Abstract An apparatus for automatically sensing trailer sway and applying trailer brakes, thereby minimizing or eliminating the sway is provided. A hydraulic device, similar to a shock absorber with the addition of a pressure operated switch at each end of the cylinder, is mounted between the trailer A frame and the hitch head assembly. A sudden sway in either direction causes one of the switches to close and apply power to the electric trailer brakes thus minimizing or eliminating the sway and causing the car and trailer to "line up". The hydraulic device has an orifice in the piston or at each end of the cylinder so that normal turns made by the car and trailer do not cause sufficient pressure build up to cause either switch to operate. Similar automatic performance can be realized by the use of a gas filled bellows device.
A sway control system for controlling brakes of a towed vehicle in response to the detection of a sway condition comprising: a hydraulic unit having first and second ends mounted to coupling means between the towed vehicle and a towing vehicle, which hydraulic unit includes first and second fluid passages associated with said first and second ends of the unit each passage including a check valve shunted by a bypass restricted orifice and a pressure switch, and an electric brake circuit for applying and releasing the brakes of the towed vehicle in response to said pressure switches being opened or closed, said hydraulic unit constituting a sway detection device for sensing the onset of a sway condition of a towed vehicle relative to a towing vehicle.
Claim 2
Dependent Claim
126 words
A sway control system for controlling brakes of a towed vehicle in response to the detection of a sway condition comprising: a hydraulic unit having first and second ends mounted to coupling means between the towed vehicle and a towing vehicle, which hydraulic unit includes first and second fluid passages associated with said first and second ends of the unit each passage including a check valve shunted by a bypass restricted orifice and a pressure switch, and an electric brake circuit for applying and releasing the brakes of the towed vehicle in response to said pressure switches being opened or closed, said hydraulic unit constituting a sway detection device for sensing the onset of a sway condition of a towed vehicle relative to a towing vehicle.