Abstract:
An insertion indicator is provided for a bell and spigot pipe connection system, including a stop ring positioned on the spigot pipe. An indicator is provided adjacent the stop ring and the bell pipe for indicating a proper insertion depth. A break away tab is provided as an insertion indicator which shears away upon an over insertion condition. A flexible insertion indicator tab is provided. Further, a flexible annular ring is provided to indicate insertion depth. An insertion indicator is further provided which includes an annular stop ring fixed to the spigot pipe and a bell stop ring slidingly engaging the spigot pipe, separated by resilient member. Compression deforms the resilient member which responds by moving the pipes into an optimal position. An insertion indicator is also provided which includes a first semi-circular stop member and a second semi-circular stop member which are angularly deflected creating an indication of proper insertion depth.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority benefit from U.S. Provisional Patent Application Ser. No. 61/216,469 entitled “Pipe Insertion Indicator and Method of Use” filed on May 18, 2009. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This disclosure relates generally to methods of joining large underground pipes having bell and spigot joining systems. 
       BACKGROUND 
       [0003]    In order to assemble long runs of large diameter buried pipe, multiple sections must be assembled. One system of joining pipe sections is a “bell and spigot” system. In joining the sections, the spigot of each successive pipe is inserted into the bell of the previous pipe until an optimal insertion depth is achieved. An optimal insertion position provides clearance between the end of the spigot and the back of the bell sufficient to allow joint pressurization, thermal expansion and angular joint deflection. Over-insertion of the spigot, so that the end of the spigot wedges against the back of the bell, induces stress that can lead to premature pipe failure. 
         [0004]    Over-insertion routinely occurs in the field. Even if care is taken to assemble a joint properly, the force used to assemble successive joints may cause over insertion in the previous joints. To complicate matters, over insertion is typically not discovered until the entire run of pipe has been buried. Removal and replacement of an incorrectly assembled joint is thus expensive, difficult and time consuming. 
         [0005]    Various unsatisfactory solutions to the problem of over-insertion have been attempted in the prior art. 
         [0006]    U.S. Pat. No. 2,953,398 to Haugen teaches a spigot inserted into a bell, where the interior of the bell has a shoulder against which the spigot stops. Haugen also teaches a gasket that is compressed by the spigot as it is inserted, holding the spigot in place. Haugen does nothing to prevent damage of the spigot against the shoulder stop of the bell. Further, the shoulder stop of Haugen acts to limit the motion of the spigot relative to the bell, rather than allowing motion to compensate for movement or thermal expansion. 
         [0007]    U.S. Pat. No. 4,127,290 to Mutschlechner teaches a clamping collar positioned around a spigot. The clamping collar locks with a flange located on the bell. A locking member is fastened between the clamping collar and flange. The two pipes are thus fixed relative to each other. However, fixing the pipes prevents movement required to compensate for soil movement and thermal expansion. 
         [0008]    A need exists for a piping connection system that provides a clear indication of over-insertion of a spigot into a bell. Further, a need exists for a piping connection system that maintains a spigot and a bell at an optimum insertion position and angle. A need also exists for a piping connection system that guides proper insertion to avoid joint separation due to joint pressurization, soil movement and thermal expansion. 
       SUMMARY OF THE INVENTION 
       [0009]    This disclosure provides for an insertion indicator for a bell and spigot pipe connection system including a stop ring positioned on the spigot pipe. An indicator is provided adjacent the stop ring and the bell pipe for indicating a proper insertion depth. The indicator can include, among other things, a breakaway tab connected to the stop ring which contacts the bell pipe upon a proper insertion depth and shears away from the stop ring upon an over insertion depth. A plurality of breakaway tabs provides an indicator of an angular displacement of the bell pipe relative to the spigot pipe. In this configuration one or more break away tabs may shear away from the indicator leaving one or more break away tabs in place. The indicator may also be a flexible annular ring made of elastomeric or polymeric material which deforms radially on an over insertion condition. 
         [0010]    This disclosure also provides for an insertion indicator which includes an annular stop ring fixed to the spigot pipe, a bell stop ring slidingly engaging the spigot pipe and positioned adjacent to bell pipe and a resilient member connecting the annular stop ring and the bell stop ring. An over insertion condition drives the bell pipe into the bell stop ring thereby compressing the resilient member until it engages the annular stop ring. When the compression force is removed from the bell pipe the resilient member decompresses and moves the bell pipe away from the spigot pipe to a position of proper insertion. The resilient member in one embodiment is a series of metallic compression springs and in other embodiments can be an elastomeric or polymeric ring. 
         [0011]    This disclosure also provides for an insertion indicator comprised of a spigot flange and a bell flange adjacent the spigot pipe and bell pipe, respectively. A plurality of compression bolts is spaced radially around the spigot flange and bell flange, connecting the two. A pipe clamp stop ring surrounds the spigot pipe and is positioned adjacent the spigot flange and the bell pipe. Advancing the compression bolts moves the spigot pipe into the bell pipe. The pipe clamp stop ring halts the advance of the bell pipe indicating a optimum insertion condition. 
