초록 ▼

An intrinsically safe system controls all miner hydraulic and electrical functions from a hand held miner remote control pendant. Pendant control devices provide on/off control signals to interfaces with miner drive and pump controllers, as well as a group of ±6 VDC differential proportional and on/

An intrinsically safe system controls all miner hydraulic and electrical functions from a hand held miner remote control pendant. Pendant control devices provide on/off control signals to interfaces with miner drive and pump controllers, as well as a group of ±6 VDC differential proportional and on/off control signals to respective electronic valve drivers. Valve driver outputs are fed to respective force motors on pilot stage valves which control each hydraulic function. Each valve driver output is modified by offset and dither signals to overcome power stage valve dead band and frictional characteristics. Pilot stage valves have an internal feedback sleeve coacting with a pilot valve spool in a hydraulic servo circuit. Pilot stage valves operate in a pilot oil system which may be isolated from power oil systems.

대표청구항 ▼

A mining machine system for remotely controlling one or more fluid-powered machine operating functions, said system comprising: (a) a pressurized fluid source, (b) electro-control valve means including a hydraulic servo-controlled pilot stage valve for each machining operation function which receive

A mining machine system for remotely controlling one or more fluid-powered machine operating functions, said system comprising: (a) a pressurized fluid source, (b) electro-control valve means including a hydraulic servo-controlled pilot stage valve for each machining operation function which receives a separate operating function control signal, each pilot stage valve connected to the fluid source and to a load having proportional flow and/or valve deadband characteristics, and (c) remote control means initiated by an operator for the separate operating function control signals, at least one of said signals having valve-related proportional flow characteristics and/or modified by an offset signal component for overcoming the valve deadband characteristic.