Abstract: A power steering system is provided in which the rack portion of the power piston is strengthened while still shortening the axial length of the power piston associated therewith. This is accomplished by providing a control valve which includes a valve lever received in a power piston of the device which is relatively rotatable with respect to the power piston and moves in an axial direction of the housing with the power piston in response to rotation from an input shaft connected with the steering wheel. The valve lever has an engaging portion which projects outside of the power piston so as to be connected therewith when the valve reciprocates. The reciprocation of the valve will assist in the operation of the power steering unit and provide the power assist. The valve lever has a portion engageable with a pin member received in the valve spool of the control valve so as to reciprocate the control valve.

Abstract: A power steering system for use in a motor has a pair of reactive pressure chambers in which the opposite ends of a valve spool are exposed, one of the reactive pressure chambers communicating with one fluid-pressure chamber in a reciprocable fluid-pressure cylinder assembly through a first orifice, the other reactive pressure chamber communicating with both fluid-pressure chambers in the cylinder assembly through second and third orifices, respectively. The first, second and third orifices are the first and second orifices are defined in the valve spool. A third passage define by a space between the spool and the valve cylinder communicates the first and third orifices.

Abstract: There is disclosed a hydraulically operated power steering system which comprises a reciprocating-type hydraulically operated cylinder unit for moving a steering link mechanism and having first and second chambers, a reservoir containing hydraulic fluid therein, a hydraulic pump feeding the hydraulic fluid in the reservoir to the cylinder unit, a control valve unit including a line coupled to communicate the hydraulic pump, a line coupled to communicate the reservoir, a valve cylinder having passages coupled between the first and second chambers to provide fluid communication therebetween, and a valve spool slidably arranged in the valve cylinder and reciprocatingly movable in response to rotation of an input shaft, the cylinder unit including therein right and left reaction chambers to which opposite ends of the valve spool are exposed, the reaction chambers being communicated with the respective first and second hydraulic chambers through orifices, and a valve for dividing the left reaction chamber into a r

Abstract: A power assisted steering mechanism comprises a power piston in engagement with sector and worm shafts, right and left cylinders selectively receiving the fluid under pressure to thereby assist the movement of the power piston, and a control valve means incorporated within the power piston to selectively transmit the fluid under pressure into said right and left cylinders. The control valve means comprises a slidable valve piston positioned so as to define a pair of primary reaction chambers and a pair of secondary reaction chambers, the primary reaction chambers being in fluid communication with the secondary reaction chambers through means of orifices, respectively, and the secondary reaction chambers being connected to each other through means of a variable orifice which reduces the fluid communication therebetween in response to a speed of the vehicle.