Abstract:
A cast-in-place gasket is provided for an associated pipe joint. The gasket is mounted to a first associated pipe and adapted to provide a seal between the first associated pipe and a second associated pipe. The gasket includes a gasket body formed into an annulus from a resilient material. A first sealing head and a second sealing head protrude from the body in an axially rearward and radially inward direction. The first sealing head is axially spaced from the second sealing head. Each of the first sealing head and the second sealing head include a sealing surface. A first mounting foot and a second mounting foot protrude from the body in a radially outward direction. The first mounting foot is axially spaced from the second mounting foot. An open annular cavity is defined in the body between the first sealing head and the second sealing head. A first lip protrudes from the body proximal to a base of the first sealing head and extends in an axially forward and radially inward direction. A second lip protrudes from the body proximal to the sealing surface of the second sealing head and extends in an axially rearward and radially inward direction. The first lip and the second lip cooperate to inhibit the flow of an associated casting material from contacting the sealing surfaces of the gasket during casting of the associated first pipe.

Description:
This application is a continuation-in-part of U.S. application Ser. No. 11/358,166, filed Feb. 21, 2006, now abandoned the disclosure of which is incorporated reference herein in its entirety. 
    
    
     BACKGROUND 
     The present invention relates generally to flexible fluid-tight seals for pipe joints. More particularly, the present invention pertains to a cast-in-place gasket for use in various pipe joints. In one embodiment, the gasket can be used for sealing bell and spigot type pipe joints. 
     Sewer pipe assemblies are generally made of plastic, polyethylene, metal, concrete or other suitable materials. These materials are fabricated in many configurations and sizes to meet specific requirements and the preferences of users. In many such pipe assemblies, but certainly not all, grooves are formed or recesses are provided in the pipe to accommodate a gasket meant to seal between two pipes, such as a bell and a spigot. Usually the spigot, i.e., the male pipe, contains the groove. However, it is also possible that a formed groove in the bell, i.e., the female pipe, can be utilized. Some gaskets are integrally installed at the factory during fabrication of the sewer pipes, while others are simply applied at the job site. 
     In some known designs, especially if the pipe sections are made out of concrete, the gasket is simply mounted onto the pipe section, for example on a spigot, at the job site before the spigot and bell are connected. However, it would be beneficial to precast the gasket in place on the pipe during the time of manufacture of the pipe. This allows for a much easier installation in the field when the various pipe sections are connected to each other. 
     It is known to cast in place elastomeric bodies in openings of concrete manholes. Such bodies can be gaskets or washers for accommodating a sewer pipe which is inserted through the opening in the manhole. In such designs, the washers or gaskets are embedded in concrete about their outer margin. The elastomeric bodies lie normal to an axis of the pipe extending through a manhole opening. One problem with such gaskets is to positively and permanently anchor the gasket in the cementicious material which defines the inner surface of the manhole opening. 
     U.S. Pat. No. 6,089,618 discloses a sealing device for sealing an annular space between two pipes. The pipes can be made of a concrete material. One of the pipes forms a bell, including a socket with a substantially cylindrical inner surface. The other pipe is a spigot which can be introduced into the bell. A sealing device, including a sealing ring consisting of an elastic material, is mounted in the bell. An annular element, consisting of a non-elastic cellular plastic, is connected with the sealing ring. The sealing device is adapted to be positioned on the bell in a mold for molding the bell and for molding the sealing device into a socket of the bell at the cylindrical inner surface thereof. The annular element is positioned axially inside the sealing ring. However, this design necessitates the use of the annular element with the sealing ring. 
     Also known are embedded bell gaskets which require the use of a forming ring during the manufacture of the bell. An embedded bell gasket which does not require the use of installation forming rings during pipe manufacture would have a considerable economic advantage over systems which utilize a removable secondary element, or a permanently installed secondary element such as is disclosed in the U.S. Pat. No. 6,089,618. 
     Accordingly, it has been considered desirable to develop and a new and improved gasket and pipe joint design which would overcome the foregoing difficulties and others while providing a cast-in-place design for a gasket used in pipe joints made of a conventional pipe material. 
