Air suspension deflation control system with automatic reinflation and control reset

Claim 1

In a vehicle pneumatic suspension of the type including air spring means for supporting the rear cargo area of a vehicle having an engine, a pneumatic suspension deflation control system for lowering the rear cargo area of said vehicle to its minimum height from the ground to facilitate loading and/or unloading of the vehicle comprising ignition switch means for activating or deactivating said engine, control valve means, inversion valve means coupled between said control valve means and said air spring means, on engine driven source of pneumatic pressure, an air reservoir coupled to said air pressure source and to said control valve means, leveling valve means coupled to said inversion valve means and to said air reservoir, an electrically controlled valve coupled to said ignition switch means and arranged in the pneumatic path between said air reservoir and said control valve means, said control valve means operating exclusively between a first deflation condition directing pneumatic pressure to said inversion valve means and causing exhaustion of all pressure from said air spring means for deflating the suspension to minimum height and a second inflation condition closing off pneumatic pressure to said inversion valve means and directing pneumatic pressure to said air spring means from said air reservoir via said leveling valve means and said inversion valve means and inflating said air spring means, said electric valve means operating to permit said control valve means to be in the first condition only when said ignition switch means is deactivated to stop said engine and automatically operating to place said control valve means in the second condition when said ignition switch means is activated to start said engine to prevent operation of the vehicle when said air spring means is deflated.