Visual guide means for ball and socket alignment during an automotive trailer coupling operation

Claim 1

A two-component sighting device adapted to facilitate vertical alignment between a coupling element on a stationary towed vehicle and a coupling element on a movable towing vehicle, said components being adapted for positioning on the respective vehicles and each component comprising a base member of blocklike configuration and presenting top, bottom, side and end faces, said base member being formed with a transverse bore therethrough in communication with said side faces and at a region appreciably closer to one end face than to the other end face, a rock shaft rotatably disposed within said bore with a friction fit, said base member being further provided with a vertical bore which opens onto said top face and intersects said tranverse bore in the medial region of the latter, an elongated extensible and contractible supporting rod consisting of telescopic sections having its lower proximate end projecting through said vertical bore and embedded in said rock shaft, the diameter of the proximate end region of the supporting rod being appreciably less than the diameter of said vertical bore whereby the supporting rod is caPable of fore and aft swinging movement about the axis of the rock shaft between extreme positions wherein it overhangs the end faces respectively, a permanent magnet embedded in the bottom face of said base member at a region remote from said one end face and relatively close to said other end face and having its pole face substantially flush with said bottom face whereby, when the base member is positioned on a magnetic surface associated with the respective vehicle the component will possess stability in any position of the supporting rod, and a sighting element mounted on the distal end of said supporting rod.