aperture in wall of a structure. The modular connection kit includes an insert defining a first cavity having a generally circular inner surface and a first threaded region. The first threaded region optionally includes substantially only a single thread, preferably extending approximately 350 degrees about the generally circular inner surface of the cavity. The insert further includes an outer, exterior surface adapted to be secured within the aperture of the structure&#39;s wall. In the preferred embodiment, the exterior surface of the insert includes at least one protrusion, for example, at least one dove-tail. Alternatively, the exterior surface of the insert includes at least one indentation.  
      The modular connection kit optionally includes an adapter. The adapter has an exterior surface including a second threaded region disposed proximate a first end and a second cavity having a diameter at least as large as an internal diameter of a first pipe end. The second threaded region is sized and shaped to releaseably engage with the first threaded of the insert. An interior surface of the second cavity preferably includes at least one notch adapted to engage with an internal wrench.  
      According to one embodiment, the adapter includes a circumferential protrusion extending generally outward from a second, generally opposite end of the adapter and generally perpendicular to a longitudinal axis of the adapter. Optionally, a gasket is sized and shaped to fit between the circumferential protrusion of the adapter and the wall of the structure.  
      The kit may further include a generally circular shaped cap for sealing the second cavity. The cap includes a circumferential lip extending generally inward from an outer lip region of the cap and generally perpendicular to a longitudinal axis of the cap such that at least a portion of the circumferential lip is sized and shaped to fit between the circumferential protrusion of the adapter and an exterior surface of the wall of the support. The cap may also include a central tab region adapted to form an opening sized and shaped to frictionally engage an outer surface of the first pipe end.  
      According to another embodiment, the adapter may include one or more grommets circumferentially disposed along the second cavity. T grommets are sized and shaped to frictionally engage an outer surface of the first pipe end. Alternatively, the kit may include a boot. The boot includes a first end adapted to be secured to the first pipe end and a second end having means for connecting the second end of the boot to a second end of the adapter.  
      One embodiment of the means for connecting the second end of the boot to a second end of the adapter according to the present invention features at least one protrusion disposed about the outer, exterior surface proximate the second end of the adapter and at least one indentation disposed on an inner surface proximate the second end of the boot. The protrusion and the indentation are adapted to matedly engage with each other when the second end of the boot is arranged about the second end of the adapter. An adhesive is optionally disposed between the protrusion and the indentation when the protrusion and the indentation are connected.  
      Alternatively, the means for connecting the second end of the boot to the adapter includes at least one indentation disposed about the outer, exterior surface proximate the second end of the adapter and at least one protrusion disposed on an inner surface proximate the second end of the boot. The protrusion and the indentation are adapted to matedly engage with each other when the second end of the boot is arranged about the second end of the adapter. Optionally, a press fit band is sized and shaped to fit about an exterior surface of the boot proximate the protrusion and the indentation that biases the boot against exterior surface of the adapter.  
      According to yet another embodiment, the means for connecting the second end of the boot to the adapter includes a circumferential protrusion extending generally outward from a second end of the adapter and generally perpendicular to a longitudinal axis of the adapter and a circumferential lip extending generally inward from a second end of the boot and generally perpendicular to a longitudinal axis of the boot. At least a portion of the circumferential lip is sized and shaped to fit between the circumferential protrusion of the adapter and an exterior surface of the wall of the support. Optionally, the wall of the structure includes a circumferential indentation disposed within the exterior surface of the wall proximate the aperture. The circumferential lip and the circumferential protrusion are sized and shaped to at least partially fit within the circumferential indentation.  
      The present invention may also feature a knockout for protecting the threads of insert during fabrication of the structure. The knockout includes a body having a generally circular outer surface sized and shaped to fit within the cavity of the insert. The body also includes an internal knockout membrane region and an exterior knockout membrane region having a protrusion extending generally outwardly beyond the internal knockout membrane region along a longitudinal axis of knockout.  
      The knockout optionally includes means for engaging the cavity of the insert. According to one embodiment, the means for engaging the cavity of the insert includes at least one thread that engages the threaded region of the insert. Alternatively, the means for engaging the cavity of the insert includes a snap-fit connection or a friction-fit connection.  
      The modular connection system may include a mandrel. The mandrel has a threaded central region for mating with a concrete form and a shoulder region over which the insert is placed to form a snap-fit connection. Optionally, the mandrel includes a slightly non-90 degree region that creates a corresponding slanted recess in the wall of the structure. 
    
    
     DESCRIPTION OF THE DRAWINGS  
      These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein:  
       FIG. 1A  is an exploded view of the modular connection system according to one embodiment of the present invention;  
       FIG. 1B  partial view of one embodiment of the modular connection system according to the present invention with standard rubber pipe to manhole connector attached to plastic portion using a hose clamp or other clamping means;  
       FIG. 2  is a partial view of the insert as shown in  FIG. 1A  according to one embodiment of the present invention;  
       FIG. 3A  is a partial view of one embodiment of the plug shown in  FIG. 1A  according to the present invention;  
       FIG. 3B  is a cross section view of the plug shown in  FIG. 3A  inserted in the insert shown in  FIG. 1A  according to one embodiment of the present invention;  
       FIG. 4  is a partial view of pipe connection member shown in  FIG. 1B  according to the present invention;  
       FIG. 5A  is a cross sectional view of another embodiment of the modular pipe connection system shown in  FIG. 1A  having a boot connected to a pipe connection member with a band according to the present invention;  
       FIG. 5B  is a partial view of the pipe connection member shown in  FIG. 5A  according to the present invention;  
       FIG. 5C  is a partial view of the band shown in  FIG. 5A  according to the present invention;  
       FIG. 6A  is a cross sectional view of another embodiment of the modular connection system shown in  FIG. 1A  wherein the pipe connection member includes a grommet;  
       FIG. 6B  is a partial view of the pipe connection member shown in  FIG. 6A  according to the present invention;  
       FIG. 7  is a partial view of one embodiment of the modular connection system for use walls of various thicknesses;  
       FIG. 8  is a partial view of another embodiment of a modular connection system for use with walls of various thicknesses and curved surfaces;  
       FIGS. 9 and 10   a  are schematic drawings illustrating an adapter threading into an insert into concrete and holding a rubber boot in place;  
       FIGS. 10   b  and  10   c  are schematic drawings illustrating another embodiment of an adapter threading into an insert into concrete and holding a rubber boot in place;  
       FIGS. 11A and 11B  are more detailed drawings of the insert of the present invention;  
       FIG. 12  is a more detailed drawing of the knockout used with the insert of the present invention;  
       FIGS. 13A and 13B  are detail drawings of the mandrel used to hold the present invention place during casting;  
       FIGS. 14A-14E  illustrate the process of using the connection system of the present invention and various component parts thereof;  
       FIGS. 15A and 15B  are schematic drawings illustrating in greater detail the adapter of the present invention;  
       FIG. 16  is a schematic drawing illustrating the use of the adapter of the present invention along with a gasket and not a rubber boot;  
       FIG. 17  is a schematic drawing of a rubber cap in accordance with one feature of the present invention;  
       FIG. 18  is a schematic drawing of a stab rubber cap in accordance with another embodiment of the present invention;  
       FIGS. 19A and 19B  are schematic drawings of a plastic or PVC and cap used with the present invention;  
       FIGS. 20-22  illustrate another embodiment of a cast-in-place retainer device and knock-out according to the present invention;  
       FIG. 23  is a perspective view of one embodiment of a mandrel and an insert disposed within a generally cylindrical wall according to one embodiment of the present invention;  
       FIG. 24  is a perspective view of one embodiment of the modular connection system assembled within a generally cylindrical wall according to one embodiment of the present invention;  
       FIG. 25  is a perspective view of one embodiment of the modular connection system shown during the manufacturing process of a wall having two mandrels;  
       FIG. 26  is a perspective view of another embodiment of the modular connection system shown during the manufacturing process of a wall including a single mandrel and an integral molded skirt;  
       FIG. 27  is a perspective view of yet another embodiment of the modular connection system shown during the manufacturing process of a wall including a knockout region and a “T” shaped protrusion;  
       FIG. 28  is a perspective view of a further embodiment of the modular connection system shown during the manufacturing process of a wall including a ring adapted to be secured to the insert;  
       FIG. 30  is a perspective view of yet a further embodiment of the modular connection system shown during the manufacturing process of a wall including an insert constructed from a generally soft plastic having an exterior surface substantially inversely corresponding to the interior threaded region; and  
       FIG. 30  is a perspective view of an insert having a generally conical or tapered interior surface.  
    
    
     DESCRIPTION OF THE INVENTION  
      A modular connection system  10 ,  FIG. 1A , according to one embodiment of the present invention, enables a pipe  51  to be connected to a wall  12  of a structure  13  such as, but not limited to, a concrete manhole, riser, septic tank, home or building foundation or virtually any concrete structure. According to one embodiment, the modular connection system  10  includes an insert  14  into which either a plug  16  and/or a pipe connection member  18  is threadably connected. The insert  14  is preferably constructed from a rigid plastic, though other materials having the required strength, rigidity, and chemical resistance are also contemplated. In another embodiment (not shown but within the scope of the present invention) threads may be formed directly in or on an inner circumference of a hole in a concrete structure, for interfacing directly with a plug  1  or pipe connection member  18 , as described herein.  
      The insert  14 ,  FIGS. 1B and 2 , is molded, adhered, or otherwise secured to the surface  24  of an opening  21  in the wall  12  of the structure  13 . In the exemplary embodiment, the insert  14  is molded into the wall  12  of the structure  13  during the manufacturing process of the structure  13  and preferably optionally includes one or more protrusions  26  (such as a dove tail), though as will be described in great detail hereinbelow, the modular connection system  10  may be added to the wall  12  of a structure  13  after the manufacturing of the structure  13 .  
      The body  25  of the insert  14  forms a cavity/opening/passageway  28  having an engagement portion  56 , preferably an interior threaded region  20 , either male or female, though the engagement portion  56 . Alternatively, the engagement portion  56  may include any other means of effecting a connection between the insert  14  and plug  16  and/or pipe connection member  18  known to those skilled in the art such as, but not limited to, a locking ring, slip ring, pressure coupling, or any other connection known to those skilled in the art or hereinafter discovered.  
      The body  25  preferably includes a shoulder region  22  and optionally includes a seal  23 , preferably an o-ring or the like. As will be described in great detail hereinbelow, the shoulder region  22  prevents over threading of the plug  16  or pipe connection member  18 . Additionally, the shoulder region  22  provides a seal between the plug  16  and/or pipe connection member  18 .  
      The plug  16 ,  FIG. 3 , is sized and shaped to fit within the opening  28  of the insert  14  as shown in  FIG. 2  such that the wall  12  of the structure  13  is sealed. The plug  16  is particularly useful when a plurality of inserts  14  are installed during the manufacturing of the structure  13  as part of a predetermined opening  28  arrangement but remain unused in the installation or when a pipe is removed from a wall  12  of a structure  13  and the structure  13  must be sealed.  
      The plug  16  includes an engagement portion  57  sized and shaped to form a connection/seal with the engagement portion  56  of the insert  14 . According to the preferred embodiment, the engagement portion  57  includes an externally threaded region  30  having threads corresponding to the internally threaded region  20  of the insert  14  and a wall or panel  34 , though the plug  16  may include any connection known to those skilled in the art such that the plug  16  is capable of forming a connection with the insert  14 . The wall or panel  34  is preferably disposed proximate an inner region of the opening  28  in the wall  12  such that the inner surface  31  of the wall  12  is substantially continuous across the opening  28 . Alternatively, the wall or panel  34  may be disposed anywhere within the plug  16  such that the plug  16  forms a barrier or seal when installed.  
      In the preferred embodiment, the plug  16 ,  FIG. 3 , includes a shoulder region  32  having a seal  36  (preferably a rubber, silicon or other appropriate material o-ring or the like) sized and shaped to engage the shoulder region  22  of the insert  14  or alternatively, to seal directly against the inner wall of the concrete hole. Optionally, the plug  16  may include a handle or a protrusion such as a knob, head, or recess  27  to facilitate the rotation/threading of the plug  16  into the insert  14  (for example, by means of a wrench, ratchet, or by hand).  
      The pipe connection member  18 ,  FIGS. 1B, 4 , and  5 A, allows the modular connection system  10  to create the connection/seal between the wall  12  of the structure  13  and a pipe  51 . The pipe connection member  18  includes an engagement portion  58  sized and shaped to form a connection with the engagement portion  56  of the insert  14 . According to the preferred embodiment, the pipe connection member  18  includes a body  49  having an externally threaded region  38  (the preferred embodiment of the engagement portion  58 ) sized and shaped to threadably engage the internally threaded region  20  of the insert  14 . The body  49  optionally includes a shoulder region  40  that engages the shoulder region  22  of the insert  14  to prevent over threading of the pipe connection member  18  relative to the insert  14 . In the exemplary embodiment, the body  49  also includes a seal  42  (preferably and o-ring or the like) to ensure a proper seal between the pipe connection member  18  in the insert  14 .  
      The pipe connection member  18  includes a connection section  44 . According to one embodiment, the connection section  44 ,  FIGS. 1   b ,  4 , and  5 A, is preferably formed from a rigid material (though it may also be resilient) and is sized and shaped to accept at least a portion of a boot  60 . According to embodiment, the boot  60 ,  FIG. 1   b , includes a section  88  (preferably a rigid section) that engages the connection section  44  of the pipe connection member  18 . In the exemplary embodiment, the connection section  44  and the section  88  of the boot  60  are joined with an adhesive or sealant. The connection section  44 ,  FIG. 4 , preferably includes one or more protrusion or ridges  89  that aid in forming a connection between the pipe connection member  18  and the boot  60  as shown in  FIG. 1   b.    
      According to another embodiment, the boot  60 ,  FIG. 5 , is a resilient, traditional rubber boot. The boot  60  is disposed about the connection section  44  (preferably on the outer surface, though the boot  60  may also be secured internally) and is secured to the pipe connection member  18  with one or more press fit bands  66 . The press fit band  66 ,  FIG. 5C , is preferably formed from a rigid plastic, though other materials such as metal and the like may also be used. The press fit band  66  is sized and shaped to fit over the surface  68  (preferably the outer surface) of the boot  60  in a friction type manner. The use of plastic reduces the overall cost of the modular connection system  10 . One or more ridges or protrusions  89  on the pipe connection member  18  may further aid in securing the boot  60  to the connection section  44 . Additionally, a sealant or adhesive may also be used.  
      In either embodiment, one or more clamps  61 ,  FIGS. 1B and 5A , such as, but not limited to, traditional band clamps, may be used to secure the other end of the boot  60  to the pipe  51 . It should be noted that other devices and methods for connecting the boot  60  to the pipe  51  are also envisioned.  
      According to a further embodiment, connection section  44 ,  FIG. 6 , of the pipe connection member  18  includes one or more flexible, resilient annular grommets  94 . The grommet  94  is size and shaped to frictionally engage the outer surface of the pipe  51  and preferably has an inner diameter slightly smaller than the outer diameter of the pipe  51 .  
      According to yet another embodiment, the modular connection system  10 ,  FIGS. 7 and 8 , is designed to fit a variety of wall  12  thicknesses T. The modular connection system  10 ,  FIG. 7 , includes a first and a second biasing portion  70 ,  72 . The modular connection system  10 , according to present embodiment, is best suited for use with walls  12  having a substantially flat or planar first and second surface  76 ,  88 . The modular connection system  10  is also particularly useful when a connection is needed and the structure  13  does not have a preformed opening in the wall  12 .  
      The first biasing portion  70  includes a body  71  having a first wall engagement section  74  disposed proximate a first end  75 . The first wall engagement section  74  is sized and shaped to fit along a portion of a first surface  76  of the wall  12  proximate the opening  28 . In the preferred embodiment, the first wall engagement section  74  also includes one or more seals  78  (preferably an o-ring or like).  
      The second end  80  of the first biasing portion  70  includes an engagement portion  82 . The engagement portion  82  preferably includes a threaded region, though other means of connecting the first and the second biasing portion  70 ,  72  such as, but not limited to, a slip ring, locking ring, and a pressure coupling are also contemplated.  
      The second biasing portion  72  includes a first end region  82  having an engagement portion  83  sized and shaped to engage the engagement portion  82  of the first biasing portion  70 . In the preferred embodiment, the engagement portion  83  includes a threaded region sized and shaped to threadably connect with the engagement portion  82  of the first biasing portion  70 .  
      A second end region  84  of the second biasing portion  72  includes a second wall engagement portion  86  sized and shaped to engage a second surface  88  of the wall  12 . According to preferred embodiment, the second wall engagement portion  86  preferably includes one or more seals  90  (preferably an o-ring or the like). The second end region  84  also preferably includes a pipe connection/seal  46  for making a connection with a boot  60  in any manner known to those skilled in the art.  
      The modular connection system  10  according to  FIG. 8  is particularly useful with structures  13  having complex or curved first and second surfaces  76 ,  88 , such as but not limited to, pipes, septic tanks, or manholes. The modular connection system  10  includes a first biasing portion  92 , a second biasing portion  93 , and a connector  94 .  
      The first biasing portion  92  includes a body  95  having a first wall engagement section  92  sized and shaped to engage a first surface  76  of the wall  12 . According to the preferred embodiment, the first wall engagement section  96  preferably includes a seal  78  as described above. The body  95  also includes an engagement portion  97  (preferably a threaded region) as described above.  
      The second biasing portion  93  includes a body  98  having a second wall engagement portion  99  sized and shaped to engage a second surface  88  of the wall  12  preferably includes a seal  90 . The body  98  also includes an engagement portion  100  (preferably a threaded region) and a pipe connection/seal  46  for creating a connection with a boot  60  as described above.  
      The connector  94  is sized and shaped to bias the first and second wall engagement sections  92 ,  99  of the first and second biasing portion  92 ,  93  against the first and second wall surfaces  76 ,  88 . The connector  94  includes at least one engagement portion  101  (preferably a threaded region) sized in shaped to engage the engagement portions  97 ,  100  of the first and second biasing portion  92 ,  93 . According to preferred embodiment, the connector  94  includes a first and at least a second engagement portion  101 ,  102  corresponding to the engagement portions  97 ,  100  of the first and second biasing portion  92 ,  93  respectively.  
      In practice, the first and second biasing portion  92 ,  93  are placed proximate the first and second surfaces  76 ,  88  of the wall  12  with the connector  94  between the first and second biasing portion  92 ,  93 . Next, the connector  94  is used to move the first and second biasing portion  92 ,  93  in a direction of arrows A and B, respectively, until the wall biasing engagement sections  96 ,  99  are biased against the first and second surfaces  76 ,  88  of the wall  12 . In the exemplary embodiment, the connector  94  threadably moves the first and second biasing portion  92 ,  93 .  
      Since only the connector  94  is rotated, the modular connection system  10  according to the present embodiment can be used when structures  13  having various thicknesses T and compound or curved first and second surfaces  76 ,  88 .  
      In another embodiment, the modular connections system  10 , in accordance with the present invention, includes a cast in place threaded insert  200 ,  FIG. 9 , and a torquing ring or adapter  202 . The threaded insert  200  is cast in place in the concrete wall or other structure  201 . During the process of casting in place the insert  200 , a recess  204  is created inside of the normal face  208  of the concrete wall  201 . This recess includes a recessed face  206  whose use will be explained further below.  
      Typically, the present invention is meant to be used with a resilient rubber boot  210 , although this is not a limitation of the present invention. In use, the resilient rubber boot  210  is placed over the first end  212  of the adapter  202 . A portion  214  of the resilient rubber boot  210  forms a vertical surface such that when the adapter or torquing ring  202 , having external threads  214  is threaded into the insert  200 ,  FIG. 10   a , the portion  214  of the resilient rubber boot  210  mates with face  206  in the concrete wall  201  forming a waterproof barrier between the adapter/insert combination and the concrete wall  201 . Alternatively, the recessed  204  may be eliminated as shown in  FIGS. 10   b  and  10   c . According to this embodiment, the portion  214  of the resilient rubber boot  210  forms a vertical surface such that when the adapter or torquing ring  202 , having external threads  214  is threaded into the insert  200 , the portion  214  of the resilient rubber boot  210  mates with normal face  208  in the concrete wall  201 . In either embodiment, the problem of how to get a watertight seal between a plastic insert and concrete is solved.  
      The threaded insert  200  is shown in greater detail in  FIGS. 11A and 11B . The threaded insert  200  is typically formed of PVC material, approximately ¼″ thick. The insert  200  has a single thread, preferably extending approximately 350° around the inside diameter of the insert. Having a single row of thread makes the insert easy to mold and in fact a two-piece mold may be utilized wherein the part line of the mold is in a helix pattern and corresponds to the single thread row. The exterior region in  220  of the threaded insert  200  may include a plurality of notches  220  which aid to mechanically interlock the insert  200  with the concrete.  
      Typically, in order to protect the inner threads of the insert  200  during the casting process, an externally threaded knockout  230 ,  FIG. 12 , is utilized. The threaded knockout includes 1 or more external threads  232  and an internal knockout membrane region  234  and a thicker, protruding region  236  forming “ears” on the knockout. The knockout  230  is threaded into the insert  200  prior to casting the concrete. The protruding region  236  will create a thinner area of concrete in the area of the circumference of the protrusion, as well as a thicker central region proximate the internal knockout central region  234 . The thicker central region of concrete created by the internal knockout membrane  234  facilitates using a hammer or other device to strike or impact solidly on the thicker central region while the thinner area of concrete proximate the protruding regions  236  facilitate the knockout  230 , as well as a plug of concrete formed by the knockout, to be dislodged from the insert  200  and the concrete. Typically, the knockout  230  is also made of a PVC type material. Although the knockout  230  is shown and described as being “threaded” into the insert  200 , this is not a limitation of the present invention since the knockout  230  may be made to “snap fit” into the insert  200  using one of more well-known techniques for interconnecting plastic parts. Alternatively, the knockout  230  may interconnect with the insert  200  by means of friction fit. An alternative knockout  300 ,  FIGS. 20-22  is disclosed and discussed below.  
      Although the insert  200 ,  FIG. 13 , and the knockout  230  may be placed alone in the concrete form, more typically, a mandrel  240 ,  FIGS. 13A and 13B  is utilized. The mandrel  240  is provided having a threaded central region  242  which mates with a bolt or other similar device inserted through a concrete form (not shown). The bolt holds the mandrel  240  to the form. The mandrel  240  also includes a slightly recessed shoulder region  244  over which the insert  200  is placed allowing the insert  200  to “snap fit” over the shoulder region  244  of the mandrel  240 .  
      In the preferred embodiment, the mandrel  240  includes a slanted or slightly non-90° region  246  which creates a corresponding slanted recess  206  in the concrete. The inwardly slanting region  246  interact with the rubber boot forcing the rubber inwardly toward the central region of the hole rather than outwardly away from the concrete face. This helps ensure a watertight seal between the modular connections system of the present invention and the concrete.  
      Although the embodiments shown have a flat profile for a flat wall, they can also be made having a radius of curvature for a curved wall, such as found in a concrete manhole or the like.  
       FIGS. 14A-14D  illustrate the method or process of using the system of the present invention. As shown in  FIG. 14A , the insert  200  including the knockout  230  is mounted onto the mandrel  240 . The mandrel  240  in turn is mounted to the concrete form  250 . After the concrete is cast in place, the form along with the mandrel  240  is removed leaving the insert  200  and the knockout  230  in place. As previously discussed, the mandrel  240  forms a recessed region  204  in the concrete. After the knockout is removed,  FIG. 14C , the adapter or torquing ring  202  is inserted into the insert  200  with either a rubber boot  210  or a rubber cap  212 . Alternatively, one or more cap&#39;s  250 ,  FIGS. 14D and 14E  may be provided. As shown in  FIG. 14E , a protruding region  252  may be provided as a “brim” on which a strap wrench or other similar device may be placed to tighten and loosen the cap  250 .  
       FIGS. 15A-15B  illustrate the adapter or torquing ring  202  in greater detail. The exterior  260  of the torquing ring  202  may be textured so as to interlock with the rubber boot which is placed over it. It is important to note that with the construction of the adapter  202  of the present invention, no additional clamp is needed to connect the rubber boot to the adapter. In addition, the interior region of the torquing ring  202  may include one or more notches  262  which serve to allow the torquing ring  202  to be screwed into the insert  200  using an internal wrench.  
       FIG. 16  illustrates the torquing ring or adapter  202  utilized not with a rubber boot but rather, with a gasket  270  which serves as a seal between the adapter  202  and the concrete.  
       FIG. 17  illustrates a rubber cap  276  which may be used with the adapter  202  to seal a hole which is not going to be used at the present time. Similarly,  FIG. 18  illustrates a rubber boot  278  which has a central “tab” region  280  allowing a pipe or other device to pierce the rubber cap  278 .  
       FIGS. 19A and 19B  illustrate a plastic or PVC cap  282  which may be used to seal a hole by mating with an insert  200 . The cap  282  is utilized with a rubber or other similar gasket  284  to provide a watertight seal against the concrete.  
      In another embodiment of a knockout used when casting in place a threaded insert  200  of the present invention, knockout  300 ,  FIGS. 20-22  may be provided. The knockout  300  utilizes a number of snap fit legs or fingers  302  having a small bump or protrusion  304  proximate their distal end. The bump or protrusion  304  is adapted to mate with a bump or protrusion  306  located on the mandrel  308  which is attached to the form, as previously described.  
      When assembled, as shown in  FIG. 21 , the user simply pushes on the knockout  300  with enough force to cause the protrusion  304  to slide over and interface with protrusion  306  on the mandrel  308 . Only approximately 10 to 20 pounds of frictional force are required to assemble/disassemble the knockout  300  onto the mandrel  308 .  
      In the preferred embodiment, the knockout  300 ,  FIG. 22 , includes three snap fit legs or fingers  302 , although this is not a limitation of the present invention as two or more fingers or legs  302  may be utilized, as desired. The embodiment shown in  FIGS. 20-22  (as well as other embodiments disclosed herein) is particularly well suited for standard configuration situations such as septic tanks, utility vaults and foundations where many waterproof knockouts may be located and only some of them used.  
      In other situations, such as manholes, the user may not want to locate so many unused knockouts but rather, may want to position openings where they will be used. The present invention may utilize a mandrel  308   a ,  FIG. 23 , mounted to the outer form used to from the manhole. Insert  200   a , having a curved inner surface  310  which matches the ID of the manhole and abuts generally the inner wall form, is mounted on the mandrel using a bolt inserted through central region  312 , by snapping onto the mandrel  308   a , by using some magnetic device or by some other device as will be clear to those skilled in the art. Once the mandrel  308   a  is removed, the insert  200   a  remains in place,  FIG. 24 .  
      In use, the resilient rubber boot  210 ,  FIG. 24 , is placed over the first end  212  of the adapter  202 . A portion  214  of the resilient rubber boot  210  forms a vertical surface such that when the adapter or torquing ring  202 , having external threads  214  is threaded into the insert  200 , the portion  214  of the resilient rubber boot  210  mates with face  206  in the concrete wall  201  forming a waterproof barrier between the adapter/insert combination and the concrete wall  201 . In this manner, the problem of how to get a watertight seal between a plastic insert and concrete is solved.  
      According to another embodiment, the present invention features an insert  200 ,  FIG. 25 , formed from an elastomeric material. The insert  200  is supported by a first and a second mandrel  240  disposed on an inside and outside surface of the wall  12  during the manufacturing process of the structure  13 . The use of two mandrels  240  positively locates the insert  200  during the manufacturing processes of the structure  13  and prevents the concrete of the structure  13  from entering into the cavity formed by the insert  200  during the manufacturing of the structure  13  thereby eliminating the need to remove the concrete knockout/plug and protecting the threaded region of the insert  200 .  
      In use, the insert  200  mates with an adapter, torquing ring, or the like (not shown) which creates a radial force urging the elastomeric insert  200  against the aperture formed in the wall  12  thereby sealing the connection. According to a preferred embodiment, the adapter, torquing ring, or the like has a tapered or conical shape that further biases the insert  200  against the aperture within the wall  12  once threaded in place further enhancing the mechanical seal.  
      According to a further embodiment, the present invention features in insert  200 ,  FIG. 26 , having an integral molded skirt  600 . The integral molded skirt  600  extends outwardly from the threaded region of the insert  200  and extends towards the inner surface of the concrete form, thereby preventing the concrete from entering the cavity formed by the insert  200  during the manufacturing process of the structure  13 .  
      Optionally, the insert  200 ,  FIG. 27 , includes a knockout disk  610 . The knockout disk  610  seals the cavity formed by the insert  200  when the insert  200  is not being used to form a connection, for example a connection with a pipe (not shown). The knockout disk  610  includes a region  612  that enable to the knockout disk  610  to be easily removed from the cavity of the insert  200 . For example, the region  612  may include a circumferentially notched area  614 . In the preferred embodiment, the knockout disc  610  is be located within the threaded region  605  of the insert  200 , however, this is not a limitation unless otherwise specified in the claims. The knockout disk  610  may also be located anywhere within the insert  200 , for example, within the skirt region  600 .  
      A “T” shaped protrusion  616  optionally extends circumferentially outward from the outer surface  618  of the insert  200 . During the manufacturing process of the structure  13 , the concrete flows around the “T” shaped protrusion  616  forming a mechanical interlock with the concrete of the structure  13 . This mechanical interlock aids in securing the insert  200  and preventing the insert  200  (which is preferably constructed from plastic) from moving relative to the structure  13 .  
      In an alternative embodiment, the insert  200 ,  FIG. 28 , is secured to a separate ring  620 . The ring  620  is preferably manufactured from a soft plastic and the insert  200  is preferably manufactured from a hard plastic. While the ring  620  may be secured to the insert  200  in any manner known to those skilled in the art, the ring  620  preferably includes a region  622  sized and shaped to engage the insert  200  and form a snap fit connection with the insert  200 . The ring  620  optionally includes a knockout disk insert  610  (preferably having a circumferentially notched area  614  as described above) and an integral skirt  600 . A “T” shaped protrusion  616  may be included to form a mechanical interlock between the ring  620  and the concrete of the structure  13  as described above.  
      According to yet another embodiment, the present invention features an insert  200 ,  FIG. 29 , is manufactured from a thin, soft plastic. The outer surface  618  of the insert  200  includes a region  630  inversely corresponding to the threaded region  605 . During the manufacturing process of the structure  13 , the concrete flows around the outer surface  618  of the insert  200  and into the region  630 . As a result, the concrete forms a threaded region corresponding to the threaded region  605  of the insert  200  thereby strengthening the threaded region  605  of the insert  200 . This also enhances the longevity of the threaded region  605  by reducing or preventing the plastic of the threaded region  605  from creeping over time. The insert  200  also preferably includes an integral molded skirt  600  as described above and optionally includes a knockout disk  610 . Additionally, the insert  200 ,  FIG. 30 , may have a generally tapered exterior and/or interior shape. The tapered shape enhances the connection between the insert  200  and the wall  12  when an adapter (not shown) is threaded in by creating a radial force urging the insert  200  against the wall  12 .  
      As mentioned above, the present invention is not intended to be limited to a system or method which must satisfy one or more of any stated or implied object or feature of the invention and should not be limited to the preferred, exemplary, or primary embodiment(s) described herein. The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as is suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the claims when interpreted in accordance with breadth to which they are fairly, legally and equitably entitled.