Patent Publication Number: US-2011074116-A1

Title: Collapsible expansion mechanism for effecting a seal

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under Title 35, U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 61/246,828, entitled COLLAPSIBLE EXPANSION MECHANISM FOR EFFECTING A SEAL, filed on Sep. 29, 2009, the entire disclosure of which is expressly incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to an internal sealing assembly for sealingly connecting a pair of pipes. In one embodiment, the present invention relates to a secondary sealing assembly that can be installed within an existing pipeline about an existing pipe-to-pipe connection to seal a leak. In another embodiment, the present invention relates to a sealing assembly that can be installed within the upper end of a concrete structure, such as a manhole chimney, to provide a seal across a manhole frame, optionally one or more grade rings, and a manhole chimney to prevent moisture infiltration. 
     2. Description of the Related Art 
     Underground pipes which are used in municipal water and sewer systems, for example, typically include bell and spigot ends that are attached to one another in a sealed manner. Typically, either the spigot end or the bell end of such pipes includes a rubber seal which is compressed between the ends of the pipes to provide a sealed joint when the spigot end of one pipe is inserted into the bell end of another pipe. Occasionally, these primary joint seals between adjacent pipes may leak after installation in the field, requiring a secondary sealing assembly to seal the connection. 
     Manhole systems, which typically facilitate access to the underground pipes from street level, also sometimes require sealing devices. For example, the manhole chimney and riser structure, which may be metal and/or concrete tubes extending from the underground pipes, may have seams through which ground water or other surrounding fluids can seep. In some cases, it is desirable to prevent the ingress of these ambient fluids to the municipal water system through these seams in the manhole chimney. 
     What is needed is a sealing assembly that can be installed within the upper end of a concrete structure, such as a manhole chimney, to provide a seal across a manhole frame, optionally one or more grade rings, and a manhole chimney to prevent moisture infiltration. 
     What is also needed is an improved sealing assembly for sealing pipe-to-pipe joints and/or for concrete structures. 
     SUMMARY OF THE INVENTION 
     The present invention provides an expansion mechanism of the type that may be used with a seal for sealing a connection about the upper end of a concrete structure, such as providing as seal across a manhole frame, optionally one or more spacer rings, and the upper end of a manhole chimney or riser, or which may be used with a seal for internally sealing a connection between a pair of pipes. The expansion mechanism includes a pair of ring portions and a pair of expansion mechanisms that include pivotal connections to the ring portions such that the assembly may be moved or folded between a folded configuration, in which the assembly has a reduced profile to allow the assembly to be moved into place at the sealing site, and a deployed configuration, in which the assembly has a cylindrical shape and is expandable to compress the seal against a cylindrical surface. 
     The present invention also provides a pipe sealing assembly for sealing a connection between a pair of pipes. The sealing assembly includes a generally cylindrical seal or gasket having a pair of axially spaced sealing portions joined by a bridge portion. Each sealing portion has a plurality of compressible sealing ridges, as well as an annular expansion band seat capable of receiving the expansion band of an expansion band assembly that is used to sealingly compress each sealing portion against a respective inner surface of a pipe. Additionally, each sealing portion may include a hollow section which houses the expansion band assembly, and may be provided with a small slit for installing the expansion band assembly and allowing access to the expansion mechanism of the expansion band assembly during installation, or a separate cover member for enclosing the expansion band assembly. 
     The present invention also provides a pipe sealing assembly, and a method of installing the pipe sealing assembly, for sealing a connection between a pair of underground pipes, including a generally cylindrical seal or gasket having at least three axially spaced sealing portions. Each sealing portion has a plurality of compressible sealing ridges, as well as an annular expansion band seat capable of receiving the expansion band of an expansion band assembly that is used to sealingly compress each sealing portion against a respective inner surface of a pipe. The sealing portions may include a middle sealing portion that may directly sealingly engage about, and bridge, a joint between two pipes, or may directly sealingly engage about, and bridge, a crack in a pipe. Additionally, each sealing portion may include a hollow section which houses the expansion band assembly, and may be provided with a small slit for installing the expansion band assembly. The expansion band assembly includes one or more expansion bands and one or more expansion mechanisms. The expansion bands may be initially installed as part of the pipe sealing assembly, while the expansion mechanisms may be installed after the pipe sealing assembly is brought underground through a structure, such as a manhole, and positioned at an installation site. 
     In one form thereof, the present invention provides a sealing assembly comprising: a cylindrical seal; and an expansion band assembly, comprising: a pair of partially-cylindrical ring portions each having opposing first and second end portions; and a pair of expansion mechanisms, each the expansion mechanism comprising: threaded first and second block members having first threads, the first block members each pivotally connected to a respective first end portion of the ring portions to define a pivot axis; and a bolt having second threads adapted to cooperate with the first threads of the first and second block members, rotation of the bolt in a first direction causing the block members to be simultaneously driven apart from one another to expand the expansion band, the ring portions pivotable with respect to one another about the pivot axes of the pair of expansion mechanisms, wherein the expansion band assembly defines a deployed configuration in which the pair of ring portions cooperate to define a substantially cylindrical shape defining an expansion band assembly diameter, and the expansion band assembly defines a collapsed configuration in which the pair of ring portions have a reduced profile smaller than the diameter. 
     In another form thereof, the present invention provides a sealing assembly comprising: a cylindrical seal; first and second ring portions at least partially captured within the cylindrical seal, each of the first and second ring portions comprising a first end portion having a first aperture formed therethrough, the aperture defining a first pivot axis; connecting means for pivotably connecting the first end portions of the first and second band portions to the second end portions thereof, wherein the sealing assembly is configurable in deployed and collapsed configurations, the collapsed configuration having a reduced profile as compared to the deployed configuration; and expansion means for expanding a diameter of the sealing assembly when in the deployed configuration. 
     In yet another form thereof, the present invention provides a method of sealing an annular wall including: providing a sealing assembly, the sealing assembly comprising: a cylindrical seal including at least one annular sealing portion, the sealing portion including an expansion band seat; and a pair of expansion band ring portions at least partially captured within the expansion band seat, the expansion band ring portions each having first and second end portions, the first end portions pivotably connected to the second end portions about a pair of pivot axes; folding the sealing assembly by pivoting the expansion band ring portions into a generally non-cylindrical configuration about the pivot axes, the step of unfolding placing the sealing assembly in a collapsed configuration; placing the sealing assembly adjacent an annular inner wall of a cylindrical structure; unfolding the sealing assembly by pivoting the expansion band ring portions into a generally cylindrical configuration, the step of unfolding placing the sealing assembly in a deployed configuration; and expanding the expansion band ring portions with respect to one another to compress the cylindrical seal against the annular inner wall of the cylindrical structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a sealing assembly according to one embodiment of the present invention, shown sealing a connection between a pair of pipes; 
         FIGS. 2A-D  are sectional views through four different embodiments of sealing assemblies according to the present invention; 
         FIG. 3  is a partial sectional view through a pipe joint, showing the sealing assembly of  FIG. 2A  installed therein; 
         FIGS. 4A-C  are sectional views through three further embodiments of sealing assemblies according to the present invention; 
         FIG. 5  is a perspective view of a sealing assembly according to another embodiment of the present invention, shown sealing a connection between a pair of pipes; 
         FIG. 6  is sectional view through the sealing assembly, taken along line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a first schematic perspective view of the sealing assembly of  FIGS. 5 and 6 , showing a user gripping the sealing assembly prior to folding same; 
         FIG. 8  is a second schematic perspective view of the sealing assembly, showing the user folding the sealing assembly about gap portions between ends of the expansion bands of the sealing assembly; 
         FIG. 9  is a perspective and sectional view of the sealing assembly being brought into an underground pipeline; 
         FIG. 10  is sectional view through another embodiment of a sealing assembly according to the present invention; 
         FIG. 11  is a schematic, multi-fragmentary view of portions of a manhole riser including the sealing assembly of  FIG. 2C  shown installed in the upper left portion of the drawing, and the sealing assembly of  FIG. 10  shown installed in the upper right portion of the drawing, each of the sealing assemblies sealing a connection between a manhole chimney and one or more grade rings; 
         FIG. 12  is an enlarged, fragmentary view of an end sealing portion of the sealing assemblies of  FIG. 11 ; 
         FIG. 13  is a perspective view of a sealing assembly according to a further embodiment, the sealing assembly shown in a folded configuration; 
         FIG. 14  is a partial sectional view of an upper portion of a concrete structure, showing the installed sealing assembly of  FIG. 13 ; 
         FIGS. 15 and 16  are perspective views of the ring end portions and expansion mechanisms of the sealing assembly of  FIG. 13 ; 
         FIG. 16A  is a perspective view of ring end portions of the sealing assembly of  FIG. 13 , with an alternative expansion mechanism attached thereto; 
         FIGS. 17 and 18  are perspective views of the ring end portions shown in  FIGS. 15 and 16 ; 
         FIG. 19  is a sectional view through a seal made in accordance with the present disclosure; 
         FIG. 20  is a partial, perspective view of the sealing assembly of  FIG. 13 , illustrating the expansion mechanism and ring end portions in the folded configuration; 
         FIG. 21  is perspective view of the sealing assembly of  FIG. 13 , illustrating a ring end portion disconnected from the expansion mechanism; and 
         FIG. 22  is a partial, perspective view of the sealing assembly of  FIG. 21 , illustrating connection of the ring end portion to the expansion mechanism. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention any manner. 
     DESCRIPTION OF THE INVENTION 
     Referring to FIGS.  1  and  2 A-D, four different embodiments of sealing assembly  10  of the present invention are shown. Except as discussed below, each sealing assembly  10   a - 10   d  includes a number of identical or substantially identical components, and identical reference numerals will be used throughout  FIGS. 2A-D  to designate identical or substantially identical components therebetween. 
     Each sealing assembly  10  includes a generally cylindrically shaped seal  12  having pair of axially spaced sealing portions  14  connected by a bridge portion  16 . Bridge portion  16  may include one or more undulations as shown in order to permit movement of sealing portions  14  toward and away from one another along their common axis, i.e., a longitudinal axis passing through the center of seal  12 . Seal  12  may be made of extruded rubber, for example, in a manner in which a length of rubber section is extruded, and then is cut to a predetermined length, followed by splicing the ends of the section together to form the cylindrical seal  12 . Seal  12  may also be made of a resilient plastic material by an injection molding process, for example. 
     Each sealing portion  14  includes a plurality of sealing ridges  18  that are compressible against the internal surface of a pipe to provide a fluid tight seal. Additionally, each sealing portion  14  further includes an annular expansion band seat  20 , shown herein as an annular recessed area of sealing portions  14 , for receiving an expansion band of an expansion mechanism, as discussed below. 
     Additionally, as shown with respect to the embodiments of  FIGS. 1 ,  2 A and  2 C, each sealing portion  14  may also be provided with a thin wall section  22  defining an annular hollow section  24  in the sealing portion  14  which accommodates the expansion band and the expansion mechanism of the expansion band assembly. As discussed below, the thin wall section  22  may include a small slit  23  for installation of the expansion band and expansion mechanism and for accessing the expansion mechanism during installation for sealingly compressing the sealing portion  12  into fluid tight engagement with the interior surface of the pipe. 
     Expansion band assembly  26  may be, for example, of the type disclosed in U.S. Pat. Nos. 6,805,359 and 7,146,689, each assigned to the assignee of the present invention, the entire disclosures of which are expressly incorporated herein by reference. Each expansion band assembly  26  generally includes an expansion mechanism  28  operable to expand the diameter of an expansion band  30  of the expansion band assembly  26  to radially outwardly to compress a sealing portion  14  against the inner surface of a pipe. In particular, as best shown in  FIG. 1  and discussed in the above-incorporated U.S. Pat. Nos. 6,805,359 and 7,146,689, each expansion mechanism  28  generally includes a bolt  32  having oppositely-threaded ends and a central nut  33 . The oppositely-threaded ends of bolt  32  are threadingly received within a pair of oppositely-threaded block members  34  which are in engagement with the opposite ends  30   a  and  30   b  of expansion band  30 . In use, nut  33  of bolt  32  is engaged by a suitable tool to rotate bolt  32  and drive block members  34  apart from one another to thereby expand the diameter of expansion band  30  to radially outwardly compress a sealing portion  14  of seal  10  into tight engagement with the inner surface of a pipe. 
