{TAIL ~ A slide valve} 3 including a groove in said guide member for receiving an end of {HEAD ~ said support column} 
{ TAIL ~ A slide valve } 3 including a groove in said guide member for receiving an end of { HEAD ~ said support column }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD