Fluid controller having rotary/axial valving, and spring arrangement therefor

Reference Number: N 02-03

Inventors: Stephenson, Dwight B.

Owner: NISTAC

USPTO Link: 5161577

Invention Summary

Accordingly, it is an object of the present invention to provide an improved neutral centering spring arrangement for use in a fluid controller of the type having spool and sleeve valving, wherein the spool and sleeve are engaged in both rotary actuation and axial actuation.

The above and other objects of the invention are accomplished by the provision of an improved controller operable to control the flow of fluid from a source of pressurized fluid to a fluid pressure operated device. The controller is of the type including housing means defining a fluid inlet port for connection to the source of pressurized fluid, a return port for connection to a system reservoir, and first and second control fluid ports for connection to the fluid pressure operated device. Valve means is disposed in the housing means and comprises a primary, rotatable valve member and a cooperating, relatively rotatable follow-up valve member. The primary and follow-up valve members define a neutral rotary position, and a first rotary operating position in which the primary valve member is rotatably displaced from the neutral rotary position, relative to the follow-up valve member. The follow-up valve member defines a neutral axial position relative to the primary valve member. The housing means and the primary and follow-up valve members, when in the first rotary operating position, cooperate to define a main fluid path providing fluid communication from the fluid inlet port to the first control fluid port, and from the second control fluid port to the return port.

The improved controller is characterized by the follow-up valve member defining a first axial operating position relative to the primary valve member, in which the housing means and the primary and follow-up valve members define a parallel fluid path providing fluid communication from the fluid inlet port to the first control fluid port and from the second control fluid port to the return port. The primary valve member and the follow-up valve member cooperate to define an annular spring chamber, and the primary valve member defines a first seat and the follow-up valve member defines a second seat. Compression spring means is disposed in the annular spring chamber, and includes a first end portion engaging the first seat, and a second end portion engaging the second seat, the compression spring means being operable to bias the primary and follow-up valve members from the rotary operating position toward the neutral rotary position. The spring chamber is configured to permit relative axial movement between the primary and follow-up valve members, as the follow-up valve members are displaced between the neutral axial position and the axial operating position.