Patent ID: 8307852

Claim:
A pinion valve body for a hydraulic power steering apparatus with an actuation cylinder including a left pressure chamber and a right pressure chamber comprising: outer diameter areas having a number of O-ring grooves circumferentially formed thereon, a number of supply holes for receiving oil from an oil pump, a number of left and right discharge holes for discharging oil to the left and right pressure chambers, respectively; inner diameter areas having raised surfaces with the supply holes formed penetrating therethrough and a number of splines recessed in a radial direction and extending alternately of the raised surfaces, the splines having the left and right discharge holes formed penetrating therethrough; a lower section having a seat extending radially outwardly from the inner diameter areas where the splines merge with the raised areas extending from the splines, a recess extending radially outwardly from circumferential surfaces of the inner diameter areas under the seat and a pin hole formed terminally of the recess; and an upper section having a sleeve mount extending radially outwardly from the inner diameter areas, wherein the lower section has a jig groove formed at the opposite side of the pin hole and two slants tapering the lower section from opposite ends of the jig groove to a bottom end of the lower section.