The cavity of the rotary button 1 serves for accommodating the bearing for displacing the rotary button 1 in a plane perpendicular to {HEAD ~ its axis} of rotation, which approximately lies in {TAIL ~ the plane} of the page of FIG 1 
The cavity of the rotary button 1 serves for accommodating the bearing for displacing the rotary button 1 in a plane perpendicular to { HEAD ~ its axis } of rotation , which approximately lies in { TAIL ~ the plane } of the page of FIG 1
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH