Patent · US Expired

Hydraulic control device

US4414881A · kind A · utility

7Cited by
4References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 21, 1981
Grant dateNov 15, 1983
Priority date
Expiry dateJan 21, 2001

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B15/1438
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

The invention provides a hydraulic servo-control device which performs the same functions as a conventional device but is much cheaper to manufacture and maintain. For this purpose, the control device comprises a cylinder device formed by a cylinder and a piston rigid with a rod and a hydraulic control unit whose body is rigid with the cylinder. The body of the hydraulic control unit defines a cavity for receiving the cylinder of the cylinder device and this cylinder is made in two main parts, namely a case partly received in the cavity and fixed to the body of the hydraulic control unit, and a tubular sleeve which is axially and radially positioned inside the case and the cavity and cooperates with the piston. Application in particular in the control of the pitch of the blades of a helicopter or the ailerons of a light aircraft.

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