Patent ID: 8919738

Claim:
A landing gear system for a trailer, said system comprising: a. a first jack, said first jack comprising a first tubular body in which a second tubular body is telescopically mounted, a hydraulic chamber and a pneumatic chamber; b. a second jack, said second jack comprising a first tubular body in which a second tubular body is telescopically mounted, a hydraulic chamber and a pneumatic chamber; c. a hydraulic fluid reservoir; d. a pneumatic fluid source; e. a pneumatic manifold in pneumatic fluid communication with the pneumatic source and in pneumatic fluid communication with said hydraulic reservoir; f. a hydraulic manifold in hydraulic fluid communication with the hydraulic reservoir; g. a first pneumatically operated hydraulic pump in pneumatic fluid communication with the pneumatic manifold and in hydraulic fluid communication with the hydraulic manifold; h. a second pneumatically operated hydraulic pump in pneumatic fluid communication with the pneumatic manifold and in hydraulic fluid communication with the hydraulic manifold; g. a central control mechanism attached to the pneumatic manifold and disposed to control pneumatic flow into the pneumatic chambers of the first and second jack, the first and second pneumatically operated hydraulic pump and the hydraulic reservoir; and h. a first pneumatically operated hydraulic valve separate from the central control mechanism, said first pneumatically operated hydraulic valve disposed to control hydraulic fluid flow from the hydraulic chamber of the first jack back into the hydraulic fluid reservoir.