Patent ID: 8602430

Claim:
A trailing arm air suspension system supporting a vehicle frame, comprising on either sides of the vehicle a trailing arm ( 09 , 10 ) pivoted at its first end ( 41 , 42 ) at top of hanger brackets ( 05 , 06 ), which trailing arms extend in longitudinal direction to axle ( 150 ) which axle is connected on its both sides to mid-portion ( 43 , 44 ) of trailing arms ( 09 , 10 ) by spherical joints with centers ( 49 , 50 ), which hanger brackets ( 05 , 06 ) are attached to a pair of oppositely spaced frame rails ( 03 , 04 ) connected by at least one cross member ( 51 ), which hanger brackets ( 05 , 06 ) extend vertically below axle axis plane ( 52 ), to which hanger bracket is pivotally connected link rods ( 13 , 14 ) at first end of the link rods to bottom end of hanger brackets more towards lower side of axle axis plane ( 52 ), link rods extending in the longitudinal direction to axle, second end of link rods pivotally connected to axle below axle axis plane, air springs ( 23 , 24 ) and shock absorbers ( 25 , 26 ) functionally disposed between a second end ( 45 , 46 ) of trailing arms and frame rails ( 03 , 04 ) wherein the axle ( 150 ) is connected to the trailing arm ( 09 , 10 ) by spherical joint with center ( 49 , 50 ), which spherical joint center is one of four nodes of a four bar mechanism disposed on both sides of axle, which trailing arm bears partial weight of suspended mass at its ends ( 41 , 42 ) and ( 45 , 46 ) wherein the trailing arm is a rolled and formed spring steel with a formed pivot hole ( 59 , 60 FIG. 5 ) disposed at its first end ( 41 , 42 ), which pivot and spherical joints with center ( 49 , 50 ) and a trailing arm portion between spherical joint center ( 49 , 50 ) and pivotal joint ( 11 , 12 ), establish one of four links of four bar mechanism, which trailing arm also has a vertically resilient length ( 57 , 58 ).