     SUMMARY OF THE INVENTION 
     According to the present invention, a cast-in-place gasket is provided for an associated pipe joint. The gasket is mounted to a first associated pipe and adapted to provide a seal between the first associated pipe and a second associated pipe. The gasket includes a gasket body formed into an annulus from a resilient material. A first sealing head and a second sealing head protrude from the body in an axially rearward and radially inward direction. The first sealing head is axially spaced from the second sealing head. Each of the first sealing head and the second sealing head include a sealing surface. A first mounting foot and a second mounting foot protrude from the body in a radially outward direction. The first mounting foot is axially spaced from the second mounting foot. An open annular cavity is defined in the body between the first sealing head and the second sealing head. A first lip protrudes from the body proximal to a base of the first sealing head and extends in an axially forward and radially inward direction. A second lip protrudes from the body proximal to the sealing surface of the second sealing head and extends in an axially rearward and radially inward direction. The first lip and the second lip cooperate to inhibit the flow of an associated casting material from contacting the sealing surfaces of the gasket during casting of the associated first pipe. 
     In accordance with another aspect of the present invention, a gasket for sealing between a pair of associated pipes is provided. The gasket includes an annular gasket body formed of a resilient material. The gasket body includes a body section, a first foot, and a second foot. The second foot is spaced from the first foot. A first head portion and a second head portion are also provided. A U-shaped opening is defined in the body section for spacing the second head portion away from the first head portion. 
     In accordance with yet another aspect of the present invention, a gasket is provided for positioning within an annular groove located in one of an outer pipe and an inner pipe. The gasket provides a seal between the outer pipe and the inner pipe. The gasket includes an annular gasket body formed of a resilient material. The gasket body includes a body section, at least one foot protruding away from the body section in a first direction, and at least two heads protruding away from the body section in a second, and opposite, direction. The at least two heads are spaced from each other, each of the at least two heads including a sealing face. The at least one foot is meant to be imbedded in a material of the associated inner or outer pipe. A lip is provided extending away from one of the at least two heads for retarding a flow of concrete mix from getting under the gasket and displacing it when the associated inner or outer pipe is being cast. 
     According to still another aspect of the present invention, a method of integrally casting a pipe section together with a gasket is provided. The method includes providing a mold for forming the pipe section to be cast, the mold including a casting surface for receiving a material to be cast. A gasket is provided including a body, a sealing head, at least one foot, a first lip extending from the body in a first direction, and a second lip extending from the body in a second, generally opposite, direction. The gasket is placed on the mold. The first lip and the second lip are placed in sealing contact with the casting surface of the mold. The material to be cast is poured into the mold. The material to be cast envelopes a rear surface of the gasket including the at least one foot. The material to be cast is prevented from flowing in between the gasket and an area of the casting surface defined between the first lip and the second lip. The poured cast material is allowed to at least partially solidify. The mold is withdrawn from the integrally casted pipe section and gasket. 
     Further benefits and advantages of the present invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may take physical form in certain structures and parts, several preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings, wherein: 
         FIG. 1  is a cross sectional view of pipes and a gasket employed in a pipe joint according to a first embodiment of the present invention; 
         FIG. 2  is an enlarged cross-sectional view of the gasket of the pipe joint of  FIG. 1 ; 
         FIG. 3  is a side elevational view of a second type of bell employing a gasket according to a second embodiment of the present invention, in the process of being manufactured; 
         FIG. 4  is a cross sectional view of the bell and gasket of  FIG. 3  being employed in a pipe joint; 
         FIG. 5  is cross sectional view of a gasket according to a third embodiment of the present invention; 
         FIG. 6  is a cross sectional view of a gasket according to a fourth embodiment of the present invention; 
         FIG. 7  is a cross sectional view of a gasket according to a fifth embodiment of the present invention; 
         FIG. 8  is a reverse cross sectional view of the gasket of  FIGS. 3 and 4 ; 
         FIG. 9  is a cross sectional view of a gasket according to a sixth embodiment of the present invention; 
         FIG. 10  is a cross sectional view of a gasket according to a seventh embodiment of the present invention; 
         FIG. 11  is a cross sectional view of a gasket according to an eighth embodiment of the present invention; 
         FIG. 12  is a cross sectional view of a gasket according to a ninth embodiment of the present invention; 
         FIG. 13  is a cross sectional view of pipes and a gasket employed in a pipe joint according to a tenth embodiment of the present invention; 
         FIG. 14  is a cross sectional view of a gasket according to an eleventh embodiment of the present invention; 
         FIG. 15  is a cross sectional view of pipes and a gasket employed in a pipe joint according to a twelfth embodiment of the present invention; and, 
         FIG. 16  is an enlarged cross-sectional view of the gasket of the pipe joint of  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein the showings are for purposes of illustrating several preferred embodiments of the invention only and not for purposes of limiting same,  FIG. 1  shows a pipe joint including a first female pipe, such as a bell  10 , a second male pipe, such as a spigot  20  and a gasket  28  which is meant to seal between the bell and the spigot. The gasket disclosed herein is particularly adapted for use in the field of sewer pipe assemblies. While the embodiment disclosed pertains to a gasket used in a pipe joint between a bell and a spigot, it should be appreciated that the gasket could be employed in a variety of other types of pipe joints as well. For example, the gasket could be used in a pipe joint in straight wall pipe. 
     It is well known that the bell  10 , the spigot  20  and the gasket  28  are all annular. The bell and spigot can be formed from conventional concrete materials, if desired. The gasket  28  can be made from a suitable elastomeric material, such as styrene-butadiene rubber, or any other known elastomer. 
     The bell  10  includes a radially inwardly directed surface  12  including an annular cavity, groove or socket  14  which is meant to accommodate at least a portion of the gasket  28 . The bell also includes an end wall  16  and, spaced therefrom, a flange  18 . The spigot  20  includes a radially outwardly directed surface comprising a first section  22  and a second section  24 . It is apparent that the first section  22  has a somewhat smaller diameter than does the second section  24 . In addition, the spigot  20  comprises an end wall  25  and a flange  26 . When the bell and spigot are brought together, the bell end wall  16  is brought adjacent the spigot flange  26 . Similarly, the spigot end wall  25  is brought adjacent the flange  18  of the bell  10 . As the bell and spigot are slid towards each other, the gasket is moved along the spigot first section  22  and approaches the spigot second section  24  such that at least a portion of the gasket contacts the second section. At this time, the gasket  28  provides a seal between the bell and the spigot in order to prevent a leakage of fluid into or out of the pipes at the joint between them. 
     With reference now to  FIG. 2 , the gasket  28  comprises a first foot portion  30  including a first wall  32 , a second wall  34  and a third wall  36 . It is apparent that the foot portion includes a somewhat triangular or trapezoidal shape such that the first and third wall sections  32  and  36  are disposed, respectively, at acute and obtuse angles in relation to an axis extending perpendicularly through the plane of the second wall  34 . Spaced from the first foot portion  30  is a second foot portion  40 . The second foot portion similarly has a first wall  42 , second wall  44  and a third wall  46 . Again, a somewhat triangular shaped foot portion is provided, such that the first and third walls  42  and  46  are disposed at, respectively, an acute and an obtuse angle in relation to an axis extending perpendicularly through a plane of the second wall portion  44 . 
     The first and second feet  30  and  40  protrude radially outwardly from a body section  50  of the gasket. The body section includes an outer wall  52  having first and second ends  54  and  56  that are angled in relation to a plane of the remainder of the outer wall  52 . The body further includes a first side wall  58  and a second side wall  60 . Finally, the body includes an inner wall  62  which is oriented approximately parallel to the outer wall  52 . Protruding from the body first side wall  58  is a first lip  64 . 
     Extending radially inwardly from the body  50 , in a direction opposite the direction of a first and second feet  30  and  40 , is a first head portion  70 . The first head portion includes a first wall  72 , a second wall  74  and a third wall  76 . Also provided is a bore  78 . The bore enables the first head portion to be more readily compressed, as necessary when the bell and spigot are brought into a connected condition. It is apparent that the first head portion first wall  72  is disposed at an acute angle in relation to an axis running perpendicular to a plane of the second wall  74 . It is noted that the third wall  76  is also disposed at an acute angle in relation to that axis. Thus, a somewhat wedge-shaped first head portion is provided. 
     The gasket further comprises a second head portion  90 , spaced from the first head portion  70  and extending radially inwardly from the body  50 . The second head portion includes a first wall  92 , a second wall  94  and a third wall  96 . Also provided is a second lip  98  which extends away from the second head portion  90 , at the intersection of the second and third walls  94  and  96 . The first and third walls  92  and  96  are each disposed at an acute angle in relation to an axis running perpendicular to a plane of the second wall  94 . The second head portion  90  can be somewhat trapezoidal in shape. 
     With this gasket design, an opening  102  is defined between the first and second head portions  70  and  90 . The opening is meant to accommodate at least a section of the first head portion  70  as it is crushed against the remainder of the gasket  28  when the spigot is advanced into the bell. 
     As is evident from  FIG. 1 , the cavity  14  in the bell  10  can accommodate not only the first and second feet  30  and  40  of the gasket, but also at least a portion of the body  50 . In fact, in the design shown, one surface of the first lip  64  is located at the internal surface  12  of the bell  10 . The concrete material of the bell  10  extends to the intersection of the second side wall  60  of the body  50  and the third wall  96  of the second head portion  90  as is evident from  FIG. 1 . Thus, the body is held in the cavity  14 . 
     With this design, two spaced seal areas are provided on the gasket  28 . The two spaced seal areas are defined by the two heads  70  and  90 . Such a design allows for sealing capabilities in both a non-pressure environment and a low pressure environment, while the gasket is in compression. It also allows for use in a pressurized condition when the pressure on the gasket is hydraulically induced. 
     The gasket  28 , can be made from an elastomeric material which can be extruded or similarly manufactured. In order to convert the extrusion into a ring gasket, it is first necessary to cut a piece of it to the desired length. The cut section of the extrusion is then curled into the form of a torus or ring such that its ends are brought together and secured to each other, such as by vulcanization. In order to avoid distortion of the extrusion during vulcanization, a dowel pin or the like (not illustrated) can be placed in the bore  78 . The dowel pin can be made of a suitable readily frangible material such as plaster of paris. After vulcanization has been completed, the dowel pin can be reduced by hammering to fine powder so that it does not block the bore  78  in the first head portion  70  of the gasket. After preparation of the gasket, it is suitably held in a mold or form into which the concrete is poured. Normally, such work would be conducted in the shop rather than in the field. With the gasket in place and the concrete of the bell cured, the bell  10  can then be transported to the field for assembly with a suitable spigot. 
     While in the embodiment illustrated in  FIG. 1 , the gasket  28  is shown as being embedded in the bell  10 , it should be appreciated that a gasket could also be cast in place in the spigot. 
     The present invention has been developed to facilitate effective sealing in a piping system where design considerations of the pipe joint forming equipment allow for the placement of the gasket on the machined pallet which forms the bell surfaces. This provides a permanently installed seal in the pipe bell, making field installation more convenient and cost effective—which saves considerable time and labor. With the present invention, design limitations which are present in the current state of the art have been taken into consideration. The primary limitation is the required placement of either a flexible or a rigid spacer or filler that positions the gasket on the machined pallet. These can be made of flexible elastomeric material, rigid plastics or foamed plastics, such a styrofoam. However, the various production methods employed by the state of the art also necessarily involve the collection and disposal of these forming rings that have been cycled through the manufacturing of the pipe product. Obviously, this costs time, effort and money. 
     In addition, the gasket  28  incorporates a novel approach to increasing the surface contact pressure which the gasket exerts against the machined pallet surface. Specifically, at least one foot and at least one head extend outwardly from each end of the gasket body. The projections, or formed sealing elements, are of such design and placement as to create a surface effect which prevents the concrete mixture from flowing underneath the gasket  28  and lifting or displacing the gasket during the pipe manufacturing process. The projections are shaped and positioned such that they will cause the gasket to be held properly in the location that will provide the pipe with a successful permanent sealing system. 
