By means of such an arrangement intermediate positions of the guide disc can also be effected, while {HEAD ~ a very compact configuration} of the positioning unit is obtained at {TAIL ~ the same time} 
By means of such an arrangement intermediate positions of the guide disc can also be effected , while { HEAD ~ a very compact configuration } of the positioning unit is obtained at { TAIL ~ the same time }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL