US Patent 7159890 Trailer hitch for a motor vehicle

A trailer hitch for a motor vehicle includes a towbar (2) having an arm (1) and a ball cup (3) provided with an opening and with a ball pivot (6). The ball pivot (6) has a ball head (4) and a pivot (5) and is mounted with the ball head (4) rotatably and pivotably in the ball cup (3) and passes through an opening (7) and juts out of the ball cup (3). An angle-measuring device having a signal transmitter (17) and two sensors (40, 41) is arranged in the joint unit formed from the ball cup (3) and the ball head (4).