Hydraulic retractable and extensible wheel suspension

A hydraulic retractable and extensible wheel suspension for a trailer for raising the trailer to a transporting position and lowering the trailer to a ground level position comprising, a pair of tandem wheels, a torsion arm for each wheel, each wheel being rotatably mounted on one end of a respective torsion arm, torsion spring means connected to the opposite end of each torion arm, a pair of levers pivotally mounted on the trailer frame, said torsion spring means being connected to each lever, a link extending between said levers and being pivotally connected at each end to a respective lever, and hydraulic cylinder means connected between the trailer frame and the link, whereby upon extension of said hydraulic cylinder means, the pair of levers are caused to pivot simultaneously in a direction to raise the tandem wheels, to thereby lower the trailer to the ground level position, and upon retraction of said hydraulic cylinder means the pair of levers are caused to pivot simultaneously in the opposite direction to lower the tandem wheels, to thereby raise the trailer from the ground level position.