HIGH-STRENGTH PICK OF PICK HAMMER Russian patent published in 2002 - IPC

FIELD: manufacture of picks of pick hammers used for breakage of strong and specially strong materials; applicable in construction engineering, highway engineering and in bridge erection. SUBSTANCE: pick is made of tool alloyed steel of high resistance o wear and consists of conical rod part, cylindrical supporting shoulder, cylindrical tail part whose hardness, after treatment amounts to HRC 50, and working part in the form of tetrahedral prism with pick angle α of 60 deg and hardness after treatment of HRC 55. Working part is made of steel with an angle of wedge of tetrahedral prism amounting to 20-25 deg. Working and rod parts are connected to each other by welding in solid phase, for instance, by friction welding. Hardness after treatment over entire length of pick smoothly increases from HRC 40-45 in rod part to 55<HRC≤60 in working part and up to 50<HRC≤58 in tail part. EFFECT: increased wear resistance of pick, higher fatigue strength of rod and tail part of pick. 3 dwg