Patent ID: 7694993

Claim:
A sealed, pumpless hydraulic trailer steering mechanism for a trailer, the trailer having steerable wheels and a frame with a rigid tongue pivotally attached to a tow vehicle, the trailer steering mechanism comprising: a rearwardly disposed, lateral hitch bar adapted for being rigidly and immovably attached to the tow vehicle; a steering frame pivotally attached to the trailer frame, said steering frame including an elongated steering arm extending substantially the entire length of said steering frame and a cross member extending laterally substantially the entire width of said steering frame; a steering linkage extending between the steering frame and the steerable wheels of the trailer; at least one hydraulic cylinder extending between the hitch bar and the steering frame parallel to the tongue of the trailer, wherein said at least one hydraulic cylinder includes a hitch bar coupling end and a steering frame attachment end; and a hydraulic cylinder control mechanism selectively locking the at least one hydraulic cylinder during backing maneuvers and opening the at least one hydraulic cylinder during forward travel, wherein said control mechanism defines a sealed, pumpless hydraulic system including a first hydraulic valve controlling hydraulic flow to the hitch bar coupling end of said hydraulic cylinder, a second hydraulic valve controlling hydraulic flow to the steering frame attachment end of said hydraulic cylinder, and a valve actuator linked to each of the hydraulic valves and controlling hydraulic fluid flow therethrough and to each end of said at least one hydraulic cylinder.