Single armed trailer coupler locking device

A locking device to be used with a coupler for obstructing towing of an object comprising:

• a lock base with a ball-shaped member erecting upright from a top main surface of the lock base;
• a leg with a top opening and a sealed bottom with portions extending both upward and downward from the lock base, wherein the leg has an aperture that extends internally from the top opening of the leg towards the sealed bottom of the leg;
• a lock bracket of one piece having a contour section and a straight section that are disposed within a plane, wherein
• the contour section of the lock bracket is bent over the ball-shaped member with an open end, and remains exposed outside the lock base, the contour section of the lock bracket is structured in three continuous portions so that when in a locked position, the contour section of the lock bracket embraces the ball-shaped member from three sides by the three continuous portions, wherein a first portion of the contour section extended from the straight section embracing an inner side of the ball-shaped member facing the leg portion extending upward, a second portion of the contour section crossing over a top side of the ball-shaped member with a curvature fitting closely around the top side of the ball-shaped member, and a third portion of the contour section bent to embrace an outer side of the ball-shaped member, opposite from the inner side, so that the end of the contour section does not reach or pass the lock base;
• and
• the straight section of the lock bracket extends from the contour section into the aperture through the top opening of the leg, wherein the straight section of the lock bracket slides in the aperture of the leg to engage in various locking positions, when locking, the straight section of the lock bracket slides downward in the aperture of the leg without penetrating through the sealed bottom, and when unlocking, the straight section of the lock bracket slides upward in the aperture and a part near an end of the straight section of the lock bracket stays attached within the aperture of the leg so that the straight section of the lock bracket does not completely slide out of the leg;
• and
• a locking means remaining housed in the lock base to interlock only with the lock bracket at one of a plurality of positions along the straight section of the lock bracket, when in a locked condition, the locking means restricts the lock bracket from swinging, and the plane of the lock bracket has an offset distance away from a center of the ball-shaped member and the lock base.