     In use, referring additionally to  FIG. 3  in which seal assembly  10   a  is shown as an example, seal assembly  10  may be used to seal a defective primary seal in a pipe-to-pipe connection between pipes  40  and  42 , such as the connection between spigot end  44  of pipe  40  and socket end  46  of pipe  42  in which a primary seal  48  ( FIG. 1 ), formed in an annular groove  49  of spigot end  44  of first pipe  40 , is ineffective. Alternatively, seal assembly  10  may be used as a primary seal to seal pipes  40  and  42  upon initial connection and installation of pipes  40  and  42 , or may be used to seal across a crack in pipes  40  and/or  42 . 
     Seal  12  is placed within the pipes  40  and  42  such that one sealing portion  14  is positioned adjacent spigot end  44  of pipe  40  and the other sealing portion  14  is positioned adjacent socket end  46  of pipe section  42 , with bridge portion  16  of seal  12  bridging the gap between pipes  40  and  42 . Thereafter, expansion mechanisms  28  of expansion band assemblies  26  are actuated in the manner described above to outwardly radially compress sealing portions  14  and their sealing ridges  18  of seal  12  into fluid tight sealing engagement with the inner surfaces  50  of pipes, respectively, thereby providing a fluid tight seal between pipes  40  and  42 . 
     In the embodiments in which sealing portions  14  include thin wall sections  22 , one or more slits  23  may be formed, or may be cut in the field, in wall sections  22  which allow for expansion bands  30  and expansion mechanisms  28  of expansion band assembly  26  to be slidably inserted within annular hollow sections  24 . The slit  23  may be disposed adjacent an expansion mechanism  28  to allow access to expansion mechanism  28  during installation to effect the seal as described above. Each slit  23  may extend around only a portion of the circumference of its wall section  22 , such as around as little as 5°, 10°, or 15°, or as great as 30°, 60°, 90° or more, for example, of the circumference of wall sections  22 , or alternatively, may extend around the entire circumference of wall sections  22 . 
     The adjacent portions  21   a  and  21   b  of thin wall sections  22  defined by slits  23  may be disposed in tight abutting end-to-end contact with one another, as shown in the embodiment of  FIG. 2A , for example, or may overlap one another, as shown in the embodiment of  FIG. 2C , for example, in order to minimize or prevent fluid entry into hollow sections  24 . Further, as shown in  FIG. 3 , the slits  23  may be optionally disposed on a side of sealing portions  14  opposite a direction of fluid flow along arrow A 1 , such as at location  23   a , for example, to minimize or prevent fluid entry into hollow sections  24 . Also, the expansion mechanisms  28  may be positioned at the upper end of the pipes  40  and  42  which are normally above the fluid level of the pipes to prevent or eliminate fluid entry into hollow sections  24 . 
     Sealing assemblies  10  for small diameter pipes, such as up to 24 inches, may include one expansion mechanism  28 , while sealing assemblies  10  for larger diameter pipes, such as greater than 24 inches, may include more than one expansion mechanism  28 , as needed. 
     Referring to  FIGS. 4A-C , sealing assemblies  10   e - f  according to further embodiments are shown, which, except as described above, are installed and function in the same manner as the embodiments discussed above, and identical reference numerals are used to identify identical or substantially identical components therebetween. 
     Sealing assembly  10   e  of  FIG. 4A  includes a ramp portion  52  at each of the ends of sealing portions  14  thereof to aid in directing a smooth or laminar flow of liquid within pipes  40  and  42  over and around the sealing assembly. 
     Sealing assembly  10   f  of  FIG. 4B  includes ramp portions  52  at each of the ends of sealing portions  14  thereof similar to sealing assembly  10   e  of  FIG. 4A , and also includes thin wall sections  54  similar to thin wall sections  22  of the embodiments discussed above, wherein thin wall sections  54  are also ramped complementary with ramp portions  52  to aid in directing the flow of liquid within pipes  40  and  42  over and around the sealing assembly. 
     Sealing assembly  10   g  of  FIG. 4C  includes a pair of separately extruded, or otherwise separately formed, annular cover members  56  each having a pair of barbed ends  58  for snap-fitting engagement with a pair of respective grooves  60  in sealing portions  14  of sealing assembly  10   g  that are disposed in either side of the expansion band seats  20 . Cover members  56  are also ramped complementary with ramp portions  52  to aid in directing the flow of liquid within pipes  40  and  42  over and around the sealing assembly. In use, either before or after the seal  10  of sealing assembly  10   g  is extruded, the expansion bands  30  and expansion mechanisms  28  are assembled in place, and an amount of adhesive, such as a liquid solvent adhesive, is applied within grooves  60  in sealing portions  14 . Thereafter, barbed ends  58  of cover members  56  are snap-fitted within grooves  60  to initially retain cover members  56  in place, covering expansion bands  30  and expansion mechanisms  28  until the adhesive cures to provide a more permanent connection of cover members  56  to sealing portions  14 . 
     Cover members  56  may also include slits, such as slits  23  described above, adjacent expansion mechanisms  28  for allowing access to expansion mechanisms during installation. Alternatively, cover members  56  that lack such slits may be secured to seal  12  in the manner described above after expansion mechanisms  28  are actuated following installation to thereby seal expansion mechanisms  28  within sealing assembly  10   g  in a fluid tight manner. 
     Referring to  FIGS. 5-10 , sealing assemblies  110   a  and  110   b  according to further embodiments are shown which, except as described below, are installed and function in the same manner as the embodiments discussed above, and identical reference numerals are used to identify identical or substantially identical components therebetween. 
