Trailer hitch for a motor vehicle

• US 7,159,890 B2
• Filed: 10/06/2004
• Issued: 01/09/2007
• Est. Priority Date: 10/06/2004
• Status: Expired due to Fees

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Lemforder Metallwaren AG
• Inventors: Spratte, Joachim, Craig, Scott C.
• Primary Examiner(s): Morris; Lesley D.
• Assistant Examiner(s): Scharich; Marc A.
• Application Number:
  US10/959,726
• Publication Number:
  US 20060071448A1
• Time in Patent Office: 825 Days
• Field of Search: 280/511, 280/492, 280/446.1, 280/432
• US Class Current: 280/511
• CPC Class Codes: B60D 1/06 Ball-and-socket hitches , e.g. constructional details, auxiliary devices, their arrangement on the vehicle
• CPC Class Codes: B60D 1/58 Auxiliary devices

Abstract

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).

Claims

1. A trailer hitch for a motor vehicle, the trailer hitch comprising:

a towbar having an arm and a ball cup provided with an opening;

a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said angle-measuring device measuring a torsion angle and a roll angle between said tow bar and said ball pivot.

2. A trailer hitch in accordance with claim 1, wherein said signal transmitter comprises a magnet and said sensors are magnetic field-sensitive sensors.

3. A trailer hitch in accordance with claim 2, wherein said sensors are magnetoresistive sensors.

4. A trailer hitch in accordance with claim 3, wherein said sensors each have a sensitive surface, wherein the two sensitive surfaces are arranged at right angles to one another.

5. A trailer hitch in accordance with claim 2, wherein said sensors each have a sensitive surface, wherein the two sensitive surfaces are arranged at right angles to one another.

6. A trailer hitch in accordance with claim 1, wherein said two sensors are directed at right angles in relation to one another.

7. A trailer hitch in accordance with claim 1, wherein said two sensors are integrated into a sensor assembly unit.

8. A trailer hitch in accordance with claim 1, wherein said ball pivot is curved.

9. A towing system, comprising:

a motor vehicle;

a trailer;

a trailer hitch with a towbar having an arm and a ball cup provided with an opening and a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said

pivot pin being fixed at the motor vehicle at a spaced location from the ball head, and said towbar being fastened to the trailer at a spaced location from said ball cup, said angle-measuring device measuring a torsion angle and a roll angle between said tow bar and said ball pivot.

10. A trailer hitch process, comprising the steps of:

providing a motor vehicle;

providing a trailer;

providing a trailer hitch with a towbar having an arm and a ball cup provided with an opening and a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

providing an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head;

connecting the trailer with the motor vehicle via the trailer hitch;

determining a roll angle and a torsion angle of the trailer in relation to the motor vehicle by means of the angle-measuring device, wherein the roll angle is located in a first plane, which forms right angles with a second plane, in which the torsion angle is located.

11. A trailer hitch for a motor vehicle, the trailer hitch comprising:

a towbar having an arm and a ball cup provided with an opening;

a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said signal transmitter being arranged in said ball head and said sensors being arranged in said ball cup.

12. A trailer hitch for a motor vehicle, the trailer hitch comprising:

a towbar having an arm and a ball cup provided with an opening;

a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said two sensors being integrated into a sensor assembly unit located on a straight line, which forms right angles with the longitudinal axis of said arm and extends through a center of said ball head.

13. A trailer hitch for a motor vehicle, the trailer hitch comprising:

a towbar having an arm and a ball cup provided with an opening;

a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said two sensors being seated in a recess provided in a wall of said ball cup.

14. A trailer hitch for a motor vehicle, the trailer hitch comprising:

a towbar having an arm and a ball cup provided with an opening;

a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said signal transmitter comprising a magnet and said sensors being magnetic field-sensitive sensors, said magnet being embedded in a nonmagnetic material and being seated in a recess provided in the ball head.

15. A towing system, comprising:

a motor vehicle having a motor vehicle vertical axis and a motor vehicle longitudinal axis extending at right angles thereto;

a trailer;

a trailer hitch with a towbar having an arm and a ball cup provided with an opening and a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said

pivot pin being fixed at the motor vehicle at a spaced location from the ball head, and said towbar being fastened to the trailer at a spaced location from said ball cup, said signal transmitter being located on a straight line that extends at right angles to said motor vehicle vertical axis and at right angles to said motor vehicle longitudinal axis.

16. A towing system in accordance with claim 15, wherein:

said trailer has a trailer vertical axis and a trailer longitudinal axis extending at right angles thereto;

said two sensors are integrated into a sensor assembly unit located on a straight line and extending at right angles to the trailer vertical axis and at right angles to the trailer longitudinal axis.

17. A towing system in accordance with claim 16, wherein the straight line, on which the sensor assembly unit is located, and the straight line, on which the signal transmitter is located, extend through the center of the ball head.

18. A towing system in accordance with claim 16, wherein said signal transmitter is a magnet, having a magnetization extending at right angles to the motor vehicle vertical axis and at right angles to the motor vehicle longitudinal axis.

19. A towing system, comprising:

a motor vehicle;

a trailer;

a trailer hitch with a towbar having an arm and a ball cup provided with an opening and a ball pivot having a ball head and a pin, said ball pivot being mounted rotatably and pivotably with said ball head in said ball cup and passing through said opening and jutting out of said ball cup;

an angle-measuring device having a signal transmitter and two sensors, said angle measuring device being arranged in a joint unit comprising said ball cup and said ball head, said

pivot pin being fixed at the motor vehicle at a spaced location from the ball head, and said towbar being fastened to the trailer at a spaced location from said ball cup, said signal transmitter being arranged in said ball head and said sensors being arranged in said ball cup.

20. A trailer hitch arrangement comprising:

a towbar having an arm connectable to a trailer and a ball cup;

a ball pivot having a ball head and a pin, said ball head being mountable rotatably and pivotably in said ball cup;

an angle-measuring device on said towbar and ball pivot, said angle-measuring device including a signal transmitter and two sensors, said angle-measuring device measuring a torsion angle and a roll angle between said tow bar and said ball pivot.

21. An arrangement in accordance with claim 20, wherein:

said torsion angle lies in a torsion plane and said roll angle lies in a roll plane, said torsion plane and said roll plane being arranged substantially perpendicular to each other.

22. An arrangement in accordance with claim 20, wherein:

said tow bar has a longitudinal axis, said roll angle-measuring device measuring an angle between said tow bar and said ball pivot which is around said longitudinal axis of said tow bar.

23. An arrangement in accordance with claim 20, further comprising:

a trailer connected to said tow bar, said trailer having a longitudinal axis substantially parallel to said longitudinal axis of said tow bar;

a tow vehicle connected to said ball pivot, said tow vehicle and said ball pivot having a longitudinal axis, said torsion angle being an angle between said longitudinal axis of said tow bar and said longitudinal axis of said ball pivot.