(under the class definition) Subject matter wherein the light source is an incandescent electric filament enclosed in an envelope and may additionally be contained in an enclosing means and wherein electric circuit means is provided to connect the filament to a source of electrical energy and wherein means are provided to disconnect the filament from its source of electrical energy or to reduce or otherwise inhibit the flow of energy through the filament in response to the breakage of the envelope or the enclosing means.
