PNEUMATIC DROP HAMMER Russian patent published in 1995 - IPC

FIELD: mining pneumatic hammer drill. SUBSTANCE: casing provided with covers accommodates a hollow piston with a double-ended rod. The piston forms piston with a double-ended rod. The piston forms forward and back stroke chambers in the casing. Control valve forms in the casing control spaces that periodically communicate with compressed-air source or exhaust port. Floating pistons are installed in casing bores on the side of each cover with formation of buffer chambers with the latters. The covers have radial grooves communicating at the end of the stroke with annular recesses made on the rods. The groove for communication of the control chambers with the compressed-air source in made as an axial passage in one of the rods and radial passage in the piston. EFFECT: improved design. 3 dwg