Pipe coupling with assembly tool

Abstract

A pipe coupling includes mating hub sections engaged by outer split clamp elements that are compressed together against mating tapered surfaces of the hub sections to draw the hub sections together into tight fitting relationship. The clamp elements are driven into a compressed condition by an outer locking ring that fits over the split clamp elements to draw the hub sections together and to retain the hub sections against axial separation. The clamp elements have locking surfaces engageable by the locking ring and axial movement of the locking ring is limited by appropriate stop surfaces and retainers. A locking sleeve installation and removal tool utilizing an actuator system is described.

I claim:  
     
         1 . A pipe coupling comprising: 
 first and second hub sections each having a longitudinal bore extending along a longitudinal axis, an outer terminal end and an inner end having a circumferentially and radially extending clamping portion including a clamping face extending concentric with the bore at an oblique angle between radially inner and outer ends of the clamping face so that the clamping face is inclined towards the inner end of the respective hub section between its radially inner and radially outer ends;    at least a pair of clamp elements configured as generally complementary segments each having an annular inner profile concentric with the bore including axially spaced radially inwardly projecting inner clamping surfaces dimensioned and configured to fit closely over and mate with the clamping faces of the first and second hub sections when the inner ends of the first and second hub sections are axially aligned and placed in close proximity to each other, and an outer circumferentially extending peripheral surface portion lying within a first radius of curvature, and a plurality of circumferentially spaced locking surface portions lying outside said first radius of curvature and along a second radius of curvature greater than said first radius of curvature and concentric with said bore;    said clamp elements having terminal ends and being dimensioned so said ends are located adjacent each other but not abutting each other when said clamping surfaces of said clamp elements are mated against said clamp faces and the inner ends of the hub sections abut each other;    a locking ring having an inner locking surface extending concentric with said bore and having a radius of curvature that is not larger than the radius of curvature of said locking surface portions when said clamp elements are fit over the inner ends of the hub portions with the clamping surfaces and clamp faces in abutting relationship and with said inner ends of said hub sections abutting each other;    whereby placement of said clamp elements over the inner ends of the hub sections with the clamp faces in abutting relationship with the clamp surfaces and placement of said inner locking surfaces of said locking ring over the locking surface portions of the clamp elements draws the inner ends of the hub sections in abutting relationship and resists axial separation of said hub sections.    
     
     
         2 . The pipe coupling as claimed in  claim 1 , wherein said locking surface portions are each defined by an area located at the end of at least one radially and axially extending sloping outer peripheral surface portion of said clamp element.  
     
     
         3 . The pipe coupling as claimed in  claim 1 , including at least one selectively removable retainer element associated with at least one clamp element arranged to prevent axial movement of the locking ring relative to said last-recited clamp element in an axial direction.  
     
     
         4 . The pipe coupling as claimed in  claim 1 , said locking ring including a radially extending motion stop surface at one end area of said locking ring, said stop surface located and dimensioned to engage a clamp element for preventing relative axial movement between the locking ring and the clamp element in one axial direction that is opposite an axial direction of fitting the locking ring over the clamp elements.  
     
     
         5 . The pipe coupling as claimed in  claim 1 , said locking ring including a radially extending motion stop surface at one end area of said locking ring, said stop surface located and dimensioned to engage a clamp element for preventing relative axial movement between the locking ring and the clamp element in one axial direction that corresponds to an axial direction of fitting the locking ring over the clamp elements; and 
 at least one selectively removable retainer element associated with at least one clamp element arranged to prevent axial movement of the locking ring relative to said last-recited clamp element in an axial direction that is opposite an axial direction of fitting the locking ring over the clamp elements.    
     
     
         6 . The pipe coupling as claimed in  claim 1 , said locking ring including a radially diverging inclined inner peripheral ramp surface at one axial end area thereof, said ramp surface intersecting said inner locking surface.  
     
     
         7 . The pipe coupling as claimed in  claim 1 , said locking ring including a radially diverging inclined inner peripheral ramp surface at one axial end area thereof, said ramp surface intersecting said inner locking surface; 
 said locking ring including a radially extending motion stop surface at one end area of said locking ring, said stop surface located at the axial end of said locking ring opposite the axial end having the ramp surface and dimensioned to engage a clamp element for preventing relative axial movement between the locking ring and the clamp element in one axial direction that corresponds to an axial direction of fitting the locking ring over the clamp elements.    
     
     
         8 . The pipe coupling as claimed in  claim 7 , including at least one selectively removable retainer element associated with at least one clamp element arranged to prevent axial movement of the locking ring relative to said last-recited clamp element in an axial direction that is opposite an axial direction of fitting the locking ring over the clamp elements.  
     
     
         9 . The pipe coupling as claimed in  claim 1 , wherein said hub sections, clamp elements and locking ring are metal.  
     
     
         10 . The pipe coupling as claimed in  claim 9 , said first and second hub sections each including an inner, radially diverging surface defining a seal seat at the inner end thereof and intersecting said bore; and an annular seal element dimensioned and configured to span the inner ends of such hub sections in contiguous and compressed relationship with said seal seats when the inner ends of the hub portions are in abutting, axially aligned relationship.  
     
     
         11 . A pipe coupling locking ring installing and removing tool comprising: 
 a bracket having an open central area dimensioned and configured to receive an axially extending pipe coupling hub section and a radially extending first face on one side thereof configured and dimensioned to engage a radially extending portion of a pipe coupling locatable in the central area;    at least a pair of actuators engaging the bracket on a second side thereof opposite said one side, said actuators located circumferentially spaced about said central area and each actuator including an axially moveable actuator rod terminating at a distal end located beyond said axially extending first face; and    a radially extending locking ring engaging feature connected to the distal end of each actuator rod.    
     
     
         12 . The pipe coupling locking ring installing and removing tool as claimed in  claim 11 , wherein the locking ring engaging feature is connected to its respective actuator rod by a lost motion device arranged to allow limited relative axial movement between the actuator rod distal end and the ring engaging feature.  
     
     
         13 . The pipe coupling locking ring installing and removing tool as claimed in  claim 12 , including a spring device biasing the ring engaging feature in a direction towards the actuator associated with the respective actuator rod.  
     
     
         14 . The pipe coupling locking ring installing and removing tool as claimed in  claim 12 , said bracket including at least a pair of radially extending actuator rod guides circumferentially spaced about said central area, each said guide defining open radial slot for receiving a respective one of said actuator rods of said actuators in radial and axial directions.  
     
     
         15 . The pipe coupling locking ring installing and removing tool as claimed in  claim 13 , wherein said bracket comprises mating complementary portions that may be selectively joined together to define said central area.  
     
     
         16 . A method of installing a locking ring on a pipe coupling including a pair of axially aligned hub sections each having an axially extending longitudinal bore, an outer terminal end and an inner end having circumferentially and radially extending clamping portions each including a clamping face extending concentric with the bore at an oblique angle between radially inner and radially outer ends of the clamping face so that the clamping face is inclined towards the inner end of the respective hub section between its radially inner and radially outer ends; at least a pair of clamp elements configured as generally circular complementary segments, each having an annular inner profile concentric with the bore including axially spaced radially inwardly projecting inner clamping surfaces dimensioned and configured to fit closely over and mate with the clamping faces of the first and second hub sections when the inner ends of the first and second hub sections are axially aligned and placed in close proximity to each other, and an outer circumferentially extending peripheral surface portion lying within a first radius of curvature, and a plurality of circumferentially spaced locking surface portions lying outside said first radius of curvature and along a second radius of curvature greater than said first radius of curvature and concentric with said bore; said clamp elements having terminal ends and being dimensioned so said ends are located adjacent each other but not abutting each other when said clamping surfaces of said clamp elements are mated against said clamping faces and the inner ends of the hub sections abut each other; a locking ring having an inner locking surface extending concentric with said bore and having a radius of curvature that is not larger than the radius of curvature of said locking surface portions when said clamp elements are fit over the inner ends of the hub portions with the clamping surfaces and clamp faces in abutting relationship and with said inner ends of said hub sections abutting each other; comprising the steps of: 
 providing a bracket having an open central area large enough to receive that portion of each hub section extending away from the inner end of the respective hub section but not so large as to permit passage therethrough of the clamps elements fitted over the inner ends of the hub sections, and a radial surface at one axial end of the bracket;    installing the bracket over one hub section with the hub section located within the central open area and the clamp elements abutting said radial surface;    locating actuators having axially extending actuator rods with distal ends on an axial end area of the bracket opposite the end including the radial surface equally circumferentially spaced about said central area, and further with said actuator rods extending towards an axial end of said locking ring opposite the end of the ring facing towards said bracket;    providing a locking ring engaging feature at the distal end of each actuator rod and engaging said locking ring engaging feature with said axial end of said locking ring;    operating said actuators to draw each actuator rod and said locking ring towards a respective actuator while reacting the axial actuator loads against the clamp elements via said radially extending surface.    
     
     
         17 . The method as claimed in  claim 16 , including connecting each said locking ring engaging feature to a respective actuator rod by means of a resilient lost motion connector that permits limited relative axial motion between each said actuator rod and a respective locking ring engaging feature, and providing radially extending actuator rod guides on said bracket that permit radial placement of said actuator rods into said guides while said locking ring is engaged by said locking ring engaging features of each actuator rod; 
 engaging each respective locking ring engaging feature with the locking ring, with each respective actuator rod located outside a respective guide; moving the respective actuator rod into a respective guide while maintaining the locking ring engaging feature in engagement with the locking ring, and placing each actuator on the side of said bracket opposite the radial surface engaging the clamp elements;    locating the respective actuator associated with said actuator rod against the side of the bracket opposite the side having the radial surface;    drawing the actuator rod, the locking ring engaging feature and the locking ring towards the bracket radial surface by energizing the actuator.    
     
     
         18 . A locking ring for use in a clamp type pipe coupling, said ring comprising an annular inner surface including a locking surface portion centered on a ring axis of curvature; 
 an inwardly radially extending motion stop surface at one axial end area of the ring extending inwardly of an axially projected diameter of the inner locking surface; and    a radially diverging inclined inner peripheral ramp surface at a second axial end of the ring, said ramp surface intersecting said annular inner surface.    
     
     
         19 . The locking ring as claimed in  claim 18 , said locking ring having a main portion having an axial length along said axis of curvature, said motion stop surface connected to an axially projecting portion of said locking ring that extends axially beyond said main portion.  
     
     
         20 . A clamp element for use in a clamp type pipe coupling, said clamp element generally shaped as a circular segment centered on an axis of curvature, and including an annular inner profile concentric with said axis of curvature including axially spaced radially inwardly projecting inner clamping surfaces extending at an oblique angle between radially outer and radially inner ends of the clamping surfaces, the surfaces tapering inwardly towards each other as they approach radially outer ends thereof in a direction away from said axis of curvature; and 
 an outer circumferentially extending peripheral surface portion lying within a first radius of curvature centered on said axis of curvature concentric with said axis of curvature, and a plurality of circumferentially spaced locking surface portions lying outside said first radius of curvature and along a second radius of curvature greater than said first radius of curvature and concentric with said axis of curvature.    
     
     
         21 . The clamp element as claimed in  claim 20 , said locking surface portions each being defined by an area located at an end of at least one radially and axially extending sloping outer peripheral surface portion of said clamp element.  
     
     
         22 . The clamp element as claimed in  claim 21 , wherein said locking surface portions are defined by an area located between a pair of radially and axially extending sloping outer peripheral surface portions of said clamp element.