Abstract:
The combination of a shower valve having a metallic movable stem to control operation of the valve and a non-metallic high strength composite handle adapter secured to the stem for movement therewith, with the non-metallic handle adapter preventing galvanic corrosion between the metallic valve stem and a metallic handle attached to the handle adapter.

Description:
THE FIELD OF THE INVENTION 
     The present invention relates to shower valves and more specifically to the interface between a zinc die cast shower handle and the brass cartridge stem which forms a part of the shower valve. Typically, shower handle adapters in use today are made from zinc and they will mount a zinc die cast handle to a brass cartridge stem. There is galvanic corrosion between these metallic elements, which corrosion makes it extremely difficult to remove the handle adapter and the handle when it is necessary to service the shower valve cartridge in the field. The present invention provides a handle adapter which is made of a high strength composite material which will prevent galvanic corrosion between the zinc or metallic handle and the brass valve stem. 
     SUMMARY OF THE INVENTION 
     The present invention relates to shower valves and more specifically to the use of a non-metallic high strength composite material as the adapter mounted between a metal shower handle and the metal cartridge valve stem. 
     A primary purpose of the invention is a shower valve installation which will utilize a non-metallic high strength composite handle adapter to prevent galvanic corrosion between the handle and the cartridge stem. 
     Another purpose is to provide a handle adapter which may be molded in a multicavity injection mold, thus increasing cost effectiveness in the production of shower valve components. 
     Another purpose is to provide a non-metallic handle adapter which will prevent galvanic corrosion between adjoining metallic components in a shower valve installation. 
     Other purposes will appear in the ensuing specification, drawings and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is illustrated diagrammatically in the following drawings wherein: 
     FIG. 1 is an exploded perspective of the components in a shower valve installation; 
     FIG. 2 is a side view of the handle adapter; and 
     FIG. 3 is a rear view of the handle adapter. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention is specifically directed to preventing galvanic corrosion between joined metallic components in a shower valve installation, and more particularly, the zinc die cast handle and the brass cartridge stem forming a part of the shower valve. The invention provides a high strength composite handle adapter interfaced between the handle and the cartridge stem which acts as a galvanic corrosion barrier. Preferably, the handle adapter will be made of a glass fiber reinforced nylon material, and more specifically, the product known as Hiloy 610 sold by A. Schulman Company. Other materials may well be satisfactory, however, this specific material has been found to be acceptable in use. 
     In FIG. 1 a shower valve installation includes a valve  10  which may have located therein a mixing valve cartridge of the type manufactured by Moen Incorporated, assignee of the present application, and sold under the trademarks “1225” and “1200.” Other forms of shower valves are also suitable. All such valves normally have a valve stem  12  which is formed of brass or a similar metallic material. Adjacent the valve  10  is a stop tube  14  which will extend over the portion of the valve  10 , indicated at  16 , which mounts the valve cartridge. Coaxially aligned with and positioned inside of the stop tube is a brake  18 . Stop tubes of the type shown herein are disclosed in U.S. Pat. No. 4,813,455, also assigned to the assignee of the present application, and the disclosure of the &#39;455 patent is herein incorporated by reference. The stop tube  14  has an axially extending rectangular projection  20 , and similarly, the brake  18  has a partial axially extending projection  22  which will interlock with the projection  20 , rendering the brake stationary relative to the stop tube during operation of the valve. 
     The handle adapter is indicated generally at  24  and may be formed of a composite material as described and has an axially extending boss  26  which will fit within the cylindrical portion  28  of the brake  18  and there will be frictional resistance between these two elements as the handle adapter is rotated, the frictional resistance providing a braking force to assist in controlling handle rotation during operation of the shower valve. A fastener  30  extends through a central opening  32  in the handle adapter  24  and will be threaded into the threaded bore of the brass cartridge stem  12  to thereby attach the handle adapter, brake, stop tube and a washer  34  into an assembly mounted on the cartridge valve stem. 
     The shower lever handle is indicated at  36  and may be of any suitable design. It will be attached by a fastener  38  to the handle adapter by means of a threaded bore  40  located in a platform  42  which is on the handle side of the adapter  24 . 
     The handle adapter has the described boss  26  which extends within the brake  18  and further has an arcuate temperature stop indicated at  44  with stop surfaces  46  and  48  at the opposite ends of the arcuate projection. The stop surfaces  46  and  48  will be moved with the handle  36  during use until one or the other contacts the axial projection  20  of the stop tube  14 . Thus, the stop tube and the temperature stops on the handle adapter limit rotation of the handle adapter, the lever and thus the cartridge stem  12  of the shower valve. This controls water temperature. 
     On the lever side of the handle adapter there is the described platform  40  with its two upstanding walls  50 , which provide strength for the threaded attachment between the lever and the handle adapter. There are also upstanding ribs  52  on each side of the platform  42  which provide structural reinforcement and integrity to the handle adapter. 
     Of importance in the invention is the use of a non-metallic material between two metallic elements, for example, a brass valve cartridge stem and a zinc lever. Prior art metal handle adapters were subject to galvanic corrosion, making it difficult to remove the components necessary to service the valve cartridge. The composite material is high strength so that it will withstand the torsional stress normally present in operation of a shower valve. Further, the handle adapter provides temperature limit stops which cooperate with the stop tube to limit rotation of the mixing valve within the valve member  10 . 
     The composite handle adapter is readily molded in a multi-cavity injection molding process which provides substantial cost savings over the prior art metallic handle adapters. 
     Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto.