CROWN BIT Russian patent published in 2015 - IPC E21B10/02 

FIELD: mining.

SUBSTANCE: drill bit comprises the body with working end divided by flushing grooves into sectors reinforced with wear-proof inserts, and damper. The latter is composed of a circular multiturn flat spring with threaded ends and guide bush provided with the seal fitted at outer surface of one of its ends. Note here that said bush is fitted telescopically inside the circular spring to overlap its interturn gaps and rigidly connected by one end with the body or with the spring. The bush seal is arranged between the body inner surface or the spring inner surface and the bush outer surface while the damper coils surface is provided with wear-proof material.

EFFECT: higher efficiency of crown bit operation, mainly, at drilling in interleaving and fractured rock.

3 cl, 1 dwg