US Patent 7234490 Hydraulic accumulator comprising a position indicator

A hydraulic accumulator includes an accumulator housing (1) formed of a non-magnetizable material and defining an axial direction of the housing. A separating element (9) can be axially displaced in the accumulator housing (1) and separates two working chambers (5, 7) from each other in the accumulator housing (1). A field-generating magnetic configuration (29) is arranged on the separating element. A series of magnetic field sensors (35) are arranged on the outer side of the accumulator housing (1), extend along the path of the axial movement of the separating element (9) and react to the field of the magnetic configuration (29) on the separating element (9) to characterize its position along the series of magnetic field sensors (35).