Distributed accumulator

A distributed accumulator for use in a hydraulic system for connecting operative components of the systems together and for attenuating pressure surges and oscillations within said system comprising

• an outer tubular, structural member defining an inner surface,
• a non-porous, tubular inner member formed of plastic sheet material, said inner member being configured with a relaxed shape having radially reentrant convolutions extending longitudinally of said member forming a plurality of longitudinal ridges separated by interspersed longitudinal troughs so that said inner member can be repeatedly expanded and contracted by flexing without stretching,
• said inner member having an expanded cross-section at least as large as the inner surface of said outer member,
• a resilient, compressible tubular support shell made of a closed cell foamed elastomeric material disposed inside said outer member and shaped to form a structure having a relaxed outer periphery conforming to the inside of said outer member and a relaxed inner periphery shaped to conform to and support the relaxed shape of said inner member,
• said inner member being disposed within and supported by said support shell, the outer circumference of said inner member, when supported in said support shell, being radially spaced inwardly from the inner surface of said outer member,
• said inner member, when stressed by internal pressure, radially expanding by flexing to a stressed configuration of greater cross-sectional area and against the return force developed by compression of said shell, said shell's closed cell structure maintaining the effect of the compression within a local region, and thereafter, in response to reduction of pressure, recovering its original configuration and cross-section by application of the return force of said resilient foam shell.