During drilling process,drilling fishing cup is applled mainly for fishing of shivers and fallen objects such as carbide tooth,drill bit and bearing which can not be carried out of hole by conventional fluid circulartion,etc it possesses important functions to keep hole toe cleaning ,increase bit service life,reduce and prevent drill bit from unexpeeted damage.

Structure
Due to the fact that the O.D of external bowl of fishing cup is bigger and a smaller circular space is available between extemal bowl of fishig cup and well hole; the mandrel diameter at cup mouth is larger so that it has a bigger annular space, therefore, the fluid at the cup mouth form a swirls and suddenly fall down so as to reduce the carrying capacity.By this way,some heavy objects will drop in cup and be fished out so that the purpose of cleaning of hole toe is carried out.