An annular space is furnished between the internal lateral wall of {TAIL ~ the circular cap} and the lateral wall of the cone frustrum, and {HEAD ~ the horizontal peripheral edge} is in contact with the rubbing plate 
An annular space is furnished between the internal lateral wall of { TAIL ~ the circular cap } and the lateral wall of the cone frustrum , and { HEAD ~ the horizontal peripheral edge } is in contact with the rubbing plate
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH