Trailer hitch lock

Claim 1

An anti-theft device for a trailer having a ball hitch of the type comprising a generally spherical socket member having an opening for receiving a ball member and a flange extending outwardly and surrounding said opening, said device comprising: (a) a body member having a generally planar surface and surrounded on three sides by a U-shaped recess adapted to slidingly engage said flange on said socket member, a first bore extending normal to said planar surface and a predetermined distance into said body member, and a transversely extending second bore intersecting with said first bore; (b) a spring loaded bolt member having a ramp surface formed on an end segment thereof disposed in said first bore with said ramp surface extending above said planar surface and into said opening of said socket member when said U-shaped recess engages said flange and when said spring is extended and retractable within said bore and below said planar surface when said spring is compressed; (c) a floating stop member disposed in said first bore for allowing depression of said ramp surface below said planar surface when in a first orientation and for preventing said depression when in a second orientation; and (d) a key operated cam element disposed in said second bore, said cam element cooperating with said floating stop member to move said stop member to said first orientation.