     Referring now to  FIGS. 5 and 6 , sealing assembly  110  includes a generally cylindrically shaped seal  112  having at least three axially spaced sealing portions  114 . Although the present invention will be discussed in connection with seal  112  having three axially spaced sealing portions  114 , including two end sealing portions  114   a  and a middle sealing portion  114   b , any other number of axially spaced sealing portions  114  can be used. For example, seal  112  may include four axially spaced sealing portions, including two end sealing portions  114   a  and two middle sealing portions  114   b . Seal  112  may be made of extruded rubber, for example, in a manner in which a length of rubber section is extruded, and then is cut to a predetermined length, followed by splicing the ends of the section together to form the cylindrical seal  112 . Seal  112  may also be made of a resilient plastic material by an injection molding process, for example. 
     Each sealing portion  114  includes a plurality of sealing ridges  18  that are compressible against the internal surface  50  of a pipe to provide a fluid tight seal. Additionally, each sealing portion  114  further includes an annular expansion band seat  20 , shown herein as an annular recessed area of sealing portions  114 , for receiving an expansion band  30  of an expansion band assembly  26 , as discussed below. 
     Additionally, as shown with respect to the embodiment of  FIG. 10  and in the same manner as the embodiments described above, each sealing portion  114  may also be provided with a thin wall section  22  defining an annular hollow section  24  in the sealing portion  114  which accommodates the expansion band  30  and the expansion mechanism  28  of the expansion band assembly  26 . As discussed below, the thin wall section  22  may include a small slit  23  or window  25  for installation of the expansion band  30  and expansion mechanism  28  and for accessing the expansion mechanism  28  during and after installation for sealingly compressing the sealing portion  112  into fluid tight engagement with the interior surface of the pipe  50 . 
     Seal assemblies  110   a  and  110   b  of  FIGS. 6 and 10 , respectively, may also include a ramp portion  52  at the outside ends of the two end sealing portions  114   a  to aid in directing a smooth or laminar flow of liquid within pipes  40  and  42  over and around the sealing assembly. 
     In use, seal assembly  110  may be used to seal a defective primary seal in a pipe-to-pipe connection between pipes  40  and  42 , such as the connection between spigot end  44  of pipe  40  and socket end  46  of pipe  42  in which a primary seal  48 , formed in an annular groove  49  of spigot end  44  of first pipe  40 , is ineffective. Alternatively, seal assembly  110  may be used as a primary seal to seal pipes  40  and  42  upon initial connection and installation of pipes  40  and  42 . Seal assembly  110  may also be used as a primary or secondary seal to seal a cracked portion within one of pipes  40  and  42 . 
     When used to seal joints and cracks in pipes that are located underground, seal assembly  110  is capable of being folded in order to easily bring seal assembly  110  through a manhole or any other type of structure to its underground installation site, as shown in  FIGS. 7-9 . Referring now to  FIG. 7 , seal  112  of seal assembly  110  is shown in an unfolded substantially annular shape and includes a diameter D 1 . The diameter D 1  of seal  112  can be as little as about 12 inches, 15 inches, or 18 inches, and as large as about 72 inches, 96 inches, or 120 inches. Seal  112  includes two end sealing portions  114   a  and one middle sealing portion  114   b . Seal  112  further includes a first side portion  72  and a second side portion  74 , disposed on substantially opposing sides of seal  112  along diameter D 1 , which is perpendicular to a diameter connecting gap portions G 1  and G 2 , discussed below. 
     In this embodiment, a pair of expansion bands  30  having ends  30   a  are received within expansion band seats  20  of end sealing portions  114   a . Expansion mechanisms  28  are not initially installed to the seal assembly  110 , but rather are installed later in the installation process, as discussed below. The area of sealing portions  114  and expansion band seats  20  that is disposed between expansion band ends  30   a  forms a gap portion G 1  oriented along an axis A 2 , which is parallel to the central longitudinal axis of seal  112 . Although not visible in  FIG. 7 , the opposite side of seal  112  also includes the above-mentioned features, including a corresponding second gap portion G 2 . Gap portions G 1  and G 2  each form an area on seal  112  with lower resistance to folding due to the absence of expansion bands  30 , thus allowing seal  112  to be folded as described below for fitting through relatively small openings or access points in underground pipelines, such as manholes. 
     To begin the positioning and installation process, as shown in  FIG. 7 , a user grasps seal  112  at a first side portion  72  with a first hand H 1  and a second side portion  74  with a second hand H 2 . The user then folds first side portion  72  and second side portion  74  of seal  112  toward each other in the directions of arrows A 3  and A 4 , respectively, as shown in  FIG. 8 . This movement will allow gap portions G 1  and G 2  of seal  112  to be folded substantially about their axes A 2 . As shown in  FIG. 8 , after folding, seal  112  will have an effective width or profile between first side portion  72  and second side portion  74 , designated W 1  in  FIGS. 8 and 9 , that is less than its initial diameter D 1 . As described above, first side portion  72  and second side portion  74 , at which a user grips seal  112 , do not have to directly oppose one another, so long as the user is able to fold seal  112  about gap portions G 1  and G 2  in the manner described above. 
     Referring now to  FIG. 9 , a method for installing seal assembly  110  in an underground pipeline is shown. First, the seal  112  of seal assembly  110 , having diameter D 1 , shown in  FIG. 7 , is provided. Next, seal  112  is folded to a width W 1 , as described above and as shown in  FIG. 8 . Then, manhole cover  41  is removed from manhole opening  45 , as shown by arrow A 5 , to provide an opening having a diameter D 2  for seal assembly  110  to be brought to its underground installation site. The diameter D 2  of the manhole opening  45  can be as little as about 18 inches, 20 inches, or 24 inches, and as large as about 48 inches, 60 inches, or 72 inches. Diameter D 2  is larger than width W 1 , but may be smaller than diameter D 1 . Thus, seal  112  having a diameter D 1 , if greater than diameter D 2 , will not fit and pass through manhole opening  45  with diameter D 2 , and it is necessary for seal  112  to be folded to a width W 1 , as described above. Seal assembly  110  is then passed through manhole opening  45  and into the manhole riser  49  along arrow A 6 . Once a crack (not shown), or a defective joint  47  between pipes  40  and  42  is located, seal assembly  110  is passed further along arrow A 6  to its installation site. The inner diameter D 3  of pipes  40  and  42  is roughly equal to diameter D 1  of seal  112 . The diameter D 3  of pipes  40  and  42  can be as little as about 12 inches, 15 inches, or 18 inches, and as large as about 72 inches, 96 inches, or 120 inches. 
