PNEUMATIC STRIKING MECHANISM Russian patent published in 2018 - IPC E21C37/22 B25D9/14 

FIELD: machine engineering.

SUBSTANCE: pneumatic striking mechanism includes a cylindrical body with outlet channels, a ring flange with a through central hole, a working tool with a stem, a stepped striker with rod portion installed in the central hole of the ring flange with piston portion with channels-grooves, constantly located in through axial hole of the stepped striker, a controlled circular chamber of the working stroke between inner surface of the cylindrical body and the striker rod portion, a cup fixed relative to the cylindrical body with a channel for supplying air from the network into the chamber of the network air, a circular distributing chamber located in the bushing of cylindrical body forming a ring bridge from the side of controlled ring chamber of the working stroke and limiting movement of the step striker, an idle stroke chamber from the side of the working tool shank held by the spring relative to the cylindrical body. There is a channel-groove or channel-flat provided on the rod portion of the stepped striker under inclination to its longitudinal axis. Said inclined surface has a curvature not lower than the second order, and the cross section of the channel-groove or channel-flat is widening towards the end of the rod portion of striker with outlet into circular distributing chamber.

EFFECT: reduced air back pressure in the working stroke chamber at the end of the idle stroke, increased air pressure at the beginning of the working stroke, impact energy and impact frequency of pneumatic striking mechanism are increased.

2 dwg