Vandal-proof thermostatic mixing valve

Abstract

A self-regulating mixing valve has a main housing having hot- and cold-water inlets and provided with an externally threaded stem defining an axis, a valve body displaceable axially in the housing between hot and cold end positions blocking flow from the inlets and through intermediate positions permitting flow from both inlets, and a thermostat in the housing connected to the valve body. An abutment ring fixed on the housing around the stem is provided with a stop. An adjustment nut threaded on the stem adjacent the ring is axially operatively engaged with the thermostat so that rotation of the nut in one direction about the axis axially displaces the thermostat in one direction and opposite rotation axially oppositely displaces it. A protective sleeve centered on the axis and fixed on the ring extends axially outward from the ring coaxially around the sleeve and projects axially outward past the sleeve. An adjustment knob having an annular skirt engaging coaxially between the protective sleeve and the knob is provided with another stop angularly engageable with the stop of the abutment ring to limit angular displacement of the knob on the stem. Interengaging axially extending formations on and between the knob and the nut rotationally couple same together while permitting same to move axially relative to each other. A screw engaged axially between the knob and the nut and fixes the knob axially to the nut.