Abstract: A hydraulic shock-absorbing jack particularly for use underwater comprises a cylinder 1 in which a piston 20 associated with an actuated rod 23 is slidable. The piston defines within the cylinder a first actuating chamber 6 provided with a first inlet 2 for actuating liquid and connected to an accumulator 7 of elastically variable volume, and a second actuating chamber 8 provided with a second inlet 3 for actuating liquid. The rod is mounted to be slidable relative to the piston such that, in the event of a shock applied to the rod which would otherwise cause an increase in the volume of the second chamber, the rod alone moves relative to the piston without affecting the volume of the second chamber. The rod is provided with an enlarged head 24 located in the first chamber and preventing its disengagement from the piston.

Abstract: An automatic hydraulic connector for connecting an hydraulic pipe to apparatus comprises a female cylindrical receptacle for connection to the apparatus and a retractable hollow male cylindrical body releasably lockable by locking means to the receptacle, under the control of a cylindrical slide member biased by a spring to its locking position and driven into its unlocking position by the action of an operating fluid which acts on a movable cylindrical core which is connectable to the slide member and also in part defines the hydraulic passage extending from an inlet in the male body to an outlet in the female receptacle.

Abstract: An apparatus for inserting a shut-off device 9 laterally into a pipe via a branch 48 which is inclined at an obtuse angle to the pipe, comprises a housing 1 for connection at one end to the branch and containing a first carriage 6 which is movable relative to the housing to a forward position projecting from the housing into the pipe and includes a receptacle for the shut-off device and a guide member 8 for guiding the shut-off device out of the receptacle, a second carriage 10 which is movable relative to the first carriage and is connected to the shut-off device by an insertion jack 13, and displacement means for first moving the first carriage to its forward position, the second carriage moving with the first carriage, and for then moving the second carriage relative to the first carriage to move the shut-off device out of its receptacle further into the pipe, the insertion jack finally being operated to move the shut-off device into position in the pipe.