Abstract: The invention relates to a hydropneumatic accumulator in which a bladder or membrane supported within a vessel establishes a chamber for confining a compressible fluid within the vessel and also provides means for supporting a valve plate opposite inlet and outlet ports arranged so that as the valve plate position responds to pressure changes normal flow between the ports may be maintained and extruding of the bladder or diaphragm into the outlet port prevented.

Abstract: A pressure vessel in the form of a hydro-pneumatic flexible bladder accumulator is provided which includes a shell formed of a cylindrical tube. An open-ended thimble-shaped deformable bladder of resilient material is positioned within the shell. A port plate is attached to one end of the tube, and a closure cap is retained in the other end of the tube. The cap may be retained in the other end of the tube, for example, by a removable locking ring. The closure cap has an inner end which may be displaced radially inwardly from the inner surface of the shell, and it has three axially spaced peripheral grooves on the inner end which respectively receive an O-ring to prevent leakage of liquid out of the accumulator, and two integral beads that surround the mouth of the bladder. One of the integral beads of the bladder has the shape of an O-ring, and it is received in one of the grooves to form an effective seal for the interior of the bladder.

Abstract: Wave-motion compensating apparatus for a crane is provided, which includes a hydro-pneumatic accumulator and an hydraulic ram, and additional components for controlling the fluid connection between the accumulator and the ram. The apparatus is intended to be coupled to a crane on an off-shore oil drilling rig, or the like, and it serves to compensate for the rising and falling wave motion between a vessel being unloaded and the crane. The compensating apparatus initially causes the load carrying cable of the crane to be maintained at a slight substantially constant tension permitting the load to rise and fall with the motion of the vessel. The apparatus at this time extracts and stores energy from the up and down motion of the load; then, after a few up and down cycles, the apparatus exerts a lifting force on the cable to lift the load clear of the crest of the next wave. The foregoing is achieved without the need for any external energy source apart from the wave motion itself.