Audible alarm for motor vehicle

Claim 1

For use in combination with the horn circuit of a motor vehicle, which horn circuit includes an electric horn, an electrical energy source, a normally open momentary contact switch, and a relay interconnected between said horn, said electrical energy source and said momentary contact switch for completing the electrical circuit between said horn and said electrical energy source in response to closure of said momentary contact switch, and which vehicle further includes a liquid fuel storage tank, a fuel tank filler neck extending from said fuel tank and having an inlet aperture at the free end thereof, and a door hingedly secured to said vehicle and having a first position for normally covering the free end of said filler neck and a second position angularly displaced from said first position for exposing said filler neck, improvements therein to provide an audible signal in response to an attempt to gain access to said filler neck when said access is not authorized by the operator of said vehicle, said improvements comprising: a. a normally open gravity-actuated switch; b. mounting means for rigidly securing said gravity switch to said door, said gravity switch being normally open when said door is in said first position and closing as said door is displaced toward said second position; c. an electrical lead communicating between said gravity switch and said relay; and d. a selective open-closed switch positioned for control by the operator of said vehicle and in series with said electrical lead, whereby said horn is energized as said door is moved toward said second position and said selective switch is closed.