Correction device in a power steering apparatus for vehicles

A power steering apparatus for a vehicle comprising a power cylinder having a pair of working chambers defined therein by means of an output piston on the opposite sides thereof, a source of fluid pressure, a fluid reservoir, and a control valve interposed in a pair of low and high pressure fluid lines connecting said power cylinder chambers with said source of fluid pressure and said fluid reservoir, said valve being operable to selectively place said power cylinder chambers into fluid communication with said pressure source and said reservoir, respectively, and a correction device connected with said respective power cylinder chambers for correcting power cylinder output in response to lateral accelerations of the vehicle, said correction device comprising:

• a casing mounted on the vehicle body and having a single closed chamber defined therein, a weight disposed centrally within said casing chamber for free movement in a lateral direction of the vehicle, a pressure restriction plate integrally formed with said weight, and a pair of nozzle members connected to said respective chambers of said power cylinder and disposed in said casing in laterally aligned opposite relation to each other, said nozzle members having their nozzle openings facing with the laterally opposite side faces of said pressure restriction plate normally at an equal spacing therefrom, whereby when the vehicle in motion is steered to turn, said weight is first moved laterally from its neutral position toward one of said nozzle members due to the pressure fluid ejecting from the nozzle opening of the other nozzle member against the associated lateral side face of said pressure restriction plate to restrict the flow of pressure fluid discharged from said casing chamber through said one nozzle member and then caused under a centrifugal force to move back in the reverse direction against the force of the pressure fluid acting thereon to a point of equilibrium, at which said centrifugal force and said force of the pressure fluid become balanced each other, thereby enlarging the spacing between said one nozzle member and the associated side face of said pressure restriction plate so that a part of the pressure fluid fed to one of said power cylinder chambers through said control valve, is bypassed therefrom to said reservoir by means of said correction device at a flow rate proportionate to the magnitude of the vehicle lateral acceleration sensed by said weight.