The upper end of the ratchet housing 92 and the lower end of the J slot sleeve 136 create a stop which limits {HEAD ~ the upward motion} of the mandrel 22 relative to {TAIL ~ the drill string} 32 
relative to
The upper end of the ratchet housing 92 and the lower end of the J slot sleeve 136 create a stop which limits { HEAD ~ the upward motion } of the mandrel 22 relative to { TAIL ~ the drill string } 32
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH