Automatic fail-safe mechanism-operated cell switch for metal-clad switchgear

Claim 1

Circuit interrupter apparatus, comprising: (a) a cabinet having spaced fixed terminals which are interconnected with a circuit which is to be opened and closed in a controlled manner; (b) main circuit interrupter means movable between an operating position and a test position within said cabinet, said main circuit interrupter means being interconnected electrically with said fixed terminals when in said operating position to thus open and close said circuit as the separable main contacts of said main circuit interrupter means are opened and closed respectively, said main circuit interrupter means being disconnected electrically from said fixed terminals when in said test position, said main circuit interrupter means having a lever means which moves in response to the operation of said separable main contacts between a first lever position when said separable main contacts are opened and a second lever position when said separable main contacts are closed; (c) auxiliary contact means disposed within said cabinet, said auxiliary contact means having a contact actuating member; (d) motion transfer support means movably disposed within said cabinet means, said motion transfer support means being interconnected with said auxiliary contact actuating member for moving said actuating member; and (e) extender means slidably disposed upon said motion transfer support means in either of a first or second slidable position, said extender means being in said first slidable position and in a disposition of mechanical interlinkage with said lever means when said main circuit interrupter means is in said operating position to thus cause said auxiliary contact means to be actuated to change state as said lever means is moved between said first and said second lever positions, said extender means remaining in said first slidable position and not in a disposition of mechanical interlinkage with said lever means when said main circuit interrupter means is in said test position unless said extender means has been manually moved to said second slidable position in which case it becomes mechanically interlinked with said lever means to thus cause said auxiliary contact means to be actuated to change state as said lever is moved between said first and said second lever means positions, said extender means always being driven to said first slidable position by said lever means as said main circuit interrupter is moved to said operating position.