Tensioning springs 26 are provided between {TAIL ~ screw heads} 24 and {HEAD ~ washers} 25 contacting member 12 
Tensioning springs 26 are provided between { TAIL ~ screw heads } 24 and { HEAD ~ washers } 25 contacting member 12
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH