Controller for fluid pressure operated devices

DETAILED DESCRIPTION Accordingly, it is an object of the present invention to provide a controller for fluid pressure operated devices and a valving arrangement therefor which overcomes the above-mentioned problems.
It is a more specific object of the present invention to provide a controller and valving arrangement having a substantially symmetrical fluid flow path for either direction of operation of the valving.
It is another object of the present invention to provide a valving configuration for such a controller which achieves the above-stated objects and at the same time has a minimum axial length.
It is still another object of the present invention to provide valving for a controller which readily accommodates any desired combination of features such as closed-center or open-center; non-reaction or load reaction; lower flow capacity or higher flow capacity.
The above and other objects of the present invention are accomplished by the provision of an improved controller for fluid pressure operated devices.
The controller comprises a housing, valve means including primary and follow-up valve members and means coupling the valve members for limited movement relative to a neutral position.
The fluid meter includes a metering member and means is provided coupling the metering member to the follow-up valve member.
The controller includes an inlet port, an outlet port, and first and second control fluid ports.
The primary and follow-up valve members cooperate with the housing to define a first plurality of fluid passages connecting the inlet port in fluid communication with the first control fluid port through the fluid meter when the valve members are relatively displaced in one direction from neutral, and a second plurality of fluid passages connecting the inlet port in fluid communication with the second control fluid port through the fluid meter when the valve members are relatively displaced in the other direction from neutral.
The first and second pluralities of fluid passages are arranged to provide substantially the same restriction to fluid flow in either direction of displacement of the valve members from neutral