In a development of the invention, the positioning unit is configured in the manner of {HEAD ~ an armature} which is rigidly attached to {TAIL ~ the piston} and is axially displaceable in a specified manner by means of a proportional magnet 
is rigidly attached to
In a development of the invention , the positioning unit is configured in the manner of { HEAD ~ an armature } which is rigidly attached to { TAIL ~ the piston } and is axially displaceable in a specified manner by means of a proportional magnet
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH