Patent · US Expired

Control device for a hydraulic cylinder for maintaining the pulling force thereof constant

US4553391A · kind A · utility

11Cited by
3References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 15, 1983
Grant dateNov 19, 1985
Priority date
Expiry dateNov 15, 2003

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B2211/76
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A hydrostatic machine having a fixed displacement volume which is connected to the operating chamber of a hydraulic cylinder which machine is mechanically coupled to a second hydrostatic machine having a variable displacement volume to control the force exerted by the hydraulic cylinder. When control liquid is displaced from the working chamber of the cylinder the first machine acting as a motor drives the second machine which displaces control liquid into an accumulator. Vice versa, liquid is taken from the accumulator and the second machine acting as a motor drives the first machine which feeds liquid into the working chamber. The pressure in the working chamber, or, respectively, the force exerted by the cylinder is maintained constant by a corresponding adjustment of the displacement volume of the second machine.

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