US Patent 7137410 Mixing valves

A single handle mixing valve of the plate valve type where a single stem controls both the temperature and flow output from the valve. A control said characteristic plate having an opening is positioned over the stem and has at least one surface defining limits of stem movement. An actuating ring positioned within an exterior cover for the mixing valve has inwardly facing cam surfaces, which interact with the control plate to adjust either maximum temperature or maximum flow from the valve. The actuating ring has a tab extending to the outside of the exterior cover for convenient operator manipulation without the need for disassembly or the use of tools.