摘要 |
A landing gear system for a trailer is described. The landing gear system includes two jacks, each with a first tubular body in which a second tubular body is telescopically mounted, a hydraulic chamber and a pneumatic chamber. The system includes a hydraulic fluid reservoir, a pneumatic fluid source, a pneumatic manifold in pneumatic fluid communication with the pneumatic source and in pneumatic fluid communication with said hydraulic reservoir and a hydraulic manifold in hydraulic fluid communication with the hydraulic reservoir. Pneumatically operated hydraulic pumps are included, along with a central control mechanism attached to the pneumatic manifold and disposed to simultaneously control pneumatic flow into the pneumatic chambers of the jacks and to pneumatically operated hydraulic pumps. Separate pneumatically operated hydraulic valve are provided to individually control hydraulic flow from the jacks. |