Hydraulic coupling

Claim 2

Apparatus suitable for use in connecting a length of pipe to a suitable tubular member in difficult working environments comprising: an elongated, generally tubular housing of a diameter greater than the diameter of the pipe length to be joined, said housing adapted to be fitted around said pipe length to define an axially extending annulus between the outer surface of said pipe length and the inner wall of said housing; an annular piston mounted in said annulus substantially free of contact with said pipe length, and in sliding and sealing engagement with the inner wall of said housing and a cylinder of smaller outside diameter than the piston attached to and extending axially from The piston, said housing having a section of reduced diameter in sliding and sealing engagement with the outer wall of the cylinder, an annular space being defined between said piston and said section of reduced diameter, an inwardly sloping cam surface on the inner wall of said housing axially spaced from said piston away from said section of reduced diameter, said surface facing toward said piston; gripping means disposed in said annular adjacent said cam surface and adapted to move axially upon actuation into contact with said cam surface and to be thereby radially moved into gripping engagement with said pipe length; a seal assembly including a packing element mounted in said annular between said piston and said gripping means and substantially free of contact with said pipe length, for movement axially by said piston an amount sufficient to move said gripping means against said cam surface, said packing element being compressed by said piston when the gripping means reaches the end of its travel into sealing engagement with the outer surface of said pipe length on one side and the inner wall of said housing on the other to effect a seal between said housing and said pipe length; stop means for limiting the distance the seal assembly can travel toward the cam surface, said stop means being located far enough from the seal assembly before he tool is actuated to allow the seal assembly to move the gripping means into firm engagement with the pipe and close enough to prevent the packing element of the seal assembly from relaxing sufficiently to move out of sealing engagement with the pipe and the housing should the gripping means move along its cam surface far enough to permit such relaxation after the gripping means are initially set, and a source of fluid under pressure remote from said housing, but connected through an opening in said housing into fluid communication with said annular space, whereupon entry of fluid under pressure into said annular space is effective to axially move said piston toward said cam surface.

Claim 3

Apparatus in accordance with claim 1, wherein said apparatus further comprises means to fix said piston in place with said gripping means in gripping engagement with said pipe and said packing element of the seal assembly in sealing engagement with said pipe.

Claim 4

Apparatus in accordance with claim 1 wherein said section of reduced diameter comprises a second piston which is free for sliding axial movement within said annulus away from said first piston member, and in which said apparatus is further provided with a second cam surface located on the opposite side of the second piston from the first cam surface, second gripping means disposed in the annulus adjacent the second cam surface for axial movement, a second seal assembly including a second packing element located between the second piston and the second gripping means to transmit the movement of the second piston to the second gripping means to move said means along the cam surface into gripping engagement with the pipe and to compress said second packing assembly between the second piston and the gripping means into sealing engagement with the pipe and the housing and a second stop means to limit the travel of the second seal assembly toward the second cam surface after said second packing element has been compressed into sealing engagement with the outside surface of the pipe length and the inner wall of the housing.

Claim 5

Apparatus suitable for connecting two lengths of pipe or for enclosing a leak in a pipe length comprising: an elongated, generally tubular, housing of a diameter greater than the diameter of the pipe lengths to be joined or repaired, said housing adapted to be fitted around the adjacent ends of said pipe lengths to be connected or the length to be repaired to define an axially extending annulus between the other surface of said pipe length or lengths and the inner wall of said housing; first and second annular piston members mounted in said annulus substantially free of contact with said pipe length in sliding sealing engagement with the inner wall of the housing, and a cylindrical member attached to one of the pistons for movement therewith and extending therefrom toward and beyond the other piston and in sliding engagement therewith to form with the pistons and the inner wall of the housing an annular space, first and second inwardly sloping cam surfaces on the inner walls of said housing and axially spaced from said first and second piston members, respectively, with the surfaces facing toward said piston members; first and second gripping means disposed in said annulus adjacent the first and second cam surfaces, respectively, for movement axially into contact with said cam surfaces and to be thereby radially moved into gripping engagement with said pipe length; first and second seal assemblies including first and second packing elements mounted in said annulus between said first and second gripping means, respectively, and said pistons, and substantially free of contact with said pipe length, said seal assemblies being movable axially by said pistons as they move apart an amount sufficient to move said first and second gripping means along said first and second cam surfaces, respectively, into gripping contact with the pipe length and upon further axial movement of said piston for said first and second packing elements to be compressed into sealing engagement with the adjacent other surface of said pipe length on one side and the inner wall of said housing on the other to effect two axially spaced seals between said housing and the pipe length or lengths positioned inside each resilient means; stop means for limiting the distance the seal assemblies can travel toward their respective cam surfaces, said stop means being located far enough from the seal assemblies before the tool is actuated to allow the assemblies to move the gripping means into firm engagement with the pipe and close enough to prevent the packing elements thereof from relaxing sufficiently after being initially compressed into sealing engagement to move out of sealing engagement with the pipe and the housing should either of the gripping means move further along its cam surface far enough to permit such relaxation after the gripping means are initially set, a source of fluid under pressure remote from said housing but connected through an opening in said housing into fluid communication with said annular space between pistons whereupon entry of fluid under pressure into said annular space is effective to axially move said pistons toward said cam surfaces.

Claim 6

Apparatus suitable for connecting two lengths of pipe or for enclosing a leak in a pipe length comprising: an elongated, generally tubular, housing of a diameter greater than the diameter of the pipe lengths to be joined or repaired, said housing adapted to be fitted around the adjacent ends of said pipe lengths to be connected or the length to be repaired to define an axially extending annulus between the other surface of said pipe length or lengths and the inner wall of said housing; first and second annular piston members mounted in said annulus substantially free of contact with said pipe length in sliding sealing engagement with the inner wall of the housing, and a cylindrical member attached to one of the pistons for movement therewith and extending therefrom toward and beyond the other piston and in sliding engagement therewith to form with the pistons and the inner wall of the housing an annular space, first and second inwardly sloping cam surfaces on the inner walls of said housing and axially spaced from said first and second piston members, respectively, with the surfaces facing toward said piston members; first and second gripping means disposed in said annulus adjacent the first and second cam surfaces, respectively, for movement axially into contact with said cam surfaces and to be thereby radially moved into gripping engagement with said pipe length; first and second seal assemblies including first and second packing elements mounted in said annulus between said first and second gripping means, respectively, and said pistons, and substantially free of contact with said pipe length, said seal assemblies being movable axially by said pistons as they move apart an amount sufficient to move said first and second gripping means along said first and second cam surfaces, respectively, into gripping contact with the pipe length and upon further axial movement of said piston for said first and second packing elements to be compressed into sealing engagement with the adjacent other surface of said pipe length on one side and the inner wall of said housing on the other to effect two axially spaced seals between said housing and the pipe length or lengths positioned inside each resilient means; stop means for limiting the distance the seal assemblies can travel toward their respective cam surfaces, said stop means being located far enough from the seal assemblies before the tool is actuated to allow the assemblies to move the gripping means into firm engagement with the pipe and close enough to prevent the packing elements thereof from relaxing sufficiently after being initially compressed into sealing engagement to move out of sealing engagement with the pipe and the housing should either of the gripping means move further along its cam surface far enough to permit such relaxation after the gripping means are initially set, a source of fluid under pressure remote from said housing but connected through an opening in said housing into fluid communication with said annular space between pistons whereupon entry of fluid under pressure into said annular space is effective to axially move said pistons toward said cam surfaces.

Claim 7

Apparatus in accordance with claim 4 wherein said fluid pumped into said type space between the piston members is adapted to harden upon setting in said annular space to thereby lock said piston members in place with said gripping means in gripping engagement with said pipe and said packing elements in sealing engagement with said pipe.

Claim 8

The apparatus of claim 4 in which said first second seal assemblies include first and second annular compression rings located between the first and second gripping means the first and second packing elements.

Claim 9

The apparatus of claim 6 in which said stop means to limit the axial movement of the packing elements comprise the compression rings and the cam surfaces, the engagement of which limit said axial movement of the packing elements to hold the packing elements in said sealing engagement with the housing and pipe after the gripping means has moved axially out of engagement therewith.

Claim 10

The apparatus of claim 7 further provided with second stop means to limit the distance the compression rings can move toward the pistons to avoid subjecting the packing elements to a compressive load inadvertently when the apparatus is being installed.