According to the invention, said adapter (20) has a shaped ring which consists of a transparent or opaque, permanently elastic material and which has adhesive surfaces for joining the spectacle lens (10) to the shield (30).
A wellhead (16) for an exploratory well carries a latch profile ring (24) at a location just above the wellhead housing (14).
This stem section is surrounded by a shaped ring (40) having radially projecting annular ribs (44) which engaged the circumferential grooves (31).
The recess may also contain a ring-shaped fairing (7) which physically separates the recess inlet (4a) from its outlet (4b) and which may serve to diminish turbulence in the air travelling through the recess.
Said electrical machine comprises a housing (2) in which a stator (3) is arranged, wherein an integral profiled ring (5) is arranged between the housing (2) and the stator (3).