DEVICE FOR PNEUMATIC IMPACT MECHANISM Russian patent published in 2020 - IPC E21C37/24 B25D9/04 B25D9/26 B25D17/02 

FIELD: construction.

SUBSTANCE: invention relates to the field of construction and mining, in particular, to pneumatic devices of percussive action. Device comprises a cylindrical housing with outlet channels, an annular flange with a through central hole, a cover with an inlet, a working tool with a shank, step striker with rod and piston parts, rod installed in central hole of annular flange with piston part with inclined channel-groove, constantly located in through axial hole of step striker, bushing of cylindrical housing with hole for passage of rod part of stepped striker, forming in bushing annular neck, limiting value of movement of step striker, barrel fixed to cylindrical housing with air supply channel, annular distribution chamber in cylindrical housing bushing, network air chamber between shell and cover, between the cover and the annular flange between the cover plate and the antechamber, and the idle stroke chamber on the side of the working tool shank retained by the spring relative to the cylindrical body. Channel-groove on rod piston part side surface features varying geometrical cross-section increasing from piston part side surface on rod side to the piston part end on the side of through axial bore of stepped hammer. 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 cylindrical annular channel-bypass of air bypass along generatrix of rod part of step striker is made and so that length of annular channel-groove of air bypass depending on position of stepped striker is sufficient for periodic air bypass when annular distribution chamber and annular controlled chamber of working stroke are interconnected.

EFFECT: higher efficiency of using internal air energy of annular controlled chamber of working stroke, higher efficiency of pneumatic percussive mechanism operating process, reduction of negative effect of stress concentrators in material of stepped striker structure and increase of its service life.

1 cl, 1 dwg