Abstract: A speed sensitive hydraulic pressure reaction device in a rack pinion type power steering device of the type employing a rotary valve. A valve body of the output shaft and the rotary valve forms a sleeve portion so as to integrally rotate around the input shaft. The sleeve portion has a plurality of holes mutually communicating through a ring ditch, and a plunger is slidably disposed in each hole. The input shaft has a plurality of slots which engage with the respective plungers at the outer periphery of the input shaft. Each slot has a bottom and a pair of slant surfaces in a cross section orthogonal to the input shaft. When the center of the plunger is aligned with a center between the pair of slant surfaces, gaps are formed between the plunger and each of the slant surfaces.

Abstract: A rotary control valve for an automotive power steering system and a method for making such a valve. The valve includes a tubular valve body and a spool valve member rotatable within the valve body, each of the valve body and spool valve having axially extending grooves. The spool valve member includes control edges formed at the axial grooves to effect control of the area of an opening defined by the edges of the axial grooves of the spool member and the axial grooves of the valve body. The control edges extend parallel to the axial grooves of the spool valve member along substantially the entire length thereof and are defined by at least one arcuate surface portion formed on the spool valve member at axially extending edges of the grooves. The arcuate surface portion has an axis that extends parallel to the axial grooves of the spool valve member.

Abstract: Disclosed is a device for controlling the pressure of a fluid supplied to a power steering apparatus in response to the speed of a vehicle. The device is arranged such that in a fluid return passage from the power steering apparatus to a pump, there is provided a throttle valve controlled by the speed of the vehicle, so that the controlled oil pressure is guided to an oil pressure reaction chamber in the power steering apparatus.

Abstract: A rack and pinion steering device which comprises a pinion operatively connected to a steering shaft of a vehicle, a long rod-like rack operatively connected to a steering lever mechanism of wheels of the vehicle, said rack having a group of rack teeth meshed with said pinion, and a spring device in contact with the back of said rack on the side opposite said pinion to resiliently bias said rack against said pinion. Said group of rack teeth includes a first portion close to and a second portion away from a center of said rack lengthwise which portions are defined symmetrically on opposite sides of said center, and said both second portions have a reference pitch line which inclines so as to approach the axis of said rack as it is away from said first portion adjacent thereto, whereby said rack gives rise to a flexure displacement under bending pressure caused by said spring device in connection with the meshed position between the rack and the pinion on said group of rack teeth.

Abstract: In a ball nut type steering gear for a motor vehicle having two trains of balls confined within passageways formed by the helical grooves in a threaded shaft and a ball nut which surrounds the threaded shaft, two major diameter portions disposed in spaced-apart relation are formed in the threaded shaft. When the motor vehicle travels straight ahead, the balls are rollingly engaged in the helical grooves in the major diameter portions of the threaded shaft and the ball nut, and there is no play between the grooves and the balls which are engaged in the grooves. However, when the steering wheel is manipulated, the balls are rollingly engaged in the helical grooves in portions of the threaded shaft which are smaller in diameter than the major diameter portions of the threaded shaft, and there is play of a certain extent between the balls and the helical grooves.