INTERNAL PIPE CUTTER Russian patent published in 2003 - IPC

FIELD: oil-gas producing and geological prospecting industries; applicable for pipe cutting in wells. SUBSTANCE: pipe cutter has cylindrical body, extensible cutters, mechanism for cutters feed to operating position and their return to initial position. Cutters feed mechanism located in cylindrical body consists of piston provided with gland, washer and adjusting screw. Piston is fastened by means of ears and pin with cam having shaped recesses from both sides. Pins of extensible cutters are engageable with shaped recesses and provide for cutters extension to operating position and their return to initial position through two radially located holes in cylindrical body. Shank is detachable with section of separate parts of zigzag shape, forming after assembly, cavity rectangular in cross-section for location of cam holder head. Cylindrical body has radial holes for fluid flow from cylindrical body cavity to well annular space. Body head has internal thread for connection to drill pipe string. Body lower part has internal thread for connection of shank. EFFECT: uniform feed of cutters in pipe cutting and higher operating reliability of cutters feed mechanism in return to initial position. 4 dwg