Patent attributes
A diaphragm assembly for use with a hydraulic apparatus. The diaphragm assembly includes a cap formed of a rigid material and a diaphragm formed of an elastomeric material. The diaphragm is generally tubular and includes an upper annular collar portion defining an open upper end of the diaphragm and a main body portion extending downwardly from the collar portion, defining a closed lower end of the diaphragm, and including, in cross-section, a plurality of hollow radially extending circumferentially spaced arms. The cap includes an upper disc portion sized to receive the collar portion of the diaphragm and a rib portion extending downwardly from the disc portion and including, in cross-section, a plurality of radially extending circumferentially spaced arms positioned respectively within the arms of the main body portion of the diaphragm whereby the elastomeric arms of the diaphragm provide large expansion and contraction capacity and the rigid arms of the cap preclude undesired distortion or wrinkling of the flexible arms of the diaphragm.