         [0012]    This disclosure further provides for an insertion indicator comprised of a first semi-circular stop member and a second semi-circular stop member surrounding the spigot pipe and connected at pair of connecting flanges. As the bell pipe is advanced toward the spigot pipe it engages the first and second semi-circular stop member and displaces them creating an angular gap between the connecting flanges which serves as an indication of proper insertion depth. In another embodiment a series of elastomeric washers is provided between the connecting flanges and between the bolts securing the connecting flanges and providing a further indication of insertion depth. Sighting portals may be include on either or both of the semi-circular stop members so that a line on the spigot may be seen during use and used to judge proper insertion depth. 
         [0013]    The elastomeric stop ring can also connected to the spigot pipe with the use of a band clamp resident in an annular channel. Over insertion deforms the stop ring providing indication of over insertion depth. Sighting portals may also be provided in the elastomeric stop ring for viewing markings on the spigot pipe during use. 
         [0014]    This disclosure also provides for an insertion indicator including a spigot flange slidingly engaged with the spigot pipe and having a first angled annular channel adjacent the spigot pipe. A bell flange is also provided, slidingly engaged with the bell pipe adjacent the bell flare. A plurality of compression bolts connects the spigot flange and the bell flange. A stop ring is fixed to the spigot pipe having first and second angled annular surfaces. This embodiment also provides an annular spacing stop having an angled annular channel adjacent the stop ring. A compression spring or other resilient member connects the annular spring stop member to the bell pipe. As the compression bolts are advanced the resilient member is compressed and the angular channel of the annular spring stop member engages an annular surface of the stop ring. Similarly, the angled annular channel of the spigot flange engages the other angled surface of the stop ring. When fully compressed the annular stop ring member, the stop ring and the annular spring stop member are lockingly engaged to prevent further advancement of the bell pipe onto the spigot pipe. An optimum insertion condition is indicated by the distance between the bell pipe and the spring stop. 
         [0015]    This disclosure further provides for a pipe clamp stop comprised of a circular outer ring having an annular beveled surface and annular reverse stop surface in a circular inner ring having a mating annular beveled surface and a mating annular reverse stop surface engaging the reverse stop surface. 
         [0016]    This disclosure further provides for a pipe clamp stop for a bell pipe and spigot connection system comprised of two semi-circular stop members including annular serrations adjacent the spigot pipe. Upon connection the annular serrations embed themselves in the surface of the spigot pipe preventing movement of the pipe clamp stop. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Some of the features and benefits of the present disclosure having been stated, others will become apparent when taken in conjunction with the accompanying drawings, in which: 
           [0018]      FIG. 1A  is an axial view of a preferred embodiment. 
           [0019]      FIG. 1B  is a partial cross section view of a preferred embodiment. 
           [0020]      FIG. 2A  is an axial view of a preferred embodiment. 
           [0021]      FIG. 2B  is a partial cross-section view of a preferred embodiment. 
           [0022]      FIG. 3A  is an isometric view of a preferred embodiment. 
           [0023]      FIG. 3B  is an axial view of a preferred embodiment. 
           [0024]      FIG. 3C  is a cross-section view of a preferred embodiment, prior to insertion. 
           [0025]      FIG. 3D  is a partial cross-section view of a preferred embodiment at an optimal insertion position. 
           [0026]      FIG. 3E  is a partial cross-section view of a preferred embodiment at an over insertion position at insertion. 
           [0027]      FIG. 3F  is a partial cross-section detail view of a preferred embodiment in use. 
           [0028]      FIG. 4A  is an isometric view of an alternate embodiment. 
           [0029]      FIG. 4B  is an axial view of an alternate embodiment. 
           [0030]      FIG. 4C  is a cross-section view of an alternate embodiment, prior to insertion. 
           [0031]      FIG. 4D  is a partial cross-section view of an alternate embodiment at an optimal insertion position. 
           [0032]      FIG. 4E  is a partial cross-section view of an alternate embodiment in use. 
           [0033]      FIG. 5A  is an isometric view of an alternate embodiment. 
           [0034]      FIG. 5B  is an axial view of an alternate embodiment. 
           [0035]      FIG. 5C  is a partial cross-section view of an alternate embodiment in use. 
           [0036]      FIG. 6A  is an isometric view of an alternate embodiment. 
           [0037]      FIG. 6B  is an axial view of an alternate embodiment. 
           [0038]      FIG. 6C  is a partial cross-sectional view of an alternate embodiment prior to insertion. 
           [0039]      FIG. 6D  is a partial cross-section view of an alternate embodiment at an optimal insertion position. 
           [0040]      FIG. 6E  is a partial cross-section view of an alternate embodiment at an over insertion position. 
           [0041]      FIG. 7A  is an isometric view of an alternate embodiment. 
           [0042]      FIG. 7B  is an axial view of an alternate embodiment. 
           [0043]      FIG. 7C  is a partial cross-section view of an alternate embodiment at an optimal insertion position. 
           [0044]      FIG. 7D  is a partial cross-section view of an alternate embodiment at an over insertion position. 
           [0045]      FIG. 8A  is an isometric view of an alternate embodiment. 
           [0046]      FIG. 8B  is an axial view of an alternate embodiment. 
           [0047]      FIG. 8C  is a partial cross-section view of an alternate embodiment, prior to insertion. 
           [0048]      FIG. 8D  is a partial cross-section view of an alternate embodiment at an optimal insertion position. 
           [0049]      FIG. 8E  is a partial cross-section view of an alternate embodiment at an over insertion position. 
           [0050]      FIG. 9A  is an isometric view of an alternate embodiment. 
           [0051]      FIG. 9B  is a partial cross-section view of an alternate embodiment in use. 
           [0052]      FIG. 9C  is a partial cross-section view of an alternate embodiment at an optimal insertion position. 
           [0053]      FIG. 10A  is an isometric view of an alternate embodiment. 
           [0054]      FIG. 10B  is a cross-section view of an alternate embodiment at an optimal insertion position. 
           [0055]      FIG. 10C  is a cross-section view of an alternate embodiment at an over insertion position. 
           [0056]      FIG. 10D  is a cross-section view of an alternate embodiment at an optimal insertion position. 
           [0057]      FIG. 10E  is a cross-section view of an alternate embodiment at an over insertion position. 
           [0058]      FIG. 11A  is an isometric view of an alternate embodiment. 
           [0059]      FIG. 11B  is a partial cross-section view of an alternate embodiment. 
           [0060]      FIG. 11C  is an isometric view of an alternate embodiment. 
           [0061]      FIG. 11D  is a partial cross-section view of an alternate embodiment. 
           [0062]      FIG. 12  is a side view of an alternate embodiment in an optimal insertion position. 
           [0063]      FIG. 13A  is an isometric view of an alternate embodiment. 
           [0064]      FIG. 13B  is a partial cross-section view of an alternate embodiment in use. 
           [0065]      FIG. 13C  is a partial cross-section view of an alternate embodiment at an optimal insertion position. 
           [0066]      FIG. 13D  is a partial cross-section view of an alternate embodiment at an over insertion position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0067]    The present invention is described with reference to the drawings as shown. The invention may take different forms and should not be construed as limited to the embodiments described. Like numbers refer to like elements throughout. 
         [0068]      FIGS. 1A and 1B  show a preferred embodiment of pipe clamp  100 . Upper section  200  and lower section  230  each have flanges  210  and  220  to secure the pipe clamp around a spigot pipe  240  by use of bolts  211 . As shown in  FIG. 1B , the pipe clamp is includes serrations  250  that deform the outer surface of spigot pipe  240 . 
         [0069]    Upper section  200  and lower section  230  are positioned around a spigot and bolts  211  are placed through flanges  210  and  220  respectively. As the bolts are tightened serrations  250  embed themselves in the outer surface of spigot pipe  240 . As the spigot pipe is inserted into the bell (not shown) the distance between the bell and the pipe clamp forms an indicator of an optimal insertion position. An over insertion position is prevented by contact of the bell with the pipe clamp. 
         [0070]      FIGS. 2A and 2B  show a preferred embodiment of pipe clamp  201 . Pipe clamp  201  consists of inner ring  300  and outer ring  310 . The outer ring includes beveled surface  311 . Outer ring  310  also includes reverse stop surface  276 . The inner ring includes a mating beveled surface  301 . Inner ring  300  includes mating reverse stop surface  277 . Inner ring  300  is provided with gap  330  and serrations  275  adjacent to and embedded in spigot pipe  240 . 
         [0071]    In use, inner ring  300  is positioned on spigot by expanding gap  330 . When in place on the spigot pipe, outer ring  310  is positioned around inner ring  300  by engaging beveled surface  311  and mating beveled surface  301 . The spigot pipe is then inserted into the bell pipe and bell front lip  321  is brought into contact with outer ring  310 , thereby forming an indication of optimal insertion. Axial pressure from spigot pipe  240  toward bell front lip  321  results in a sliding movement between the beveled surface and the mating beveled surface. The diameter of inner ring  300  is thereby reduced, increasing friction between inner ring  300  and spigot pipe  240  and embedding serrations  275  in spigot pipe  240 . Movement of spigot pipe  240  is stopped when bell front lip  321  contacts surface  302  of inner ring  300 . Gap  330  allows for compression of inner ring  300 . Reverse stop surface  276  engages mating reverse stop surface  277  thereby preventing outer ring  310  from disengaging with inner ring  300 . 
