Automatic leveling system for recreational vehicles

An automatic leveling system for a recreational vehicle, comprising:

• a source of pressurized hydraulic fluid;
• a manifold having an inlet in fluid communication with said source and a plurality of fluid outlets communicating with said inlet;
• a plurality of hydraulic jacks, each of said hydraulic jacks including a pressure sensor for sensing when an hydraulic pressure in the jack exceeds a predetermined threshold;
• means for mounting said hydraulic jacks adjacent the underside of the recreational vehicle;
• a plurality of hydraulic lines for communicating hydraulic fluid from said fluid outlets to said jacks;
• a plurality of solenoid controlled valves coupled to said hydraulic lines and operable to control hydraulic fluid flow from said fluid outlets to said hydraulic jacks;
• a level sensor;
• and
• an electronic control circuit responsive to said pressure sensors and operable to close the solenoid valve of a particular one of said hydraulic lines when hydraulic pressure in the jack coupled to said particular hydraulic line exceeds said predetermined threshold;
• said predetermined threshold being sufficiently high as to extend said hydraulic jacks into contact with the ground when said jacks are mounted adjacent the underside of the recreational vehicle;
• said electronic control circuit being nonresponsive to said level sensor as long as hydraulic pressure in any of said hydraulic jacks is below said predetermined threshold, said electrical contact circuit being responsive to said level sensor during an automatic leveling period that begins only after hydraulic pressure in all of said hydraulic jacks exceeds said predetermined threshold.

A method of operating a recreational vehicle automatic leveling system of the type having a plurality of hydraulic jacks and a level sensor for sensing a level condition, said method comprising the steps of:

• extending each of the jacks until each of the jacks contacts the ground below the recreational vehicle with a first predetermined pressure;
• thereafter extending selected ones of the jacks until the level sensor senses a level condition;
• and
• thereafter actuating any of the jacks that do not then exert a predetermined minimum pressure on the ground to ensure thereby that each of the jacks is in contact with the ground following establishment of the level condition.