DEVICE FOR A PNEUMATIC IMPACT MECHANISM Russian patent published in 2021 - IPC E21C37/24 B25D9/14 B25D9/26 

FIELD: construction; mining industry.

SUBSTANCE: invention relates to pneumatic impact devices. Device for a pneumatic impact mechanism comprises a cylindrical housing with outlet channels, an annular flange with a through central hole, a cover with an inlet opening, a working tool with a shank, step striker with rod and piston parts, rod in central hole of annular flange with piston part with inclined channel-groove, constantly located in the through axial hole of the stepped drummer, the sleeve of the cylindrical body with the hole for the passage of the rod part of the stepped drummer and forming an annular isthmus in the sleeve, limiting the amount of movement of the stepped impactor, fixed with respect to the cylindrical body cup with a channel for supplying air, an annular distribution chamber in the sleeve of the cylindrical body, chamber of network air between shell and cover, prechamber between shell and annular flange, idle stroke chamber on the side of working tool shank, retained by spring relative to cylindrical housing, wherein groove channel on side surface of piston part of rod has variable geometrical cross-section, increasing from the side surface of the piston part from the side of the rod to the end of its piston part from the side of the through axial bore of the stepped drummer. Between ring part of stepped striker and cylindrical housing on the side of annular isthmus of sleeve there is an annular controlled chamber of working stroke. On stepped striker rod part side surface annular air bypass groove is made in the form of truncated cones convergent with peaks along the generatrix of the rod part of the stepped striker with decreasing geometrical cross-section areas in the side of annular distributing chamber and annular controlled chamber of working stroke and so, that the groove channel length is sufficient for periodic air bypass when the annular distribution chamber and the circular controlled chamber of the working stroke are interconnected.

EFFECT: higher efficiency of using internal air energy of annular controlled chamber of working stroke, higher efficiency of working process of pneumatic percussive mechanism and increased resource of device.

1 cl, 1 dwg