     Moreover, the dual sealing elements or heads  70  and  90  illustrated in  FIG. 2  allow for a pipe joint that can effectively seal against the spigot mating surface in situations were a deflection of the joint occurs. The bore  78  and the opening  102  are beneficial to allow for compression and movement of the gasket heads  70  and  90  under various conditions of installation and operation. The bore  78  is advantageous where insertion force or point loading during coupling is a concern. Such bores or openings allow the gasket to yield and distribute the load in a broader pattern of the gasket face than solid designs would. 
     With reference now to  FIG. 3 , a method of manufacturing the cast-in-place gasket according to a second embodiment of the present invention is there illustrated. In this embodiment, a bell  110  includes an internal surface  112  which includes a cavity or socket  114 . The bell also includes an end wall  116 , as well as a connecting wall  117  which leads from the end wall to the internal surface  112 . As is evident from  FIGS. 3 and 4 , the cavity or socket  114  is located along the internal surface between it and the connecting wall  117 . The bell also includes a flange  118 . 
     With reference to  FIG. 4 , a suitable mating spigot  120  includes an internal wall with a first section  122 , a second section  124  and a third section  125  which leads to a flange  126 . It is apparent that the first, second and third sections have differing diameters. The spigot also includes an end wall  127 . A gasket  128  is positioned in the cavity or socket  114 . During the manufacture of the cast-in-place gasket in the bell, a bell pallet  130  is employed, as shown in  FIG. 3 . Once the concrete has hardened, the pallet is removed. After the concrete has cured, the bell can be taken to a work site and installed. 
     With reference now also to  FIG. 8 , the gasket  128  includes a first foot  132 , a second foot  140 , a body  150 , as well as a first head  160 , including a bore  162 , and a second head  170  spaced therefrom. It is noted that the bore  162  is triangular in shape unlike the circular bore  78  illustrated in the gasket of  FIG. 2 . A somewhat U-shaped opening  172  is disposed between the first and second heads  160  and  170 . The shape of the opening can be similar to the shape of the opening  102  illustrated in the gasket  28  of  FIG. 2 . 
     With reference now also to  FIG. 5 , a gasket  180  according to a third embodiment of the present invention is there illustrated. This gasket includes a first foot  182  having a first wall  184 , a second wall  186  and a third wall  188 . A somewhat triangular foot is thus disclosed, similar to the foot  30  illustrated in  FIG. 2 . Spaced from the first foot  182  is a second foot  190 . The second foot can also include a first wall  192 , a second wall  194  and a third wall  196 . It is apparent that the second foot, which is also somewhat triangular in shape, is significantly smaller in size than is the first foot  182 . 
     The gasket  180  also includes a body  200  including an end wall  202  which is similar in design to the end wall  52  illustrated in  FIG. 2 . The body also includes a side wall having a first section  204 , a recess  206  and a second section  208 . The body also includes a second side wall having a first section  210 , a recess  212  and a second section  214 . The recesses  206  and  212  serve to lock the gasket in the cavity defined in the bell. 
     Moreover, the gasket  180  includes a first head  220  having a first wall  222  and a second wall  224 . Both of these are planar. The first head also includes a curved third wall  226 . Defined at the intersection of the first head  220  and the body first side wall second section  208  is a first lip  228 . Located in the first head  220  is a bore  230 . In this embodiment, the bore can be rectangular in shape. Finally, the gasket  180  includes a second head  240 . The second head comprises a first wall  242  and a second wall  244 , both of which can be approximately planar, as well as a curved third wall  246 . A lip  248  is defined at the intersection of the first and second walls  240  and  244 . An opening  250  is defined between the first and second heads  220  and  240 . In this embodiment, the opening is semi-circular in shape. The lips  228  and  248  serve to prevent the concrete from flowing over the sealing surfaces or heads of the gasket during the casting of the bell. 
