Patent · US Expired

Two pump power steering system

US5257670A · kind A · utility

9Cited by
5References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 27, 1991
Grant dateNov 2, 1993
Priority date
Expiry dateSep 27, 2011

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB62D5/32
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

An apparatus provides hydraulic fluid for power steering assistance for steering a vehicle. A valve controls flow of hydraulic fluid from a first, engine driven, pump and a second, wheel driven, pump. The valve includes a valve housing and a valve member. The valve member is movable relative to the valve housing in response to a pressure differential in the hydraulic fluid from the first pump. The valve member in one range of relative positions provides a first flow passage from the first pump toward a steering valve, provides a variable second flow passage from the first pump toward the steering valve, and blocks hydraulic fluid flow from the second pump toward the steering valve. The first and second flow passages are in fluid parallel. The valve member in a control position provide a third flow passage from the second pump to the steering valve.

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