Trailer Lighting and Braking System with Pressure Failure Alarm

A system for selectively and automatically operating electrical safety apparatus of a trailer towed by a tow vehicle having at least one item of electrical safety apparatus in the event of unintended decoupling of the trailer from the tow vehicle, wherein the electrical safety apparatus is connected to power from the tow vehicle when the trailer is not decoupled from the tow vehicle, comprising:

• an emergency source of electric power compatible with the electrical safety apparatus;
• safety circuitry extending from the emergency source of electric power to the electrical safety apparatus, and wherein the trailer comprises a manually separable multi-conductor;
• a manually installed and removed plug-in type multi-conductor connector disposed to conduct power to the operating electrical safety apparatus from the electrical system of the tow vehicle and to impose a voltage on at least one item of electrical safety apparatus;
• a pressure sensor in pressure sensing relation to a pneumatic brake operating system of the tow vehicle, and pressure sensor related electrical circuitry connecting at least one of a battery of the tow vehicle and the emergency source of electric power to at least one item of the electrical safety apparatus, wherein
• the pressure sensor is arranged to open the pressure sensor related electrical circuitry when pressure in the pneumatic brake operating system falls below a predetermined pressure threshold, and
• the pressure sensor related electrical circuitry is arranged in parallel to the safety circuitry;
• an anti-feedback feature which automatically inhibits electrical power from the tow vehicle to be connected to the at least one item of the electrical safety apparatus by the safety circuitry while the trailer remains coupled to the tow vehicle, and while the tow vehicle remains in motion, when the multi-conductor connector is connected to the electrical system of the tow vehicle, wherein
• the safety circuitry is disposed to connect the electrical safety apparatus to power from the emergency source of electric power of the trailer when voltage imposed on at least one item of the electrical safety apparatus by the multi-conductor connector located between the electrical supply system of the tow vehicle and the safety circuitry has been discontinued.

A road going trailer capable of being towed by a road going tow vehicle, having a system for selectively and automatically operating electrical safety apparatus of the trailer in the event of unintended decoupling of the trailer from the tow vehicle, wherein the electrical safety apparatus of the trailer is ordinarily connected to power from the tow vehicle when the trailer is coupled to the tow vehicle, comprising:

• a trailer comprising a load bed, a plurality of wheels mounted to the load bed, a mechanical tow connection fixed to the trailer and disposed to releasably engage a corresponding mechanical tow element of the tow vehicle, and at least one item of electrical safety apparatus;
• an emergency source of electric power compatible with the electrical safety apparatus;
• safety circuitry extending from the emergency source of electric power to the electrical safety apparatus;
• a pressure sensor in pressure sensing relation to a pneumatic brake operating system of the tow vehicle, and pressure sensor related electrical circuitry connecting at least one of a battery of the tow vehicle and the emergency source of electric power to at least one item of the electrical safety apparatus, wherein
• the pressure sensor is arranged to open the pressure sensor related electrical circuitry when pressure in the pneumatic brake operating system falls below a predetermined pressure threshold, and
• the pressure sensor related electrical circuitry is arranged in parallel to the safety circuitry;
• a manually installed and removed plug-in type multi-conductor connector disposed to conduct power to and impose voltage on the operating electrical safety apparatus from the tow vehicle;
• an electrically operated transfer relay which responds to opening of the power connection between the electrical supply system of the tow vehicle and the safety circuitry and consequent loss of voltage of the power from the electrical supply system of the tow vehicle by transferring the safety circuitry from connection with the electrical supply system of the tow vehicle to connection with the emergency source of electrical power of the trailer;
• and
• an anti-feedback feature which automatically inhibits electrical power from the tractor to be backfed to the at least one item of the electrical safety apparatus by the safety circuitry while the trailer remains coupled to the tow vehicle, and while the tow vehicle remains in motion when the trailer is coupled to the tractor.