Pedestal mounted full reservoir air spring piston

A piston for attachment to a flexible sleeve of an air spring, said piston including:

• a one-piece integral main shell formed of plastic having inner and outer generally concentric annular walls forming a second subchamber within the inner wall and a first subchamber In an annular space formed between said inner and outer walls, at least said second subchamber being adapted to be In fluid communication with a main fluid chamber formed within the flexible sleeve;
• a plurality of stiffening ribs extending between said inner and outerwalls and located within said first subchamber, and between said inner wall within said second subchamber;
• a generally planar bottom end wall enclosing an open bottom of the inner annular wall;
• a one-piece integral annular end closure plate formed of plastic extending between the outer and inner annular walls and sealingly connected thereto for enclosing the first subchamber, said bottom end wall extending beyond said end closure plate to provide a central pedestal having a reduced area than an area defined by said outer wall for mounting the piston on a supporting member;
• a central post extending upwards from the bottom end wall into the second subchamber, with certain of the stiffening ribs extend radially between said central post and the inner wall;
• a top wall extending between the outer and inner walls and forming a top closure for the first subchamber, with at least one opening being formed in the inner wall to provide fluid communication between said first and second subchambers;
• and
• an annular portion of the inner wall extending beyond the top wall and providing a sealing surface for engagement with a beaded area of the flexible sleeve.