TRAILER POSITION INDICATOR

• US 3,825,921 A
• Filed: 11/17/1972
• Issued: 07/23/1974
• Est. Priority Date: 11/17/1972
• Status: Expired due to Term

• Current Assignee: James D. Abernathy, Louis J. Marus
• Original Assignee: James D. Abernathy, Louis J. Marus
• Inventors: Marus, Louis J., Abernathy, James D.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Wannisky, William M.
• Application Number:
  US05/307,475
• Time in Patent Office: 613 Days
• Field of Search: 340/282,52R,275,196,285 180/103 280/477 33/264 336/30,115,121,122,123
• US Class Current: 340/431
• CPC Class Codes: B60D 1/36 for facilitating connection, e.g. hitch catchers , visual guide means, signalling aids B60D1/465 takes precedence; vehicle signalling in general B60Q; optical arrangements specially adapted for viewing trailer-hitches B60R1/003
• CPC Class Codes: B60Q 1/305 Indicating devices for towed vehicles

Abstract

A system for indicating to an operator of a towing vehicle the relative disposition of a towed trailer, comprising an emitter provided on said towing vehicle, a coil mounted upon the trailer for induction of a current therein, the strength of which current will depend upon the relative positioning of said emitter and said coil, an instrument provided in said towing vehicle for indicating the strength of the induced current and being connected to said coil, and a source of alternating current connected to said emitter.

Claims

1. A trailer position indicator system for indicating the angular position of a trailer with respect to a towing vehicle to which said trailer is coupled in swinging relationship to said towing vehicle, said system comprising a first coil carried by said towing vehicle, a second coil carried by said trailing vehicle, said coils being inductively coupled, means for positioning said coils with respect to each other such that the inductive coupling between said coils is increased when said trailer swings toward one side of said towing vehicle and is decreased when said trailer swings toward the opposite side of said towing vehicle, means for energizing one of said coils with an alternating current (a.c.) signal, detector means interconnected with the other of said coils for detecting the a.c. signal inductively coupled from the energized coil to the other coil, and indicator means interconnected with said detector means and operative to provide indication of relative increase in the detected inductively coupled a.c. signal, thereby to indicate swinging of the trailer from axial alignment toward said one side of the towing vehicle, and said indicator means being operative to provide indication of relative decrease in the detected inductively coupled a.c. signal, thereby to indicate swinging of the trailer from axial alignment toward said opposite side of the towing vehicle.

2. A trailer position indicator system as set forth in claim 1 wherein said trailer and said towing vehicle are coupled by coupling means, said coils each being spaced laterally with respect to said coupling means and each being located to the same side of said coupling means.

3. A trailer position indicator system as set forth in claim 2 wherein said coupling means comprises a first hitch element extending from the rear of said towing vehicle and a second hitch element extending from the front of said trailer, one of said coils being carried by said first hitch element laterally and to one side thereof, the other of said coils being carried by said second hitch element laterally and to the same side thereof.

4. A trailer position indicator system as set forth in claim 3 wherein said first and second hitch elements are positioned along the respective longitudinal axes of the towing vehicle and the trailer, said coils being coaxially aligned when the respective longitudinal axes of the towing vehicle and the trailer are coaxially aligned.

5. A trailer position indicator system as set forth in claim 1 wherein said detector means comprises a bridge rectifier for providing a d.c. signal the magnitude of which is a function of the proximity of said coils, the proximity of said coils increasing to increase the inductive coupling between said coils upon swinging of the trailer laterally from axial alignment toward said one side of the towing vehicle, the proximity of said coils decreasing to decrease the inductive coupling between said coils upon swinging of the trailer laterally from axial alignment toward said opposite side of the towing vehicle, whereby the magnitude of said d.c. signal increases upon swinging of the trailer to said one side and decreases upon swinging of the trailer to said opposite side.

6. A trailer position indicator system as set forth in claim 5 wherein said indicator means comprises a meter interconnected with said bridge rectifier, said meter having a pointer and scale, said meter being calibrated such that the pointer is at the midpoint Of the scale when the trailer and towing vehicle are axially aligned, the meter pointer moving from the midpoint toward one side of the scale to indicate swinging of the trailer from axial alignment toward one side of the vehicle and the pointer moving from the midpoint toward the other side of the scale to indicate swinging of the trailer from axial alignment toward the opposite side of the vehicle.