EP 0630853 B1 19971008 - Hydraulic lifting equipment for battery-propelled handling trucks or the like
Title (en)
Hydraulic lifting equipment for battery-propelled handling trucks or the like
Title (de)
Hydraulische Hubvorrichtung für batteriegetriebene Flurförderzeuge oder dergleichen
Title (fr)
Equipement de levage hydraulique pour chariots de manutention mûs par batterie ou analogues
Publication
Application
Priority
DE 4317782 A 19930528
Abstract (en)
[origin: US5505043A] A hydraulic lift device for battery operated industrial trucks comprising a hydraulic ram, a hydraulic machine operating as a pump in a load raising cycle and as a motor in a load lowering cycle, a separately excited DC machine operating as a motor in the load raising cycle and as a generator in the load lowering cycle, and energy recovering circuitry which is fed by the DC machine in the load lowering cycle. A load holding valve is disposed in the fluid path between the hydraulic ram and the hydraulic machine. Speed of the DC machine is set by a speed control. A separate field current control includes a desired value setting circuit for determining a desired value for the field current (IFSoll) from a predetermined relationship between the speed (nIst) and the armature current (IASoll). Power switches are associated with the field winding and the armature, and are actuated by the current control. The power switches are arranged and controlled such than the intensity and the direction of the current through the armature and field winding are defined. The current control comprises a directional setting control for the lowering and raising cycle generating signals to control the load holding valve.
IPC 1-7
IPC 8 full level
B66F 9/20 (2006.01); B66F 9/24 (2006.01); D04B 35/04 (2006.01); H02P 3/14 (2006.01); H02P 3/18 (2006.01)
CPC (source: EP US)
B66F 9/20 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT SE
DOCDB simple family (publication)
US 5505043 A 19960409; DE 4317782 A1 19941201; DE 4317782 C2 19960118; DE 59404249 D1 19971113; EP 0630853 A1 19941228; EP 0630853 B1 19971008
DOCDB simple family (application)
US 25051494 A 19940527; DE 4317782 A 19930528; DE 59404249 T 19940303; EP 94103149 A 19940303