A vacuum switch with a driving device for switching {HEAD ~ a vacuum tight switching tube} into {TAIL ~ on and off positions} 
into
A vacuum switch with a driving device for switching { HEAD ~ a vacuum tight switching tube } into { TAIL ~ on and off positions }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL