Global Patent Index - EP 3689814 A1

EP 3689814 A1 20200805 - HYDRAULIC LIFTING SYSTEM

Title (en)

HYDRAULIC LIFTING SYSTEM

Title (de)

HYDRAULISCHES HUBSYSTEM

Title (fr)

SYSTÈME DE LEVAGE HYDRAULIQUE

Publication

EP 3689814 A1 20200805 (EN)

Application

EP 19155238 A 20190204

Priority

EP 19155238 A 20190204

Abstract (en)

The invention relates to a hydraulic lifting system (1) comprising a hydraulic circuit (3), having a feed line (5) and a return line (7), to which circuit (3) a plurality of components are coupled, comprising: a lifting device (9), at least one hydraulic auxiliary device (11), at least a first pump (13), at least one electric motor (15) for operating the at least one pump (13), a tank (17) for holding hydraulic fluid, a first control valve (19), a second control valve (21), and a control unit, for operating the valves (19, 21) and the at least one electric motor (15). The first control valve (19) is arranged on the feed line (5), to control a flow of hydraulic fluid there through, which flow is provided to the feed line (5) by means of the pump (13), to be directed to the lifting device (9), which lifting device (9) performs a lifting operation when provided with hydraulic fluid. The second control valve (21) is arranged on the return line (7), to re-direct the flow of hydraulic fluid from the feed line (5) to the return line (7), which leads said hydraulic fluid to the tank (17), wherein the lifting device (9) performs a lowering operation when the hydraulic fluid is drained therefrom by means of the second control valve (21). The system (1) further comprises a hydraulic motor (27), arranged on the return line (7), between the second control valve (21) and the tank (17), wherein the hydraulic motor (27) when provided with hydraulic fluid from the return line (7) is arranged to generate mechanical energy to a rotatable axle (29). The invention further relates to a fork-lift truck (53) comprising such a hydraulic lifting system (1) and a method for providing such a hydraulic system (1) to a fork-lift truck (53).

IPC 8 full level

B66F 9/22 (2006.01)

CPC (source: EP)

B66F 9/22 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA ME

DOCDB simple family (publication)

EP 3689814 A1 20200805; EP 3689814 B1 20211117

DOCDB simple family (application)

EP 19155238 A 20190204