CROWN BIT Russian patent published in 2004 - IPC

FIELD: rock-destroying equipment engineering.

SUBSTANCE: device has body with cleaning channels, connecting tail and working head with diametric groove for hard-allow insert. Body is made with at least one safety boss displaced relatively to hard-alloy insert vertex towards connecting tail. Height H of hard-alloy insert and displacement value h of safety boss from vertex of hard-alloy insert are connected by equation h/H=0.1-0.5. On scheme, outer surface of each boss may have arced shape with radius matching radius of body of working head. Body of crown may be made with two safety bosses, placed on scheme symmetrically relatively to hard-allow insert. Safety bosses in frontal plane may have wedged shape, while vertex of wedge is placed on the side of connecting tail.

EFFECT: higher efficiency of crown operation with fractured rock.

4 cl, 3 dwg