1. Field of the Invention
This invention relates to a lever mechanism for operating a mixing valve which controls both flow volume and relative proportion of hot and cold water.
2. Description of the Prior Art
In a single handled mixing valve, the axial position of a control stem establishes the flow volume and the angular position of the stem controls the mixture. In typical faucet installations, the valve is operated by a handle which is part of a lever mechanism.
Prior art mixing valve lever mechanisms suffer certain shortcomings. Most have crevices or other recesses which accumulate dirt and soap, and are hard to clean. One object of the present invention is to provide a lever mechanism having a smooth exterior cowl or shield which is easy to clean and which prevents dirt, fluids and the like from getting into the mechanism. Another shortcoming is difficulty of assembly, particularly attachment of the lever arm to the valve control stem. Another object of this invention is to provide an easy to assemble lever mechanism including simplified attachment of the control valve stem.
Typical prior art lever mechanisms are shown in the patent literature. In the Hennessey U.S. Pat. No. 1,693,758, the lever arm has a handle at one end. The other end rides in an angular groove opening inwardly toward the center of the valve cover. The U.S. Pat. No. 1,882,953 to Saelzler discloses a lever handle pivotally connected to the control stem which extends exteriorly of the valve housing. The fulcrum end of the lever handle seats in a bracket integral with a ring which encircles the valve housing and is free to rotate about the valve axis. The control handle shown in the U.S. Pat. No. 2,087,223 to Thompson includes an elongate fulcrum-pin receiving slot which compensates for slack motion of the fulcrum point as the lever is operated.
In the mixing valve assemblies shown in the U.S. Pat. Nos. 2,800,923 and 2,818,878 to Russell, the lever handle projects through an opening in a lever retaining tap threaded to the faucet assembly. A ball-like projection, integral with the pivotally connected end of the lever, rides in a channel opening to the interior of the retaining cap. The ball-like projection is situated on the same side of the control stem as the lever handle. A similar mechanism is shown in the U.S. Pat. No. 2,757,687 to Moen.