Rotary control valve

Claim 1

A rotary control valve comprising: a. a casing defining a closure-receiving chamber having a main axis and having openings communicating with said chamber at spaced points to define a flowway therethrough disposed at an acute angle to said main axis; and b. a flow-control member rotatably disposed in said chamber comprising: i. a hollow body shaped to fit said chamber and having an axis of rotation coaxial with said chamber axis; ii. a tubular flow-conduit extending through said body generally at said acute angle with respect to said axis of rotation and opening through the wall of said body whereby the ends of the conduit will be in register with said openings at the full flowway-open position of said control member; iii. elongate slots through the wall of said body extending circumferentially of the body in opposite directions from the opposite ends of said flow-conduit, each of said slots being defined by walls converging toward their trailing ends; iv. said body having nonslotted portions between the trailing ends of said slots and the adjacent ends of said conduit defining closure portions adapted to close off the flowway openings in the flowway-closing position of the control member; v. said slots and the ends of said conduit cooperating with the related flowway openings to vary the effective cross-sectional area of the flowway in accordance with the angular position of the slots and conduit ends relative to said openings while maintaining substantially straight-line flow through the flowway at all valve-open positions; and vi. cylindrical trunnion members carried by the opposite ends of said body and journaled in said casing on said main axis.