Patent ID: 6338534
Filing Date: 2002-01-15
Classification: B60R

Abstract:
In a tractor-trailer transport vehicle having a tractor with a cab, a trailer, electrical cables and connectors therebetween, said tractor having an air pressure operated brake system with air pressure supply means and a parking air supply line to a parking brake air line of said trailer, a safety and security system comprising:an electric signal transmitter installed in said cab; a signal receiver in said trailer adapted to detect signals from said transmitter and produce a low voltage output; a solenoid valve in said trailer responsive to be activated by a low voltage DC output from said signal receiver and adapted to open a normally closed valve from said parking brake air line to said parking air supply line, wherein said solenoid valve includes a latch element responsive to high pressure air in said parking brake line to hold said normally closed valve in an open position in response to a predetermined minimum air pressure in said parking brake air line; whereby the parking brakes of said trailer can only be released when an appropriate signal is transmitted from said cab-installed transmitter.