Patent · US Expired

Hydraulic valve

US7146998B2 · kind B2 · utility

2Cited by
12References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 8, 2002
Grant dateDec 12, 2006
Priority date
Expiry dateOct 15, 2023

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/8671
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A stepped down groove 53 is provided around the peripheral surface of a rod portion 43 of a spool 40 which faces a third oil groove 33. Both the axial ends 53a and 53b of the stepped down groove 53 are located axially outside of both the axial ends 33a and 33b of the third oil groove 33 at least while the valve is in pressure-adjusting condition. Also, another stepped down groove 52 is provided around a land 42 which faces a first oil groove 31. Both the axial ends 52a and 52b of the stepped down groove 52 come, respectively, to the right and left sides of the axial end 31b of the first oil groove 31 to which end the spool 40 shifts to increase the opening of the oil groove at least while the valve is in pressure-adjusting condition.

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