| 摘要 |
A wireline fishing tool for retrieving a fish or object from an inaccesible loction as a broken drill bit deep in a well comprises an elongated rod with two toothed jaws pivotally connected to the lower end thereof and being extendible from a bell shaped housing toward the inaccessible object and being retractable into the housing for closing the jaws around the fish, or object and a shear pin for maintaining the jaws open as the tool is lowered into the well until the jaws contact the object. Additional movement towards the object starts retraction of the jaws into the bell shaped housing, which first shears a shear pin holding the rod extended from the housing while further movement shears the second shear pin holding the jaws open whereby the jaws are then closed tight on the object by contact with the bell shpaed housing and held tight with a ratchet and pawl for locking the jaws and rod in the housing for retrieval at the surface.
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