Directional control valve with spool delay mechanism

Patent metadata

Field	Value
Publication number	US-9599248-B2
Application number	US-201314758317-A
Country	US
Kind code	B2
Filing date	Dec 31, 2013
Priority date	Dec 31, 2012
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A mechanism for implementing a delay in a directional control valve in the movement of a valve spool within a valve body from a first position of the spool to a second position of the spool.

First claim

The invention claimed is:

1. A mechanism for implementing a delay in a directional control valve in the movement of a valve spool within a valve body from a first position of the spool to a second position of the spool through a third position of the spool, where the third position of the spool is located between the first and second positions, where:
the valve spool transits between the first and third positions and between the second and third positions at a first velocity;
the valve spool transits through the third position at a second velocity; and
the first velocity is greater than the second velocity

the mechanism is located within the spool;
the mechanism is a fluid damping mechanism;
the mechanism comprises a piston assembly, which remains fixed relative to a valve body, such that the valve spool moves over the piston assembly as it moves within the valve body;
the spool contains a bore through the length of the spool; and
the spool bore contains at least one region in which the bore has a smaller diameter relative to the remainder of the bore.

2. The mechanism of claim 1 , where the fluid is a hydraulic fluid.

3. The mechanism of claim 1 , where the fluid is a pneumatic fluid.

4. The mechanism of claim 1 , where the piston assembly comprises a central piston, contiguous with smaller diameter piston rods, subsequently contiguous with larger diameter support rods.

5. The mechanism of claim 1 , where the region of smaller diameter is in the central portion of the spool.

6. The mechanism of claim 5 , where the region of smaller diameter in the bore overlaps the central piston as the spool moves through the region of the third spool position.

7. The mechanism of claim 1 , where the spool is actuated by an air pilot, where the pilot moves the spool through an annular piston that slides over a uniform section of the piston assembly.

8. The mechanism of claim 7 , where the spool is returned by an air return, where the air return moves the spool through an annular piston that slides over a uniform section of the piston assembly.

Assignees

• Univ Vanderbilt

Inventors

• Goldfarb Michael
• Mitchell Jason

Classifications

• F16K1/123

  with stationary valve member and moving sleeve · CPC title

• F16K29/00

  Arrangements for movement of valve members other than for opening and closing the valve, e.g. for grinding-in, for preventing sticking · CPC title

• Y10T137/7762

  Fluid pressure type · CPC title

• Y10T137/8671

  With annular passage [e.g., spool] · CPC title

• F16K31/383

  the fluid acting on a piston · CPC title