         [0072]      FIGS. 3A through 3F  show various views of a preferred embodiment. Bell  500  on pipe  510  includes bell back  545 , bell front lip  321 , and seal  535 . Spigot  570  on spigot pipe  240  includes spigot end  590  and insertion mark  580  appearing on the outer wall surface. Breakaway insertion indicators  530 ,  540 ,  550  and  555  are attached to outer ring  313 . The breakaway insertion indicators include scoring lines which circumscribe the base of each indicator. Examples are shown at  520 ,  525 , and  560  for breakaway insertion indicators  530 ,  540 , and  550 , respectively. Each scoring line forms a reduced perimeter cross section relative to the indicator. The reduced perimeter cross section forms a stress riser. Bending of the indicator in any direction causes a crack to nucleate at the stress riser and propagate across the cross section of the indicator causing the indicator to shear away from the outer ring. 
         [0073]    In the preferred embodiment, the breakaway insertion indicators are constructed of an acrylic plastic such as poly (methylmethacrylate). Each indicator preferably includes an iridescent dye aiding in visual location. The iridescent dye is also capable of fluorescing under ultraviolet light aiding in location during inclement or low light conditions with the aid of a fluorescent lamp. In another preferred embodiment the acrylic plastic is polarized allowing detection of induced stress under normal light with the aid of a polarizing filter. Attachment is accomplished by, way of, solvent welding or application of a suitable epoxy adhesive. In other embodiments the break away insertion indicators are constructed of a brittle cast iron or metal alloy. Alternatively, the break away insertion indicators are integrally formed with outer ring  313 . 
         [0074]      FIG. 3B  shows an axial view. A plurality of breakaway insertion indicators  530 ,  550 ,  540  and  555  are shown. The plurality is equally radially spaced about the perimeter of the stop ring. Other embodiments may include a greater or lesser number of breakaway indicators. 
         [0075]      FIG. 3C  is a cross-section view of the preferred embodiment in position on spigot  570  and bell  500  prior to insertion. Coaxial alignment of the pipes in indicated. 
         [0076]      FIG. 3D  shows the preferred embodiment at an optimal insertion position. In its optimal insertion position, bell front lip  321  is in contact with each of breakaway insertion indicators  530  and  550 . Also bell front lip  321  and insertion mark  580  are aligned around the circumference of the spigot pipe. In an optimal position, a clearance is provided between spigot end  590  and bell back  545 . The clearance allows movement between bell  500  and spigot  570  to compensate for pipe pressurization, soil movement and thermal expansion. 
         [0077]      FIG. 3E  shows a cross-sectional view of a bell and spigot at an over insertion position.  FIG. 3F  shows a partial cross-section detail view of the preferred embodiment at an over insertion condition. Breakaway insertion indicators  530   a  and  550   a  a have sheared away, indicating over insertion of spigot  570  into bell  500 . Bell front lip  321  is in contact with outer ring  313  which prevents further movement. Alternatively, if some but not all of the insertion indicators shear away, an indication may be derived that spigot  570  was inserted into bell  500  at an undesirable angle. 
         [0078]      FIG. 4A  shows an isometric view of an alternate embodiment having an outer ring  314  and an inner ring  304  attached to a spigot and adjacent a bell.  FIG. 4B  shows an axial view of the alternate embodiment. Insertion indicators  601 ,  610 ,  630  and  640  are shown. The insertion indicators exhibit a “wedge shaped” profile. Insertion indicators  601 ,  610 ,  630  and  640  of are preferably formed of natural rubber or silicon. In other embodiments, synthetic rubbers such as, neoprene and polychloroprene may also be used with equal success. In this embodiment four insertion indicators are provided at equal distances around the perimeter of outer ring  314 . Of course, those skilled in the art will recognize that a lesser or greater number of insertion indicators would also function. 
         [0079]      FIG. 4C  is a cross section view of an alternate embodiment in position on spigot  570  and bell  500  prior to insertion. Axial alignment of the pipes is shown. 
         [0080]      FIG. 4D  shows the alternate embodiment at an optimal insertion position. In an optimal insertion position, bell front lip  321  is in contact with insertion indicators  601 ,  610 ,  630  and  640 . Also bell front lip  321  and insertion mark  580  are aligned. 
         [0081]      FIG. 4E  shows a cross section view of a bell and spigot at an over insertion position. Insertion indicators  601  and  630  have flared out as they override bell front lip  321 . Bell front lip  321  is in contact with outer ring  314  which prevents further movement. Alternatively, if some but not all of the insertion indicators are deformed, an indication may be derived that spigot  570  was inserted into bell  500  at an undesirable angle. 
         [0082]      FIG. 5A through 5C  show various views of an alternate embodiment. Insertion indicator  600  forms a continuous annular collar with a wedge shaped cross section. Insertion indicator  600  in the preferred embodiment is formed of a natural or synthetic rubber as previously described. Insertion indicator  600  is adhered to outer ring  316  with a suitable epoxy adhesive. 
         [0083]      FIG. 5C  shows a partial cross section view of the alternate embodiment in use. As spigot  570  advances with respect to bell front lip  321  (shown in position  500   a ), insertion indicator  600  moves into position  600   a  flaring out over bell  500 . An over insertion condition is indicated by position  600   a,  which is easily visible upon pipe connection. Maximum travel of bell  500  over spigot  570  is stopped by inner ring  315  and outer ring  316 . 
         [0084]      FIGS. 6A through 6E  show various views of an alternate embodiment. Ring  710  is a flat annular plate having an inner diameter generally the same as the outer diameter of spigot  570 . Ring  710  has holes  713  equally spaced around its outer perimeter. In the preferred embodiment, the holes are approximately half as deep as the width of the ring. In the preferred embodiment the ring is made of ⅛″ plate steel. Outer ring  316  is provided with a plurality of holes  712 . Holes  712  are aligned with the axis of the ring and are aligned with holes  713 . In each of holes  713  and  712  is a compression spring  700 . Each compression spring is preferably spring steel and provides a resistance of approximately 25 pounds per inch of deflection. Compression springs  700  are retained in holes  712  and  713  by a suitable adhesive. Other means of attachment such as spot welding may also be employed. In applications with different diameter pipes a greater or lesser number of springs can be employed. Notch  711  is included for visual inspection of optimal insertion mark  580  circumscribing spigot  570 . 
         [0085]      FIG. 6C  is a cross-section view of the alternate embodiment in position on spigot  570  prior to insertion.  FIG. 6D  is a cross-section view of a bell and spigot at an optimal insertion position. Bell front lip  321  is in contact with ring  710 . Bell front lip  321 , ring  710  and insertion mark  580  are aligned. The insertion mark may be viewed through notch  711 . Gap  721  provides an indication of insertion depth. In situations when precise insertion is required this gap may be measured by hand. 
         [0086]      FIG. 6E  shows the alternate embodiment at an over insertion position. As ring  710  is pressed toward spigot  570  compression springs  700  advance into holes  712 . An over insertion condition is indicated by observing gap  721 . Ring  710  moves out of alignment with insertion mark  580 , also indicating an over insertion position. Spigot end  590  is prevented from contacting bell back  545  by bell front lip  321  contacting ring  710 , which cannot move past inner ring  306  and outer ring  316 . 
         [0087]    In this alternate embodiment, compression springs  700  respond to an over insertion position by exerting a force on ring  710 . Responding to the force from the compression springs, ring  710  forces bell  500  away from spigot  570  into an optimal insertion position. Visual confirmation of an optimal insertion position is carried out by visual inspection through notch  711  for insertion mark  580 . The restoration of spigot  570  and bell  500  into an optimal insertion position provides clearance between spigot end  590  and bell back  545 . 
         [0088]      FIGS. 7A through 7D  show various views of an alternate embodiment. In this embodiment, spigot pipe includes annular stop  598  integrally formed with spigot pipe  241 . Spigot pipe  241  includes a spigot  571  and spigot end  591 . Stop ring  599  is an annular steel ring including a plurality of holes  596  and concave surface  597 . Concave surface  597  corresponds to the convex shape of annular stop  598 . Stop ring  599  also includes inner diameter  595 . Inner diameter  595  is generally the same as the outer diameter of spigot pipe  241 . Clearance is provided for a sliding fit between the stop ring and the spigot pipe. Stop ring  599  includes a series of holes  596  which are axially aligned with the spigot pipe. Compression springs  700  are provided in each of the plurality of holes  596  and aligned holes  713  in ring  710 , as previously described. The compression springs are fixed in the holes with a suitable adhesive or by spot welding. Spigot pipe includes alignment line  581  etched in its surface. 
         [0089]    In use, as spigot  571  is advanced toward bell  500 , bell  500  contacts ring  710 . Ring  710  compresses springs  700  thereby advancing stop ring  599  into annular stop  598 . As compression springs  700  are compressed, the gap between stop ring  599  and ring  710  is reduced. Gap  721  provides a visual means of verifying optimal insertion. When compression springs  700  are fully compressed, bell front lip  321 , ring  710 , stop ring  599  and annular stop  598  are in contact with one another, preventing additional movement of the bell with respect to the spigot. In this embodiment sufficient force is stored in the compression springs in an over insertion position to then push the bell away from the spigot and into an optimal position, when the insertion pressure in removed from the spigot pipe. 
         [0090]      FIG. 8A  shows an isometric view of an alternate embodiment.  FIG. 8B  is an axial view of the alternate embodiment. Elastomeric insertion indicator  800  is positioned adjacent to outer ring  310 . Elastomeric insertion indicator  800  forms a continuous annular ring. Inner diameter  804  of elastomeric insertion indicator  800  is slightly larger than the outer diameter of spigot  570 . Clearance of 1/16 to ⅛ of an inch is generally preferred. Sighting holes  802  are provided allowing visual inspection of the surface of spigot  570 . In the preferred embodiment, elastomeric insertion indicator  800  is comprised of natural rubber or synthetic polyisoprene butyl rubber including polybutadiene. Nitrile rubber and neoprene can also be employed with equal success. Other thermoplastic elastimers, polysulfide rubbers and silicone rubbers may employed with equal success. 
         [0091]      FIG. 8C  shows the alternate embodiment in position on spigot  570  prior to insertion. Axial alignment of the pipes is indicated. 
         [0092]      FIG. 8D  shows the alternate embodiment in position on spigot  570  and adjacent bell  500  in an optimal insertion position. As can be seen, bell  500  is in contact with elastomeric insertion indicator  800 . Elastomeric insertion indicator  800  is also in contact with outer ring  310 . Bell front lip  321  is aligned with insertion mark  580 . 
         [0093]      FIG. 8E , shows the alternate embodiment in an over insertion position. Bell  500  engages elastomeric insertion indicator  800 , compressing it into a deformed position  801 . The deformed position serves as an indicator of over insertion. Alternatively, if some portions of elastomeric insertion indicator  800  are more compressed than other portions, insertion at an undesirable angle is indicated. Elastomeric insertion indicator  800  moves out of alignment with insertion mark  580 , also indicating an over insertion position. 
         [0094]    Spigot end  590 , however, is prevented from contacting bell back  545  because bell front lip  321  cannot move past elastomeric insertion indicator  800 , which is constrained by outer ring  310 . Elastomeric insertion indicator  800  expands to its original dimensions when the pressure on spigot pipe  240  is released. Elastomeric insertion indicator  800  forces spigot  570  and bell  500  back into an optimal insertion position. 
         [0095]      FIGS. 9A through 9C  show various views of an alternate embodiment. Spigot flange  900  is comprised of an annular ring having an inside diameter  901 . Inside diameter  901  is generally the same diameter as outside diameter of spigot pipe  240  but provides sufficient clearance for a sliding fit. Spigot flange  900  is preferably made of plate steel approximately ¼ inch thick. Spigot flange  900  includes two semi-circular pieces  903  and  904 . Stepped joints  922  are provided at opposite sides of the semi-circular pieces to prevent movement between the semi-circular pieces. The stepped joints are joined by bolts  923 . Spigot flange  900  includes equally spaced holes  902  through which bolts  920  are passed. Bell flange  910  includes inner diameter  911 . Inner diameter  911  is generally the same dimension as outer diameter of pipe  510  but provides clearance for a sliding fit. 
         [0096]    Bell flange  910  includes holes  912  which are axially aligned with holes  902 . Two semi-circular pieces  921  and  924  make up bell flange  910 . The semi-circular pieces are connected by stepped joints  914  and bolts  915 . 
         [0097]    Pipe clamp  100  (as shown and described with respect to  FIGS. 1A and 1B ) is positioned adjacent spigot flange  900  and bell  500 . Serrations  250  engage the spigot pipe and prevent axial movement of the pipe clamp with respect to the spigot pipe. 
         [0098]    Bolts  920  are positioned in holes  902  and  912 . Nuts  930  and  940  are secured to bolts  920  adjacent spigot flange  900  and bell flange  910  respectively. Six bolts are provided in the preferred embodiment, spaced  60  degrees apart around the perimeter of the flanges. However, a greater or lesser or number of bolts may be used depending on the diameter of the pipe or the connection strength required for the application as will be understood. 
         [0099]    As shown in  FIG. 9B , in use, spigot flange  900  is positioned on the exterior surface of spigot pipe  240 . Bell flange  910  is positioned adjacent to bell back  545  is a similar manner. Pipe clamp  100  is positioned on the spigot adjacent spigot flange  900 . Bolts  920  are positioned in holes  902  and  912  and nuts  930  and  940  are attached. Moving to  FIG. 9C , as nuts  930  and  940  are advanced, spigot pipe  240  is drawn into bell  500  until spigot flange  900  is in contact with pipe clamp  100 . As seen in this position, pipe clamp  100  is also in contact with bell front lip  321 . This is the optimal insertion position. 
         [0100]    The embodiment possesses the additional benefit of constraining the pipe insertion within a given range. At maximum joint expansion, spigot nut  930  rests against spigot flange  900  and bell nut  940  rests against bell flange  910 . Thus, over-insertion is prevented while a maximum range of motion is preserved. 
