Patent ID: 6223533
Filing Date: 2001-05-01
Classification: F16H

Abstract:
A pressurized fluid system for operating a device, comprising:a hydraulic or pneumatic primary pipe system including a master cylinder with at least one cylinder space forming a primary chamber, an operating body for operation of the master cylinder by an increase in the pressure of operating fluid in the primary chamber, and at least one primary pressure sensor arranged to detect the pressure of the operating fluid and transmit a primary electrical corresponding to that pressure;a working cylinder device having a cylinder space to form a secondary chamber;a secondary pipe system for generating a secondary pressure on a secondary fluid in the secondary chamber as a function of the primary signal, the secondary pipe system including a fluid reservoir, a fluid pump for receiving the secondary fluid from the reservoir and discharging the secondary fluid under pressure to the secondary chamber, at least one electromagnetic valve with first and second operational positions, the first operational position connecting the fluid pump to the secondary chamber for supply of pressurized fluid thereto, the second operational position connecting the secondary chamber with the fluid reservoir for removal of fluid therefrom, and at least one secondary pressure sensor to detect the secondary pressure and transmit a secondary electrical signal corresponding to the secondary pressure; anda computer for controlling the electromagnetic valve;wherein the computer is arranged to receive the primary and secondary electrical signals, and to transmit electrical signals at a fixed frequency with a period (T) to the at least one electromagnetic valve, the period (T) being divided into a first interval (T1), during which the electromagnetic valve is kept in the first operational position, and a second interval (T2), during which the electromagnetic valve is kept in the second operational position, the intervals (T1 and T2) being variable by the computer according to an algorithm, a mean pressure in the secondary chamber during the alternating supply and removal of the secondary fluid from the secondary chamber corresponding to the secondary pressure, and wherein the working cylinder device exerts an operating force corresponding to the secondary pressure.