{HEAD ~ A mounting member} 50 having {TAIL ~ a curved surface} 51 that is convex in section is attached so that the mounting member 50 can slide along the arc of the curved recessed portion 71 
{ HEAD ~ A mounting member } 50 having { TAIL ~ a curved surface } 51 that is convex in section is attached so that the mounting member 50 can slide along the arc of the curved recessed portion 71
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH