Abstract: A rack and pinion apparatus comprising a toothed rack, the tops of the teeth of which lie in a common plane, the rack and pinion apparatus further comprising an anti-roll mechanism having a rack teeth engaging pad mounted to permit relative movement between the rack and teeth engaging means and so as to be in contact, at any given instant, with the tops of at least two rack teeth.

Abstract: A single-ended power assisted rack and pinion steering gear comprising a housing defining a cylinder, double-acting piston means reciprocable within said cylinder, said piston means including a piston rod one end of which is connectable to a wheel lever of a steerable road wheel of a vehicle to impart steering thereto, a pinion connectable to the steering control of a vehicle, a toothed rack one end of which is pivotally connected to the other end of the piston rod and the other end of which is free, means resiliently urging the toothed rack into meshing engagement with the pinion, and valve means associated with the pinion for directing fluid under pressure to one side or the other of the double acting piston means.

Abstract: The invention provides a closed center rotary valve and a power-assisted steering mechanism for a motor vehicle incorporating the rotary valve.The closed center rotary valve comprises cooperating relatively rotatable sleeve and core members having cooperating axially-extending grooves therein and means relatively biassing the members towards a neutral position.Said grooves comprise at least one inlet groove connectable to a source of fluid under pressure, a cylinder groove angularly spaced from the inlet groove on each side thereof and connectable to opposite sides of a double-acting piston-and-cylinder, and a return groove in overlapping relation with each of the cylinder grooves in the neutral position of the valve and connectable to a reservoir for the fluid under pressure, the inlet groove being closed from communication with the cylinder and return grooves in the neutral position of the valve.

Abstract: The invention provides a method of and apparatus for imparting a required metering form to the longitudinal outer edges of axially extending grooves of cylindrical rotor members of rotary valves by moving an impressing tool or tools having the required metering form thereon against a said edge or edges of a rotor member or members generally in the direction of a chord extending between a point on said edge and a similar point on an adjacent edge of the nearest adjacent groove so as to displace the material of the edge being worked away from the groove.

Abstract: A rotary valve in or for a power-assisted rack-and-pinion steering mechanism for a motor vehicle, the rotary valve comprising a valve sleeve, a rotor member rotatable within the valve sleeve, the rotor member and the valve sleeve each having axially extending grooves therein which cooperate to control the flow of fluid under pressure through the valve according to the angular disposition of the rotor member relative to the valve sleeve, and a torsion bar connecting the rotor member to the pinion of the rack-and-pinion steering mechanism, wherein the said pinion is cylindrical and is rigidly connected to the valve sleeve by means of an annular coupling member having an end portion which fits over an end portion of the pinion and has internal teeth which intermesh with the teeth of the pinion, the annular coupling member being brazed or otherwise bonded to both the pinion and to the valve sleeve.

Abstract: A power-assisted rack-and-pinion steering mechanism for a vehicle provided with a beam axle and semi-elliptical springs, the steering mechanism comprising double-acting piston-and-cylinder means having a piston rod opposite ends of which are provided with ball joints whereby the piston rod is connectable with the steerable road wheels of a vehicle, a toothed rack spaced radially of the piston rod and extending away from the piston rod beyond one end thereof, a pinion connectable with the steering control of a vehicle and in meshing engagement with the toothed rack, the pinion being located outside, not between, said ball joints, a connecting member connecting adjacent ends of the piston rod and toothed rack, the connecting member being rigidly connected to the piston rod and being pivotally connected to the toothed rack, and a bifurcation of said connecting member for restraining the toothed rack against pivotal movement about an axis normal to the axis of said pivotal connection.