Abstract: A coupling device provides a pre-tensioned coupling between a first member and a second member. The members are arranged to define a sealed compartment. A piston is housed within the compartment and is translated between the first member and the second member. A first ratchet lock is mounted within the second member and on translation of the piston, the first ratchet lock engages with the piston. A second ratchet is mounted within the second member and, on translation of the piston into the second member, the piston engages with the ratchet. The second ratchet is mounted on a piston, and translation of the second ratchet on the piston applies a tensile force to the first piston to tension or pre-tension the piston. As the ratchets substantially prevent reverse movement of the piston, the tensile force is retained.

Abstract: A coupling device provides a pre-tensioned coupling between a first member and a second member. The members are arranged to define a sealed compartment. A piston is housed within the compartment and is translated between the first member and the second member. A first ratchet lock is mounted within the second member and on translation of the piston, the first ratchet lock engages with the piston. A second ratchet is mounted within the second member and, on translation of the piston into the second member, the piston engages with the ratchet. The second ratchet is mounted on a piston, and translation of the second ratchet on the piston applies a tensile force to the first piston to tension or pre-tension the piston. As the ratchets substantially prevent reverse movement of the piston, the tensile force is retained.