Pipe coupling

Abstract

A pipe connection used in corrugated pipe includes a male/female connection that is configured to accommodate movement of the male connector in the female connector after installation of the pipe. The ability to maintain a satisfactory pipe connection throughout a desired and designed range of movement is helpful in applications where the pipe may be exposed to changing conditions such as ground settling, ground shifting, earthquake or other conditions. The male connector and the female connector for receiving the male connector are oversized to allow additional insertion of the male connector or partial withdrawal of the male connector while maintaining the pipe connection throughout the range of movement. The pipe connection can also he used to provide an effective two stage male/female connection between reinforced plastic pipe sections.

1 . In combination first and second corrugated pipe sections connected by a male connector of the first pipe section received in a female connector of the second pipe section and each pipe section is of at least a double wall configuration having an inner wall defining a tubular passage through said pipe section reinforced by a connected outer corrugated wall attached to said inner wall;
 said male connector including an elongate spigot portion forming a projecting extension of said inner wall of said first pipe section partially received in an outwardly stepped socket of said second pipe section;   said outwardly stepped socket of said second pipe section including an inner wall about said spigot portion with a majority of said spigot portion overlapping with said stepped socket; said stepped socket being reinforced by a connected corrugated outer wall;   said female connector at a free end of said second pipe section including a cuff portion overlapping with a corrugated section of said first pipe section that is immediately adjacent said spigot portion and is received in said cuff portion;   wherein said first stepped portion at an inner end thereof extends beyond said spigot portion and said spigot portion at an inner end extends into said cuff portion to accommodate further inward movement of said spigot portion and said corrugated section of said first pipe section if required; and   wherein said spigot portion overlaps with said stepped socket sufficiently to allow partial separation of said spigot portion from said stepped socket if required while maintaining the male/female connection of said pipe sections.   
     
     
         2 . In combination as claimed in  claim 1  wherein a space void is defined at junction of said first stepped portion and said cuff portion that surrounds the portion of said spigot portion extending into said cuff portion that is limited by said cuff portion and limited by a front edge of said corrugated section at the junction with said spigot portion. 
     
     
         3 . In combination as claimed in  claim 1  wherein said male/female connection is capable of being displaced in an inward compressive movement of said pipe sections at least 50 mm and is capable of being displaced outwardly in a separating direction at least 50 mm and maintain an effective male/female connection throughout this range. 
     
     
         4 . In combination first and second corrugated pipe sections connected at opposed ends by a male connector of said first pipe section inserted in a female connector of said second pipe section;
 said first and second corrugated pipe sections each having a long corrugated body portion of at least a double wall configuration having an inner tubular wall with a corrugated reinforcing wall secured to an exterior surface of said inner tubular wall;   said male connector including an elongate spigot portion of a size and shape to form an extension of said inner tubular wall at one end of said first pipe section and being of a unitary construction with said first pipe section;   said female connector including a first stepped portion at one end of said second pipe section joined to said inner tubular of said second pipe section and being of a unitary construction with said second pipe section;   said first stepped portion including an inner wall of a shape and size defining an opening configured to receive and effectively sleeve a major portion of said elongate spigot portion,   said first stepped portion being outwardly stepped relative to the inner tubular wall of said first pipe section to accommodate the wall thickness of said elongate spigot portion;   said female connector at a junction between said long corrugated section and said female connector including a first stepped portion of a length corresponding to a length of said spigot portion and sized to receive the spigot portion, said first stepped portion merging with and being outwardly stepped relative to the inner wall of said long corrugated section, said first stepped portion then merging with an outer cuff of a length and size capable of receiving said second series of corrugations.   
     
     
         5 . A corrugated pipe section, said corrugated pipe section having a generally smooth inner wall of consistent cross section and an outer wall defining a first series of corrugations attached to and forming a reinforcing wall about said inner wall;
 said corrugated pipe section having a female connector at one end of said corrugated pipe section and a male connector at an opposite end of said long corrugated pipe section with said male connector being of a size for insertion in the female connector;   said male connector including an elongate spigot portion having an inner surface sized to correspond to an inner surface of said smooth inner wall of said long corrugated section;   said male connector including at one end of said elongate spigot portion a second series of corrugations of a reduced exterior size relative to said first series of corrugations, said second series of corrugations transitioning to said first series of corrugations at a junction of said male connector and said long corrugated section;   said female connector at a junction between said long corrugated section and said female connector including a first stepped portion of a length corresponding to a length of said spigot portion and sized to receive the spigot portion, said first stepped portion merging with and being outwardly stepped relative to the inner wall of said long corrugated section, said first stepped portion then merging with an outer cuff of a length and size capable of receiving said second series of corrugations.   
     
     
         6 . A corrugated pipe section as claimed in  claim 5  wherein said outer cuff has an outer edge generally aligned with the outer edge of said long corrugated section. 
     
     
         7 . A corrugated pipe section as claimed in  claim 6  wherein said first stepped portion has a center position with respect to an axial position of said corrugated pipe corresponding to a normal received position of a spigot portion of a male connector that allows for limited additional insertion of said spigot in said first stepped portion or limited withdrawal of said spigot portion from said center position while maintaining the integrity of a male/female connection between two connected lengths of corrugated pipes. 
     
     
         8 . A corrugated pipe section as claimed in  claim 7  including an identification marking associate with said male connector or said female connector used to provide guidance when connected components are generally in said center position. 
     
     
         9 . A corrugated pipe section as claimed in  claim 5  wherein said first stepped portion includes a recess seal cavity immediately adjacent to said second stepped portion with said recess seal cavity opening into said length of corrugated pipe, and wherein, said recess seal cavity includes a separate wiper seal located therein. 
     
     
         10 . A corrugated pipe section as claimed in  claim 9  wherein said second series of corrugations of said male connector include at least one corrugation with a recessed exterior surface forming a wiper seal seat for a separate ring seal. 
     
     
         11 . A corrugated pipe section as claimed in  claim 7  wherein an end of said spigot is spaced from an inner end of said first stepped portion at least 75 mm when said spigot and said first stepped portion are in said centered position. 
     
     
         12 . A reinforced plastic pipe having an inner pipe section of a first inner diameter reinforced by a series of outwardly extending reinforcing portions of a second greater diameter that reinforce and increase the strength of said inner pipe section;
 an improved male/female connector with one end of said reinforced plastic pipe having a two stage male connector and an opposite end of said reinforced plastic pipe having a two stage female connector sized to receive a male connector of the same construction as said two stage male connector;   said male connector comprising a first spigot portion with an inner wall of said first diameter and an outer wall section of a diameter less than an outer diameter of said female connector;   said male connector further including a second spigot portion having an inner diameter the same as said first spigot portion and a plurality of spaced outwardly extending reinforcing members separated by inwardly extending recesses; and   wherein said female connector at a free end thereof includes a first cuff portion with an inner wall defining an outer connecting cavity sized to receive and engage said second spigot portion and an inner cuff portion defining a smaller cavity merging with said outer cavity and said inner cuff portion being of a size to receive and engage said first spigot portion.   
     
     
         13 . A reinforced plastic pipe as claimed in  claim 12  wherein said first spigot portion is of reduced stiffness relative to said second spigot portion. 
     
     
         14 . A reinforced plastic pipe as claimed in  claim 13  wherein said first cuff portion is of reduced stiffness relative to said inner cuff portion. 
     
     
         15 . A reinforced plastic pipe as claimed in  claim 13  wherein a coupling formed by insertion of said male connector in said female connector forms a section of pipe having a stiffness greater than the stiffness of said pipe intermediate the male and female connectors. 
     
     
         16 . A reinforced plastic pipe as claimed in  claim 15  wherein said reinforced plastic pipe includes a series of outwardly extending reinforcing corrugations or outwardly extending reinforcing ribs. 
     
     
         17 . A reinforced plastic pipe as claimed in  claim 12  wherein the outer diameter of said female connector is the same as the outer diameter of said reinforced pipe. 
     
     
         18 . A reinforced plastic pipe as claimed in  claim 13  wherein the outer diameter of said female connector is slightly larger than the outer diameter of said reinforced pipe. 
     
     
         19 . A reinforced plastic pipe as claimed in  claim 18  wherein an outer diameter of said outwardly extending reinforcing members of said male connector are at least approximately equal to an outer diameter of said series of outwardly extending reinforcing portions of said reinforced plastic pipe. 
     
     
         20 . A reinforced plastic pipe as claimed in  claim 19  including at least one compressible circumferential sealing member located on an exterior surface of said second spigot portion sized for sealing with a cavity of the size defined by the outer cavity of said female connector. 
     
     
         21 . A reinforced plastic pipe as claimed in  claim 26  wherein said first spigot portion and said second cuff portion cooperate along the length thereof to form a sleeve arrangement generally extending the extent of overlap therebetween and said second spigot portion and said first cuff portion form a sleeve arrangement determined by the extent of overlap thereof; and wherein said sleeve arrangements are each effective without full insertion of said male connector in said female connector. 
     
     
         22 . A reinforced plastic pipe as claimed in  claim 12  wherein said first spigot section is of a generally constant wall thickness approximately equal to the greatest wall thickness of said inner pipe section between said outwardly extending reinforcing portions. 
     
     
         23 . A reinforced plastic pipe as claimed in  claim 13  wherein said reinforced plastic pipe is a corrugated reinforced plastic pipe with a series of spaced reinforcing corrugations selectively connected to said inner pipe section; and wherein said first spigot portion is of a length at least equal to a length of said reinforced plastic pipe necessary to fully include two adjacent corrugations. 
     
     
         24 . A reinforced plastic pipe as claimed in  claim 23  wherein said second spigot portion is of a length at least equal to a length of said reinforced plastic pipe that fully includes three adjacent corrugations. 
     
     
         25 . A reinforced plastic pipe as claimed in  claim 24  wherein a first step is defined between said first spigot portion and a lead corrugation of said second spigot portion and a second step is defined between an inner corrugation of said second spigot portion and an adjacent larger diameter corrugation of said reinforced plastic pipe. 
     
     
         26 . A reinforced plastic pipe as claimed in  claim 25  wherein said first and second steps are approximately equal. 
     
     
         27 . A reinforced plastic pipe as claimed in  claim 12  wherein said two stage male connector cooperates with said two stage female connector to provide two spaced overlapped sleeve connecting segments of different diameters with a first sleeve connecting segment defined by the extent of overlap of said first spigot portion with said second cuff portion and a second sleeve connecting segment defined by the extent of overlap of said second spigot portion and said first cuff portion. 
     
     
         28 . A reinforced plastic pipe as claimed in  claim 27  wherein said inner cuff portion includes a series of outwardly extending reinforcing ribs and/or reinforcing corrugations of a diameter equal to or less than said second diameter. 
     
     
         29 . A pipe corrugator having a series of opposed mold blocks adapted to produce reinforced plastic pipe as claimed in  claim 12 .