Patent · US Expired

Hydraulic control arrangement

US4613257A · kind A · utility

4Cited by
8References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 21, 1983
Grant dateSep 23, 1986
Priority date
Expiry dateDec 21, 2003

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21D23/18
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A hydraulic control arrangement comprises a first hydraulic ram, a second hydraulic ram, and a hydraulic control circuit associated with the first and second hydraulic rams. Each of the hydraulic rams has a cylinder, a piston reciprocable within the cylinder, and a piston rod fixed to the piston. Each of the hydraulic rams has a cylindrical working chamber and an annular working chamber positioned on opposite sides of its piston. The piston rod of each hydraulic ram constitutes the cylinder of a respective metering ram, a respective metering piston being reciprocable within the cylinder of each metering ram to define a metering chamber therewithin. The hydraulic control circuit includes a line, which interconnects the two metering chambers, and a hydraulic valve positioned in a hydraulic fluid supply line leading to the cylindrical working chamber of the second hydraulic ram. The metering piston of the second hydraulic ram controls the hydraulic valve, thereby controlling the flow of hydraulic fluid to the cylindrical working chamber of the second hydraulic ram.

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