Coupling ring having lined bayonet slot
This invention relates to an electrical connector assembly of the type having a bayonet coupling. 
     An electrical connector assembly is generally comprised of two separate housings connected together by a coupling member mounted on one of the housings. In bayonet type couplings, the coupling member on one housing includes an internal groove which mates with a pin on the other housing so that when the coupling member is rotated, the housings are drawn together. An example of electrical connectors having such bayonet type couplings may be found in U.S. Pat. Nos. 3,551,880, issued Dec. 29, 1970 and entitled &#34;Electrical Connector Having An Improved Locking Means&#34;; 3,805,379, issued Apr. 23, 1974 and entitled &#34;Method of Assembling An Electrical Connector to Effect A Preloading Thereof&#34;; and 3,393,927, issued July 23, 1968 and entitled &#34;Electrical Connector&#34;. In all of the foregoing patents, the grooves in the coupling ring described therein are subjected to wear during mating with the pin on the other housing. This is especially true in a connector assembly comprised of plastic as is shown in U.S. Pat. No. 3,551,880. 
     DISCLOSURE OF THE INVENTION 
     The invention is a coupling member for connector assembly that includes a novel means for reducing wear in the side of a groove in the coupling member. An electrical connector employing the invention is characterized by a coupling member having a strip of metal mounted in and along the sides of the groove in the forward mating portion of the coupling member. 
     Accordingly, one advantage of the invention is that it extends the useful life of a plastic coupling ring. 
     Another advantage of the invention is that it protects the sides of the groove in the plastic coupling ring. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a strip of metal. 
     FIG. 2 illustrates a coupling member utilizing the principles of the invention. 
     FIG. 3 illustrates a cross-sectional view of the groove in the coupling member shown in FIG. 2. 
     FIG. 4 is an enlarged view of the metal strip in the coupling ring groove. 
     FIG. 5 illustrates an electrical connector assembly utilizing the principles of this invention. 
    
    
     Referring now to the drawings, FIG. 1 illustrates a strip of metal that may be comprised of beryllium copper or brass. The strip of metal 10 is folded over to include a rounded portion 12 and two ends 13 and 14 that are curved outwardly. 
     FIG. 2 illustrates a coupling member 20 that is comprised of a plastic. The coupling member 20 includes a groove 21 having mounted along the sides thereof a strip of metal 10. 
     FIG. 3 is a cross-sectional view of the groove in the coupling member 20 shown in FIG. 2 and illustrates how the metal strip 10 is press fit or molded into the sides of the groove. 
     FIG. 4 illustrates the metal strip 10 in the groove 21 with the curved end portions 13 and 14 of the metal strip located in recesses 24 in the sides of the groove 21 to prevent the metal strip from moving out of the groove. 
     FIG. 5 illustrates a connector assembly which includes a housing 30, contacts 40 mounted within the housing and the coupling ring 20 shown in FIG. 2. 
     While a preferred embodiment of the invention has been disclosed, it will be apparent to those skilled in the art that certain changes may be made to the invention as set forth in the appended claims, and in some instances, certain features of the invention may be used to advantage without corresponding use of other features. Accordingly, it is intended that the illustrative and descriptive materials herein be used to illustrate the principles of the invention and not to limit the scope thereof.