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