Arrangement for relieving the mechanical stresses in power assisted steering for vehicles in the full-lock steering positions

Claim 1

An arrangement for reducing the stresses on mechanical parts of an hydraulic power-assisted steering system for motor vehicles at the full-lock steering positions during hydraulic operation, comprising a hollow body defining an hydraulic cylinder having an end wall, a piston mounted displaceably within the said cylinder and defining therein two chambers, and hydraulic distributor means responsive to the steering direction for connecting said chambers selectively to a source of fluid under pressure and to a discharge outlet, wherein the improvement consists in the provision of at least two conduits traversing the piston parallel to its direction of movement, said conduits connecting the two chambers defined by the piston within the hollow body, respective rods secured to and projecting from said end wall, said rods being slidably located within the conduits, the said rods each having a narrow part the transverse cross section of which is less than the internal cross section of the respective conduit whilst the remainder of each rod has a cross section equal to that of the respective conduit to seal the latter, the said narrow part on one of the said rods being positioned on its associated conduit in one end of stroke position of the piston and the narrow part in the other of the said rods being positioned in its associated conduit in the other end of stroke position of the piston whereby in these respective end of stroke positions of the piston the respective conduits are at least partially open.