     Once seal assembly  110  is brought to its underground installation site, seal  112  is placed within the pipes  40  and  42  such that one end sealing portion  114   a  is positioned adjacent spigot end  44  of pipe  40  and the other end sealing portion  114   a  is positioned adjacent socket end  46  of pipe section  42 . The third, middle sealing portion  114   b  is positioned with sealing ridges  18  substantially centered about and bridging joint line  47  formed by and between pipes  40  and  42 . Alternatively, seal assembly  110  may be positioned such that the third, middle sealing portion  114   b  is positioned with sealing ridges  18  substantially centered about and bridging a crack formed in a single pipe. 
     Once seal assembly  110  is positioned at its underground installation site, the three expansion mechanisms  28  are positioned in expansion band seats  20  and connected to expansion band ends  30   a , thus completing assembly of the expansion band assemblies  26 . Expansion band assemblies  26  may be, for example, of the type disclosed in U.S. Pat. Nos. 6,805,359 and 7,146,689, each assigned to the assignee of the present invention, the disclosures of which are expressly incorporated herein by reference. Each expansion band assembly  26  generally includes an expansion mechanism  28  operable to expand the diameter of expansion band  30  of the expansion band assembly  26  radially outwardly to compress a sealing portion  114  against the inner surface  50  of pipes  40  and  42 . In particular, as best shown in  FIG. 5  and discussed in the above-incorporated U.S. Pat. Nos. 6,805,359 and 7,146,689, each expansion mechanism  28  generally includes a bolt  32  having oppositely-threaded ends and a central nut  33 . The oppositely-threaded ends of bolt  32  are threadingly received within a pair of oppositely-threaded block members  34  which are in engagement with expansion band ends  30   a . In use, nut  33  of bolt  32  is engaged by a suitable tool to rotate bolt  32  and drive block members  34  apart from one another to thereby expand the diameter of expansion band  30  to radially outwardly compress a sealing portion  114  of seal  10  into tight engagement with the inner surface of a pipe. Thereafter, expansion mechanisms  28  of expansion band assemblies  26  are actuated in the manner described above to outwardly radially compress sealing portions  114  and their sealing ridges  18  of seal  112  into fluid tight sealing engagement with the inner surfaces  50  of pipes, respectively, thereby providing a fluid tight seal between pipes  40  and  42  and joint line  47 . 
     Each expansion band assembly  26  includes at least two semi-circular expansion bands  30 , each having end portions  30   a  and at least two expansion mechanisms  28 , while sealing assemblies  110  for larger diameter pipes may include three or more expansion bands  30  and three or more expansion mechanisms  28 , as needed. 
     Referring to  FIG. 10 , in the embodiments in which sealing portions  114  include thin wall sections  22 , one or more slits  23  or windows  25  may be formed, or may be cut in the field, in wall sections  22  which allow for expansion bands  30  and expansion mechanisms  28  of expansion band assembly  26  to be slidably inserted within annular hollow sections  24 . The slit  23  or window  25  may be disposed adjacent an expansion mechanism  28  to allow access to expansion mechanism  28  during or after installation to effect the seal as described above. Each slit  23  or window  25  may extend around only a portion of the circumference of its wall section  22 , such as around as little as 5°, 10°, or 15°, or as great as 30°, 60°, 90° or more, for example, of the circumference of wall sections  22 , or alternatively, may extend around the entire circumference of wall sections  22 . 
     The adjacent portions  21   a  and  21   b  of thin wall sections  22  defined by slits  23  may be disposed in tight abutting end-to-end contact with one another, similar to the embodiment shown in  FIG. 2A , for example, or may overlap one another, as shown in the embodiment of  FIG. 10 , for example, in order to minimize or prevent fluid entry into hollow sections  24 . Further, similar to the embodiment shown in  FIG. 3 , the slits  23  may be optionally disposed on a side of sealing portions  114  opposite a direction of fluid flow along arrow A 1 , such as at location  23   a , for example, to minimize or prevent fluid entry into hollow sections  24 . Also, the expansion mechanisms  28  may be positioned at the upper end of the pipes  40  and  42  which are normally above the fluid level of the pipes to prevent or eliminate fluid entry into hollow sections  24 . 
     When sealing assembly  110  is positioned across joint line  47  between pipes  40  and  42 , middle sealing portion  114   b  of seal  112  may directly sealingly engage about and bridge joint line  47 . Middle sealing portion  114   b  may also directly sealingly engage about and bridge a crack in pipes  40  and  42 . Due to this positioning, middle sealing portion  114   b  applies pressure directly to, and about, the joint line  47 . This is advantageous in that middle sealing portion  114   b  will therefore prevent water, or any other liquid, from leaking into and/or building up and forming a pressurized space between the outer surface of sealing assembly  110  and the inner surfaces  50  of pipes  40  and  42 , thus preventing any potential for the shifting of end sealing portions  114   a  of sealing assembly  110  along the inner surfaces of pipes  40  and/or  42 , or other movement or distortion of end sealing portions  114   a  of sealing assembly  110 . 
