Multi-function control valve
AssigneeFiat-Allis Construction Machinery, Inc.
InventorsDavid F. Carl, Gary A. Drone
Life of this patent
Estimating the term…
Abstract
A valve for controlling the flow and pressure of fluid in a fluid operated system in which a hollow, ported control valve spool is movable in response to selective operation of a manually actuated actuator valve spool to effect modulation of a first fluid flow through the valve. One end of the hollow, ported control valve spool engages a plug portion of a freely floating piston movable in response to fluid pressure from a second fluid source to close a normally open port in the hollow control valve spool.
Claims12
A multi-function control valve for controlling fluid flow and pressure in a fluid operated system comprising
- a valve body having a bore, an inlet port, an outlet port, at least one sump port and a service port normally in fluid communication with said sump port,
- fluid pressure and flow regulating means carried by said valve body for regulating fluid pressure and flow therethrough,
- fluid pressure relief means carried by said valve body for limiting the pressure of fluid therein,
- said valve body communicating said inlet port with said fluid pressure and flow regulating means, and communicating said fluid pressure relief means with said sump port,
- a selectively positionable valve spool supported in the bore of said valve body for movement among positions to communicate said inlet port with said service port and to close communication between said service port and said sump port, and to close communication through said fluid pressure and flow regulating means and said sump port, and to communicate said inlet port with said fluid pressure relief means,
- a fluid passageway formed in said valve body intersecting with said bore formed therein and connecting said fluid pressure and flow regulating means in fluid communication with said outlet port for passing fluid therethrough in a direction to apply a fluid pressure to control valve means,
- control valve means supported in said bore for reciprocal movement in response to fluid pressure in said fluid passageway,
- biasing means for applying a variable biasing force to said control valve means in a direction opposed to the direction of the force applied thereto by the fluid pressure in said fluid passageway, and
- reaction means operatively connected between said valve spool and said biasing means for varying the biasing force of said biasing means in response to the positioning of said selectively positionable valve spool to control fluid pressure in said passageway.
Dependencies are inferred from the claim text.