Material handling vehicle stabilizer

Abstract

Apparatus for stabilizing a material handling vehicle during implement manipulation is provided. Dual hydraulic cylinders are provided on each side of the vehicle intermediate the vehicle's frame and a spring-biased solid axle. A lockout valve having a pneumatically actuated check valve in fluid communication with one-way check valves and flow restriction valves corresponding to each of the upper and lower ports of the respective hydraulic cylinders is mounted on the vehicle's frame and is in fluid communication with a reservoir of hydraulic fluid. When the vehicle is not caused to travel, the pneumatically actuated check valve is closed allowing no hydraulic fluid flow between the ports of the hydraulic cylinders and thereby locking the then-present fluid in each of the chambers of the hydraulic cylinders which prevents the movement of the pistons thereof and, hence, any displacement of the front axle relative to the vehicle frame. When the joystick controlling travel is actuated, a hydraulic signal is generated which is translated into a pneumatic signal effective to open the check valve. The system provided greatly increases vehicle stability during implement manipulation thereby increasing vehicle capacity without necessitating the use of means such as outriggers.