Abstract: 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 (I.sub.FSoll) from a predetermined relationship between the speed (n.sub.Ist) and the armature current (I.sub.ASoll). Power switches are associated with the field winding and the armature, and are actuated by the current control.

Abstract: In an apparatus for measuring the heart wall movement of a person, including a measuring head (10, 12) placeable on the breast with an electrode arrangement (76, 78) and a measuring circuit (84) for capacitively measuring the skin movement with respect to the electrode arrangement (76, 78), the measuring head has a holding ring (10) with an annular surface perpendicular to the ring axis (26) intended for placement on the body (30, 32) and straps for fastening the measuring head (10, 12) to the body. In the holding ring (10) is an adapter (12) including the electrode arrangement (76, 78) resiliently supported for movement in the direction of the ring axis (26) as well as in two other axes perpendicular to the ring axis and to one another.