Shock absorber for liquid flow lines

Claim 1

A SHOCK ABSORBER UNIT FOR A LIQUID CONVEYING LINE, A HOLLOW TIGHT CASING HAVING OPPOSITE END WALLS AND AN ENCLOSING WALL JOINING THE END WALLS, SAID CASING BEING SUBSTANTIALLY NON-EXPANSIBLE UNDER OPERATING CONDITIONS TO DEFINE A SUBSTANTIALLY FIXED INTERNAL VOLUME; SAID CASING LIQUID AND GAS-TIGHT EXCEPT FOR THE HEREINAFTER DESCRIBED PASSAGES, A BELLOWS SLEEVE OF FLEXIBLE MATERIAL IMPERMEABLE TO THE LIQUID IN SUCH LINE AND TO A PRESSURIZING GAS SAID BELLOWS SLEEVE HAVING OPPOSITE ENDS ANCHORED TO SAID END WALLS RESPECTIVELY TO DIVIDE THE INTERIOR OF SAID CASING INTO TWO VARIABLE SPACE REGIONS INTERNAL AND EXTERNAL OF THE SAID BELLOWS SLEEVE RESPECTIVELY; A CHARGE OF PRESSURIZING GAS CONTAINED IN ONE OF SAID SPACE REGIONS; ONE OF SAID END WALLS HAVING THERETHROUGH A LIQUID PASSAGE TO THE OTHER SAID SPACE REGION; AND MEANS ON SAID ONE END WALL FOR CONNECTING SAID UNIT TO, AND WITH SAID PASSAGE COMMUNICATING WITH, SAID LINE; SAID BELLOWS SLEEVE OVER SUBSTANTIALLY ITS ENTIRE LENGTH HAVING FORMED THEREIN LIKE LONGITUDINAL PLEATS OR CORRUGATIONS PRESENTING IN THE UNSTRESSED SLEEVE A CLOSED-CURVE SINUOUS CROSS-SECTION IN WHICH THE SHAPE OF THE TROUGHS IS SIMILAR TO THE SHAPE OF THE CRESTS, THE BELLOWS SLEEVE BEING FREE OVER SUBSTANTIALLY ITS ENTIRE PLEATED LENGTH TO CONTRACT IN CROSS-SECTION WITH THE PLEAT SURFACES ON OPPOSITE SIDES OF EACH TROUGH FOLDING TOWARD EACH OTHER, WHEREBY THE VOLUME OF THE BELLOWS SLEEVE MAY CHANGE BY RADIAL DISPLACEMENT OF THE BELLOWS SLEEVE PRIMARILY BY FLEXING WITH THE PLEATS FLATTENING OUT FOR INCREASED VOLUME AND APPROACHING OR FOLDING TOWARD EACH OTHER FOR DECREASED VOLUME OF THE BELLOWS SLEEVE RATHER THAN BY POSITIVE OR NEGATIVE TENSILE STRAINING OF THE BELLOWS MATERIAL AND WHEREBY THE LIQUID-SHOCK ABSORBING ACTION OF THE SAID UNIT RESULTS PRIMARILY BY COMPRESSION OF SAID CHARGE WITH RADIAL MOVEMENT OF SAID BELLOWS SLEEVE UPON RISE OF LIQUID PRESSURE IN SAID LINE.