In a preferred embodiment of a device according to the invention, said positioning arm comprises {HEAD ~ a double working cylinder} to perform the movement of {TAIL ~ the positioning arm} 
In a preferred embodiment of a device according to the invention , said positioning arm comprises { HEAD ~ a double working cylinder } to perform the movement of { TAIL ~ the positioning arm }
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 OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL