CONTROL SYSTEM FOR A FLUID OPERATED JACK

摘要

A control system for a fluid operated jack reduces the speed of retraction of a piston rod of the jack to an acceptable rate during a preselected range of operation by adding pressurized fluid flow to the fluid being exhausted from the jack through a restrictor valve to the reservoir. This reduction in speed reduces the potential for damage to the jack and associated componentry without sacrificing efficiency of operation. An implement controller causes fluid flow from a fluid source to be combined with the flow of fluid being exhausted from the jack in response to receiving a position signal from a implement position sensor and subsequent to the implement controller commanding the shifting of a control valve to a position at which fluid flow is passed from the fluid operated jack to the reservoir. The control system is particularly suitable for use on an automatic guided vehicle.