1. Field of Invention
This invention relates to an improved mirror assembly which can be removably attached to a vehicle in order to view a trailer hitch.
2. Description of the Prior Art
When a driver attempts to back a vehicle and align its hitch with a trailer, it is not possible to see the hitch. The driver must often back up a few feet, stop, and get out and walk around to the rear of the vehicle in order to check the alignment. This problem has been recognized for many years, and numerous patents have issued on attempted solutions.
Recognizing that pick-up trucks are often used to tow trailers, several inventions involve methods of mounting a mirror on the tailgate of a pick-up truck. Illustrating this approach are U.S. Pat. No. 4,905,376 to Neeley (1990), U.S. Pat. No. 4,951,913 to Quesada (1990), U.S. Pat. No. 5,478,101 to Roberson (1995), and U.S. Pat. No. 5,550,681 to Mazarac (1996). All these devices mount a mirror to the top of a tailgate. While they are useful for pick-up trucks, they cannot be adapted to other types of vehicles. Another limitation is present as well. The '681, '913, and '376 devices all use frictional contact to hold them against the painted surfaces of the tailgate. As the vehicle moves, the clamping forces exerted by these devices may damage the vehicle's paint finish.
Other inventions have been patented for use on vehicles without a tailgate. U.S. Pat. No. 5,111,342 to Quesada (1992) and U.S. Pat. No. 5,625,500 to Ackerman (1997) are designed to be attached to the rear window of a sport utility vehicle or motor home. The Quesada device uses two suction cups and two suspension arms. The Ackerman device uses a single suction cup with a second adjustable mirror panel. Both devices use a planar mirror, with the result that the mirror must be fairly large to provide the needed field of view. In addition, while both devices are easily attached to a rear glass surface, neither can be attached to a pick-up truck tailgate. They work for sport utility vehicles and RV's, but only for these types of vehicles.
U.S. Pat. No. 4,925,287 to Lord et. al. (1990) discloses a device which can be attached to pick-up trucks, sport utility vehicles, and conventional automobiles. The Lord device uses a pair of suction cups to attach a mirror assembly to a glass or metal surface. It has four adjustable links used to position the mirror in the correct location. Unfortunately, because the invention uses only two suction cups, it is prone to wobble when the vehicles is moved. The fact that it employs so many moveable links also makes it difficult to adjust. Thus, while the '287 device may be applied to a variety of vehicles, it does not provide the needed stability and ease of adjustment.
The known methods for removably mounting a mirror on the rear of a vehicle for viewing a trailer hitch are therefore limited in that they: (1) Are limited to one type of vehicle; (2) Are not sufficiently stable to provide a clear view; (3) May mar the painted surface of the vehicle; and (4) Are difficult to adjust.