US 3,970,860 AGranted

Electrical apparatus to connect towing vehicle light circuits to a trailer light circuit when the towing vehicle has separate circuits respectively for turning and stop lights and the trailer has a common light circuit for both turning and stop lights

OwnerJames P. Purdyinventor

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Abstract

The adapter circuit is interposed between the towing vehicle light circuit including at least a right turn light circuit, a brake light circuit, a left turn light circuit, and a light system common and the trailer light circuit including at least a left signal lamp and a right signal lamp. A right turn relay, operating a single normally closed contact, is connected to and responds to energization of the right turn light circuit. A brake relay, operating two normally closed contacts, is connected to and responds to energization of the brake light circuit. A left turn relay, operating a single normally closed contact, is connected to and responds to energization of the left turn light circuit. The right signal lamp is connected on one side to the light system common and on the other side through the first of the brake relay operated contacts to the right turn light circuit. The latter side is also connected through the right turn relay operated contact to the brake light circuit. The left signal lamp is connected on one side to the light system common and on the other side through the second of the brake relay operated contacts to the left turn light circuit. The latter side is also connected through the left turn relay operated contact to the brake light circuit. The adapter circuit results in operation of the trailer lamps to give the same type of signals on the trailer as appear on the towing vehicle. The adapter may be interposed between the trailer lights and the towing vehicle light circuits by the use of two of multiple contact adapters at each interface with the adapter.

Claims2

Dependent claims

An electrical apparatus for connecting trailer towing vehicle light circuits to trailer signal light circuits when the towing vehicle has separate circuits for turning and stop lights including a right turn light circuit, a brake light circuit, a left turn light circuit, and a light system common and the trailer has a common light circuit for both turning and stop lights including a right signal lamp and a left signal lamp each having a first and second terminal for connection to an electrical system, comprising:

a. a first relay responsive to the operation of the right turn light circuit;
b. a second relay responsive to the operation of the left turn light circuit;
c. a third relay responsive to the operation of the brake light circuit;
d. a means for electrically connecting the right turn light circuit to the first terminal of the right signal lamp said means having a contact operated by a third relay, the contact being open when the brake circuit is energized and closed when it is not;
e. a means for electrically connecting the brake light circuit to the first terminal of the right signal lamp said means having a contact operated by the first relay, the contact being open when the right turn light circuit is energized and closed when it is not;
f. a means for electrically connecting the brake light circuit to the first terminal of the left signal lamp said means having a contact operated by the second relay, the contact being open when the left turn light circuit is energized and closed when it is not;
g. a means for electrically connecting the left turn light circuit to the first terminal of the left signal lamp said means having a contact operated by the third relay, the contact being open when the left turn signal lamp is energized and closed when it is not;
h. a means for electrically connecting the common to the second terminal of the right signal lamp;
and
i. a means for electrically connecting the common to the second terminal of the left signal lamp;
whereby turn and stop signals will appear on the towed vehicle signal lamps when such signals are present on the towing vehicle light circuits.

8 more elements

a. a first relay responsive to the operation of the right turn light circuit;
b. a second relay responsive to the operation of the left turn light circuit;
c. a third relay responsive to the operation of the brake light circuit;
d. a fourth relay responsive to the operation of the brake circuit;
e. a means for electrically connecting the right turn light circuit to the first terminal of the right signal lamp said means having a contact operated by the third relay, the contact being open when the brake circuit is energized and closed when it is not;
f. a means for electrically connecting the brake light circuit to the first terminal of the right signal lamp said means having a contact operated by the first relay, the contact being open when the right turn light circuit is energized and closed when it is not;
g. a means for electrically connecting the brake light circuit to the first terminal of the left signal lamp, said means having a contact operated by the second relay, the contact being open when the left turn light circuit is energized and closed when it is not;
h. a means for electrically connecting the left turn light circuit to the first terminal of the left signal lamp said means having a contact operated by the fourth relay, the contact being open when the left turn signal lamp is energized and closed when it is not;
i. a means for electrically connecting the common to the second terminal of the right signal lamp;
and
j. a means for electrically connecting the common to the second terminal of the left signal lamp;
whereby turn and stop signals will appear on the towed vehicle signal lamps when such signals are present on the towing vehicle light circuits.

9 more elements

Dependencies are inferred from the claim text.