Lock plug for glad hand brake line coupler

Claim 1

In combination with a glad hand brake line coupler, a lock plug for insertion into and locking in place in a passage opening formed in said brake line coupler, said lock plug comprising a hollow cylindrical body having a base formed integrally with said body at one end thereof and a moveable locking member rotatably held in said body at the other end thereof; a plurality of locking fingers connected to said moveable locking member and extendable from and retractable into said body, and operating means insertable into an opening formed in said moveable locking member whereby the turning of said operating means from a first position to a second position will rotate said moveable locking member to retract said locking fingers into said hollow body to allow said lock plug to be inserted into said passage opening with the base thereof pressed against an interior wall of said coupler, and the turning of said operating means back from said second position to said first position will rotate said moveable locking member to thereby extend said locking fingers from said hollow body to thereby hold said lock plug within said brake line coupler by the abutment of said fingers against an interior wall of said fitting opposite said interior wall against which said base is pressed.