Patent · US Expired

Valve assembly for attenuating bounce of hydraulically driven members of a machine

US6959726B2 · kind B2 · utility

2Cited by
13References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 1, 2003
Grant dateNov 1, 2005
Priority date
Expiry dateJun 2, 2024

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/86928
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A member that is driven by a hydraulic actuator tends oscillate when fluid flow to the hydraulic actuator is terminated. A pressure relief device reduces that oscillation by connecting first and second first relief valves to the hydraulic actuator. The first relief valve provides a relatively large first relief passage as long as pressure in the hydraulic actuator remains above a threshold. A second relief valve opens a second relief passage at substantially the same threshold pressure and thereafter remains open as long as the pressure remains above another lower threshold. A timer causes the second relief valve to close a given interval of time, if the pressure does not drop below the other lower threshold.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.