Coring device with an improved weighted core sleeve and anti-gripping collar

摘要

An improved coring device that incorporates a nonrotatable inner barrel disposed within the outer driving structure of the drill string which is coupled to a coring bit. A woven metal mesh sleeve is circumferentially mounted outside the inner barrel and tucked around its lower end. The lower end of the mesh sleeve in the inner barrel is in turn connected to a stripper tube which is pulled upwardly during the coring operation. As the core is cut by the coring bit and enters the inner barrel, the woven metal mesh sleeve is disposed about the core and constricts about the core when pulled upwardly by the stripper tube. The opposing end of the woven metal mesh sleeve is connected to a weight which serves to compress the metal sleeve when outside the inner barrel, thereby increasing its diameter to prevent binding or jamming.