Vehicle suspensions

Claim 1

A suspension unit for a vehicle wheel comprising a sole, fluidtight cylinder, a stub axle for mounting said wheel attached to said cylinder, a piston in said cylinder including a piston rod adapted to be attached at its upper end to the chassis of a vehicle, a helical compression spring coaxial with said cylinder and engaging spring-retaining means carried by the piston rod and by the cylinder respectively, hydraulic fluid partly filling said cylinder, a free volume of gaseous fluid under pressure in said cylinder and serving as a fluid spring cooperating with said compression spring, said volume being unrestricted within said cylinder so as to be free to rise above said hydraulic fluid, a guide assembly at the upper end of the cylinder and slidably receiving the piston rod, a closed reservoir in said guide assembly and in open communication with said piston rod to receive and trap oil carried on said piston rod to said reservoir when said rod is reciprocated relative to said reservoir as the result of vehicle use, an oil seal on the upper side of said reservoir and sealingly surrounding said rod, the oil in said reservoir contacting said seal to lubricate the same and prevent it from drying out and cracking during periods of vehicle nonuse.