ROTATIVE-PERCUSSIVE DRILLING MACHINE Russian patent published in 2003 - IPC

FIELD: construction industry, geological prospecting and blasting operations, formation of holes in rocks, building materials, disintegration of materials. SUBSTANCE: given rotative-percussive drilling machine can be switched to two operational modes, as minimum, secured by two axial positions of bushing mounted in body for rotation. Rotative-percussive mode is ensured while bushing remains in first extreme position and percussive mode is provided when bushing stays in second extreme position with the help of mechanism shutting off rotation of guiding cylinder and of percussive working tool and mechanism that fixes it with reference to body. Percussive compression-vacuum mechanism which piston and striker separated by air cushion are located in guiding cylinder operates under both modes. Guiding cylinder houses percussive and drilling working tools. Guiding cylinder carries driving gear coupled to driven gear of intermediate shaft imparted with rotation from drive and hub possessing longitudinal recesses separated by protrusions. On one side bushing is engaged with its bead with ring bead of driven gear coupled to intermediate shaft by means of splined joint and spring which ensure rotative-percussive mode of operation of machine in first extreme position of bushing. On other side bushing has starting chamfer. Additional bushing arranged around hub and carrying radial holes to accommodate fixing members for engagement with hub in second extreme position of bushing that secures simultaneous disengagement of splined joint of driven gear and intermediate shaft is also coupled to body. In this position of bushing rotation of working tool is stopped and it is fixed relative to body which provides for percussive mode of operation. EFFECT: reliable operation of machine under two modes: rotative-percussive and percussive. 3 cl, 13 dwg