AIR-DRIVEN PERCUSSION MECHANISM Russian patent published in 2015 - IPC E21B1/30 E21C37/22 

FIELD: process engineering.

SUBSTANCE: invention relates to construction and mining, particularly, air-operated percussion tools. Percussion mechanism comprises cylindrical case with outlets, circular flange with central through bore, working tool with shank and stepped hammer with rod part. Rod with piston part is fitted in circular flange central through bore to stay permanently in thorough axial bore of stepped hammer. Pneumatic buffer has circular chamber. Cylindrical case bushing has the bore for rod part passage to make a circular web no pneumatic buffer circular chamber side that limits the stroke of steeped hammer. Cup with air feed channel is secured relative to cylindrical case. Circular distribution chamber is arranged in cylindrical case bushing while circuit air chamber is located on circular flange side. Idle stroke chamber is arranged on working tool shank retained by spring relative to cylindrical case. 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.

EFFECT: decreased counter pressure of air in idle stroke chamber, higher power of impact and frequency of impacts.

1 dwg