Patent ID: 8056940
Filing Date: 2011-11-15
Classification: E21B

Abstract:
1. A pipe connector, comprising: a tubular pin member having a generally frustoconical outer surface forming an engagement surface thereof, and a tubular inner surface opposite the engagement surface, a tubular box member having a generally frustoconical inner surface forming an engagement surface thereof which corresponds to, and overlies, the engagement surface of the pin member when the members are fully engaged together, and a tubular outer surface opposite the engagement surface, the members having inter-engageable annular projections and grooves on the engagement surfaces for axially locking the members together when they are fully engaged together, the projections and grooves being spaced apart along the engagement surfaces, means for supplying hydraulic fluid under pressure between the overlying parts of the surfaces of the members when fully engaged together to expand the box member and/or contract the pin member to bring the projections out of engagement with the corresponding grooves and permit the members to be disengaged, and means for radially restraining the free end of one of the members, wherein at least one of the inner surface of the pin member and the outer surface of the box member includes at least one of a recess and a protrusion which reduces and/or increases the thickness of the tubular wall along the length of the at least one member so as to balance the displacement of the at least one member at different points along the length thereof under injection pressure, and wherein the at least one recess or protrusion is formed by inwardly and outwardly tapering sections in the respective surface of the respective member.