HYDRAULIC PUNCHER Russian patent published in 1996 - IPC

FIELD: mining, well building, operation and repair. SUBSTANCE: device includes a case. The case is sectional. Pipe with coupling in upper part and semi- coupling in lower part is placed in upper case part. The pipe enables to move in axial direction. Two step sleeve spring loaded to the case is placed in the case. This sleeve is placed in the case between the pipe and extensions. Additional annular cavity is formed between the pipe and the case. The cavity is filled with oil. Differential sleeve has conical surface in lower part and return spring. The spring is placed in lower case section. Radial opening is provided in the case opposite differential sleeve. Spring loaded slips with half-spherical surfaces are installed in the openings. The slips are interacted to conical surface of differential sleeve. Extendable rods are provided in the case opposite two-step sleeve. The rods are made in the form of pistons. Over piston space is hydraulically open to the additional annular cavity. Lateral openings are provided in the case under two-step sleeve. The openings may be overlapped with two step sleeve moved axially. EFFECT: higher reliability. 3 dwg