acting as a formation in the well bore and the tool then becomes a weight set tool setting weight on the tool causes the pins 40 to shear due to the planar arrangement of surfaces 46 48 the body 12 together with the work string will disengage from the sleeve 24 sleeve 24 will remain at the liner top 36 while the body 12 and work string can descend further into the well bore a tool connected to the work string not shown can then perform any required function at a greater depth in the well bore when all functions are complete in the well bore the work string is removed in the standard manner when the string brings the mating portion 44 a of the body 12 up to the mating portion 44 b of the sleeve 24 if the surfaces 46 48 do not align the sleeve 24 will be picked up by virtue of the top ledge formed from the surface 46 meeting the bottom ledge formed from surface 48 alternatively if the surfaces 46 48 match then the body mating portion 44 a slides into the matching mating portion 44 b of the sleeve the sleeve 24 is then picked up by the upper ledge formed from the planar sections of the surface 48 now mating with a shoulder 64 see fig1 in the sleeve 24 the shoulder 64 is further illustrated in fig3 on picking up the sleeve 24 the sleeve 24 moves with the body 12 and is removed from the well bore reference is now made to fig4 of the drawings which illustrates a safety mechanism mounted on the sleeve 24 of the tool 10 according to a second embodiment of.