         [0101]      FIG. 10A  shows an isometric view of an alternate embodiment.  FIGS. 10B and 10C  show cross sectional views of the alternate embodiment. Pipe clamp  1001  is comprised of two semi-circular rings surrounding spigot pipe  240 . Each of the semi-circular rings includes flanges  1010  and  1020  secured by bolts  1030  and nuts  1033 . Bolts  1030  are positioned in holes  1031  and  1032  on each of the pipe clamps  1001  and  1002 . Pipe clamps  1001  and  1002  both include teeth  1003  and  1004 . Pipe clamps  1001  and  1002  include indicator protrusions  1000  and  1007 . Indicator protrusions  1000  and  1007  are positioned adjacent bell  500 . In the preferred embodiment, each pipe clamp  1001  and  1002  includes a single indicator protrusion  1000  and  1007 . However, in alternate embodiments additional protrusions may be provided. Furthermore, each pipe clamp  1001  and  1002  in the preferred embodiment includes two notches  1005  and  1006  spaced at 90 degree intervals adjacent each indicator protrusion  1000  and  1007 , respectively. A scribed line  1008  is included on spigot pipe  240  for alignment purposes. 
         [0102]    Elastomeric ring  1080  is positioned adjacent pipe clamp  1001 . Elastomeric ring  1080  includes receiving notches  1085  adjacent to and receiving indicator protrusions  1000  and  1007 . 
         [0103]    As shown best in  FIG. 10C , as spigot pipe  240  is inserted into bell  500 , bell front lip  321  comes into contact with elastomeric ring  1080 . As insertion pressure is increased, the elastomeric ring  1080  deforms into position  1080   a.  As insertion pressure is increased, indicator protrusions  1000  and  1007  pivot relative to flanges  1010  and  1020 . Teeth  1003  and  1004  increase the force applied to the spigot pipe and prevent the pipe clamp from sliding axially along the spigot pipe. The increased insertion pressure results in an angular displacement between flanges  1010  and  1020 , causing a gap  1040 . 
         [0104]    As insertion pressure is decreased the elastomeric ring expands, thereby moving the bell back to the position shown in  FIG. 10   b  from the position shown in  FIG. 10   c.    
         [0105]    Gap  1040  serves as an indicator of over insertion. Scribed line  1008  is placed on spigot pipe  240  to also indicate proper insertion. Notch  1005  allows observation of the scribed line, even when the pipes are over-inserted. The deformating of the resulting ring  1080   a  also serves as an application of over insertion. 
         [0106]      FIGS. 10D and 10E  show a cross-section view of an alternate embodiment. Compressible washers  1060  are positioned between flanges  1010  and  1020  adjacent holes  1031  and  1032 . Similarly, compressible washers  1050  and  1070  are interspersed between flanges  1010  and  1020  and bolt  1030  and nut  1033 , respectively. The composition of the compressible washers in the preferred embodiment is of an elastomeric material as previously described. In another preferred embodiment where insertion pressures are far greater, the elastomeric washers with a lower modulus are preferred such as Teflon®. 
         [0107]    In use, as insertion pressure from bell  500  on indicator protrusion  1000  and  1007  increases, pipe clamps  1001  and  1002  are angularly displaced about bolts  1030 . Angular gap  1041  is created. Compressible washers  1050 ,  1060  and  1070  are deformed thereby preventing bending of pipe clamps  1001  and  1002 . 
         [0108]      FIGS. 11A and 11B  show an isometric view of an alternate embodiment.  FIG. 11B  shows a partial cross section of the alternate embodiment. Insertion indicator system  1100  consists of an insertion indicator  1140  and band clamp  1130 . Insertion indicator  1140  is an annular ring positioned adjacent spigot pipe  240 . Insertion indicator  1140  includes annular channel  1141 . Insertion indicator  1140  is comprised of an elastomeric or polymeric material as previously described. 
         [0109]    Within annular channel  1141  resides band clamp  1130 . Band clamp  1130  includes support  1120  and auger  1121 . The threads of auger  1121  engage band clamp  1130 . Insertion indicator  1140  also includes viewing portal  1122 . In the preferred embodiment a single viewing portal is provided; however, in alternate embodiments additional viewing ports may be provided spaced about the perimeter of the insertion indicator. Insertion indicator  1140  has inner diameter  1142 . Inner diameter  1142  is slightly larger than the outer diameter of spigot pipe  240 . In practice clearance of approximately 1/16 to ⅛ of an inch is preferred. 
         [0110]    In use, as auger  1121  is advanced in support  1120 , band clamp  1130  is tightened within annular channel  1141 , thereby compressing insertion indicator  1140  against the external surface of spigot pipe  240 . As bell  500  contacts insertion indicator  1140 , an optimal insertion position is indicated. Deformation of the insertion indicator is used to identify an over insertion position. Viewing portal  1122  is used to “site” or observe a marking (not shown) placed on the surface of spigot pipe  240 . 
         [0111]      FIGS. 11C and 11D  show an alternate embodiment. Pipe clamp  1150  includes upper section  1151  and lower section  1152 , each having flanges  1154 ,  1155 ,  1156  and  1157  respectively, to secure the pipe clamp around the spigot pipe  240  by use of bolts  1158 . Pipe clamp  1150  is situated in annular channel  1141 . 
         [0112]    In use, as bolts  1158  are advanced, pipe clamp  1150  compresses insertion indicator  1140  against the external surface of spigot pipe  240 . As bell  500  contacts insertion indicator  1140 , an optimal insertion position is indicated. Deformation of the insertion indicator is used to identify an over insertion position period. 
         [0113]      FIG. 12  shows an alternate embodiment. Pipe clamp  1220  includes notches  1205 . A circumferential line  1200  is provided on the circumference of spigot pipe  240 . Bell  500  includes notch  1210 . Notches  1205  and  1210  may be aligned or staggered. In use, circumferential line  1200  is sighted through either or both of notch  1205  and notch  1210  to assist in optimum insertion of the spigot into the bell. 
         [0114]    An alternate embodiment is shown in  FIGS. 13A through 13D . Spigot flange  1300  is an annular ring having an inner diameter  1321 . Inner diameter  1321  is sized slightly larger than the outside diameter of spigot pipe  240  to provide a sliding fit. Spigot flange  1300  includes six holes  1302  spaced at generally  60  degree radial angles. Each hole is axially aligned with spigot pipe. Spigot flange  1300  is provided in two semi-circular pieces, each of the two semi-circular pieces is connected by a set of two joints  1301 , spaced  180  degrees apart on the perimeter of spigot flange  1300 . Bolts  1320  and nuts  1303  retain joints  1301 . Spigot flange  1300  includes annular channel  1322 . 
         [0115]    Adjacent spigot flange  1300  is locating stop  1350 . Locating stop is circular in form and is positioned around spigot  570 . Locating stop  1350  includes sloping surfaces  1352  and  1353 . Locating stop  1350  also includes serrations  1354 . Serrations  1354  are positioned to engage the outer surface of spigot pipe. 
         [0116]    Adjacent locating stop  1350  is spring stop  1360 . Spring stop  1360  forms a circular ring having an inner diameter  1361  and annular channel  1363 . Inner diameter  1361  is sized to provide sufficient clearance to allow sliding movement between spring stop  1360  and spigot pipe. Spring stop  1360  includes a series of holes  1362 . Within holes  1362  resides a series of compression springs  1370 . Spring stop  1360  is positioned adjacent bell  500 . Compression springs  1370  are also adjacent bell  500 . 
         [0117]    Bell flange  1310  includes inner diameter  1311 . Inner diameter  1311  is sized to accommodate pipe  510  with sufficient clearance to allow a sliding movement. Bell flange  1310  is provided in two semi-circular pieces, each of the two semi-circular pieces is connected by a set of two joints  1351 , spaced 180 degrees apart on the perimeter of bell flange  1310 . Bolts  1358  and nuts  1357  retain joints  1351 . Bell flange  1310  includes a series of holes  1312 . The holes are axially aligned with the axis of pipe  510 . Resident within holes  1312  are bolts  1313 . Bolts  1313  are also resident in holes  1302 . Bolts  1313  are held in place by nuts  1340  adjacent bell flange  1310  and nuts  1330  adjacent spigot flange  1300 . 
         [0118]    In use, nuts  1340  and  1330  are advanced on bolts  1313  compressing spigot flange  1300  and bell flange  1310 . Spigot flange  1300  and bell flange  1310  slide axially over the surface of spigot pipe  240  and pipe  510 . Bell flange  1310  engages bell back  545  thereby forcing bell  500  axially towards spigot pipe  240 . 
         [0119]    Annular channel  1322  of spigot flange  1300  encounters sloped surface  1352  of locating stop  1350  and comes to rest. Bell  500  compresses compression springs  1370  thereby advancing spring stop  1360  until annular channel  1363  encounters sloped surface  1353  and comes to rest. Visual evaluation of the distance between bell  500  and spring stop  1360 , shown as gap  1400 , provides an indication of insertion depth. 
         [0120]    An over insertion condition is shown best at  FIG. 13D . In this position bell  500  is in contact with spring stop  1360 . Spring stop  1360  is in contact with locating stop  1350 . Locating stop  1350  is in contact with spigot flange  1300 . The spring stop, locating stop and spigot flange are locked together by the contact of sloped surface  1352  an annular channel  1322  and by the contact of sloped surface  1353  with annular channel  1363 . When pressure is released on spigot pipe  240 , compression springs  1370  exert force on bell  500  and spring stop  1360  thereby returning the pipe to an optimal insertion position.