ROBERT P MONTESI
Engineers in Kendall Creek, PA

5100183, Mar 31, 1992

May 10, 1991

7/701356

Robert P. Montesi - Bradford PA
Gerald L. Anderson - Bradford PA
Phillip E. Frair - Singlehouse PA

Dresser Industries, Inc. - Dallas TX

F16L 1706

285337

A pipe coupling for the joining of plain end pipe that includes an annular gasket and a compressible lock ring at each end of the coupling between a tubular middle ring and an annular follower. Bolts extending between the opposite followers are effective when tightened to compress both the gasket and lock ring into their operative relation for sealing and gripping a coupled pipe end, respectively. The follower is comprised of a unitary structure integrally cast to define an internal annular protuberance that juxtaposedly confronts the radially rearward surface of the gasket. Also defined by the follower inward of the protuberance is a central opening at least partially tapered frusto-conically and in which the lock ring is initially supported controllably spaced from the gasket. Tightening of the bolts enables gasket sealing pressure to be achieved about the pipe end sequentially before a completed restraing grip on the pipe end is attained by the lock ring.