Hydraulic height-adjustment vehicle suspension

Claim 1

In a vehicle of the type including a chassis, a hand brake control operably movable from a non-brake applying position to a brake applying position, a suspension system including at least one suspension member movable with respect to said chassis, and means for blocking-up said suspension system to prevent said suspension system from collapsing when the vehicle is stationary for a prolonged period of time; the improvement wherein said blocking-up means comprises: a retractable buffer movable from a first retracted position to a second blocking position between a portion of said chassis and said suspension member; first spring means urging said buffer to said retracted position; hydraulic receiver means, acting against the force of said first spring means, for receiving therein hydraulic fluid and for moving said buffer against said first spring means into said blocking position; a hydraulic control chamber having therein hydraulic fluid and being fluid communication with said receiver means; a movable member mounted in said control chamber; second spring means, mounted between said movable member and said hand brake control, for biasing said movable member into said control chamber against said hydraulic fluid said control chamber; and actuator means, operably associated with said hand brake control, for, upon movement of said hand brake control to said brake applying position thereof, moving said second spring means and thereby said movable member toward said control chamber, thereby forcing hydraulic fluid from said control chamber into said receiver means, and thus moving said buffer against said force of said first spring means into said blocking position, said vehicle further including an ignition circuit having an ignition switch, land further comprising a solenoid valve positioned between said control chamber and said receiver means, said solenoid valve having a coil which is part of said ignition switch circuit of the vehicle, said solenoid controlling the flow of hydraulic fluid between said control chamber and said receiver means.