Dual operational and brake light control for trailers

• US 6,177,865 B1
• Filed: 06/15/1998
• Issued: 01/23/2001
• Est. Priority Date: 06/16/1997
• Status: Expired due to Term

• Current Assignee: Horizon Global Americas Inc. (Horizon Global Corporation), Masco Tech, Inc.
• Original Assignee: Masotech, Inc.
• Inventors: Johnson, Richard, Bryant, Richard C.
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US09/097,270
• Time in Patent Office: 953 Days
• Field of Search: 340/475, 340/431, 340/465, 340/479, 307/10.8, 315/77, 315/82
• US Class Current: 340/431
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B60Q 1/305 Indicating devices for towed vehicles

Abstract

A dual operational and stop light control for adapting combined stop and turn signal lights on a trailer to independent stop signal and turn signal lights on a towing vehicle. The adaptor has a pair of switching circuits, each including a PNP transistor connected in series with an NPN transistor to chassis ground and each transistor connected to both stop and turn signal circuits of the towing vehicle and also to an NPN output transistor which is connected to an independent voltage source to drive the trailer signal lights independent of the voltage at the towing vehicle signal lights.

Claims

1. A device for adapting combined brake and turn signal lights of a trailer to independent brake and turn signal lights on an associated towing vehicle, the towing vehicle having right and left turn signal circuits and a stop signal circuit, the trailer having right-hand and left-hand signal lights, each of which has a common filament for stop and turn signals, the device comprising:

first switching means connected to both the right turn signal circuit and to the stop signal circuit of the towing vehicle, a voltage source being connected directly to the first switching means independent of the turn signal circuits;

second switching means connected to both the left turn signal circuit and the stop signal circuit of the towing vehicle, the voltage source connected directly to the second switching means independent of the turn signal circuits;

each of the first and second switching means operating as an exclusive “

or”

gate to connect the voltage source to the associated one of the common filaments of the trailer lights when only one, but not both, of the stop signal and the turn signal circuits is energized; and

each of said switching means comprising a PNP transistor and an NPN transistor connected in series, each of said transistors also connected to both said stop signal circuit and one of said turn signal circuits, and a PNP output transistor connected with said transistors, said output transistor also connected to said independent voltage source.

2. A device for adapting combined stop and turn signal lights of a trailer to independent brake signal and turn signal lights on an associated towing vehicle, the towing vehicle having right and left turn signal circuits and a stop signal circuit, the trailer having right-hand and left-hand signal lights, each of which has a common filament for stop and turn signals, said device comprising:

a first switch configured to be connected to both the right turn signal circuit and to the stop signal circuit on the vehicle, and also configured to be connected to the right-hand turn-and-stop signal light on the trailer;

a second switch configured to be connected to both the left turn signal light and to the stop signal circuit on the vehicle, and also configured to be connected to the left-hand turn-and-stop signal light on the trailer;

said first and second switches configured to connect directly to a voltage source rather than connecting to the voltage source through the stop signal or turn signal lights of the towing vehicle;

said first and second switches each being operable to transmit current directly from the voltage source to the respective right and left turn-and-stop signal lights on the trailer when only one of the corresponding signal circuits on the towing vehicle is operating; and

each of said switches being operable, responsive to signals from both the stop signal circuit and the corresponding turn signal circuit on the towing vehicle to switch current from the independent voltage source alternately on and off to the associated turn-and-stop signal light of the trailer, when both the brakes and turn signal circuits are operating; and

each of the switches comprising a PNP transistor and an NPN transistor connected in series, each of the transistors also connected to both the stop signal circuit and one of the turn signal circuits, and a PNP output transistor connected with the transistors, the output transistor also connected to the independent voltage source.

3. A device for adapting combined stop and turn signal lights of a trailer to independent brake signal and turn signal lights on an associated towing vehicle, the towing vehicle having right and left turn signal circuits and a stop signal circuit, the trailer having right-hand and left-hand signal lights, each of which has a common filament for stop and turn signals, said device comprising:

a first switch configured to be connected to the right turn and stop signal circuits of the towing vehicle and to a voltage source and further configured to transmit current directly from the voltage source to the right turn and stop signal circuits of the trailer without drawing that current through the right turn and stop signal circuits of the towing vehicle;

a second switch configured to be connected to both the left turn and stop signal circuits of the towing vehicle and to the voltage source and further configured to transmit current directly from the voltage source to the left turn and stop signal circuits of the trailer without drawing that current through the left turn and stop signal circuits of the towing vehicle;

each of the first and second switches operating as an exclusive “

or”

gate to connect the voltage source to the associated one of the common filaments of the trailer lights when only one, but not both, of the stop signal and the turn signal circuits is energized; and

each of the switches comprising a PNP transistor and an NPN transistor connected in series, each of the transistors also connected to both the stop signal circuit and one of the turn signal circuits, and a PNP output transistor connected with the transistors, the output transistor also connected to the independent voltage source.

4. An electrical circuit adapter for use between a towing vehicle lighting system having independent brake and turn signal lamps and a trailer lighting system having combined brake and turn signal lamps, the circuit adapter comprising:

first and second vehicle signal inputs configured to receive respective electrical signals from the towing vehicle lighting system each signal representing the state of a particular towing vehicle lamp;

a power supply input connectable to a power source for receiving a power input signal;

a first transistor having a first terminal coupled to the first and second signal inputs, a second terminal coupled to the power supply input, and a third terminal;

a second transistor having a first terminal coupled to the first and second signal inputs, a second terminal, and a third terminal coupled to ground;

a third transistor having a first terminal, a second terminal coupled to the power supply input, and a third terminal; and

a trailer signal output coupled to the third terminal of the third transistor and configured to transmit a power signal from the circuit adapter to the trailer lighting system;

wherein the third terminal of the first transistor is coupled to the second terminal of the second transistor forming a series connection, the series connection being coupled to the first terminal of the third transistor such that the signal output is coupled to the power supply input only when one of the first and second signal inputs are high, but not both.

5. The electrical circuit adapter as defined in claim 4, wherein the circuit adapter is configured such that both the first and second transistors must have an available current path between their respective first terminals and one of the signal inputs for the circuit adapter to couple the power supply input to the signal output.

6. The electrical circuit adapter as defined in claim 4, wherein one of the signal inputs is representative of the vehicle brake signal and another is representative of one of the vehicle turn signals.

7. The electrical circuit adapter as defined in claim 4, wherein the series connection comprises an PNP and an NPN transistor.