Power steering regulation for automobiles

Claim 1

A hydraulic pressure control for use in a power-assisted steering system of a motor vehicle including a source of hydraulic pressure comprising a. a valve body interposed between said source of hydraulic pressure and said steering system and having an inlet passageway communicating with said hydraulic pressure source and said steering system for delivering pressure fluid to the latter, b. an outlet passageway in said valve body parallel to said inlet passageway and also communicating with said steering system and said pressure source to enable return fluid flow to said source, c. a rotary plug valve in said valve body provided with parallel ducts adapted to align respectively with said inlet and outlet passageways, and a channel adapted to connect portions of said inlet and outlet passageways on the hydraulic pressure source side, thereby to enable unrestricted fluid flow and afford relatively easy steering operation, d. said valve being shiftable for selectively restricting or stopping the hydraulic flow therethrough for reducing the sensitivity and ease by which steering is accomplished, or rendering said power-assisted steering system ineffective, e. means on said valve on the outside of said valve body affording manual operating means for said valve, thereby to predetermine the resistance imposed on the steering effort of the operator, f. indicia means on said last means and valve body for visually indicating the adjusted position of the valve, and g. set screw means for securely holding said valve in position of adjustment.