AIR HAMMER Russian patent published in 2006 - IPC E21B4/14 

FIELD: mining, particularly percussion mechanisms used to drill wells.

SUBSTANCE: air hammer comprises cylinder connected to sub from the first cylinder side and to head from another side thereof. The sub comprises partition with central orifice. The head is provided with chisel retained in the head. Cylinder is divided into two cavities communicated with hole annuity through slot-like orifices. One cylinder cavity faces head provided with inclined channels to supply working agent to well bottom. Another cavity faces the sub. Piston has central channel, widened section and striking part passing in axial head channel. Widened piston section is provided with borings and is adapted to receive slide. Spring is installed between sub and piston end to press the piston to chisel shank. Piston is provided with shank, which may be inserted in central sub orifice. Borings are created in central piston channel and are arranged at three levels. Piston channel borings, namely one the nearest to the sub and one distant from the sub are connected one to another and to cylinder cavity facing the head by F-shaped channels. Central boring is connected to cylinder cavity facing the sub by -shaped channels. The slide is tubular and provided with solid partition arranged inside the slide and with side windows formed from both partition sides. Windows located upstream from the partition near the sub are aligned with piston boring, which is the nearest to the sub. Side windows located downstream from the partition are aligned with central cylinder boring. Distant cylinder boring is closed with cylindrical surface of tubular slide. Annular bead is formed on outer tubular slide surface over windows located near the sub. The annular bead divides the boring, which is the nearest to sub, into two cavities. One boring cavity faces piston shank, another one is communicated with cylinder cavity facing the head with F-shaped channels. The tubular slide is loaded with spring located between tubular slide and inner ledge formed in zone of central piston channel diameter reduction. Longitudinal blind cuts are created in bush secured in piston shank so that the cuts extend over outer surface and arranged from bush end facing tubular slide bead. Longitudinal blind cut openings are opened in the nearest boring cavity located over the bead, end parts thereof are aligned with radial piston shank orifices and are adapted to communicate boring cavity located over the bead with cylinder cavity facing the sub in inoperative position and with sub cavity located over partition during working travel performing.

EFFECT: increased efficiency, increased quantity of exhaust working agent to be supplied to well bottom for intensive well cleaning.

1 dwg