Coring device with an improved core sleeve and anti-gripping collar with a collective core catcher

An improved coring device that incorporates a nonrotatable inner barrel disposed within the outer driving structure of the drill string which is coupled to the 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 under a weight which serves to compress the metal sleeve when outside the inner barrel, thereby increasing its diameter. The plurality of wedge-shaped segments located on the top of the sleeve are collectively brought together to form a core catcher when that end of the woven metal mesh sleeve to which the segments are connected is drawn around and into the lower end of the inner barrel.