Abstract: A method for joining pipe elements in end to end relation uses a coupling that includes interconnectable coupling segments having connection members at opposite ends. The connection members are tightenable for drawing the segments toward one another and into engagement with the pipe elements. Each segment has a concavity positioned between inwardly projecting arcuate surfaces that engage grooves in the pipe elements. The concavities house a sealing member that extends circumferentially around the pipe elements. Angularly oriented surfaces are positioned adjacent to the connection members. The surfaces on facing segments engage one another and cause the segments to rotate in opposite directions about an axis perpendicular to the pipe elements. The concavities are angularly oriented with respect to the axis so that when the segments rotate, the concavities are oriented substantially parallel to the seal.

Abstract: A concave bearing surface for use with lugs of pipe coupling segments and a method of joining pipe ends. The concave bearing surface is positioned on the lug and surrounds an aperture which receives a fastener attaching the coupling segments together end to end surrounding pipe ends to be joined. Either the nut or the head of the fastener that engages the concave surface may be rotated to tighten the fastener. Engagement between the concave surface and the rotating member reduces the torque required to tighten the fastener and effect a stiff, fluid tight joint.

Abstract: A method for joining pipe elements end-to-end using a pair of pipe couplings attached to one another end to end surrounding a central space includes inserting the pipe elements into the central space, moving the coupling segments toward one another and engaging surface regions of the coupling segments with outer surfaces of the pipe elements, initially at a first contact point on the coupling segments and subsequently at second and third contact points on the coupling segments. The first contact point is located between opposite ends of the coupling segments and may be located on a region of infinite radius of curvature, may project radially inwardly toward the pipe elements, and may be located midway between the opposite ends of the segments. The second and third contact points are located at opposite ends of the coupling segments.

Abstract: A method for joining pipe elements in end to end relation uses a coupling that includes interconnectable coupling segments having connection members at opposite ends. The connection members are tightenable for drawing the segments toward one another and into engagement with the pipe elements. Each segment has a concavity positioned between inwardly projecting arcuate surfaces that engage grooves in the pipe elements. The concavities house a sealing member that extends circumferentially around the pipe elements. Angularly oriented surfaces are positioned adjacent to the connection members. The surfaces on facing segments engage one another and cause the segments to rotate in opposite directions about an axis perpendicular to the pipe elements. The concavities are angularly oriented with respect to the axis so that when the segments rotate, the concavities are oriented substantially parallel to the seal.

Abstract: A mechanical pipe coupling is formed of segments attached end to end to surround a central space. Each segment has arcuate keys which project toward the central space. Each key is formed of a pair of side surfaces and a mid surface between them. The mid surface is angularly oriented relative to a longitudinal axis perpendicular to a plane containing the segments. When used to couple pipe elements having grooves the angular orientation of the mid surfaces provides flexibility to the joint. A method of joining pipe elements end to end is also disclosed.

Abstract: A pipe coupling for joining pipe elements end-to-end is disclosed. The pipe coupling is formed of segments attached to one another circumferentially straddling the pipe elements. The segments are formed from sub-sections connected to one another end-to-end. Each sub-section has a surface region disposed to engage the outer surfaces of the pipe elements. Each surface region has a different radius of curvature from a surface region on a neighboring sub-section. The radii are selected so that when the coupling segments are deformed around the pipe elements, portions of surface regions of selected sub-sections contact the pipe elements, while portions of surface regions of those sub-sections between the selected portions remain in spaced relation away from the pipe elements. A constant and minimal torque is required to bolt the segments together as a result.

Abstract: A coupling for joining pipe elements in end to end relation is disclosed. The coupling includes interconnectable coupling segments having connection members at opposite ends. The connection members are tightenable for drawing the segments toward one another and into engagement with the pipe elements. Each segment has a concavity positioned between inwardly projecting arcuate surfaces that engage grooves in the pipe elements. The concavities house a sealing member that extends circumferentially around the pipe elements. Angularly oriented surfaces are positioned adjacent to the connection members. The surfaces on facing segments engage one another and cause the segments to rotate in opposite directions about an axis perpendicular to the pipe elements. The concavities are angularly oriented with respect to the axis so that when the segments rotate, the cavities receive the sealing member without distorting it. A method of joining pipe elements end to end is also disclosed.