     Referring now to  FIG. 11 , in another application the sealing assemblies described herein, such as sealing assemblies  10   c ,  110   a , or  110   b , may be installed in manhole riser  49  sealing a connection across joint lines  83 ,  84  formed between one or more grade rings  80  and/or manhole chimney  43  or manhole frame  92 . Grade rings  80  are used to raise manhole frame  92  and its cover  41  to a position substantially flush with street surface  90 . Sealing assembly  10   c ,  110   a , or  110   b  may be prepared for installation and installed the same way as described above in the method for installing sealing assembly  110 . However, in this instance, sealing assembly  10   c ,  110   a , or  110   b  is brought to joint lines  83 ,  84  formed between grade rings  80  and manhole chimney  43 , rather than to a crack or defective joint  47  between pipes  40  and  42 . Once sealing assembly  10   c ,  110   a , or  110   b  is brought to joint lines  83 ,  84  formed between grade rings  80  and manhole chimney  43 , seal  12 ,  112  is positioned such that all joint lines  83 ,  84  between grade rings  80  and manhole chimney  43  and/or between grade ring  80  and manhole frame  92 , are completely covered by seal assembly  10   c ,  110   a , or  110   b . This occurs when each end sealing portion  14 ,  114   a  is positioned adjacent grade rings  80  and manhole chimney  43 . The remainder of the installation and the expansion of sealing assembly  10   c ,  110   a , or  110   b  is performed as described above to provide a fluid tight seal across the inner surfaces  81  of grade rings  80  and the inner surface  82  of manhole chimney  43  and/or manhole frame  92 , to prevent fluid infiltration into, or out of, manhole riser  49 . 
     Although sealing assembly  10   f ,  110   a ,  110   b  are shown and described above, any other of the aforementioned sealing assemblies may be installed in manhole riser  49  to seal a connection across joint lines  83 ,  84  formed between grade rings  80  and manhole chimney  43 . In an alternative embodiment, in cases where many grade rings  80  are utilized, sealing assembly  10   c ,  110   a ,  110   b  may be installed to seal a connection across joint lines  83  formed between each grade ring  80 . 
     Turning now to  FIGS. 13-22 , sealing assembly  200  according to a further embodiment is shown which, except as described below, is installed and functions in the same manner as the embodiments discussed above. 
     Referring initially to  FIGS. 13 and 14 , a collapsible pipe seal assembly  200  generally includes seal  202  and expansion band assembly  204 . As shown in  FIGS. 14 and 19 , seal  202  includes upper seal portion  206  and lower seal portion  208 , with upper and lower portions  206 ,  208  joined by bridge portion  210 . Seal assembly  200  is adapted to sealingly engage with a generally annular rigid surface, such as the opening of an underground pipe system  212  ( FIG. 14 ) in the exemplary manner described below. 
     For example, in the illustrated embodiment of  FIG. 14 , pipe system  212  includes rigid base  214 , which is shown as a concrete structure and, in particular, a manhole riser or chimney. Rigid base  214  leads to an underground pipeline system, such as a sewer system or a fluid storage system. Grade rings or spacers  216  are received at an upwardly facing surface of base  214  to form one or more seams  215  therebetween. Spacers  216  are typically used to space frame  218  (shown in  FIG. 14  as a frame sized and adapted to receive a manhole cover) upwardly from base  214 , such as to align frame  218  at street grade. Frame  218 , which is typically formed of a cast metal, is received upon an upwardly facing surface of spacer  216  to form seam  217  therebetween. 
     In some cases, seams  215 ,  217  may not be fluid-tight. Pipe seal assembly  200  may be installed adjacent to frame  218 , spacers  216  and/or base  214  to prevent infiltration of liquid through the non-fluid tight seams  215 ,  217  from the surrounding environment. As shown in  FIG. 14 , pipe seal assembly  200  may be received within opening O so that seal  202  spans frame  218 , risers  216 , and base  214 . As described in detail below, seal assembly  200  creates a barrier between seams  215 ,  217  and opening O to create a fluid-tight seal between the area about opening O and the surrounding subterranean environment. An exemplary seal is disclosed in U.S. patent application Ser. No. 12/409,656 filed Mar. 24, 2009, entitled INTERNAL PIPE SEAL and assigned to the assignee of the present invention, the disclosure of which is hereby expressly incorporated herein by reference in its entirety. 
     Referring additionally to FIGS.  13  and  15 - 18 , expansion band assembly  204  includes identical first and second ring portions  205   a ,  205   b  joined by a pair of pivoting expansion mechanisms  224 . Ring portions  205   a ,  205   b  are each semi-cylindrically shaped, i.e., are curved about 180° though generally half of a circular span, so that ring portions  205   a ,  205   b  can cooperate to form a generally circular, cylindrical assembly when configured to an unfolded configuration (described below). However, it is contemplated that ring portions  205   a ,  205   b  may be partially cylindrical to define any angular sweep, and that additional ring portions may be added to yield an assembly encompassing 360° in an unfolded configuration. 
     As shown in  FIG. 13 , ring portions  205   a ,  205   b  each include first ring end portion  220  and an opposite second ring end portion  222 . Ring end portions  220 ,  222  of ring portions  205   a ,  205   b  are joined by adjustable expansion/pivot mechanisms  224  to form expansion band assembly  204 , which is can be configured into a generally non-circular, non-cylindrical collapsed or folded configuration and a generally circular, cylindrical deployed or unfolded configuration, as described in detail below. 
     Referring still to  FIG. 13 , the two ring portions  205   a  and  205   b  are identical to one another and oppositely-oriented. Thus, at one end of assembly  204  (i.e., the left end as shown in  FIG. 13 ), first ring end portion  220  of ring portion  205   a  is pivotally connected to second ring end portion  222  of the other ring portion  205   b . Similarly, at the other end of assembly  204  (i.e., the right end as shown in  FIG. 13 ), second ring end portion  222  of ring portion  205   a  is pivotally connected to first ring end portion  220  of the other ring portion  205   b.    
     In an alternative embodiment, ring portions  205   a ,  205   b  may not be identical to one another. For example, both ends of ring portion  205   a  may comprise first ring end portions  220 , while both ends of ring portion  205   b  may comprise second ring end portions  222 . In this alternative embodiment, ring portions  205   a  and  205   b  are still pivotally connected to one another in a similar manner as shown in  FIG. 13  in a similar manner. In another alternative embodiment, expansion band assembly  204  may include more than two ring portions  205   a ,  205   b , such as four ring portions with four pivot/expansion mechanisms  224 , such that multiple pivot points for folding are provided. Each of these configurations is operable in the manner described herein. 
     As best seen in  FIGS. 15 and 16 , expansion mechanism  224  includes first block  226  and second block  228 , which are joined by adjuster  230 . In the illustrative embodiment shown, adjuster  230  is a bolt with oppositely-threaded ends  232 ,  234  and central nut  236 . Exemplary adjusters are disclosed in U.S. Pat. Nos. 6,805,359 and 7,146,689, each incorporated by reference above. As described in detail below, expansion band assembly  204  uses expansion/pivot mechanisms  224  both to pivotably connect ring portions  205   a ,  205   b , as well as to expand expansion band assembly  204  by selectively spreading ring portions  205   a ,  205   b  apart. 
     Adjuster  230  of expansion mechanism  224  is threadingly received within blocks  226 ,  228  so that first threaded end  232  engages with block  226  and the second, oppositely threaded end  234  engages with block  228 . Nut  236  is disposed between and coupled to first end  232  and second end  234 , so that rotation of nut  236  correspondingly rotates ends  232 ,  234 . Because first and second ends  232 ,  234  are oppositely threaded, rotation of adjuster  230  (i.e., via nut  236 ) results in blocks  226 ,  228  moving either away from each other or toward one another depending on the direction of rotation. When expansion band assembly  204  is in the generally circular, unfolded configuration ( FIG. 13 ) and blocks  226 ,  228  are moved away from each other, the diameter of assembly  204  expands to radially outwardly. This outward expansion compresses the portion of seal  202  that is adjacent assembly  204 , i.e., upper seal portion  206  or lower seal portion  208 , into tight or sealing engagement with the adjacent annular surface, as discussed in detail below. 
     In an alternative embodiment, the threaded engagement between blocks  226 ,  228  and adjuster  230  may be reversed. As shown in  FIG. 16A , for example, blocks  226 ′,  228 ′ may be provided having oppositely-threaded studs  232 ′,  234 ′ extending therefrom, respectively. Studs  232 ′,  234 ′ are received by oppositely-threaded apertures at each end of adjuster  230 ′. Thus, rotating adjuster  230 ′ spreads apart or draws together blocks  226 ′,  228 ′ via studs  232 ′,  234 ′, depending on the direction of rotation. Moreover, it is contemplated that any type of threaded engagement may be utilized to expand or contract an expansion band assembly in accordance with the present disclosure. 
     As shown in  FIGS. 16 ,  20  and  22 , first block  226  of expansion mechanism  224  is pivotably attached to an ring end portion  220  by fastener  238 , with such connected adapted to allow rotation of block  226  with respect to ring end portion  220 . In an exemplary embodiment, fastener  238  is a fastener having a smooth outer cylindrical surface to facilitate such rotation, with fastener  238  held in place by a swaged or otherwise enlarged head portion  239  at one end and nut  262  at the other end ( FIG. 22 ). However, fastener  238  may be any suitable fastener that allows pivoting motion between block  226  and ring end portion  220 , such as a bolt, rivet or pin for example. Block  226  rotates with respect to fastener  238  about pivot axis A 8  ( FIG. 16 ), which is generally perpendicular to central axis A 7  of expansion band assembly  204  ( FIG. 14 ). Axis A 8  may intersect or run askew from central axis A 7  of expansion band assembly  204 . 
     Referring to  FIG. 17 , ring end portion  220  of ring portions  205   a ,  205   b  includes aperture  242  formed therein. When ring end portion  220  is attached to block  226  via fastener  238 , aperture  242  is coincident with pivot axis A 8 . Aperture is formed in flattened portion  243  of ring end portion  220 , which mates with the correspondingly flat face of flange  227  ( FIG. 16 ) formed in block  226 . To join block  226  to end portion  220 , flange  227  includes an aperture (not shown) located and sized to align with aperture  242  and receive fastener  238 . 
     As best seen in  FIGS. 15 and 16 , second block  228  of expansion mechanism  224  is pivotably attached to ring end portion  222  by fastener  240 , such that rotation of block  228  with respect to ring end portion  222  is permitted. As shown in  FIG. 18 , ring end portion  222  includes an integral, monolithically formed clevis  244 , which may be created by cutting and bending material from the body of ring end portion  222 . Clevis  244  includes legs  246  having apertures  248 , with apertures  248  substantially aligned with one another. Block  228  includes opening  252  sized and positioned to receive clevis  244 . Apertures  254  pass through the body of block  228  into opening  252 , and are sized and positioned to align with apertures  248  of ring end portion  222 . 
     More particularly, when ring end portion  222  is assembled with second block  228  ( FIG. 15 ), apertures  248 ,  254 , respectively, receive fastener  240  to pivotably secure ring end portion  222  to block  228  about axis A 9  ( FIGS. 15 and 16 ). In an exemplary embodiment, fastener  240  has a smooth outer cylindrical surface, and is held in place by a swaged or otherwise enlarged head portion at one end and nut at the other end, similar to fastener  238  used to rotatably secure block  226  to end portion  220  as described above. However, fastener  240  may be any other suitable fastener that allows pivoting motion between block  228  and ring end portion  222 , including a permanent fastener such as a rivet. 
     During use of assembly  204 , a relatively small rotation or pivoting of block  228  with respect to ring end portion  222  occurs about pivot axis A 9 , which is the common axis of apertures  248 , fastener  240  and apertures  254  formed in block  228 . Pivot axis A 9  is generally parallel to central axis A 7  of expansion band assembly  204 , and generally perpendicular to pivot axis A 8  of aperture  242  formed in block  226 . When ring portions  205   a ,  205   b  are pivoted with respect to one another about pivot axis A 8 , a relatively large angular movement may occur, such as up to 180 degrees. During such movement, and depending on the particular arrangement of expansion band assembly  204 , some angular movement of end portions  220 ,  222  with respect to one another may also occur. Pivot axis A 9  accommodates this movement and therefore facilitates smooth motion of ring portions  205   a ,  205   b  between the collapsed and deployed configurations. However, it is contemplated that blocks  228  may be rigidly coupled to ring end portions  222 , such that any movement that would have been accommodated by pivoting about pivot axis A 9  is instead accommodated by slight material deflection in one or both of ring portions  205   a ,  205   b.    
     Ring end portion  222  further includes overlap portion  250 , which extends beyond clevis  244  to the end of ring end portion  222 . Overlap portion  250  of ring end portion  222  ensures that pressure is evenly distributed against seal  202  in the region of expansion mechanism  224  during operation of the device. More particularly, when adjusters  230  are rotated to increase pressure between expansion band assembly  204  and an adjacent annular surface, overlap portion  250  is disposed between outer surface  221  of ring end portion  220  ( FIGS. 15 and 17 ) and seal  202 . Thus, overlap portion  250  prevents seal  202  from directly contacting the components of expansion mechanism  224 , and ensures that expansion band assembly  204  presents a substantially continuous outer ring surface (i.e., the outer surfaces of ring portions  205   a ,  205   b ) for contact with seal  202 . To further enhance the even distribution of pressure forces from assembly  204  to seal  202 , block  226  may include shoulder  256  ( FIGS. 15 and 16 ) extending toward ring end portion  222 , such that shoulder  256  further distributes pressure exerted on ring end portion  222  in the region of expansion mechanism  224 . 
     When expansion band assembly  204  is in service, assembly  204  is disposed in a deployed, opened, or unfolded configuration shown in  FIG. 14 . In this deployed configuration, ring portions  205   a ,  205   b  form a generally cylindrical or circular profile of expansion band assembly  204  having outer diameter D ( FIG. 14 ). Expansion band assembly  204  may be pivoted about pivot axis A 8  in the manner described above and shown in  FIGS. 13 ,  20 ,  25 , and  26  into an undeployed, closed, or folded position, in which ring portions  205   a ,  205   b  are disposed at an angle with respect to one another. In the undeployed position, expansion band assembly  204  has a reduced profile that may be easily passed through an opening, such as opening O ( FIG. 14 ) of an underground structure and, once positioned therein, may be opened or unfolded into the deployed position in which expansion band assembly  204  substantially corresponds with the size of the opening in which it is received. 
     Expansion band assembly  204  may be installed into seal  202  to create pipe seal assembly  200 , as shown in  FIG. 13 . More specifically, expansion band assembly  204  may be captured within seal  202  by passing each of ring portions  205   a ,  205   b  through windows  257  ( FIG. 14 , which may optionally be in the form of slits, such as slits  23  described above) into partially annular tunnels or slots  258  ( FIG. 19 ) of seal  202 . Respective ring end portions  220 ,  222  are then joined by affixing expansion mechanisms  224  thereto, as shown in  FIG. 22  and described above. 
     Once expansion band assembly  204  is captured within slots  258  of seal  202 , collapsing or folding expansion band assembly  204  to a folded configuration also collapses or folds seal  202 . Thus, while pipe seal assembly  200  in the resulting undeployed position ( FIG. 13 ), assembly  200  may be passed through opening O ( FIG. 14 ) with little or no interference. Once received within the underground structure, pipe seal assembly  200  can be opened or unfolded by configuring expansion band assembly  204  to the unfolded configuration, as shown in  FIG. 14 . Expansion band assembly  204  can then be expanded by turning adjuster  230  to move blocks  226 ,  228  away from one another, thereby expanding the effective diameter of expansion band assembly  204  and urging upper portion  206  of seal  202  against the adjacent annular surface, such as the surfaces of frame  218  and risers  216  as shown in  FIG. 14 . Once this sealing step is completed, the initial installation of pipe seal assembly  200  is complete. 
     With upper portion  206  of seal  202  now secured within opening O, a second expansion band assembly  204  may be passed into opening O in its folded or undeployed position for securement of the lower portion of pipe seal assembly  200  to the adjacent annular wall. Lower portion  208  of seal  202  includes groove  260 , which is sized to receive expansion band assembly  204 . Unlike slot  258  at upper seal portion  206 , groove  260  is open, so that expansion band assembly  204  need not be disassembled to pass ring portions  205   a ,  205   b  into groove  260 . Thus, with a folded expansion band assembly  204  received within opening O, expansion band assembly  204  may be fitted within groove  260  and moved to its opened or deployed position to seat assembly  204  to lower portion  208  of seal  202 . Adjuster  230  may then be turned to move blocks  226 ,  228  away from one another, thereby expanding the lower expansion band assembly  204  and urging lower seal portion  208  against the adjacent annular surface, such as the inner surface of base  214  as shown in  FIG. 14 . 
     Advantageously, the closed profile of slot  258  and the ability to fold pipe seal assembly  200  allows pipe seal assembly  200  to be installed into opening O by a single installer. Specifically, seal  202  need not be held in place by one installer while a second installer installs expansion band assembly  204  at upper portion  206 . Also, since the lower expansion band assembly  204  need not be installed at lower seal portion  208  until after the upper expansion band assembly  204  has been secured, one installer can secure lower seal portion  208  after upper portion  206  is already firmly secured. Thus, there is no need for a second installer to hold pipe seal assembly  200  in place while a second, lower expansion band assembly  204  is installed. 
     Although seal  202  is described as being a single unitary seal above, a plurality of seals may be used in conjunction with a plurality of expansion band assemblies to seal openings with large inner annular surfaces, and/or several seams. For example, an extension seal (not shown) may be installed to seal  202 , with the extension seal having an upper seal portion sized to fit within groove  260  so that the lower expansion band assembly and seal  202  engages both the lower seal portion  208  of seal  202  and the upper seal portion of the extension seal (not shown). The extension seal may then have a lower seal portion similar to lower seal portion  208 . In an exemplary embodiment, extension seals may be used where the vertical distance to be sealed exceeds approximately 10 inches. 
     Although sealing assembly  200  is shown and described above in an application in which same is used to provide a seal at the upper end of an underground structure, such as providing a seal between a manhole chimney and a manhole frame, sealing assembly  200  may also be used to provide a seal across a pipe joint in the manner described above and shown in  FIGS. 1 ,  3  and  5 . 
     While this invention has been described as having an exemplary design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.