     With reference now to  FIG. 6 , a gasket  260  according to a fourth embodiment of the present invention is there illustrated. This embodiment of the gasket is similar to the third embodiment illustrated in  FIG. 5  with two exceptions. First, a bore  262  in a first head is generally triangular in shape wherein at least one wall of triangular bore  262  is curved. Secondly, an opening  264  between the two heads of the gasket is generally U-shaped in cross section. 
     With reference now to  FIG. 7 , a gasket  270  according to a fifth embodiment of the present invention is there illustrated. In this embodiment, the gasket includes a first foot  272 , a second foot  274 , a first head  276  and a second head  278 . As with the embodiment of  FIG. 5 , the first foot is larger than the second foot. A somewhat triangular bore  280  is defined in the gasket. The bore is relatively large compared to the size of the first head  276  and also extends into a body  282  of the gasket. Also, in this embodiment, an opening  284  between the first head  276  and the second head  278  is somewhat wedge shaped in cross section. 
     With reference now to  FIG. 9 , a gasket  290  according to a sixth embodiment of the present invention is there illustrated. In this design, a gasket comprises a first head  292  and a second head  294  separated by an opening  296 . The gasket first head  292  does not include a bore. Thus, the first head is stiffer than, e.g., the gasket embodiment of  FIG. 8 . 
     A seventh embodiment of the present invention is illustrated in  FIG. 10 . In this design, a gasket  300  includes a first foot  302 , a second foot  304 , a first head  306  and a second head  308 . It is apparent that the first foot  302  is significantly larger than the second foot  304 . The first head includes a triangular shaped bore  310 . An opening  312 , which can be somewhat U-shaped, again separates the first head  306  from the second head  308 . 
     With reference now to  FIG. 11 , an eighth embodiment of a gasket  320  is there illustrated. In this embodiment, a first head  326  of the gasket includes a circular bore  330 . 
       FIG. 12  illustrates a ninth embodiment of a gasket  340 . In this embodiment, a first head  346  of the gasket does not include a bore, unlike the embodiment of  FIG. 11 , thus forming a stiffer, less yielding, first head. In addition, the gasket  340  includes a middle support protrusion, located between a first foot and a second foot. 
       FIG. 13  illustrates another embodiment in which a bell  410 , a spigot  420  and a gasket  428  are provided. The gasket  428  provides a seal between the bell and the spigot, in order to prevent a leakage of fluid into or out of the pipes at the joint between them. The gasket comprises a pair of feet  430  and  440 , which are each somewhat triangular in shape. Extending radially away from a body  450  of the gasket are located are a first head portion  470  and a second head portion  490 . Thus, the feet  430  and  440  extend away from the body  450  in a first direction and the two head portions  470  and  490  extend away in a second, opposite, direction. Also provided are a pair of fins  464  and  498  extending, respectively, from the first and second heads  470  and  490 . These fins have been found very advantageous in preventing the concrete mix of the bell from getting under the gasket and displacing it, during the pipe manufacturing process. These two fins also prevent the sealing surfaces of the gaskets from becoming contaminated by the slurry that is present during the concrete pipe manufacturing cycle. 
     With reference to  FIG. 14 , a gasket  500 , according to yet another embodiment, includes a first foot  502 , a second foot  504 , a first head  506  and a second head  508 . In this embodiment, there is also provided a middle support protrusion  510 , located between the first and second feet  502  and  504 . The middle support protrusion is advantageous in order to increase the contact pressure of the front or first head  506  against the spigot. The middle support protrusion  510  may serve to prevent a collapse of the gasket  500  when contacted by the spigot during installation of the spigot in the bell. 
     With reference to  FIGS. 15 and 16 , another embodiment of a pipe joint and a gasket according to the present invention is illustrated. With particular reference to  FIG. 15 , a bell  610  includes an inner wall surface  612 , an end wall surface  616 , a curved portion  617  and a flange  618 . Complementing the bell  610 , a spigot  620  includes an inner wall surface  622 , a first seal mating surface  624 , a second seal mating surface  625 , and an end wall  627 . A gasket  630  is cast-in-place in the bell  610 , as shown, such that the gasket  630  provides a seal between the bell  610  and the spigot  620 . 
     With reference to  FIG. 16 , the gasket  630  includes many similar features to those described with respect to the previously discussed embodiments. In particular, the gasket  630  includes a generally triangular first foot  640  having a first wall  642 , a second wall  644 , and a third wall  646 . The gasket  630  also includes a second foot  650  similarly defined by a first wall  652 , a second wall  654 , and a third wall  656 . Unlike the previous embodiments, the gasket  630  includes an oversized third foot  660  disposed between the first and second feet  640 ,  650 . The third foot can be similar in shape to the first and or second feet and include a first wall  662 , a second wall  664 , and a third wall  666 , forming a somewhat triangular or trapezoidal shape in side view, as shown in  FIG. 16 . Once the pipe joint containing the gasket  630 , e.g. the bell, has been cast, the third foot  660  (together with the first foot  640 ) will securely retain the forward portion of the gasket in the bell. This is particularly advantageous during insertion of the spigot into the bell where a slight alignment error could cause a portion of the spigot end wall  627  ( FIG. 15 ) to impact the forward portion of the gasket  630 , potentially dislodging or pulling the gasket  630  out of the bell or otherwise spoiling the seal between the bell and spigot. 
     By adding the oversized third foot  660  the risk of such an occurrence is dramatically reduced due to the increased pressure required to extract the third foot  660  from the casted material of the joint. Because, the third foot  660  is larger than the first or second foot  640 ,  650  and displaces a greater amount of casted material than the first or second foot  640 ,  650  it necessarily includes a greater volume of gasket material that also results in a larger contact area with the casted material of the pipe joint. In addition, this added volume of gasket material requires a greater amount of tensile force and/or compression to be applied to the gasket  630  in order to cause it to shear, pull out, collapse, or otherwise fail. 
     With continued reference to  FIG. 16 , the gasket  630  further includes a first sealing head  670  having a first sealing wall  672 , a second sealing wall  674 , and a third wall  676 . Similarly, the gasket  630  includes a second sealing head  680  defined by a first wall  682 , a second or sealing wall  684 , and a third wall  686 . Between the first and second sealing heads  670 ,  680  is a generally U-shaped cavity in a body  690  of the gasket  630 . The cavity is defined by the third wall  676  of the first sealing head  670 , the first wall  682  of the second sealing head  680 , and a body wall  696 . As described with respect to the previous embodiments, the U-shaped cavity provides a relief area such that when the first sealing head is biased rearwardly toward the second sealing head, during insertion of the spigot, the first sealing head can deflect so as to facilitate the engagement of the spigot into the bell. Furthermore, an annular bore  702  may be provided in the generally vicinity of the first sealing head  670  so as to provide a localized region of reduced stiffness in or around the first sealing head  670 . Such bore, or relieved area in the first sealing head, allows the first sealing head to be more compliant and more likely provide a satisfactory seal against the spigot. 
     Finally, it should be noted that the gasket  630  includes a first lip  698  that protrudes forward of the first sealing wall  672  of the first sealing head  670 . Similarly, a second lip  700  protrudes rearward of the sealing and third walls,  684 ,  686  of the second sealing head  680 . By comparison to the previous embodiments, the first and second lips  698 ,  700  are larger and angled more aggressively to prevent the material to be cast, e.g. concrete, from seeping past the lips  698 ,  702  during the casting process. As described previously, any such seepage is disadvantageous. If the material to be cast comes into contact with or contaminates the sealing surfaces of the gasket  630  the connection between the spigot and bell will likely leak or the gasket will otherwise fail. 
     While the gasket has been discussed as being made of a resilient material, which in one embodiment can be styrene-butadiene rubber, the gasket can be made of any other suitable known elastomeric material. In addition, the gasket can also be made of a dual durometer material. In other words, the top, sealing portions of the gasket can be made of a softer material than the feet which are imbedded in the concrete. Thus, with reference, e.g., to  FIG. 13 , the feet  430  and  440  of the gasket could be made of a harder, higher durometer, material while the heads  470  and  490  are made of a softer, lower durometer, material. 
     The invention has been described with reference to several preferred embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.